From 7003b3ce21e0ddf9028e124fd9add5ac2319e112 Mon Sep 17 00:00:00 2001 From: Ronnie Sahlberg Date: Tue, 10 Nov 2015 12:42:31 +0100 Subject: verify_refname_available(): rename function Rename verify_refname_available() to verify_refname_available_dir() to make the old name available for a more general purpose. Signed-off-by: Ronnie Sahlberg Signed-off-by: David Turner Signed-off-by: Junio C Hamano Signed-off-by: Michael Haggerty Signed-off-by: Jeff King --- refs.c | 44 ++++++++++++++++++++++---------------------- 1 file changed, 22 insertions(+), 22 deletions(-) diff --git a/refs.c b/refs.c index 132eff52ca..0617e0c6b9 100644 --- a/refs.c +++ b/refs.c @@ -279,7 +279,7 @@ struct ref_dir { * presence of an empty subdirectory does not block the creation of a * similarly-named reference. (The fact that reference names with the * same leading components can conflict *with each other* is a - * separate issue that is regulated by verify_refname_available().) + * separate issue that is regulated by verify_refname_available_dir().) * * Please note that the name field contains the fully-qualified * reference (or subdirectory) name. Space could be saved by only @@ -911,11 +911,11 @@ static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata) * * extras and skip must be sorted. */ -static int verify_refname_available(const char *refname, - const struct string_list *extras, - const struct string_list *skip, - struct ref_dir *dir, - struct strbuf *err) +static int verify_refname_available_dir(const char *refname, + const struct string_list *extras, + const struct string_list *skip, + struct ref_dir *dir, + struct strbuf *err) { const char *slash; int pos; @@ -2465,8 +2465,8 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, strbuf_git_path(&orig_ref_file, "%s", orig_refname); if (remove_empty_directories(&orig_ref_file)) { last_errno = errno; - if (!verify_refname_available(orig_refname, extras, skip, - get_loose_refs(&ref_cache), err)) + if (!verify_refname_available_dir(orig_refname, extras, skip, + get_loose_refs(&ref_cache), err)) strbuf_addf(err, "there are still refs under '%s'", orig_refname); goto error_return; @@ -2479,8 +2479,8 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, if (!refname) { last_errno = errno; if (last_errno != ENOTDIR || - !verify_refname_available(orig_refname, extras, skip, - get_loose_refs(&ref_cache), err)) + !verify_refname_available_dir(orig_refname, extras, skip, + get_loose_refs(&ref_cache), err)) strbuf_addf(err, "unable to resolve reference %s: %s", orig_refname, strerror(last_errno)); @@ -2493,8 +2493,8 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, * our refname. */ if (is_null_oid(&lock->old_oid) && - verify_refname_available(refname, extras, skip, - get_packed_refs(&ref_cache), err)) { + verify_refname_available_dir(refname, extras, skip, + get_packed_refs(&ref_cache), err)) { last_errno = ENOTDIR; goto error_return; } @@ -3127,10 +3127,10 @@ static int rename_ref_available(const char *oldname, const char *newname) int ret; string_list_insert(&skip, oldname); - ret = !verify_refname_available(newname, NULL, &skip, - get_packed_refs(&ref_cache), &err) - && !verify_refname_available(newname, NULL, &skip, - get_loose_refs(&ref_cache), &err); + ret = !verify_refname_available_dir(newname, NULL, &skip, + get_packed_refs(&ref_cache), &err) + && !verify_refname_available_dir(newname, NULL, &skip, + get_loose_refs(&ref_cache), &err); if (!ret) error("%s", err.buf); @@ -4376,12 +4376,12 @@ int initial_ref_transaction_commit(struct ref_transaction *transaction, if ((update->flags & REF_HAVE_OLD) && !is_null_sha1(update->old_sha1)) die("BUG: initial ref transaction with old_sha1 set"); - if (verify_refname_available(update->refname, - &affected_refnames, NULL, - loose_refs, err) || - verify_refname_available(update->refname, - &affected_refnames, NULL, - packed_refs, err)) { + if (verify_refname_available_dir(update->refname, + &affected_refnames, NULL, + loose_refs, err) || + verify_refname_available_dir(update->refname, + &affected_refnames, NULL, + packed_refs, err)) { ret = TRANSACTION_NAME_CONFLICT; goto cleanup; } -- cgit v1.2.3 From d336123160a4d9d31b01ae096ed3cdf135f92216 Mon Sep 17 00:00:00 2001 From: Ronnie Sahlberg Date: Tue, 10 Nov 2015 12:42:32 +0100 Subject: verify_refname_available(): new function Add a new verify_refname_available() function, which checks whether the refname is available for use, taking all references (both packed and loose) into account. This function, unlike the old verify_refname_available(), has semantics independent of the choice of reference storage, and can therefore be implemented by alternative reference backends. Use the new function in a couple of places. Signed-off-by: Ronnie Sahlberg Signed-off-by: David Turner Signed-off-by: Junio C Hamano Signed-off-by: Michael Haggerty Signed-off-by: Jeff King --- refs.c | 66 ++++++++++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 40 insertions(+), 26 deletions(-) diff --git a/refs.c b/refs.c index 0617e0c6b9..ddcdf81fab 100644 --- a/refs.c +++ b/refs.c @@ -279,7 +279,7 @@ struct ref_dir { * presence of an empty subdirectory does not block the creation of a * similarly-named reference. (The fact that reference names with the * same leading components can conflict *with each other* is a - * separate issue that is regulated by verify_refname_available_dir().) + * separate issue that is regulated by verify_refname_available().) * * Please note that the name field contains the fully-qualified * reference (or subdirectory) name. Space could be saved by only @@ -897,19 +897,7 @@ static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata) /* * Return 0 if a reference named refname could be created without * conflicting with the name of an existing reference in dir. - * Otherwise, return a negative value and write an explanation to err. - * If extras is non-NULL, it is a list of additional refnames with - * which refname is not allowed to conflict. If skip is non-NULL, - * ignore potential conflicts with refs in skip (e.g., because they - * are scheduled for deletion in the same operation). Behavior is - * undefined if the same name is listed in both extras and skip. - * - * Two reference names conflict if one of them exactly matches the - * leading components of the other; e.g., "refs/foo/bar" conflicts - * with both "refs/foo" and with "refs/foo/bar/baz" but not with - * "refs/foo/bar" or "refs/foo/barbados". - * - * extras and skip must be sorted. + * See verify_refname_available for more information. */ static int verify_refname_available_dir(const char *refname, const struct string_list *extras, @@ -3120,6 +3108,40 @@ out: return ret; } +/* + * Return 0 if a reference named refname could be created without + * conflicting with the name of an existing reference. Otherwise, + * return a negative value and write an explanation to err. If extras + * is non-NULL, it is a list of additional refnames with which refname + * is not allowed to conflict. If skip is non-NULL, ignore potential + * conflicts with refs in skip (e.g., because they are scheduled for + * deletion in the same operation). Behavior is undefined if the same + * name is listed in both extras and skip. + * + * Two reference names conflict if one of them exactly matches the + * leading components of the other; e.g., "foo/bar" conflicts with + * both "foo" and with "foo/bar/baz" but not with "foo/bar" or + * "foo/barbados". + * + * extras and skip must be sorted. + */ +static int verify_refname_available(const char *newname, + struct string_list *extras, + struct string_list *skip, + struct strbuf *err) +{ + struct ref_dir *packed_refs = get_packed_refs(&ref_cache); + struct ref_dir *loose_refs = get_loose_refs(&ref_cache); + + if (verify_refname_available_dir(newname, extras, skip, + packed_refs, err) || + verify_refname_available_dir(newname, extras, skip, + loose_refs, err)) + return -1; + + return 0; +} + static int rename_ref_available(const char *oldname, const char *newname) { struct string_list skip = STRING_LIST_INIT_NODUP; @@ -3127,10 +3149,7 @@ static int rename_ref_available(const char *oldname, const char *newname) int ret; string_list_insert(&skip, oldname); - ret = !verify_refname_available_dir(newname, NULL, &skip, - get_packed_refs(&ref_cache), &err) - && !verify_refname_available_dir(newname, NULL, &skip, - get_loose_refs(&ref_cache), &err); + ret = !verify_refname_available(newname, NULL, &skip, &err); if (!ret) error("%s", err.buf); @@ -4334,8 +4353,6 @@ static int ref_present(const char *refname, int initial_ref_transaction_commit(struct ref_transaction *transaction, struct strbuf *err) { - struct ref_dir *loose_refs = get_loose_refs(&ref_cache); - struct ref_dir *packed_refs = get_packed_refs(&ref_cache); int ret = 0, i; int n = transaction->nr; struct ref_update **updates = transaction->updates; @@ -4376,12 +4393,9 @@ int initial_ref_transaction_commit(struct ref_transaction *transaction, if ((update->flags & REF_HAVE_OLD) && !is_null_sha1(update->old_sha1)) die("BUG: initial ref transaction with old_sha1 set"); - if (verify_refname_available_dir(update->refname, - &affected_refnames, NULL, - loose_refs, err) || - verify_refname_available_dir(update->refname, - &affected_refnames, NULL, - packed_refs, err)) { + if (verify_refname_available(update->refname, + &affected_refnames, NULL, + err)) { ret = TRANSACTION_NAME_CONFLICT; goto cleanup; } -- cgit v1.2.3 From f4a5721ccb73efe33d345190f38058b45eaadca8 Mon Sep 17 00:00:00 2001 From: David Turner Date: Tue, 10 Nov 2015 12:42:33 +0100 Subject: copy_msg(): rename to copy_reflog_msg() We will soon increase the visibility of this function, so make its name more distinctive. Signed-off-by: David Turner Signed-off-by: Junio C Hamano Signed-off-by: Michael Haggerty Signed-off-by: Jeff King --- refs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/refs.c b/refs.c index ddcdf81fab..480de9ac92 100644 --- a/refs.c +++ b/refs.c @@ -3287,7 +3287,7 @@ static int commit_ref(struct ref_lock *lock) * large, while cleaning up the whitespaces. Especially, convert LF to space, * because reflog file is one line per entry. */ -static int copy_msg(char *buf, const char *msg) +static int copy_reflog_msg(char *buf, const char *msg) { char *cp = buf; char c; @@ -3391,7 +3391,7 @@ static int log_ref_write_fd(int fd, const unsigned char *old_sha1, sha1_to_hex(new_sha1), committer); if (msglen) - len += copy_msg(logrec + len - 1, msg) - 1; + len += copy_reflog_msg(logrec + len - 1, msg) - 1; written = len <= maxlen ? write_in_full(fd, logrec, len) : -1; free(logrec); -- cgit v1.2.3 From a935ebd4a7df505da819371ef10add6ad7bd77d7 Mon Sep 17 00:00:00 2001 From: Michael Haggerty Date: Tue, 10 Nov 2015 12:42:34 +0100 Subject: pack_if_possible_fn(): use ref_type() instead of is_per_worktree_ref() is_per_worktree_ref() will soon be made private, so use the public interface, ref_type(), in its place. And now that we're using ref_type(), we can make it clear that we won't pack pseudorefs. This was the case before, but due to the not-so-obvious reason that this function is applied to references via the loose reference cache, which only includes references that live inside "refs/". Signed-off-by: Michael Haggerty Signed-off-by: Jeff King --- refs.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/refs.c b/refs.c index 480de9ac92..82129f06e2 100644 --- a/refs.c +++ b/refs.c @@ -2671,8 +2671,6 @@ struct pack_refs_cb_data { struct ref_to_prune *ref_to_prune; }; -static int is_per_worktree_ref(const char *refname); - /* * An each_ref_entry_fn that is run over loose references only. If * the loose reference can be packed, add an entry in the packed ref @@ -2687,7 +2685,7 @@ static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data) int is_tag_ref = starts_with(entry->name, "refs/tags/"); /* Do not pack per-worktree refs: */ - if (is_per_worktree_ref(entry->name)) + if (ref_type(entry->name) != REF_TYPE_NORMAL) return 0; /* ALWAYS pack tags */ -- cgit v1.2.3 From 03b32623d82d20835d8dda3f9ce9900f09485d11 Mon Sep 17 00:00:00 2001 From: Michael Haggerty Date: Tue, 10 Nov 2015 12:42:35 +0100 Subject: refname_is_safe(): improve docstring Signed-off-by: Michael Haggerty Signed-off-by: Jeff King --- refs.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/refs.c b/refs.c index 82129f06e2..f48c58a7b6 100644 --- a/refs.c +++ b/refs.c @@ -341,13 +341,17 @@ static struct ref_dir *get_ref_dir(struct ref_entry *entry) } /* - * Check if a refname is safe. - * For refs that start with "refs/" we consider it safe as long they do - * not try to resolve to outside of refs/. + * Return true iff refname is minimally safe. "Safe" here means that + * deleting a loose reference by this name will not do any damage, for + * example by causing a file that is not a reference to be deleted. + * This function does not check that the reference name is legal; for + * that, use check_refname_format(). * - * For all other refs we only consider them safe iff they only contain - * upper case characters and '_' (like "HEAD" AND "MERGE_HEAD", and not like - * "config"). + * We consider a refname that starts with "refs/" to be safe as long + * as any ".." components that it might contain do not escape "refs/". + * Names that do not start with "refs/" are considered safe iff they + * consist entirely of upper case characters and '_' (like "HEAD" and + * "MERGE_HEAD" but not "config" or "FOO/BAR"). */ static int refname_is_safe(const char *refname) { -- cgit v1.2.3 From 4cb77009e1fa692e56048754e2032ed044f28c26 Mon Sep 17 00:00:00 2001 From: Michael Haggerty Date: Tue, 10 Nov 2015 12:42:36 +0100 Subject: refs/refs-internal.h: new header file There are a number of constants, structs, and static functions defined in refs.c and treated as private to the references module. But we want to support multiple reference backends within the reference module, and those backends will need access to some heretofore private declarations. We don't want those declarations to be visible to non-refs code, so we don't want to move them to refs.h. Instead, add a new header file, refs/refs-internal.h, that is intended to be included only from within the refs module. Make some functions non-static and move some declarations (and their corresponding docstrings) from refs.c to this file. In a moment we will add more content to the "refs" subdirectory. Signed-off-by: Michael Haggerty Signed-off-by: Jeff King --- refs.c | 174 +++---------------------------------------------- refs/refs-internal.h | 180 +++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 189 insertions(+), 165 deletions(-) create mode 100644 refs/refs-internal.h diff --git a/refs.c b/refs.c index f48c58a7b6..e6b82ee06b 100644 --- a/refs.c +++ b/refs.c @@ -1,6 +1,7 @@ #include "cache.h" #include "lockfile.h" #include "refs.h" +#include "refs/refs-internal.h" #include "object.h" #include "tag.h" #include "dir.h" @@ -34,41 +35,6 @@ static unsigned char refname_disposition[256] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4 }; -/* - * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken - * refs (i.e., because the reference is about to be deleted anyway). - */ -#define REF_DELETING 0x02 - -/* - * Used as a flag in ref_update::flags when a loose ref is being - * pruned. - */ -#define REF_ISPRUNING 0x04 - -/* - * Used as a flag in ref_update::flags when the reference should be - * updated to new_sha1. - */ -#define REF_HAVE_NEW 0x08 - -/* - * Used as a flag in ref_update::flags when old_sha1 should be - * checked. - */ -#define REF_HAVE_OLD 0x10 - -/* - * Used as a flag in ref_update::flags when the lockfile needs to be - * committed. - */ -#define REF_NEEDS_COMMIT 0x20 - -/* - * 0x40 is REF_FORCE_CREATE_REFLOG, so skip it if you're adding a - * value to ref_update::flags - */ - /* * Try to read one refname component from the front of refname. * Return the length of the component found, or -1 if the component is @@ -340,20 +306,7 @@ static struct ref_dir *get_ref_dir(struct ref_entry *entry) return dir; } -/* - * Return true iff refname is minimally safe. "Safe" here means that - * deleting a loose reference by this name will not do any damage, for - * example by causing a file that is not a reference to be deleted. - * This function does not check that the reference name is legal; for - * that, use check_refname_format(). - * - * We consider a refname that starts with "refs/" to be safe as long - * as any ".." components that it might contain do not escape "refs/". - * Names that do not start with "refs/" are considered safe iff they - * consist entirely of upper case characters and '_' (like "HEAD" and - * "MERGE_HEAD" but not "config" or "FOO/BAR"). - */ -static int refname_is_safe(const char *refname) +int refname_is_safe(const char *refname) { if (starts_with(refname, "refs/")) { char *buf; @@ -1823,39 +1776,7 @@ static int filter_refs(const char *refname, const struct object_id *oid, return filter->fn(refname, oid, flags, filter->cb_data); } -enum peel_status { - /* object was peeled successfully: */ - PEEL_PEELED = 0, - - /* - * object cannot be peeled because the named object (or an - * object referred to by a tag in the peel chain), does not - * exist. - */ - PEEL_INVALID = -1, - - /* object cannot be peeled because it is not a tag: */ - PEEL_NON_TAG = -2, - - /* ref_entry contains no peeled value because it is a symref: */ - PEEL_IS_SYMREF = -3, - - /* - * ref_entry cannot be peeled because it is broken (i.e., the - * symbolic reference cannot even be resolved to an object - * name): - */ - PEEL_BROKEN = -4 -}; - -/* - * Peel the named object; i.e., if the object is a tag, resolve the - * tag recursively until a non-tag is found. If successful, store the - * result to sha1 and return PEEL_PEELED. If the object is not a tag - * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively, - * and leave sha1 unchanged. - */ -static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1) +enum peel_status peel_object(const unsigned char *name, unsigned char *sha1) { struct object *o = lookup_unknown_object(name); @@ -3110,27 +3031,10 @@ out: return ret; } -/* - * Return 0 if a reference named refname could be created without - * conflicting with the name of an existing reference. Otherwise, - * return a negative value and write an explanation to err. If extras - * is non-NULL, it is a list of additional refnames with which refname - * is not allowed to conflict. If skip is non-NULL, ignore potential - * conflicts with refs in skip (e.g., because they are scheduled for - * deletion in the same operation). Behavior is undefined if the same - * name is listed in both extras and skip. - * - * Two reference names conflict if one of them exactly matches the - * leading components of the other; e.g., "foo/bar" conflicts with - * both "foo" and with "foo/bar/baz" but not with "foo/bar" or - * "foo/barbados". - * - * extras and skip must be sorted. - */ -static int verify_refname_available(const char *newname, - struct string_list *extras, - struct string_list *skip, - struct strbuf *err) +int verify_refname_available(const char *newname, + struct string_list *extras, + struct string_list *skip, + struct strbuf *err) { struct ref_dir *packed_refs = get_packed_refs(&ref_cache); struct ref_dir *loose_refs = get_loose_refs(&ref_cache); @@ -3284,12 +3188,7 @@ static int commit_ref(struct ref_lock *lock) return 0; } -/* - * copy the reflog message msg to buf, which has been allocated sufficiently - * large, while cleaning up the whitespaces. Especially, convert LF to space, - * because reflog file is one line per entry. - */ -static int copy_reflog_msg(char *buf, const char *msg) +int copy_reflog_msg(char *buf, const char *msg) { char *cp = buf; char c; @@ -3310,7 +3209,7 @@ static int copy_reflog_msg(char *buf, const char *msg) return cp - buf; } -static int should_autocreate_reflog(const char *refname) +int should_autocreate_reflog(const char *refname) { if (!log_all_ref_updates) return 0; @@ -3963,61 +3862,6 @@ int for_each_reflog(each_ref_fn fn, void *cb_data) return retval; } -/** - * Information needed for a single ref update. Set new_sha1 to the new - * value or to null_sha1 to delete the ref. To check the old value - * while the ref is locked, set (flags & REF_HAVE_OLD) and set - * old_sha1 to the old value, or to null_sha1 to ensure the ref does - * not exist before update. - */ -struct ref_update { - /* - * If (flags & REF_HAVE_NEW), set the reference to this value: - */ - unsigned char new_sha1[20]; - /* - * If (flags & REF_HAVE_OLD), check that the reference - * previously had this value: - */ - unsigned char old_sha1[20]; - /* - * One or more of REF_HAVE_NEW, REF_HAVE_OLD, REF_NODEREF, - * REF_DELETING, and REF_ISPRUNING: - */ - unsigned int flags; - struct ref_lock *lock; - int type; - char *msg; - const char refname[FLEX_ARRAY]; -}; - -/* - * Transaction states. - * OPEN: The transaction is in a valid state and can accept new updates. - * An OPEN transaction can be committed. - * CLOSED: A closed transaction is no longer active and no other operations - * than free can be used on it in this state. - * A transaction can either become closed by successfully committing - * an active transaction or if there is a failure while building - * the transaction thus rendering it failed/inactive. - */ -enum ref_transaction_state { - REF_TRANSACTION_OPEN = 0, - REF_TRANSACTION_CLOSED = 1 -}; - -/* - * Data structure for holding a reference transaction, which can - * consist of checks and updates to multiple references, carried out - * as atomically as possible. This structure is opaque to callers. - */ -struct ref_transaction { - struct ref_update **updates; - size_t alloc; - size_t nr; - enum ref_transaction_state state; -}; - struct ref_transaction *ref_transaction_begin(struct strbuf *err) { assert(err); diff --git a/refs/refs-internal.h b/refs/refs-internal.h new file mode 100644 index 0000000000..9077c114d0 --- /dev/null +++ b/refs/refs-internal.h @@ -0,0 +1,180 @@ +#ifndef REFS_REFS_INTERNAL_H +#define REFS_REFS_INTERNAL_H + +/* + * Data structures and functions for the internal use of the refs + * module. Code outside of the refs module should use only the public + * functions defined in "refs.h", and should *not* include this file. + */ + +/* + * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken + * refs (i.e., because the reference is about to be deleted anyway). + */ +#define REF_DELETING 0x02 + +/* + * Used as a flag in ref_update::flags when a loose ref is being + * pruned. + */ +#define REF_ISPRUNING 0x04 + +/* + * Used as a flag in ref_update::flags when the reference should be + * updated to new_sha1. + */ +#define REF_HAVE_NEW 0x08 + +/* + * Used as a flag in ref_update::flags when old_sha1 should be + * checked. + */ +#define REF_HAVE_OLD 0x10 + +/* + * Used as a flag in ref_update::flags when the lockfile needs to be + * committed. + */ +#define REF_NEEDS_COMMIT 0x20 + +/* + * 0x40 is REF_FORCE_CREATE_REFLOG, so skip it if you're adding a + * value to ref_update::flags + */ + +/* + * Return true iff refname is minimally safe. "Safe" here means that + * deleting a loose reference by this name will not do any damage, for + * example by causing a file that is not a reference to be deleted. + * This function does not check that the reference name is legal; for + * that, use check_refname_format(). + * + * We consider a refname that starts with "refs/" to be safe as long + * as any ".." components that it might contain do not escape "refs/". + * Names that do not start with "refs/" are considered safe iff they + * consist entirely of upper case characters and '_' (like "HEAD" and + * "MERGE_HEAD" but not "config" or "FOO/BAR"). + */ +int refname_is_safe(const char *refname); + +enum peel_status { + /* object was peeled successfully: */ + PEEL_PEELED = 0, + + /* + * object cannot be peeled because the named object (or an + * object referred to by a tag in the peel chain), does not + * exist. + */ + PEEL_INVALID = -1, + + /* object cannot be peeled because it is not a tag: */ + PEEL_NON_TAG = -2, + + /* ref_entry contains no peeled value because it is a symref: */ + PEEL_IS_SYMREF = -3, + + /* + * ref_entry cannot be peeled because it is broken (i.e., the + * symbolic reference cannot even be resolved to an object + * name): + */ + PEEL_BROKEN = -4 +}; + +/* + * Peel the named object; i.e., if the object is a tag, resolve the + * tag recursively until a non-tag is found. If successful, store the + * result to sha1 and return PEEL_PEELED. If the object is not a tag + * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively, + * and leave sha1 unchanged. + */ +enum peel_status peel_object(const unsigned char *name, unsigned char *sha1); + +/* + * Return 0 if a reference named refname could be created without + * conflicting with the name of an existing reference. Otherwise, + * return a negative value and write an explanation to err. If extras + * is non-NULL, it is a list of additional refnames with which refname + * is not allowed to conflict. If skip is non-NULL, ignore potential + * conflicts with refs in skip (e.g., because they are scheduled for + * deletion in the same operation). Behavior is undefined if the same + * name is listed in both extras and skip. + * + * Two reference names conflict if one of them exactly matches the + * leading components of the other; e.g., "foo/bar" conflicts with + * both "foo" and with "foo/bar/baz" but not with "foo/bar" or + * "foo/barbados". + * + * extras and skip must be sorted. + */ +int verify_refname_available(const char *newname, + struct string_list *extras, + struct string_list *skip, + struct strbuf *err); + +/* + * Copy the reflog message msg to buf, which has been allocated sufficiently + * large, while cleaning up the whitespaces. Especially, convert LF to space, + * because reflog file is one line per entry. + */ +int copy_reflog_msg(char *buf, const char *msg); + +int should_autocreate_reflog(const char *refname); + +/** + * Information needed for a single ref update. Set new_sha1 to the new + * value or to null_sha1 to delete the ref. To check the old value + * while the ref is locked, set (flags & REF_HAVE_OLD) and set + * old_sha1 to the old value, or to null_sha1 to ensure the ref does + * not exist before update. + */ +struct ref_update { + /* + * If (flags & REF_HAVE_NEW), set the reference to this value: + */ + unsigned char new_sha1[20]; + /* + * If (flags & REF_HAVE_OLD), check that the reference + * previously had this value: + */ + unsigned char old_sha1[20]; + /* + * One or more of REF_HAVE_NEW, REF_HAVE_OLD, REF_NODEREF, + * REF_DELETING, and REF_ISPRUNING: + */ + unsigned int flags; + struct ref_lock *lock; + int type; + char *msg; + const char refname[FLEX_ARRAY]; +}; + +/* + * Transaction states. + * OPEN: The transaction is in a valid state and can accept new updates. + * An OPEN transaction can be committed. + * CLOSED: A closed transaction is no longer active and no other operations + * than free can be used on it in this state. + * A transaction can either become closed by successfully committing + * an active transaction or if there is a failure while building + * the transaction thus rendering it failed/inactive. + */ +enum ref_transaction_state { + REF_TRANSACTION_OPEN = 0, + REF_TRANSACTION_CLOSED = 1 +}; + +/* + * Data structure for holding a reference transaction, which can + * consist of checks and updates to multiple references, carried out + * as atomically as possible. This structure is opaque to callers. + */ +struct ref_transaction { + struct ref_update **updates; + size_t alloc; + size_t nr; + enum ref_transaction_state state; +}; + +#endif /* REFS_REFS_INTERNAL_H */ -- cgit v1.2.3 From 7bd9bcf372d4c03bb7034346d72ae1318e2d0742 Mon Sep 17 00:00:00 2001 From: Michael Haggerty Date: Mon, 9 Nov 2015 14:34:01 +0100 Subject: refs: split filesystem-based refs code into a new file As another step in the move to pluggable reference backends, move the code that is specific to the filesystem-based reference backend (i.e., the current system of storing references as loose and packed files) into a separate file, refs/files-backend.c. Aside from a tiny bit of file header boilerplate, this commit only moves a subset of the code verbatim from refs.c to the new file, as can easily be verified using patience diff: git diff --patience $commit^:refs.c $commit:refs.c git diff --patience $commit^:refs.c $commit:refs/files-backend.c Signed-off-by: Michael Haggerty Signed-off-by: Jeff King --- Makefile | 3 +- refs.c | 3971 +++----------------------------------------------- refs/files-backend.c | 3539 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 3761 insertions(+), 3752 deletions(-) create mode 100644 refs/files-backend.c diff --git a/Makefile b/Makefile index 43ceeb966c..5bd68e0b5d 100644 --- a/Makefile +++ b/Makefile @@ -768,6 +768,7 @@ LIB_OBJS += reachable.o LIB_OBJS += read-cache.o LIB_OBJS += reflog-walk.o LIB_OBJS += refs.o +LIB_OBJS += refs/files-backend.o LIB_OBJS += ref-filter.o LIB_OBJS += remote.o LIB_OBJS += replace_object.o @@ -2419,7 +2420,7 @@ profile-clean: $(RM) $(addsuffix *.gcno,$(addprefix $(PROFILE_DIR)/, $(object_dirs))) clean: profile-clean coverage-clean - $(RM) *.o *.res block-sha1/*.o ppc/*.o compat/*.o compat/*/*.o + $(RM) *.o *.res refs/*.o block-sha1/*.o ppc/*.o compat/*.o compat/*/*.o $(RM) xdiff/*.o vcs-svn/*.o ewah/*.o builtin/*.o $(RM) $(LIB_FILE) $(XDIFF_LIB) $(VCSSVN_LIB) $(RM) $(ALL_PROGRAMS) $(SCRIPT_LIB) $(BUILT_INS) git$X diff --git a/refs.c b/refs.c index e6b82ee06b..1620a53c48 100644 --- a/refs.c +++ b/refs.c @@ -1,18 +1,13 @@ +/* + * The backend-independent part of the reference module. + */ + #include "cache.h" #include "lockfile.h" #include "refs.h" #include "refs/refs-internal.h" #include "object.h" #include "tag.h" -#include "dir.h" -#include "string-list.h" - -struct ref_lock { - char *ref_name; - char *orig_ref_name; - struct lock_file *lk; - struct object_id old_oid; -}; /* * How to handle various characters in refnames: @@ -123,189 +118,6 @@ int check_refname_format(const char *refname, int flags) return 0; } -struct ref_entry; - -/* - * Information used (along with the information in ref_entry) to - * describe a single cached reference. This data structure only - * occurs embedded in a union in struct ref_entry, and only when - * (ref_entry->flag & REF_DIR) is zero. - */ -struct ref_value { - /* - * The name of the object to which this reference resolves - * (which may be a tag object). If REF_ISBROKEN, this is - * null. If REF_ISSYMREF, then this is the name of the object - * referred to by the last reference in the symlink chain. - */ - struct object_id oid; - - /* - * If REF_KNOWS_PEELED, then this field holds the peeled value - * of this reference, or null if the reference is known not to - * be peelable. See the documentation for peel_ref() for an - * exact definition of "peelable". - */ - struct object_id peeled; -}; - -struct ref_cache; - -/* - * Information used (along with the information in ref_entry) to - * describe a level in the hierarchy of references. This data - * structure only occurs embedded in a union in struct ref_entry, and - * only when (ref_entry.flag & REF_DIR) is set. In that case, - * (ref_entry.flag & REF_INCOMPLETE) determines whether the references - * in the directory have already been read: - * - * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose - * or packed references, already read. - * - * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose - * references that hasn't been read yet (nor has any of its - * subdirectories). - * - * Entries within a directory are stored within a growable array of - * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < - * sorted are sorted by their component name in strcmp() order and the - * remaining entries are unsorted. - * - * Loose references are read lazily, one directory at a time. When a - * directory of loose references is read, then all of the references - * in that directory are stored, and REF_INCOMPLETE stubs are created - * for any subdirectories, but the subdirectories themselves are not - * read. The reading is triggered by get_ref_dir(). - */ -struct ref_dir { - int nr, alloc; - - /* - * Entries with index 0 <= i < sorted are sorted by name. New - * entries are appended to the list unsorted, and are sorted - * only when required; thus we avoid the need to sort the list - * after the addition of every reference. - */ - int sorted; - - /* A pointer to the ref_cache that contains this ref_dir. */ - struct ref_cache *ref_cache; - - struct ref_entry **entries; -}; - -/* - * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, - * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are - * public values; see refs.h. - */ - -/* - * The field ref_entry->u.value.peeled of this value entry contains - * the correct peeled value for the reference, which might be - * null_sha1 if the reference is not a tag or if it is broken. - */ -#define REF_KNOWS_PEELED 0x10 - -/* ref_entry represents a directory of references */ -#define REF_DIR 0x20 - -/* - * Entry has not yet been read from disk (used only for REF_DIR - * entries representing loose references) - */ -#define REF_INCOMPLETE 0x40 - -/* - * A ref_entry represents either a reference or a "subdirectory" of - * references. - * - * Each directory in the reference namespace is represented by a - * ref_entry with (flags & REF_DIR) set and containing a subdir member - * that holds the entries in that directory that have been read so - * far. If (flags & REF_INCOMPLETE) is set, then the directory and - * its subdirectories haven't been read yet. REF_INCOMPLETE is only - * used for loose reference directories. - * - * References are represented by a ref_entry with (flags & REF_DIR) - * unset and a value member that describes the reference's value. The - * flag member is at the ref_entry level, but it is also needed to - * interpret the contents of the value field (in other words, a - * ref_value object is not very much use without the enclosing - * ref_entry). - * - * Reference names cannot end with slash and directories' names are - * always stored with a trailing slash (except for the top-level - * directory, which is always denoted by ""). This has two nice - * consequences: (1) when the entries in each subdir are sorted - * lexicographically by name (as they usually are), the references in - * a whole tree can be generated in lexicographic order by traversing - * the tree in left-to-right, depth-first order; (2) the names of - * references and subdirectories cannot conflict, and therefore the - * presence of an empty subdirectory does not block the creation of a - * similarly-named reference. (The fact that reference names with the - * same leading components can conflict *with each other* is a - * separate issue that is regulated by verify_refname_available().) - * - * Please note that the name field contains the fully-qualified - * reference (or subdirectory) name. Space could be saved by only - * storing the relative names. But that would require the full names - * to be generated on the fly when iterating in do_for_each_ref(), and - * would break callback functions, who have always been able to assume - * that the name strings that they are passed will not be freed during - * the iteration. - */ -struct ref_entry { - unsigned char flag; /* ISSYMREF? ISPACKED? */ - union { - struct ref_value value; /* if not (flags&REF_DIR) */ - struct ref_dir subdir; /* if (flags&REF_DIR) */ - } u; - /* - * The full name of the reference (e.g., "refs/heads/master") - * or the full name of the directory with a trailing slash - * (e.g., "refs/heads/"): - */ - char name[FLEX_ARRAY]; -}; - -static void read_loose_refs(const char *dirname, struct ref_dir *dir); -static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len); -static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, - const char *dirname, size_t len, - int incomplete); -static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry); - -static struct ref_dir *get_ref_dir(struct ref_entry *entry) -{ - struct ref_dir *dir; - assert(entry->flag & REF_DIR); - dir = &entry->u.subdir; - if (entry->flag & REF_INCOMPLETE) { - read_loose_refs(entry->name, dir); - - /* - * Manually add refs/bisect, which, being - * per-worktree, might not appear in the directory - * listing for refs/ in the main repo. - */ - if (!strcmp(entry->name, "refs/")) { - int pos = search_ref_dir(dir, "refs/bisect/", 12); - if (pos < 0) { - struct ref_entry *child_entry; - child_entry = create_dir_entry(dir->ref_cache, - "refs/bisect/", - 12, 1); - add_entry_to_dir(dir, child_entry); - read_loose_refs("refs/bisect", - &child_entry->u.subdir); - } - } - entry->flag &= ~REF_INCOMPLETE; - } - return dir; -} - int refname_is_safe(const char *refname) { if (starts_with(refname, "refs/")) { @@ -330,2479 +142,317 @@ int refname_is_safe(const char *refname) return 1; } -static struct ref_entry *create_ref_entry(const char *refname, - const unsigned char *sha1, int flag, - int check_name) +char *resolve_refdup(const char *refname, int resolve_flags, + unsigned char *sha1, int *flags) { - int len; - struct ref_entry *ref; - - if (check_name && - check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) - die("Reference has invalid format: '%s'", refname); - len = strlen(refname) + 1; - ref = xmalloc(sizeof(struct ref_entry) + len); - hashcpy(ref->u.value.oid.hash, sha1); - oidclr(&ref->u.value.peeled); - memcpy(ref->name, refname, len); - ref->flag = flag; - return ref; + return xstrdup_or_null(resolve_ref_unsafe(refname, resolve_flags, + sha1, flags)); } -static void clear_ref_dir(struct ref_dir *dir); +/* The argument to filter_refs */ +struct ref_filter { + const char *pattern; + each_ref_fn *fn; + void *cb_data; +}; -static void free_ref_entry(struct ref_entry *entry) +int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags) { - if (entry->flag & REF_DIR) { - /* - * Do not use get_ref_dir() here, as that might - * trigger the reading of loose refs. - */ - clear_ref_dir(&entry->u.subdir); - } - free(entry); + if (resolve_ref_unsafe(refname, resolve_flags, sha1, flags)) + return 0; + return -1; } -/* - * Add a ref_entry to the end of dir (unsorted). Entry is always - * stored directly in dir; no recursion into subdirectories is - * done. - */ -static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry) +int read_ref(const char *refname, unsigned char *sha1) { - ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc); - dir->entries[dir->nr++] = entry; - /* optimize for the case that entries are added in order */ - if (dir->nr == 1 || - (dir->nr == dir->sorted + 1 && - strcmp(dir->entries[dir->nr - 2]->name, - dir->entries[dir->nr - 1]->name) < 0)) - dir->sorted = dir->nr; + return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL); } -/* - * Clear and free all entries in dir, recursively. - */ -static void clear_ref_dir(struct ref_dir *dir) +int ref_exists(const char *refname) { - int i; - for (i = 0; i < dir->nr; i++) - free_ref_entry(dir->entries[i]); - free(dir->entries); - dir->sorted = dir->nr = dir->alloc = 0; - dir->entries = NULL; + unsigned char sha1[20]; + return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL); } -/* - * Create a struct ref_entry object for the specified dirname. - * dirname is the name of the directory with a trailing slash (e.g., - * "refs/heads/") or "" for the top-level directory. - */ -static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, - const char *dirname, size_t len, - int incomplete) +static int filter_refs(const char *refname, const struct object_id *oid, + int flags, void *data) { - struct ref_entry *direntry; - direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1); - memcpy(direntry->name, dirname, len); - direntry->name[len] = '\0'; - direntry->u.subdir.ref_cache = ref_cache; - direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0); - return direntry; + struct ref_filter *filter = (struct ref_filter *)data; + + if (wildmatch(filter->pattern, refname, 0, NULL)) + return 0; + return filter->fn(refname, oid, flags, filter->cb_data); } -static int ref_entry_cmp(const void *a, const void *b) +enum peel_status peel_object(const unsigned char *name, unsigned char *sha1) { - struct ref_entry *one = *(struct ref_entry **)a; - struct ref_entry *two = *(struct ref_entry **)b; - return strcmp(one->name, two->name); -} + struct object *o = lookup_unknown_object(name); -static void sort_ref_dir(struct ref_dir *dir); + if (o->type == OBJ_NONE) { + int type = sha1_object_info(name, NULL); + if (type < 0 || !object_as_type(o, type, 0)) + return PEEL_INVALID; + } -struct string_slice { - size_t len; - const char *str; -}; + if (o->type != OBJ_TAG) + return PEEL_NON_TAG; -static int ref_entry_cmp_sslice(const void *key_, const void *ent_) -{ - const struct string_slice *key = key_; - const struct ref_entry *ent = *(const struct ref_entry * const *)ent_; - int cmp = strncmp(key->str, ent->name, key->len); - if (cmp) - return cmp; - return '\0' - (unsigned char)ent->name[key->len]; + o = deref_tag_noverify(o); + if (!o) + return PEEL_INVALID; + + hashcpy(sha1, o->sha1); + return PEEL_PEELED; } -/* - * Return the index of the entry with the given refname from the - * ref_dir (non-recursively), sorting dir if necessary. Return -1 if - * no such entry is found. dir must already be complete. - */ -static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len) -{ - struct ref_entry **r; - struct string_slice key; +struct warn_if_dangling_data { + FILE *fp; + const char *refname; + const struct string_list *refnames; + const char *msg_fmt; +}; - if (refname == NULL || !dir->nr) - return -1; +static int warn_if_dangling_symref(const char *refname, const struct object_id *oid, + int flags, void *cb_data) +{ + struct warn_if_dangling_data *d = cb_data; + const char *resolves_to; + struct object_id junk; - sort_ref_dir(dir); - key.len = len; - key.str = refname; - r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries), - ref_entry_cmp_sslice); + if (!(flags & REF_ISSYMREF)) + return 0; - if (r == NULL) - return -1; + resolves_to = resolve_ref_unsafe(refname, 0, junk.hash, NULL); + if (!resolves_to + || (d->refname + ? strcmp(resolves_to, d->refname) + : !string_list_has_string(d->refnames, resolves_to))) { + return 0; + } - return r - dir->entries; + fprintf(d->fp, d->msg_fmt, refname); + fputc('\n', d->fp); + return 0; } -/* - * Search for a directory entry directly within dir (without - * recursing). Sort dir if necessary. subdirname must be a directory - * name (i.e., end in '/'). If mkdir is set, then create the - * directory if it is missing; otherwise, return NULL if the desired - * directory cannot be found. dir must already be complete. - */ -static struct ref_dir *search_for_subdir(struct ref_dir *dir, - const char *subdirname, size_t len, - int mkdir) +void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname) { - int entry_index = search_ref_dir(dir, subdirname, len); - struct ref_entry *entry; - if (entry_index == -1) { - if (!mkdir) - return NULL; - /* - * Since dir is complete, the absence of a subdir - * means that the subdir really doesn't exist; - * therefore, create an empty record for it but mark - * the record complete. - */ - entry = create_dir_entry(dir->ref_cache, subdirname, len, 0); - add_entry_to_dir(dir, entry); - } else { - entry = dir->entries[entry_index]; - } - return get_ref_dir(entry); + struct warn_if_dangling_data data; + + data.fp = fp; + data.refname = refname; + data.refnames = NULL; + data.msg_fmt = msg_fmt; + for_each_rawref(warn_if_dangling_symref, &data); } -/* - * If refname is a reference name, find the ref_dir within the dir - * tree that should hold refname. If refname is a directory name - * (i.e., ends in '/'), then return that ref_dir itself. dir must - * represent the top-level directory and must already be complete. - * Sort ref_dirs and recurse into subdirectories as necessary. If - * mkdir is set, then create any missing directories; otherwise, - * return NULL if the desired directory cannot be found. - */ -static struct ref_dir *find_containing_dir(struct ref_dir *dir, - const char *refname, int mkdir) +void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames) { - const char *slash; - for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { - size_t dirnamelen = slash - refname + 1; - struct ref_dir *subdir; - subdir = search_for_subdir(dir, refname, dirnamelen, mkdir); - if (!subdir) { - dir = NULL; - break; - } - dir = subdir; - } + struct warn_if_dangling_data data; - return dir; + data.fp = fp; + data.refname = NULL; + data.refnames = refnames; + data.msg_fmt = msg_fmt; + for_each_rawref(warn_if_dangling_symref, &data); } -/* - * Find the value entry with the given name in dir, sorting ref_dirs - * and recursing into subdirectories as necessary. If the name is not - * found or it corresponds to a directory entry, return NULL. - */ -static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname) +int for_each_tag_ref(each_ref_fn fn, void *cb_data) { - int entry_index; - struct ref_entry *entry; - dir = find_containing_dir(dir, refname, 0); - if (!dir) - return NULL; - entry_index = search_ref_dir(dir, refname, strlen(refname)); - if (entry_index == -1) - return NULL; - entry = dir->entries[entry_index]; - return (entry->flag & REF_DIR) ? NULL : entry; + return for_each_ref_in("refs/tags/", fn, cb_data); } -/* - * Remove the entry with the given name from dir, recursing into - * subdirectories as necessary. If refname is the name of a directory - * (i.e., ends with '/'), then remove the directory and its contents. - * If the removal was successful, return the number of entries - * remaining in the directory entry that contained the deleted entry. - * If the name was not found, return -1. Please note that this - * function only deletes the entry from the cache; it does not delete - * it from the filesystem or ensure that other cache entries (which - * might be symbolic references to the removed entry) are updated. - * Nor does it remove any containing dir entries that might be made - * empty by the removal. dir must represent the top-level directory - * and must already be complete. - */ -static int remove_entry(struct ref_dir *dir, const char *refname) +int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) { - int refname_len = strlen(refname); - int entry_index; - struct ref_entry *entry; - int is_dir = refname[refname_len - 1] == '/'; - if (is_dir) { - /* - * refname represents a reference directory. Remove - * the trailing slash; otherwise we will get the - * directory *representing* refname rather than the - * one *containing* it. - */ - char *dirname = xmemdupz(refname, refname_len - 1); - dir = find_containing_dir(dir, dirname, 0); - free(dirname); - } else { - dir = find_containing_dir(dir, refname, 0); - } - if (!dir) - return -1; - entry_index = search_ref_dir(dir, refname, refname_len); - if (entry_index == -1) - return -1; - entry = dir->entries[entry_index]; - - memmove(&dir->entries[entry_index], - &dir->entries[entry_index + 1], - (dir->nr - entry_index - 1) * sizeof(*dir->entries) - ); - dir->nr--; - if (dir->sorted > entry_index) - dir->sorted--; - free_ref_entry(entry); - return dir->nr; + return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data); } -/* - * Add a ref_entry to the ref_dir (unsorted), recursing into - * subdirectories as necessary. dir must represent the top-level - * directory. Return 0 on success. - */ -static int add_ref(struct ref_dir *dir, struct ref_entry *ref) +int for_each_branch_ref(each_ref_fn fn, void *cb_data) { - dir = find_containing_dir(dir, ref->name, 1); - if (!dir) - return -1; - add_entry_to_dir(dir, ref); - return 0; + return for_each_ref_in("refs/heads/", fn, cb_data); } -/* - * Emit a warning and return true iff ref1 and ref2 have the same name - * and the same sha1. Die if they have the same name but different - * sha1s. - */ -static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2) +int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) { - if (strcmp(ref1->name, ref2->name)) - return 0; - - /* Duplicate name; make sure that they don't conflict: */ - - if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) - /* This is impossible by construction */ - die("Reference directory conflict: %s", ref1->name); - - if (oidcmp(&ref1->u.value.oid, &ref2->u.value.oid)) - die("Duplicated ref, and SHA1s don't match: %s", ref1->name); - - warning("Duplicated ref: %s", ref1->name); - return 1; + return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data); } -/* - * Sort the entries in dir non-recursively (if they are not already - * sorted) and remove any duplicate entries. - */ -static void sort_ref_dir(struct ref_dir *dir) +int for_each_remote_ref(each_ref_fn fn, void *cb_data) { - int i, j; - struct ref_entry *last = NULL; - - /* - * This check also prevents passing a zero-length array to qsort(), - * which is a problem on some platforms. - */ - if (dir->sorted == dir->nr) - return; - - qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp); - - /* Remove any duplicates: */ - for (i = 0, j = 0; j < dir->nr; j++) { - struct ref_entry *entry = dir->entries[j]; - if (last && is_dup_ref(last, entry)) - free_ref_entry(entry); - else - last = dir->entries[i++] = entry; - } - dir->sorted = dir->nr = i; + return for_each_ref_in("refs/remotes/", fn, cb_data); } -/* Include broken references in a do_for_each_ref*() iteration: */ -#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 - -/* - * Return true iff the reference described by entry can be resolved to - * an object in the database. Emit a warning if the referred-to - * object does not exist. - */ -static int ref_resolves_to_object(struct ref_entry *entry) +int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) { - if (entry->flag & REF_ISBROKEN) - return 0; - if (!has_sha1_file(entry->u.value.oid.hash)) { - error("%s does not point to a valid object!", entry->name); - return 0; - } - return 1; + return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data); } -/* - * current_ref is a performance hack: when iterating over references - * using the for_each_ref*() functions, current_ref is set to the - * current reference's entry before calling the callback function. If - * the callback function calls peel_ref(), then peel_ref() first - * checks whether the reference to be peeled is the current reference - * (it usually is) and if so, returns that reference's peeled version - * if it is available. This avoids a refname lookup in a common case. - */ -static struct ref_entry *current_ref; +int head_ref_namespaced(each_ref_fn fn, void *cb_data) +{ + struct strbuf buf = STRBUF_INIT; + int ret = 0; + struct object_id oid; + int flag; -typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data); + strbuf_addf(&buf, "%sHEAD", get_git_namespace()); + if (!read_ref_full(buf.buf, RESOLVE_REF_READING, oid.hash, &flag)) + ret = fn(buf.buf, &oid, flag, cb_data); + strbuf_release(&buf); -struct ref_entry_cb { - const char *base; - int trim; - int flags; - each_ref_fn *fn; - void *cb_data; -}; + return ret; +} -/* - * Handle one reference in a do_for_each_ref*()-style iteration, - * calling an each_ref_fn for each entry. - */ -static int do_one_ref(struct ref_entry *entry, void *cb_data) +int for_each_glob_ref_in(each_ref_fn fn, const char *pattern, + const char *prefix, void *cb_data) { - struct ref_entry_cb *data = cb_data; - struct ref_entry *old_current_ref; - int retval; + struct strbuf real_pattern = STRBUF_INIT; + struct ref_filter filter; + int ret; - if (!starts_with(entry->name, data->base)) - return 0; + if (!prefix && !starts_with(pattern, "refs/")) + strbuf_addstr(&real_pattern, "refs/"); + else if (prefix) + strbuf_addstr(&real_pattern, prefix); + strbuf_addstr(&real_pattern, pattern); - if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && - !ref_resolves_to_object(entry)) - return 0; + if (!has_glob_specials(pattern)) { + /* Append implied '/' '*' if not present. */ + strbuf_complete(&real_pattern, '/'); + /* No need to check for '*', there is none. */ + strbuf_addch(&real_pattern, '*'); + } + + filter.pattern = real_pattern.buf; + filter.fn = fn; + filter.cb_data = cb_data; + ret = for_each_ref(filter_refs, &filter); - /* Store the old value, in case this is a recursive call: */ - old_current_ref = current_ref; - current_ref = entry; - retval = data->fn(entry->name + data->trim, &entry->u.value.oid, - entry->flag, data->cb_data); - current_ref = old_current_ref; - return retval; + strbuf_release(&real_pattern); + return ret; } -/* - * Call fn for each reference in dir that has index in the range - * offset <= index < dir->nr. Recurse into subdirectories that are in - * that index range, sorting them before iterating. This function - * does not sort dir itself; it should be sorted beforehand. fn is - * called for all references, including broken ones. - */ -static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset, - each_ref_entry_fn fn, void *cb_data) -{ - int i; - assert(dir->sorted == dir->nr); - for (i = offset; i < dir->nr; i++) { - struct ref_entry *entry = dir->entries[i]; - int retval; - if (entry->flag & REF_DIR) { - struct ref_dir *subdir = get_ref_dir(entry); - sort_ref_dir(subdir); - retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data); - } else { - retval = fn(entry, cb_data); - } - if (retval) - return retval; - } - return 0; -} - -/* - * Call fn for each reference in the union of dir1 and dir2, in order - * by refname. Recurse into subdirectories. If a value entry appears - * in both dir1 and dir2, then only process the version that is in - * dir2. The input dirs must already be sorted, but subdirs will be - * sorted as needed. fn is called for all references, including - * broken ones. - */ -static int do_for_each_entry_in_dirs(struct ref_dir *dir1, - struct ref_dir *dir2, - each_ref_entry_fn fn, void *cb_data) -{ - int retval; - int i1 = 0, i2 = 0; - - assert(dir1->sorted == dir1->nr); - assert(dir2->sorted == dir2->nr); - while (1) { - struct ref_entry *e1, *e2; - int cmp; - if (i1 == dir1->nr) { - return do_for_each_entry_in_dir(dir2, i2, fn, cb_data); - } - if (i2 == dir2->nr) { - return do_for_each_entry_in_dir(dir1, i1, fn, cb_data); - } - e1 = dir1->entries[i1]; - e2 = dir2->entries[i2]; - cmp = strcmp(e1->name, e2->name); - if (cmp == 0) { - if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { - /* Both are directories; descend them in parallel. */ - struct ref_dir *subdir1 = get_ref_dir(e1); - struct ref_dir *subdir2 = get_ref_dir(e2); - sort_ref_dir(subdir1); - sort_ref_dir(subdir2); - retval = do_for_each_entry_in_dirs( - subdir1, subdir2, fn, cb_data); - i1++; - i2++; - } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { - /* Both are references; ignore the one from dir1. */ - retval = fn(e2, cb_data); - i1++; - i2++; - } else { - die("conflict between reference and directory: %s", - e1->name); - } - } else { - struct ref_entry *e; - if (cmp < 0) { - e = e1; - i1++; - } else { - e = e2; - i2++; - } - if (e->flag & REF_DIR) { - struct ref_dir *subdir = get_ref_dir(e); - sort_ref_dir(subdir); - retval = do_for_each_entry_in_dir( - subdir, 0, fn, cb_data); - } else { - retval = fn(e, cb_data); - } - } - if (retval) - return retval; - } -} - -/* - * Load all of the refs from the dir into our in-memory cache. The hard work - * of loading loose refs is done by get_ref_dir(), so we just need to recurse - * through all of the sub-directories. We do not even need to care about - * sorting, as traversal order does not matter to us. - */ -static void prime_ref_dir(struct ref_dir *dir) -{ - int i; - for (i = 0; i < dir->nr; i++) { - struct ref_entry *entry = dir->entries[i]; - if (entry->flag & REF_DIR) - prime_ref_dir(get_ref_dir(entry)); - } -} - -struct nonmatching_ref_data { - const struct string_list *skip; - const char *conflicting_refname; -}; - -static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata) -{ - struct nonmatching_ref_data *data = vdata; - - if (data->skip && string_list_has_string(data->skip, entry->name)) - return 0; - - data->conflicting_refname = entry->name; - return 1; -} - -/* - * Return 0 if a reference named refname could be created without - * conflicting with the name of an existing reference in dir. - * See verify_refname_available for more information. - */ -static int verify_refname_available_dir(const char *refname, - const struct string_list *extras, - const struct string_list *skip, - struct ref_dir *dir, - struct strbuf *err) -{ - const char *slash; - int pos; - struct strbuf dirname = STRBUF_INIT; - int ret = -1; - - /* - * For the sake of comments in this function, suppose that - * refname is "refs/foo/bar". - */ - - assert(err); - - strbuf_grow(&dirname, strlen(refname) + 1); - for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { - /* Expand dirname to the new prefix, not including the trailing slash: */ - strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len); - - /* - * We are still at a leading dir of the refname (e.g., - * "refs/foo"; if there is a reference with that name, - * it is a conflict, *unless* it is in skip. - */ - if (dir) { - pos = search_ref_dir(dir, dirname.buf, dirname.len); - if (pos >= 0 && - (!skip || !string_list_has_string(skip, dirname.buf))) { - /* - * We found a reference whose name is - * a proper prefix of refname; e.g., - * "refs/foo", and is not in skip. - */ - strbuf_addf(err, "'%s' exists; cannot create '%s'", - dirname.buf, refname); - goto cleanup; - } - } - - if (extras && string_list_has_string(extras, dirname.buf) && - (!skip || !string_list_has_string(skip, dirname.buf))) { - strbuf_addf(err, "cannot process '%s' and '%s' at the same time", - refname, dirname.buf); - goto cleanup; - } - - /* - * Otherwise, we can try to continue our search with - * the next component. So try to look up the - * directory, e.g., "refs/foo/". If we come up empty, - * we know there is nothing under this whole prefix, - * but even in that case we still have to continue the - * search for conflicts with extras. - */ - strbuf_addch(&dirname, '/'); - if (dir) { - pos = search_ref_dir(dir, dirname.buf, dirname.len); - if (pos < 0) { - /* - * There was no directory "refs/foo/", - * so there is nothing under this - * whole prefix. So there is no need - * to continue looking for conflicting - * references. But we need to continue - * looking for conflicting extras. - */ - dir = NULL; - } else { - dir = get_ref_dir(dir->entries[pos]); - } - } - } - - /* - * We are at the leaf of our refname (e.g., "refs/foo/bar"). - * There is no point in searching for a reference with that - * name, because a refname isn't considered to conflict with - * itself. But we still need to check for references whose - * names are in the "refs/foo/bar/" namespace, because they - * *do* conflict. - */ - strbuf_addstr(&dirname, refname + dirname.len); - strbuf_addch(&dirname, '/'); - - if (dir) { - pos = search_ref_dir(dir, dirname.buf, dirname.len); - - if (pos >= 0) { - /* - * We found a directory named "$refname/" - * (e.g., "refs/foo/bar/"). It is a problem - * iff it contains any ref that is not in - * "skip". - */ - struct nonmatching_ref_data data; - - data.skip = skip; - data.conflicting_refname = NULL; - dir = get_ref_dir(dir->entries[pos]); - sort_ref_dir(dir); - if (do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) { - strbuf_addf(err, "'%s' exists; cannot create '%s'", - data.conflicting_refname, refname); - goto cleanup; - } - } - } - - if (extras) { - /* - * Check for entries in extras that start with - * "$refname/". We do that by looking for the place - * where "$refname/" would be inserted in extras. If - * there is an entry at that position that starts with - * "$refname/" and is not in skip, then we have a - * conflict. - */ - for (pos = string_list_find_insert_index(extras, dirname.buf, 0); - pos < extras->nr; pos++) { - const char *extra_refname = extras->items[pos].string; - - if (!starts_with(extra_refname, dirname.buf)) - break; - - if (!skip || !string_list_has_string(skip, extra_refname)) { - strbuf_addf(err, "cannot process '%s' and '%s' at the same time", - refname, extra_refname); - goto cleanup; - } - } - } - - /* No conflicts were found */ - ret = 0; - -cleanup: - strbuf_release(&dirname); - return ret; -} - -struct packed_ref_cache { - struct ref_entry *root; - - /* - * Count of references to the data structure in this instance, - * including the pointer from ref_cache::packed if any. The - * data will not be freed as long as the reference count is - * nonzero. - */ - unsigned int referrers; - - /* - * Iff the packed-refs file associated with this instance is - * currently locked for writing, this points at the associated - * lock (which is owned by somebody else). The referrer count - * is also incremented when the file is locked and decremented - * when it is unlocked. - */ - struct lock_file *lock; - - /* The metadata from when this packed-refs cache was read */ - struct stat_validity validity; -}; - -/* - * Future: need to be in "struct repository" - * when doing a full libification. - */ -static struct ref_cache { - struct ref_cache *next; - struct ref_entry *loose; - struct packed_ref_cache *packed; - /* - * The submodule name, or "" for the main repo. We allocate - * length 1 rather than FLEX_ARRAY so that the main ref_cache - * is initialized correctly. - */ - char name[1]; -} ref_cache, *submodule_ref_caches; - -/* Lock used for the main packed-refs file: */ -static struct lock_file packlock; - -/* - * Increment the reference count of *packed_refs. - */ -static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) -{ - packed_refs->referrers++; -} - -/* - * Decrease the reference count of *packed_refs. If it goes to zero, - * free *packed_refs and return true; otherwise return false. - */ -static int release_packed_ref_cache(struct packed_ref_cache *packed_refs) -{ - if (!--packed_refs->referrers) { - free_ref_entry(packed_refs->root); - stat_validity_clear(&packed_refs->validity); - free(packed_refs); - return 1; - } else { - return 0; - } -} - -static void clear_packed_ref_cache(struct ref_cache *refs) -{ - if (refs->packed) { - struct packed_ref_cache *packed_refs = refs->packed; - - if (packed_refs->lock) - die("internal error: packed-ref cache cleared while locked"); - refs->packed = NULL; - release_packed_ref_cache(packed_refs); - } -} - -static void clear_loose_ref_cache(struct ref_cache *refs) -{ - if (refs->loose) { - free_ref_entry(refs->loose); - refs->loose = NULL; - } -} - -static struct ref_cache *create_ref_cache(const char *submodule) -{ - int len; - struct ref_cache *refs; - if (!submodule) - submodule = ""; - len = strlen(submodule) + 1; - refs = xcalloc(1, sizeof(struct ref_cache) + len); - memcpy(refs->name, submodule, len); - return refs; -} - -/* - * Return a pointer to a ref_cache for the specified submodule. For - * the main repository, use submodule==NULL. The returned structure - * will be allocated and initialized but not necessarily populated; it - * should not be freed. - */ -static struct ref_cache *get_ref_cache(const char *submodule) -{ - struct ref_cache *refs; - - if (!submodule || !*submodule) - return &ref_cache; - - for (refs = submodule_ref_caches; refs; refs = refs->next) - if (!strcmp(submodule, refs->name)) - return refs; - - refs = create_ref_cache(submodule); - refs->next = submodule_ref_caches; - submodule_ref_caches = refs; - return refs; -} - -/* The length of a peeled reference line in packed-refs, including EOL: */ -#define PEELED_LINE_LENGTH 42 - -/* - * The packed-refs header line that we write out. Perhaps other - * traits will be added later. The trailing space is required. - */ -static const char PACKED_REFS_HEADER[] = - "# pack-refs with: peeled fully-peeled \n"; - -/* - * Parse one line from a packed-refs file. Write the SHA1 to sha1. - * Return a pointer to the refname within the line (null-terminated), - * or NULL if there was a problem. - */ -static const char *parse_ref_line(struct strbuf *line, unsigned char *sha1) -{ - const char *ref; - - /* - * 42: the answer to everything. - * - * In this case, it happens to be the answer to - * 40 (length of sha1 hex representation) - * +1 (space in between hex and name) - * +1 (newline at the end of the line) - */ - if (line->len <= 42) - return NULL; - - if (get_sha1_hex(line->buf, sha1) < 0) - return NULL; - if (!isspace(line->buf[40])) - return NULL; - - ref = line->buf + 41; - if (isspace(*ref)) - return NULL; - - if (line->buf[line->len - 1] != '\n') - return NULL; - line->buf[--line->len] = 0; - - return ref; -} - -/* - * Read f, which is a packed-refs file, into dir. - * - * A comment line of the form "# pack-refs with: " may contain zero or - * more traits. We interpret the traits as follows: - * - * No traits: - * - * Probably no references are peeled. But if the file contains a - * peeled value for a reference, we will use it. - * - * peeled: - * - * References under "refs/tags/", if they *can* be peeled, *are* - * peeled in this file. References outside of "refs/tags/" are - * probably not peeled even if they could have been, but if we find - * a peeled value for such a reference we will use it. - * - * fully-peeled: - * - * All references in the file that can be peeled are peeled. - * Inversely (and this is more important), any references in the - * file for which no peeled value is recorded is not peelable. This - * trait should typically be written alongside "peeled" for - * compatibility with older clients, but we do not require it - * (i.e., "peeled" is a no-op if "fully-peeled" is set). - */ -static void read_packed_refs(FILE *f, struct ref_dir *dir) -{ - struct ref_entry *last = NULL; - struct strbuf line = STRBUF_INIT; - enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; - - while (strbuf_getwholeline(&line, f, '\n') != EOF) { - unsigned char sha1[20]; - const char *refname; - const char *traits; - - if (skip_prefix(line.buf, "# pack-refs with:", &traits)) { - if (strstr(traits, " fully-peeled ")) - peeled = PEELED_FULLY; - else if (strstr(traits, " peeled ")) - peeled = PEELED_TAGS; - /* perhaps other traits later as well */ - continue; - } - - refname = parse_ref_line(&line, sha1); - if (refname) { - int flag = REF_ISPACKED; - - if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { - if (!refname_is_safe(refname)) - die("packed refname is dangerous: %s", refname); - hashclr(sha1); - flag |= REF_BAD_NAME | REF_ISBROKEN; - } - last = create_ref_entry(refname, sha1, flag, 0); - if (peeled == PEELED_FULLY || - (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/"))) - last->flag |= REF_KNOWS_PEELED; - add_ref(dir, last); - continue; - } - if (last && - line.buf[0] == '^' && - line.len == PEELED_LINE_LENGTH && - line.buf[PEELED_LINE_LENGTH - 1] == '\n' && - !get_sha1_hex(line.buf + 1, sha1)) { - hashcpy(last->u.value.peeled.hash, sha1); - /* - * Regardless of what the file header said, - * we definitely know the value of *this* - * reference: - */ - last->flag |= REF_KNOWS_PEELED; - } - } - - strbuf_release(&line); -} - -/* - * Get the packed_ref_cache for the specified ref_cache, creating it - * if necessary. - */ -static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs) -{ - char *packed_refs_file; - - if (*refs->name) - packed_refs_file = git_pathdup_submodule(refs->name, "packed-refs"); - else - packed_refs_file = git_pathdup("packed-refs"); - - if (refs->packed && - !stat_validity_check(&refs->packed->validity, packed_refs_file)) - clear_packed_ref_cache(refs); - - if (!refs->packed) { - FILE *f; - - refs->packed = xcalloc(1, sizeof(*refs->packed)); - acquire_packed_ref_cache(refs->packed); - refs->packed->root = create_dir_entry(refs, "", 0, 0); - f = fopen(packed_refs_file, "r"); - if (f) { - stat_validity_update(&refs->packed->validity, fileno(f)); - read_packed_refs(f, get_ref_dir(refs->packed->root)); - fclose(f); - } - } - free(packed_refs_file); - return refs->packed; -} - -static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache) -{ - return get_ref_dir(packed_ref_cache->root); -} - -static struct ref_dir *get_packed_refs(struct ref_cache *refs) -{ - return get_packed_ref_dir(get_packed_ref_cache(refs)); -} - -/* - * Add a reference to the in-memory packed reference cache. This may - * only be called while the packed-refs file is locked (see - * lock_packed_refs()). To actually write the packed-refs file, call - * commit_packed_refs(). - */ -static void add_packed_ref(const char *refname, const unsigned char *sha1) -{ - struct packed_ref_cache *packed_ref_cache = - get_packed_ref_cache(&ref_cache); - - if (!packed_ref_cache->lock) - die("internal error: packed refs not locked"); - add_ref(get_packed_ref_dir(packed_ref_cache), - create_ref_entry(refname, sha1, REF_ISPACKED, 1)); -} - -/* - * Read the loose references from the namespace dirname into dir - * (without recursing). dirname must end with '/'. dir must be the - * directory entry corresponding to dirname. - */ -static void read_loose_refs(const char *dirname, struct ref_dir *dir) -{ - struct ref_cache *refs = dir->ref_cache; - DIR *d; - struct dirent *de; - int dirnamelen = strlen(dirname); - struct strbuf refname; - struct strbuf path = STRBUF_INIT; - size_t path_baselen; - - if (*refs->name) - strbuf_git_path_submodule(&path, refs->name, "%s", dirname); - else - strbuf_git_path(&path, "%s", dirname); - path_baselen = path.len; - - d = opendir(path.buf); - if (!d) { - strbuf_release(&path); - return; - } - - strbuf_init(&refname, dirnamelen + 257); - strbuf_add(&refname, dirname, dirnamelen); - - while ((de = readdir(d)) != NULL) { - unsigned char sha1[20]; - struct stat st; - int flag; - - if (de->d_name[0] == '.') - continue; - if (ends_with(de->d_name, ".lock")) - continue; - strbuf_addstr(&refname, de->d_name); - strbuf_addstr(&path, de->d_name); - if (stat(path.buf, &st) < 0) { - ; /* silently ignore */ - } else if (S_ISDIR(st.st_mode)) { - strbuf_addch(&refname, '/'); - add_entry_to_dir(dir, - create_dir_entry(refs, refname.buf, - refname.len, 1)); - } else { - int read_ok; - - if (*refs->name) { - hashclr(sha1); - flag = 0; - read_ok = !resolve_gitlink_ref(refs->name, - refname.buf, sha1); - } else { - read_ok = !read_ref_full(refname.buf, - RESOLVE_REF_READING, - sha1, &flag); - } - - if (!read_ok) { - hashclr(sha1); - flag |= REF_ISBROKEN; - } else if (is_null_sha1(sha1)) { - /* - * It is so astronomically unlikely - * that NULL_SHA1 is the SHA-1 of an - * actual object that we consider its - * appearance in a loose reference - * file to be repo corruption - * (probably due to a software bug). - */ - flag |= REF_ISBROKEN; - } - - if (check_refname_format(refname.buf, - REFNAME_ALLOW_ONELEVEL)) { - if (!refname_is_safe(refname.buf)) - die("loose refname is dangerous: %s", refname.buf); - hashclr(sha1); - flag |= REF_BAD_NAME | REF_ISBROKEN; - } - add_entry_to_dir(dir, - create_ref_entry(refname.buf, sha1, flag, 0)); - } - strbuf_setlen(&refname, dirnamelen); - strbuf_setlen(&path, path_baselen); - } - strbuf_release(&refname); - strbuf_release(&path); - closedir(d); -} - -static struct ref_dir *get_loose_refs(struct ref_cache *refs) -{ - if (!refs->loose) { - /* - * Mark the top-level directory complete because we - * are about to read the only subdirectory that can - * hold references: - */ - refs->loose = create_dir_entry(refs, "", 0, 0); - /* - * Create an incomplete entry for "refs/": - */ - add_entry_to_dir(get_ref_dir(refs->loose), - create_dir_entry(refs, "refs/", 5, 1)); - } - return get_ref_dir(refs->loose); -} - -/* We allow "recursive" symbolic refs. Only within reason, though */ -#define MAXDEPTH 5 -#define MAXREFLEN (1024) - -/* - * Called by resolve_gitlink_ref_recursive() after it failed to read - * from the loose refs in ref_cache refs. Find in the - * packed-refs file for the submodule. - */ -static int resolve_gitlink_packed_ref(struct ref_cache *refs, - const char *refname, unsigned char *sha1) -{ - struct ref_entry *ref; - struct ref_dir *dir = get_packed_refs(refs); - - ref = find_ref(dir, refname); - if (ref == NULL) - return -1; - - hashcpy(sha1, ref->u.value.oid.hash); - return 0; -} - -static int resolve_gitlink_ref_recursive(struct ref_cache *refs, - const char *refname, unsigned char *sha1, - int recursion) -{ - int fd, len; - char buffer[128], *p; - char *path; - - if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN) - return -1; - path = *refs->name - ? git_pathdup_submodule(refs->name, "%s", refname) - : git_pathdup("%s", refname); - fd = open(path, O_RDONLY); - free(path); - if (fd < 0) - return resolve_gitlink_packed_ref(refs, refname, sha1); - - len = read(fd, buffer, sizeof(buffer)-1); - close(fd); - if (len < 0) - return -1; - while (len && isspace(buffer[len-1])) - len--; - buffer[len] = 0; - - /* Was it a detached head or an old-fashioned symlink? */ - if (!get_sha1_hex(buffer, sha1)) - return 0; - - /* Symref? */ - if (strncmp(buffer, "ref:", 4)) - return -1; - p = buffer + 4; - while (isspace(*p)) - p++; - - return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1); -} - -int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1) -{ - int len = strlen(path), retval; - char *submodule; - struct ref_cache *refs; - - while (len && path[len-1] == '/') - len--; - if (!len) - return -1; - submodule = xstrndup(path, len); - refs = get_ref_cache(submodule); - free(submodule); - - retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0); - return retval; -} - -/* - * Return the ref_entry for the given refname from the packed - * references. If it does not exist, return NULL. - */ -static struct ref_entry *get_packed_ref(const char *refname) -{ - return find_ref(get_packed_refs(&ref_cache), refname); -} - -/* - * A loose ref file doesn't exist; check for a packed ref. The - * options are forwarded from resolve_safe_unsafe(). - */ -static int resolve_missing_loose_ref(const char *refname, - int resolve_flags, - unsigned char *sha1, - int *flags) -{ - struct ref_entry *entry; - - /* - * The loose reference file does not exist; check for a packed - * reference. - */ - entry = get_packed_ref(refname); - if (entry) { - hashcpy(sha1, entry->u.value.oid.hash); - if (flags) - *flags |= REF_ISPACKED; - return 0; - } - /* The reference is not a packed reference, either. */ - if (resolve_flags & RESOLVE_REF_READING) { - errno = ENOENT; - return -1; - } else { - hashclr(sha1); - return 0; - } -} - -/* This function needs to return a meaningful errno on failure */ -static const char *resolve_ref_1(const char *refname, - int resolve_flags, - unsigned char *sha1, - int *flags, - struct strbuf *sb_refname, - struct strbuf *sb_path, - struct strbuf *sb_contents) -{ - int depth = MAXDEPTH; - int bad_name = 0; - - if (flags) - *flags = 0; - - if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { - if (flags) - *flags |= REF_BAD_NAME; - - if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) || - !refname_is_safe(refname)) { - errno = EINVAL; - return NULL; - } - /* - * dwim_ref() uses REF_ISBROKEN to distinguish between - * missing refs and refs that were present but invalid, - * to complain about the latter to stderr. - * - * We don't know whether the ref exists, so don't set - * REF_ISBROKEN yet. - */ - bad_name = 1; - } - for (;;) { - const char *path; - struct stat st; - char *buf; - int fd; - - if (--depth < 0) { - errno = ELOOP; - return NULL; - } - - strbuf_reset(sb_path); - strbuf_git_path(sb_path, "%s", refname); - path = sb_path->buf; - - /* - * We might have to loop back here to avoid a race - * condition: first we lstat() the file, then we try - * to read it as a link or as a file. But if somebody - * changes the type of the file (file <-> directory - * <-> symlink) between the lstat() and reading, then - * we don't want to report that as an error but rather - * try again starting with the lstat(). - */ - stat_ref: - if (lstat(path, &st) < 0) { - if (errno != ENOENT) - return NULL; - if (resolve_missing_loose_ref(refname, resolve_flags, - sha1, flags)) - return NULL; - if (bad_name) { - hashclr(sha1); - if (flags) - *flags |= REF_ISBROKEN; - } - return refname; - } - - /* Follow "normalized" - ie "refs/.." symlinks by hand */ - if (S_ISLNK(st.st_mode)) { - strbuf_reset(sb_contents); - if (strbuf_readlink(sb_contents, path, 0) < 0) { - if (errno == ENOENT || errno == EINVAL) - /* inconsistent with lstat; retry */ - goto stat_ref; - else - return NULL; - } - if (starts_with(sb_contents->buf, "refs/") && - !check_refname_format(sb_contents->buf, 0)) { - strbuf_swap(sb_refname, sb_contents); - refname = sb_refname->buf; - if (flags) - *flags |= REF_ISSYMREF; - if (resolve_flags & RESOLVE_REF_NO_RECURSE) { - hashclr(sha1); - return refname; - } - continue; - } - } - - /* Is it a directory? */ - if (S_ISDIR(st.st_mode)) { - errno = EISDIR; - return NULL; - } - - /* - * Anything else, just open it and try to use it as - * a ref - */ - fd = open(path, O_RDONLY); - if (fd < 0) { - if (errno == ENOENT) - /* inconsistent with lstat; retry */ - goto stat_ref; - else - return NULL; - } - strbuf_reset(sb_contents); - if (strbuf_read(sb_contents, fd, 256) < 0) { - int save_errno = errno; - close(fd); - errno = save_errno; - return NULL; - } - close(fd); - strbuf_rtrim(sb_contents); - - /* - * Is it a symbolic ref? - */ - if (!starts_with(sb_contents->buf, "ref:")) { - /* - * Please note that FETCH_HEAD has a second - * line containing other data. - */ - if (get_sha1_hex(sb_contents->buf, sha1) || - (sb_contents->buf[40] != '\0' && !isspace(sb_contents->buf[40]))) { - if (flags) - *flags |= REF_ISBROKEN; - errno = EINVAL; - return NULL; - } - if (bad_name) { - hashclr(sha1); - if (flags) - *flags |= REF_ISBROKEN; - } - return refname; - } - if (flags) - *flags |= REF_ISSYMREF; - buf = sb_contents->buf + 4; - while (isspace(*buf)) - buf++; - strbuf_reset(sb_refname); - strbuf_addstr(sb_refname, buf); - refname = sb_refname->buf; - if (resolve_flags & RESOLVE_REF_NO_RECURSE) { - hashclr(sha1); - return refname; - } - if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) { - if (flags) - *flags |= REF_ISBROKEN; - - if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) || - !refname_is_safe(buf)) { - errno = EINVAL; - return NULL; - } - bad_name = 1; - } - } -} - -const char *resolve_ref_unsafe(const char *refname, int resolve_flags, - unsigned char *sha1, int *flags) -{ - static struct strbuf sb_refname = STRBUF_INIT; - struct strbuf sb_contents = STRBUF_INIT; - struct strbuf sb_path = STRBUF_INIT; - const char *ret; - - ret = resolve_ref_1(refname, resolve_flags, sha1, flags, - &sb_refname, &sb_path, &sb_contents); - strbuf_release(&sb_path); - strbuf_release(&sb_contents); - return ret; -} - -char *resolve_refdup(const char *refname, int resolve_flags, - unsigned char *sha1, int *flags) -{ - return xstrdup_or_null(resolve_ref_unsafe(refname, resolve_flags, - sha1, flags)); -} - -/* The argument to filter_refs */ -struct ref_filter { - const char *pattern; - each_ref_fn *fn; - void *cb_data; -}; - -int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags) -{ - if (resolve_ref_unsafe(refname, resolve_flags, sha1, flags)) - return 0; - return -1; -} - -int read_ref(const char *refname, unsigned char *sha1) -{ - return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL); -} - -int ref_exists(const char *refname) -{ - unsigned char sha1[20]; - return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL); -} - -static int filter_refs(const char *refname, const struct object_id *oid, - int flags, void *data) -{ - struct ref_filter *filter = (struct ref_filter *)data; - - if (wildmatch(filter->pattern, refname, 0, NULL)) - return 0; - return filter->fn(refname, oid, flags, filter->cb_data); -} - -enum peel_status peel_object(const unsigned char *name, unsigned char *sha1) -{ - struct object *o = lookup_unknown_object(name); - - if (o->type == OBJ_NONE) { - int type = sha1_object_info(name, NULL); - if (type < 0 || !object_as_type(o, type, 0)) - return PEEL_INVALID; - } - - if (o->type != OBJ_TAG) - return PEEL_NON_TAG; - - o = deref_tag_noverify(o); - if (!o) - return PEEL_INVALID; - - hashcpy(sha1, o->sha1); - return PEEL_PEELED; -} - -/* - * Peel the entry (if possible) and return its new peel_status. If - * repeel is true, re-peel the entry even if there is an old peeled - * value that is already stored in it. - * - * It is OK to call this function with a packed reference entry that - * might be stale and might even refer to an object that has since - * been garbage-collected. In such a case, if the entry has - * REF_KNOWS_PEELED then leave the status unchanged and return - * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID. - */ -static enum peel_status peel_entry(struct ref_entry *entry, int repeel) -{ - enum peel_status status; - - if (entry->flag & REF_KNOWS_PEELED) { - if (repeel) { - entry->flag &= ~REF_KNOWS_PEELED; - oidclr(&entry->u.value.peeled); - } else { - return is_null_oid(&entry->u.value.peeled) ? - PEEL_NON_TAG : PEEL_PEELED; - } - } - if (entry->flag & REF_ISBROKEN) - return PEEL_BROKEN; - if (entry->flag & REF_ISSYMREF) - return PEEL_IS_SYMREF; - - status = peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash); - if (status == PEEL_PEELED || status == PEEL_NON_TAG) - entry->flag |= REF_KNOWS_PEELED; - return status; -} - -int peel_ref(const char *refname, unsigned char *sha1) -{ - int flag; - unsigned char base[20]; - - if (current_ref && (current_ref->name == refname - || !strcmp(current_ref->name, refname))) { - if (peel_entry(current_ref, 0)) - return -1; - hashcpy(sha1, current_ref->u.value.peeled.hash); - return 0; - } - - if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag)) - return -1; - - /* - * If the reference is packed, read its ref_entry from the - * cache in the hope that we already know its peeled value. - * We only try this optimization on packed references because - * (a) forcing the filling of the loose reference cache could - * be expensive and (b) loose references anyway usually do not - * have REF_KNOWS_PEELED. - */ - if (flag & REF_ISPACKED) { - struct ref_entry *r = get_packed_ref(refname); - if (r) { - if (peel_entry(r, 0)) - return -1; - hashcpy(sha1, r->u.value.peeled.hash); - return 0; - } - } - - return peel_object(base, sha1); -} - -struct warn_if_dangling_data { - FILE *fp; - const char *refname; - const struct string_list *refnames; - const char *msg_fmt; -}; - -static int warn_if_dangling_symref(const char *refname, const struct object_id *oid, - int flags, void *cb_data) -{ - struct warn_if_dangling_data *d = cb_data; - const char *resolves_to; - struct object_id junk; - - if (!(flags & REF_ISSYMREF)) - return 0; - - resolves_to = resolve_ref_unsafe(refname, 0, junk.hash, NULL); - if (!resolves_to - || (d->refname - ? strcmp(resolves_to, d->refname) - : !string_list_has_string(d->refnames, resolves_to))) { - return 0; - } - - fprintf(d->fp, d->msg_fmt, refname); - fputc('\n', d->fp); - return 0; -} - -void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname) -{ - struct warn_if_dangling_data data; - - data.fp = fp; - data.refname = refname; - data.refnames = NULL; - data.msg_fmt = msg_fmt; - for_each_rawref(warn_if_dangling_symref, &data); -} - -void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames) -{ - struct warn_if_dangling_data data; - - data.fp = fp; - data.refname = NULL; - data.refnames = refnames; - data.msg_fmt = msg_fmt; - for_each_rawref(warn_if_dangling_symref, &data); -} - -/* - * Call fn for each reference in the specified ref_cache, omitting - * references not in the containing_dir of base. fn is called for all - * references, including broken ones. If fn ever returns a non-zero - * value, stop the iteration and return that value; otherwise, return - * 0. - */ -static int do_for_each_entry(struct ref_cache *refs, const char *base, - each_ref_entry_fn fn, void *cb_data) -{ - struct packed_ref_cache *packed_ref_cache; - struct ref_dir *loose_dir; - struct ref_dir *packed_dir; - int retval = 0; - - /* - * We must make sure that all loose refs are read before accessing the - * packed-refs file; this avoids a race condition in which loose refs - * are migrated to the packed-refs file by a simultaneous process, but - * our in-memory view is from before the migration. get_packed_ref_cache() - * takes care of making sure our view is up to date with what is on - * disk. - */ - loose_dir = get_loose_refs(refs); - if (base && *base) { - loose_dir = find_containing_dir(loose_dir, base, 0); - } - if (loose_dir) - prime_ref_dir(loose_dir); - - packed_ref_cache = get_packed_ref_cache(refs); - acquire_packed_ref_cache(packed_ref_cache); - packed_dir = get_packed_ref_dir(packed_ref_cache); - if (base && *base) { - packed_dir = find_containing_dir(packed_dir, base, 0); - } - - if (packed_dir && loose_dir) { - sort_ref_dir(packed_dir); - sort_ref_dir(loose_dir); - retval = do_for_each_entry_in_dirs( - packed_dir, loose_dir, fn, cb_data); - } else if (packed_dir) { - sort_ref_dir(packed_dir); - retval = do_for_each_entry_in_dir( - packed_dir, 0, fn, cb_data); - } else if (loose_dir) { - sort_ref_dir(loose_dir); - retval = do_for_each_entry_in_dir( - loose_dir, 0, fn, cb_data); - } - - release_packed_ref_cache(packed_ref_cache); - return retval; -} - -/* - * Call fn for each reference in the specified ref_cache for which the - * refname begins with base. If trim is non-zero, then trim that many - * characters off the beginning of each refname before passing the - * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include - * broken references in the iteration. If fn ever returns a non-zero - * value, stop the iteration and return that value; otherwise, return - * 0. - */ -static int do_for_each_ref(struct ref_cache *refs, const char *base, - each_ref_fn fn, int trim, int flags, void *cb_data) -{ - struct ref_entry_cb data; - data.base = base; - data.trim = trim; - data.flags = flags; - data.fn = fn; - data.cb_data = cb_data; - - if (ref_paranoia < 0) - ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0); - if (ref_paranoia) - data.flags |= DO_FOR_EACH_INCLUDE_BROKEN; - - return do_for_each_entry(refs, base, do_one_ref, &data); -} - -static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data) -{ - struct object_id oid; - int flag; - - if (submodule) { - if (resolve_gitlink_ref(submodule, "HEAD", oid.hash) == 0) - return fn("HEAD", &oid, 0, cb_data); - - return 0; - } - - if (!read_ref_full("HEAD", RESOLVE_REF_READING, oid.hash, &flag)) - return fn("HEAD", &oid, flag, cb_data); - - return 0; -} - -int head_ref(each_ref_fn fn, void *cb_data) -{ - return do_head_ref(NULL, fn, cb_data); -} - -int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) -{ - return do_head_ref(submodule, fn, cb_data); -} - -int for_each_ref(each_ref_fn fn, void *cb_data) -{ - return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data); -} - -int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) -{ - return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data); -} - -int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data) -{ - return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data); -} - -int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken) -{ - unsigned int flag = 0; - - if (broken) - flag = DO_FOR_EACH_INCLUDE_BROKEN; - return do_for_each_ref(&ref_cache, prefix, fn, 0, flag, cb_data); -} - -int for_each_ref_in_submodule(const char *submodule, const char *prefix, - each_ref_fn fn, void *cb_data) -{ - return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data); -} - -int for_each_tag_ref(each_ref_fn fn, void *cb_data) -{ - return for_each_ref_in("refs/tags/", fn, cb_data); -} - -int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) -{ - return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data); -} - -int for_each_branch_ref(each_ref_fn fn, void *cb_data) -{ - return for_each_ref_in("refs/heads/", fn, cb_data); -} - -int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) -{ - return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data); -} - -int for_each_remote_ref(each_ref_fn fn, void *cb_data) -{ - return for_each_ref_in("refs/remotes/", fn, cb_data); -} - -int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) -{ - return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data); -} - -int for_each_replace_ref(each_ref_fn fn, void *cb_data) -{ - return do_for_each_ref(&ref_cache, git_replace_ref_base, fn, - strlen(git_replace_ref_base), 0, cb_data); -} - -int head_ref_namespaced(each_ref_fn fn, void *cb_data) -{ - struct strbuf buf = STRBUF_INIT; - int ret = 0; - struct object_id oid; - int flag; - - strbuf_addf(&buf, "%sHEAD", get_git_namespace()); - if (!read_ref_full(buf.buf, RESOLVE_REF_READING, oid.hash, &flag)) - ret = fn(buf.buf, &oid, flag, cb_data); - strbuf_release(&buf); - - return ret; -} - -int for_each_namespaced_ref(each_ref_fn fn, void *cb_data) -{ - struct strbuf buf = STRBUF_INIT; - int ret; - strbuf_addf(&buf, "%srefs/", get_git_namespace()); - ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data); - strbuf_release(&buf); - return ret; -} - -int for_each_glob_ref_in(each_ref_fn fn, const char *pattern, - const char *prefix, void *cb_data) -{ - struct strbuf real_pattern = STRBUF_INIT; - struct ref_filter filter; - int ret; - - if (!prefix && !starts_with(pattern, "refs/")) - strbuf_addstr(&real_pattern, "refs/"); - else if (prefix) - strbuf_addstr(&real_pattern, prefix); - strbuf_addstr(&real_pattern, pattern); - - if (!has_glob_specials(pattern)) { - /* Append implied '/' '*' if not present. */ - strbuf_complete(&real_pattern, '/'); - /* No need to check for '*', there is none. */ - strbuf_addch(&real_pattern, '*'); - } - - filter.pattern = real_pattern.buf; - filter.fn = fn; - filter.cb_data = cb_data; - ret = for_each_ref(filter_refs, &filter); - - strbuf_release(&real_pattern); - return ret; -} - -int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data) +int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data) { return for_each_glob_ref_in(fn, pattern, NULL, cb_data); } -int for_each_rawref(each_ref_fn fn, void *cb_data) -{ - return do_for_each_ref(&ref_cache, "", fn, 0, - DO_FOR_EACH_INCLUDE_BROKEN, cb_data); -} - const char *prettify_refname(const char *name) { return name + ( starts_with(name, "refs/heads/") ? 11 : - starts_with(name, "refs/tags/") ? 10 : - starts_with(name, "refs/remotes/") ? 13 : - 0); -} - -static const char *ref_rev_parse_rules[] = { - "%.*s", - "refs/%.*s", - "refs/tags/%.*s", - "refs/heads/%.*s", - "refs/remotes/%.*s", - "refs/remotes/%.*s/HEAD", - NULL -}; - -int refname_match(const char *abbrev_name, const char *full_name) -{ - const char **p; - const int abbrev_name_len = strlen(abbrev_name); - - for (p = ref_rev_parse_rules; *p; p++) { - if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) { - return 1; - } - } - - return 0; -} - -static void unlock_ref(struct ref_lock *lock) -{ - /* Do not free lock->lk -- atexit() still looks at them */ - if (lock->lk) - rollback_lock_file(lock->lk); - free(lock->ref_name); - free(lock->orig_ref_name); - free(lock); -} - -/* - * Verify that the reference locked by lock has the value old_sha1. - * Fail if the reference doesn't exist and mustexist is set. Return 0 - * on success. On error, write an error message to err, set errno, and - * return a negative value. - */ -static int verify_lock(struct ref_lock *lock, - const unsigned char *old_sha1, int mustexist, - struct strbuf *err) -{ - assert(err); - - if (read_ref_full(lock->ref_name, - mustexist ? RESOLVE_REF_READING : 0, - lock->old_oid.hash, NULL)) { - int save_errno = errno; - strbuf_addf(err, "can't verify ref %s", lock->ref_name); - errno = save_errno; - return -1; - } - if (hashcmp(lock->old_oid.hash, old_sha1)) { - strbuf_addf(err, "ref %s is at %s but expected %s", - lock->ref_name, - sha1_to_hex(lock->old_oid.hash), - sha1_to_hex(old_sha1)); - errno = EBUSY; - return -1; - } - return 0; -} - -static int remove_empty_directories(struct strbuf *path) -{ - /* - * we want to create a file but there is a directory there; - * if that is an empty directory (or a directory that contains - * only empty directories), remove them. - */ - return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY); -} - -/* - * *string and *len will only be substituted, and *string returned (for - * later free()ing) if the string passed in is a magic short-hand form - * to name a branch. - */ -static char *substitute_branch_name(const char **string, int *len) -{ - struct strbuf buf = STRBUF_INIT; - int ret = interpret_branch_name(*string, *len, &buf); - - if (ret == *len) { - size_t size; - *string = strbuf_detach(&buf, &size); - *len = size; - return (char *)*string; - } - - return NULL; -} - -int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref) -{ - char *last_branch = substitute_branch_name(&str, &len); - const char **p, *r; - int refs_found = 0; - - *ref = NULL; - for (p = ref_rev_parse_rules; *p; p++) { - char fullref[PATH_MAX]; - unsigned char sha1_from_ref[20]; - unsigned char *this_result; - int flag; - - this_result = refs_found ? sha1_from_ref : sha1; - mksnpath(fullref, sizeof(fullref), *p, len, str); - r = resolve_ref_unsafe(fullref, RESOLVE_REF_READING, - this_result, &flag); - if (r) { - if (!refs_found++) - *ref = xstrdup(r); - if (!warn_ambiguous_refs) - break; - } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) { - warning("ignoring dangling symref %s.", fullref); - } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) { - warning("ignoring broken ref %s.", fullref); - } - } - free(last_branch); - return refs_found; -} - -int dwim_log(const char *str, int len, unsigned char *sha1, char **log) -{ - char *last_branch = substitute_branch_name(&str, &len); - const char **p; - int logs_found = 0; - - *log = NULL; - for (p = ref_rev_parse_rules; *p; p++) { - unsigned char hash[20]; - char path[PATH_MAX]; - const char *ref, *it; - - mksnpath(path, sizeof(path), *p, len, str); - ref = resolve_ref_unsafe(path, RESOLVE_REF_READING, - hash, NULL); - if (!ref) - continue; - if (reflog_exists(path)) - it = path; - else if (strcmp(ref, path) && reflog_exists(ref)) - it = ref; - else - continue; - if (!logs_found++) { - *log = xstrdup(it); - hashcpy(sha1, hash); - } - if (!warn_ambiguous_refs) - break; - } - free(last_branch); - return logs_found; -} - -/* - * Locks a ref returning the lock on success and NULL on failure. - * On failure errno is set to something meaningful. - */ -static struct ref_lock *lock_ref_sha1_basic(const char *refname, - const unsigned char *old_sha1, - const struct string_list *extras, - const struct string_list *skip, - unsigned int flags, int *type_p, - struct strbuf *err) -{ - struct strbuf ref_file = STRBUF_INIT; - struct strbuf orig_ref_file = STRBUF_INIT; - const char *orig_refname = refname; - struct ref_lock *lock; - int last_errno = 0; - int type, lflags; - int mustexist = (old_sha1 && !is_null_sha1(old_sha1)); - int resolve_flags = 0; - int attempts_remaining = 3; - - assert(err); - - lock = xcalloc(1, sizeof(struct ref_lock)); - - if (mustexist) - resolve_flags |= RESOLVE_REF_READING; - if (flags & REF_DELETING) { - resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME; - if (flags & REF_NODEREF) - resolve_flags |= RESOLVE_REF_NO_RECURSE; - } - - refname = resolve_ref_unsafe(refname, resolve_flags, - lock->old_oid.hash, &type); - if (!refname && errno == EISDIR) { - /* - * we are trying to lock foo but we used to - * have foo/bar which now does not exist; - * it is normal for the empty directory 'foo' - * to remain. - */ - strbuf_git_path(&orig_ref_file, "%s", orig_refname); - if (remove_empty_directories(&orig_ref_file)) { - last_errno = errno; - if (!verify_refname_available_dir(orig_refname, extras, skip, - get_loose_refs(&ref_cache), err)) - strbuf_addf(err, "there are still refs under '%s'", - orig_refname); - goto error_return; - } - refname = resolve_ref_unsafe(orig_refname, resolve_flags, - lock->old_oid.hash, &type); - } - if (type_p) - *type_p = type; - if (!refname) { - last_errno = errno; - if (last_errno != ENOTDIR || - !verify_refname_available_dir(orig_refname, extras, skip, - get_loose_refs(&ref_cache), err)) - strbuf_addf(err, "unable to resolve reference %s: %s", - orig_refname, strerror(last_errno)); - - goto error_return; - } - /* - * If the ref did not exist and we are creating it, make sure - * there is no existing packed ref whose name begins with our - * refname, nor a packed ref whose name is a proper prefix of - * our refname. - */ - if (is_null_oid(&lock->old_oid) && - verify_refname_available_dir(refname, extras, skip, - get_packed_refs(&ref_cache), err)) { - last_errno = ENOTDIR; - goto error_return; - } - - lock->lk = xcalloc(1, sizeof(struct lock_file)); - - lflags = 0; - if (flags & REF_NODEREF) { - refname = orig_refname; - lflags |= LOCK_NO_DEREF; - } - lock->ref_name = xstrdup(refname); - lock->orig_ref_name = xstrdup(orig_refname); - strbuf_git_path(&ref_file, "%s", refname); - - retry: - switch (safe_create_leading_directories_const(ref_file.buf)) { - case SCLD_OK: - break; /* success */ - case SCLD_VANISHED: - if (--attempts_remaining > 0) - goto retry; - /* fall through */ - default: - last_errno = errno; - strbuf_addf(err, "unable to create directory for %s", - ref_file.buf); - goto error_return; - } - - if (hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) < 0) { - last_errno = errno; - if (errno == ENOENT && --attempts_remaining > 0) - /* - * Maybe somebody just deleted one of the - * directories leading to ref_file. Try - * again: - */ - goto retry; - else { - unable_to_lock_message(ref_file.buf, errno, err); - goto error_return; - } - } - if (old_sha1 && verify_lock(lock, old_sha1, mustexist, err)) { - last_errno = errno; - goto error_return; - } - goto out; - - error_return: - unlock_ref(lock); - lock = NULL; - - out: - strbuf_release(&ref_file); - strbuf_release(&orig_ref_file); - errno = last_errno; - return lock; -} - -/* - * Write an entry to the packed-refs file for the specified refname. - * If peeled is non-NULL, write it as the entry's peeled value. - */ -static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1, - unsigned char *peeled) -{ - fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname); - if (peeled) - fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled)); -} - -/* - * An each_ref_entry_fn that writes the entry to a packed-refs file. - */ -static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data) -{ - enum peel_status peel_status = peel_entry(entry, 0); - - if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG) - error("internal error: %s is not a valid packed reference!", - entry->name); - write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash, - peel_status == PEEL_PEELED ? - entry->u.value.peeled.hash : NULL); - return 0; -} - -/* - * Lock the packed-refs file for writing. Flags is passed to - * hold_lock_file_for_update(). Return 0 on success. On errors, set - * errno appropriately and return a nonzero value. - */ -static int lock_packed_refs(int flags) -{ - static int timeout_configured = 0; - static int timeout_value = 1000; - - struct packed_ref_cache *packed_ref_cache; - - if (!timeout_configured) { - git_config_get_int("core.packedrefstimeout", &timeout_value); - timeout_configured = 1; - } - - if (hold_lock_file_for_update_timeout( - &packlock, git_path("packed-refs"), - flags, timeout_value) < 0) - return -1; - /* - * Get the current packed-refs while holding the lock. If the - * packed-refs file has been modified since we last read it, - * this will automatically invalidate the cache and re-read - * the packed-refs file. - */ - packed_ref_cache = get_packed_ref_cache(&ref_cache); - packed_ref_cache->lock = &packlock; - /* Increment the reference count to prevent it from being freed: */ - acquire_packed_ref_cache(packed_ref_cache); - return 0; -} - -/* - * Write the current version of the packed refs cache from memory to - * disk. The packed-refs file must already be locked for writing (see - * lock_packed_refs()). Return zero on success. On errors, set errno - * and return a nonzero value - */ -static int commit_packed_refs(void) -{ - struct packed_ref_cache *packed_ref_cache = - get_packed_ref_cache(&ref_cache); - int error = 0; - int save_errno = 0; - FILE *out; - - if (!packed_ref_cache->lock) - die("internal error: packed-refs not locked"); - - out = fdopen_lock_file(packed_ref_cache->lock, "w"); - if (!out) - die_errno("unable to fdopen packed-refs descriptor"); - - fprintf_or_die(out, "%s", PACKED_REFS_HEADER); - do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache), - 0, write_packed_entry_fn, out); - - if (commit_lock_file(packed_ref_cache->lock)) { - save_errno = errno; - error = -1; - } - packed_ref_cache->lock = NULL; - release_packed_ref_cache(packed_ref_cache); - errno = save_errno; - return error; -} - -/* - * Rollback the lockfile for the packed-refs file, and discard the - * in-memory packed reference cache. (The packed-refs file will be - * read anew if it is needed again after this function is called.) - */ -static void rollback_packed_refs(void) -{ - struct packed_ref_cache *packed_ref_cache = - get_packed_ref_cache(&ref_cache); - - if (!packed_ref_cache->lock) - die("internal error: packed-refs not locked"); - rollback_lock_file(packed_ref_cache->lock); - packed_ref_cache->lock = NULL; - release_packed_ref_cache(packed_ref_cache); - clear_packed_ref_cache(&ref_cache); + starts_with(name, "refs/tags/") ? 10 : + starts_with(name, "refs/remotes/") ? 13 : + 0); } -struct ref_to_prune { - struct ref_to_prune *next; - unsigned char sha1[20]; - char name[FLEX_ARRAY]; -}; - -struct pack_refs_cb_data { - unsigned int flags; - struct ref_dir *packed_refs; - struct ref_to_prune *ref_to_prune; +static const char *ref_rev_parse_rules[] = { + "%.*s", + "refs/%.*s", + "refs/tags/%.*s", + "refs/heads/%.*s", + "refs/remotes/%.*s", + "refs/remotes/%.*s/HEAD", + NULL }; -/* - * An each_ref_entry_fn that is run over loose references only. If - * the loose reference can be packed, add an entry in the packed ref - * cache. If the reference should be pruned, also add it to - * ref_to_prune in the pack_refs_cb_data. - */ -static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data) +int refname_match(const char *abbrev_name, const char *full_name) { - struct pack_refs_cb_data *cb = cb_data; - enum peel_status peel_status; - struct ref_entry *packed_entry; - int is_tag_ref = starts_with(entry->name, "refs/tags/"); - - /* Do not pack per-worktree refs: */ - if (ref_type(entry->name) != REF_TYPE_NORMAL) - return 0; - - /* ALWAYS pack tags */ - if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref) - return 0; - - /* Do not pack symbolic or broken refs: */ - if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry)) - return 0; + const char **p; + const int abbrev_name_len = strlen(abbrev_name); - /* Add a packed ref cache entry equivalent to the loose entry. */ - peel_status = peel_entry(entry, 1); - if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG) - die("internal error peeling reference %s (%s)", - entry->name, oid_to_hex(&entry->u.value.oid)); - packed_entry = find_ref(cb->packed_refs, entry->name); - if (packed_entry) { - /* Overwrite existing packed entry with info from loose entry */ - packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED; - oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid); - } else { - packed_entry = create_ref_entry(entry->name, entry->u.value.oid.hash, - REF_ISPACKED | REF_KNOWS_PEELED, 0); - add_ref(cb->packed_refs, packed_entry); - } - oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled); - - /* Schedule the loose reference for pruning if requested. */ - if ((cb->flags & PACK_REFS_PRUNE)) { - int namelen = strlen(entry->name) + 1; - struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen); - hashcpy(n->sha1, entry->u.value.oid.hash); - memcpy(n->name, entry->name, namelen); /* includes NUL */ - n->next = cb->ref_to_prune; - cb->ref_to_prune = n; + for (p = ref_rev_parse_rules; *p; p++) { + if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) { + return 1; + } } + return 0; } /* - * Remove empty parents, but spare refs/ and immediate subdirs. - * Note: munges *name. + * *string and *len will only be substituted, and *string returned (for + * later free()ing) if the string passed in is a magic short-hand form + * to name a branch. */ -static void try_remove_empty_parents(char *name) -{ - char *p, *q; - int i; - p = name; - for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */ - while (*p && *p != '/') - p++; - /* tolerate duplicate slashes; see check_refname_format() */ - while (*p == '/') - p++; - } - for (q = p; *q; q++) - ; - while (1) { - while (q > p && *q != '/') - q--; - while (q > p && *(q-1) == '/') - q--; - if (q == p) - break; - *q = '\0'; - if (rmdir(git_path("%s", name))) - break; - } -} - -/* make sure nobody touched the ref, and unlink */ -static void prune_ref(struct ref_to_prune *r) +static char *substitute_branch_name(const char **string, int *len) { - struct ref_transaction *transaction; - struct strbuf err = STRBUF_INIT; - - if (check_refname_format(r->name, 0)) - return; - - transaction = ref_transaction_begin(&err); - if (!transaction || - ref_transaction_delete(transaction, r->name, r->sha1, - REF_ISPRUNING, NULL, &err) || - ref_transaction_commit(transaction, &err)) { - ref_transaction_free(transaction); - error("%s", err.buf); - strbuf_release(&err); - return; - } - ref_transaction_free(transaction); - strbuf_release(&err); - try_remove_empty_parents(r->name); -} + struct strbuf buf = STRBUF_INIT; + int ret = interpret_branch_name(*string, *len, &buf); -static void prune_refs(struct ref_to_prune *r) -{ - while (r) { - prune_ref(r); - r = r->next; + if (ret == *len) { + size_t size; + *string = strbuf_detach(&buf, &size); + *len = size; + return (char *)*string; } -} - -int pack_refs(unsigned int flags) -{ - struct pack_refs_cb_data cbdata; - memset(&cbdata, 0, sizeof(cbdata)); - cbdata.flags = flags; - - lock_packed_refs(LOCK_DIE_ON_ERROR); - cbdata.packed_refs = get_packed_refs(&ref_cache); - - do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0, - pack_if_possible_fn, &cbdata); - - if (commit_packed_refs()) - die_errno("unable to overwrite old ref-pack file"); - - prune_refs(cbdata.ref_to_prune); - return 0; + return NULL; } -/* - * Rewrite the packed-refs file, omitting any refs listed in - * 'refnames'. On error, leave packed-refs unchanged, write an error - * message to 'err', and return a nonzero value. - * - * The refs in 'refnames' needn't be sorted. `err` must not be NULL. - */ -static int repack_without_refs(struct string_list *refnames, struct strbuf *err) +int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref) { - struct ref_dir *packed; - struct string_list_item *refname; - int ret, needs_repacking = 0, removed = 0; + char *last_branch = substitute_branch_name(&str, &len); + const char **p, *r; + int refs_found = 0; - assert(err); + *ref = NULL; + for (p = ref_rev_parse_rules; *p; p++) { + char fullref[PATH_MAX]; + unsigned char sha1_from_ref[20]; + unsigned char *this_result; + int flag; - /* Look for a packed ref */ - for_each_string_list_item(refname, refnames) { - if (get_packed_ref(refname->string)) { - needs_repacking = 1; - break; + this_result = refs_found ? sha1_from_ref : sha1; + mksnpath(fullref, sizeof(fullref), *p, len, str); + r = resolve_ref_unsafe(fullref, RESOLVE_REF_READING, + this_result, &flag); + if (r) { + if (!refs_found++) + *ref = xstrdup(r); + if (!warn_ambiguous_refs) + break; + } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) { + warning("ignoring dangling symref %s.", fullref); + } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) { + warning("ignoring broken ref %s.", fullref); } } - - /* Avoid locking if we have nothing to do */ - if (!needs_repacking) - return 0; /* no refname exists in packed refs */ - - if (lock_packed_refs(0)) { - unable_to_lock_message(git_path("packed-refs"), errno, err); - return -1; - } - packed = get_packed_refs(&ref_cache); - - /* Remove refnames from the cache */ - for_each_string_list_item(refname, refnames) - if (remove_entry(packed, refname->string) != -1) - removed = 1; - if (!removed) { - /* - * All packed entries disappeared while we were - * acquiring the lock. - */ - rollback_packed_refs(); - return 0; - } - - /* Write what remains */ - ret = commit_packed_refs(); - if (ret) - strbuf_addf(err, "unable to overwrite old ref-pack file: %s", - strerror(errno)); - return ret; + free(last_branch); + return refs_found; } -static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err) +int dwim_log(const char *str, int len, unsigned char *sha1, char **log) { - assert(err); + char *last_branch = substitute_branch_name(&str, &len); + const char **p; + int logs_found = 0; - if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) { - /* - * loose. The loose file name is the same as the - * lockfile name, minus ".lock": - */ - char *loose_filename = get_locked_file_path(lock->lk); - int res = unlink_or_msg(loose_filename, err); - free(loose_filename); - if (res) - return 1; + *log = NULL; + for (p = ref_rev_parse_rules; *p; p++) { + unsigned char hash[20]; + char path[PATH_MAX]; + const char *ref, *it; + + mksnpath(path, sizeof(path), *p, len, str); + ref = resolve_ref_unsafe(path, RESOLVE_REF_READING, + hash, NULL); + if (!ref) + continue; + if (reflog_exists(path)) + it = path; + else if (strcmp(ref, path) && reflog_exists(ref)) + it = ref; + else + continue; + if (!logs_found++) { + *log = xstrdup(it); + hashcpy(sha1, hash); + } + if (!warn_ambiguous_refs) + break; } - return 0; + free(last_branch); + return logs_found; } static int is_per_worktree_ref(const char *refname) @@ -2926,265 +576,9 @@ int delete_ref(const char *refname, const unsigned char *old_sha1, ref_transaction_free(transaction); strbuf_release(&err); return 1; - } - ref_transaction_free(transaction); - strbuf_release(&err); - return 0; -} - -int delete_refs(struct string_list *refnames) -{ - struct strbuf err = STRBUF_INIT; - int i, result = 0; - - if (!refnames->nr) - return 0; - - result = repack_without_refs(refnames, &err); - if (result) { - /* - * If we failed to rewrite the packed-refs file, then - * it is unsafe to try to remove loose refs, because - * doing so might expose an obsolete packed value for - * a reference that might even point at an object that - * has been garbage collected. - */ - if (refnames->nr == 1) - error(_("could not delete reference %s: %s"), - refnames->items[0].string, err.buf); - else - error(_("could not delete references: %s"), err.buf); - - goto out; - } - - for (i = 0; i < refnames->nr; i++) { - const char *refname = refnames->items[i].string; - - if (delete_ref(refname, NULL, 0)) - result |= error(_("could not remove reference %s"), refname); - } - -out: - strbuf_release(&err); - return result; -} - -/* - * People using contrib's git-new-workdir have .git/logs/refs -> - * /some/other/path/.git/logs/refs, and that may live on another device. - * - * IOW, to avoid cross device rename errors, the temporary renamed log must - * live into logs/refs. - */ -#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log" - -static int rename_tmp_log(const char *newrefname) -{ - int attempts_remaining = 4; - struct strbuf path = STRBUF_INIT; - int ret = -1; - - retry: - strbuf_reset(&path); - strbuf_git_path(&path, "logs/%s", newrefname); - switch (safe_create_leading_directories_const(path.buf)) { - case SCLD_OK: - break; /* success */ - case SCLD_VANISHED: - if (--attempts_remaining > 0) - goto retry; - /* fall through */ - default: - error("unable to create directory for %s", newrefname); - goto out; - } - - if (rename(git_path(TMP_RENAMED_LOG), path.buf)) { - if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) { - /* - * rename(a, b) when b is an existing - * directory ought to result in ISDIR, but - * Solaris 5.8 gives ENOTDIR. Sheesh. - */ - if (remove_empty_directories(&path)) { - error("Directory not empty: logs/%s", newrefname); - goto out; - } - goto retry; - } else if (errno == ENOENT && --attempts_remaining > 0) { - /* - * Maybe another process just deleted one of - * the directories in the path to newrefname. - * Try again from the beginning. - */ - goto retry; - } else { - error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s", - newrefname, strerror(errno)); - goto out; - } - } - ret = 0; -out: - strbuf_release(&path); - return ret; -} - -int verify_refname_available(const char *newname, - struct string_list *extras, - struct string_list *skip, - struct strbuf *err) -{ - struct ref_dir *packed_refs = get_packed_refs(&ref_cache); - struct ref_dir *loose_refs = get_loose_refs(&ref_cache); - - if (verify_refname_available_dir(newname, extras, skip, - packed_refs, err) || - verify_refname_available_dir(newname, extras, skip, - loose_refs, err)) - return -1; - - return 0; -} - -static int rename_ref_available(const char *oldname, const char *newname) -{ - struct string_list skip = STRING_LIST_INIT_NODUP; - struct strbuf err = STRBUF_INIT; - int ret; - - string_list_insert(&skip, oldname); - ret = !verify_refname_available(newname, NULL, &skip, &err); - if (!ret) - error("%s", err.buf); - - string_list_clear(&skip, 0); - strbuf_release(&err); - return ret; -} - -static int write_ref_to_lockfile(struct ref_lock *lock, - const unsigned char *sha1, struct strbuf *err); -static int commit_ref_update(struct ref_lock *lock, - const unsigned char *sha1, const char *logmsg, - int flags, struct strbuf *err); - -int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg) -{ - unsigned char sha1[20], orig_sha1[20]; - int flag = 0, logmoved = 0; - struct ref_lock *lock; - struct stat loginfo; - int log = !lstat(git_path("logs/%s", oldrefname), &loginfo); - const char *symref = NULL; - struct strbuf err = STRBUF_INIT; - - if (log && S_ISLNK(loginfo.st_mode)) - return error("reflog for %s is a symlink", oldrefname); - - symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING, - orig_sha1, &flag); - if (flag & REF_ISSYMREF) - return error("refname %s is a symbolic ref, renaming it is not supported", - oldrefname); - if (!symref) - return error("refname %s not found", oldrefname); - - if (!rename_ref_available(oldrefname, newrefname)) - return 1; - - if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG))) - return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s", - oldrefname, strerror(errno)); - - if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) { - error("unable to delete old %s", oldrefname); - goto rollback; - } - - if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) && - delete_ref(newrefname, sha1, REF_NODEREF)) { - if (errno==EISDIR) { - struct strbuf path = STRBUF_INIT; - int result; - - strbuf_git_path(&path, "%s", newrefname); - result = remove_empty_directories(&path); - strbuf_release(&path); - - if (result) { - error("Directory not empty: %s", newrefname); - goto rollback; - } - } else { - error("unable to delete existing %s", newrefname); - goto rollback; - } - } - - if (log && rename_tmp_log(newrefname)) - goto rollback; - - logmoved = log; - - lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, 0, NULL, &err); - if (!lock) { - error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf); - strbuf_release(&err); - goto rollback; - } - hashcpy(lock->old_oid.hash, orig_sha1); - - if (write_ref_to_lockfile(lock, orig_sha1, &err) || - commit_ref_update(lock, orig_sha1, logmsg, 0, &err)) { - error("unable to write current sha1 into %s: %s", newrefname, err.buf); - strbuf_release(&err); - goto rollback; - } - - return 0; - - rollback: - lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, 0, NULL, &err); - if (!lock) { - error("unable to lock %s for rollback: %s", oldrefname, err.buf); - strbuf_release(&err); - goto rollbacklog; - } - - flag = log_all_ref_updates; - log_all_ref_updates = 0; - if (write_ref_to_lockfile(lock, orig_sha1, &err) || - commit_ref_update(lock, orig_sha1, NULL, 0, &err)) { - error("unable to write current sha1 into %s: %s", oldrefname, err.buf); - strbuf_release(&err); - } - log_all_ref_updates = flag; - - rollbacklog: - if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname))) - error("unable to restore logfile %s from %s: %s", - oldrefname, newrefname, strerror(errno)); - if (!logmoved && log && - rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname))) - error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s", - oldrefname, strerror(errno)); - - return 1; -} - -static int close_ref(struct ref_lock *lock) -{ - if (close_lock_file(lock->lk)) - return -1; - return 0; -} - -static int commit_ref(struct ref_lock *lock) -{ - if (commit_lock_file(lock->lk)) - return -1; + } + ref_transaction_free(transaction); + strbuf_release(&err); return 0; } @@ -3219,305 +613,11 @@ int should_autocreate_reflog(const char *refname) !strcmp(refname, "HEAD"); } -/* - * Create a reflog for a ref. If force_create = 0, the reflog will - * only be created for certain refs (those for which - * should_autocreate_reflog returns non-zero. Otherwise, create it - * regardless of the ref name. Fill in *err and return -1 on failure. - */ -static int log_ref_setup(const char *refname, struct strbuf *logfile, struct strbuf *err, int force_create) -{ - int logfd, oflags = O_APPEND | O_WRONLY; - - strbuf_git_path(logfile, "logs/%s", refname); - if (force_create || should_autocreate_reflog(refname)) { - if (safe_create_leading_directories(logfile->buf) < 0) { - strbuf_addf(err, "unable to create directory for %s: " - "%s", logfile->buf, strerror(errno)); - return -1; - } - oflags |= O_CREAT; - } - - logfd = open(logfile->buf, oflags, 0666); - if (logfd < 0) { - if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR)) - return 0; - - if (errno == EISDIR) { - if (remove_empty_directories(logfile)) { - strbuf_addf(err, "There are still logs under " - "'%s'", logfile->buf); - return -1; - } - logfd = open(logfile->buf, oflags, 0666); - } - - if (logfd < 0) { - strbuf_addf(err, "unable to append to %s: %s", - logfile->buf, strerror(errno)); - return -1; - } - } - - adjust_shared_perm(logfile->buf); - close(logfd); - return 0; -} - - -int safe_create_reflog(const char *refname, int force_create, struct strbuf *err) -{ - int ret; - struct strbuf sb = STRBUF_INIT; - - ret = log_ref_setup(refname, &sb, err, force_create); - strbuf_release(&sb); - return ret; -} - -static int log_ref_write_fd(int fd, const unsigned char *old_sha1, - const unsigned char *new_sha1, - const char *committer, const char *msg) -{ - int msglen, written; - unsigned maxlen, len; - char *logrec; - - msglen = msg ? strlen(msg) : 0; - maxlen = strlen(committer) + msglen + 100; - logrec = xmalloc(maxlen); - len = xsnprintf(logrec, maxlen, "%s %s %s\n", - sha1_to_hex(old_sha1), - sha1_to_hex(new_sha1), - committer); - if (msglen) - len += copy_reflog_msg(logrec + len - 1, msg) - 1; - - written = len <= maxlen ? write_in_full(fd, logrec, len) : -1; - free(logrec); - if (written != len) - return -1; - - return 0; -} - -static int log_ref_write_1(const char *refname, const unsigned char *old_sha1, - const unsigned char *new_sha1, const char *msg, - struct strbuf *logfile, int flags, - struct strbuf *err) -{ - int logfd, result, oflags = O_APPEND | O_WRONLY; - - if (log_all_ref_updates < 0) - log_all_ref_updates = !is_bare_repository(); - - result = log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG); - - if (result) - return result; - - logfd = open(logfile->buf, oflags); - if (logfd < 0) - return 0; - result = log_ref_write_fd(logfd, old_sha1, new_sha1, - git_committer_info(0), msg); - if (result) { - strbuf_addf(err, "unable to append to %s: %s", logfile->buf, - strerror(errno)); - close(logfd); - return -1; - } - if (close(logfd)) { - strbuf_addf(err, "unable to append to %s: %s", logfile->buf, - strerror(errno)); - return -1; - } - return 0; -} - -static int log_ref_write(const char *refname, const unsigned char *old_sha1, - const unsigned char *new_sha1, const char *msg, - int flags, struct strbuf *err) -{ - struct strbuf sb = STRBUF_INIT; - int ret = log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags, - err); - strbuf_release(&sb); - return ret; -} - int is_branch(const char *refname) { return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/"); } -/* - * Write sha1 into the open lockfile, then close the lockfile. On - * errors, rollback the lockfile, fill in *err and - * return -1. - */ -static int write_ref_to_lockfile(struct ref_lock *lock, - const unsigned char *sha1, struct strbuf *err) -{ - static char term = '\n'; - struct object *o; - int fd; - - o = parse_object(sha1); - if (!o) { - strbuf_addf(err, - "Trying to write ref %s with nonexistent object %s", - lock->ref_name, sha1_to_hex(sha1)); - unlock_ref(lock); - return -1; - } - if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) { - strbuf_addf(err, - "Trying to write non-commit object %s to branch %s", - sha1_to_hex(sha1), lock->ref_name); - unlock_ref(lock); - return -1; - } - fd = get_lock_file_fd(lock->lk); - if (write_in_full(fd, sha1_to_hex(sha1), 40) != 40 || - write_in_full(fd, &term, 1) != 1 || - close_ref(lock) < 0) { - strbuf_addf(err, - "Couldn't write %s", get_lock_file_path(lock->lk)); - unlock_ref(lock); - return -1; - } - return 0; -} - -/* - * Commit a change to a loose reference that has already been written - * to the loose reference lockfile. Also update the reflogs if - * necessary, using the specified lockmsg (which can be NULL). - */ -static int commit_ref_update(struct ref_lock *lock, - const unsigned char *sha1, const char *logmsg, - int flags, struct strbuf *err) -{ - clear_loose_ref_cache(&ref_cache); - if (log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, flags, err) < 0 || - (strcmp(lock->ref_name, lock->orig_ref_name) && - log_ref_write(lock->orig_ref_name, lock->old_oid.hash, sha1, logmsg, flags, err) < 0)) { - char *old_msg = strbuf_detach(err, NULL); - strbuf_addf(err, "Cannot update the ref '%s': %s", - lock->ref_name, old_msg); - free(old_msg); - unlock_ref(lock); - return -1; - } - if (strcmp(lock->orig_ref_name, "HEAD") != 0) { - /* - * Special hack: If a branch is updated directly and HEAD - * points to it (may happen on the remote side of a push - * for example) then logically the HEAD reflog should be - * updated too. - * A generic solution implies reverse symref information, - * but finding all symrefs pointing to the given branch - * would be rather costly for this rare event (the direct - * update of a branch) to be worth it. So let's cheat and - * check with HEAD only which should cover 99% of all usage - * scenarios (even 100% of the default ones). - */ - unsigned char head_sha1[20]; - int head_flag; - const char *head_ref; - head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, - head_sha1, &head_flag); - if (head_ref && (head_flag & REF_ISSYMREF) && - !strcmp(head_ref, lock->ref_name)) { - struct strbuf log_err = STRBUF_INIT; - if (log_ref_write("HEAD", lock->old_oid.hash, sha1, - logmsg, 0, &log_err)) { - error("%s", log_err.buf); - strbuf_release(&log_err); - } - } - } - if (commit_ref(lock)) { - error("Couldn't set %s", lock->ref_name); - unlock_ref(lock); - return -1; - } - - unlock_ref(lock); - return 0; -} - -int create_symref(const char *ref_target, const char *refs_heads_master, - const char *logmsg) -{ - char *lockpath = NULL; - char ref[1000]; - int fd, len, written; - char *git_HEAD = git_pathdup("%s", ref_target); - unsigned char old_sha1[20], new_sha1[20]; - struct strbuf err = STRBUF_INIT; - - if (logmsg && read_ref(ref_target, old_sha1)) - hashclr(old_sha1); - - if (safe_create_leading_directories(git_HEAD) < 0) - return error("unable to create directory for %s", git_HEAD); - -#ifndef NO_SYMLINK_HEAD - if (prefer_symlink_refs) { - unlink(git_HEAD); - if (!symlink(refs_heads_master, git_HEAD)) - goto done; - fprintf(stderr, "no symlink - falling back to symbolic ref\n"); - } -#endif - - len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master); - if (sizeof(ref) <= len) { - error("refname too long: %s", refs_heads_master); - goto error_free_return; - } - lockpath = mkpathdup("%s.lock", git_HEAD); - fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666); - if (fd < 0) { - error("Unable to open %s for writing", lockpath); - goto error_free_return; - } - written = write_in_full(fd, ref, len); - if (close(fd) != 0 || written != len) { - error("Unable to write to %s", lockpath); - goto error_unlink_return; - } - if (rename(lockpath, git_HEAD) < 0) { - error("Unable to create %s", git_HEAD); - goto error_unlink_return; - } - if (adjust_shared_perm(git_HEAD)) { - error("Unable to fix permissions on %s", lockpath); - error_unlink_return: - unlink_or_warn(lockpath); - error_free_return: - free(lockpath); - free(git_HEAD); - return -1; - } - free(lockpath); - -#ifndef NO_SYMLINK_HEAD - done: -#endif - if (logmsg && !read_ref(refs_heads_master, new_sha1) && - log_ref_write(ref_target, old_sha1, new_sha1, logmsg, 0, &err)) { - error("%s", err.buf); - strbuf_release(&err); - } - - free(git_HEAD); - return 0; -} - struct read_ref_at_cb { const char *refname; unsigned long at_time; @@ -3636,232 +736,6 @@ int read_ref_at(const char *refname, unsigned int flags, unsigned long at_time, return 1; } -int reflog_exists(const char *refname) -{ - struct stat st; - - return !lstat(git_path("logs/%s", refname), &st) && - S_ISREG(st.st_mode); -} - -int delete_reflog(const char *refname) -{ - return remove_path(git_path("logs/%s", refname)); -} - -static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data) -{ - unsigned char osha1[20], nsha1[20]; - char *email_end, *message; - unsigned long timestamp; - int tz; - - /* old SP new SP name SP time TAB msg LF */ - if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' || - get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' || - get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' || - !(email_end = strchr(sb->buf + 82, '>')) || - email_end[1] != ' ' || - !(timestamp = strtoul(email_end + 2, &message, 10)) || - !message || message[0] != ' ' || - (message[1] != '+' && message[1] != '-') || - !isdigit(message[2]) || !isdigit(message[3]) || - !isdigit(message[4]) || !isdigit(message[5])) - return 0; /* corrupt? */ - email_end[1] = '\0'; - tz = strtol(message + 1, NULL, 10); - if (message[6] != '\t') - message += 6; - else - message += 7; - return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data); -} - -static char *find_beginning_of_line(char *bob, char *scan) -{ - while (bob < scan && *(--scan) != '\n') - ; /* keep scanning backwards */ - /* - * Return either beginning of the buffer, or LF at the end of - * the previous line. - */ - return scan; -} - -int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data) -{ - struct strbuf sb = STRBUF_INIT; - FILE *logfp; - long pos; - int ret = 0, at_tail = 1; - - logfp = fopen(git_path("logs/%s", refname), "r"); - if (!logfp) - return -1; - - /* Jump to the end */ - if (fseek(logfp, 0, SEEK_END) < 0) - return error("cannot seek back reflog for %s: %s", - refname, strerror(errno)); - pos = ftell(logfp); - while (!ret && 0 < pos) { - int cnt; - size_t nread; - char buf[BUFSIZ]; - char *endp, *scanp; - - /* Fill next block from the end */ - cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos; - if (fseek(logfp, pos - cnt, SEEK_SET)) - return error("cannot seek back reflog for %s: %s", - refname, strerror(errno)); - nread = fread(buf, cnt, 1, logfp); - if (nread != 1) - return error("cannot read %d bytes from reflog for %s: %s", - cnt, refname, strerror(errno)); - pos -= cnt; - - scanp = endp = buf + cnt; - if (at_tail && scanp[-1] == '\n') - /* Looking at the final LF at the end of the file */ - scanp--; - at_tail = 0; - - while (buf < scanp) { - /* - * terminating LF of the previous line, or the beginning - * of the buffer. - */ - char *bp; - - bp = find_beginning_of_line(buf, scanp); - - if (*bp == '\n') { - /* - * The newline is the end of the previous line, - * so we know we have complete line starting - * at (bp + 1). Prefix it onto any prior data - * we collected for the line and process it. - */ - strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1)); - scanp = bp; - endp = bp + 1; - ret = show_one_reflog_ent(&sb, fn, cb_data); - strbuf_reset(&sb); - if (ret) - break; - } else if (!pos) { - /* - * We are at the start of the buffer, and the - * start of the file; there is no previous - * line, and we have everything for this one. - * Process it, and we can end the loop. - */ - strbuf_splice(&sb, 0, 0, buf, endp - buf); - ret = show_one_reflog_ent(&sb, fn, cb_data); - strbuf_reset(&sb); - break; - } - - if (bp == buf) { - /* - * We are at the start of the buffer, and there - * is more file to read backwards. Which means - * we are in the middle of a line. Note that we - * may get here even if *bp was a newline; that - * just means we are at the exact end of the - * previous line, rather than some spot in the - * middle. - * - * Save away what we have to be combined with - * the data from the next read. - */ - strbuf_splice(&sb, 0, 0, buf, endp - buf); - break; - } - } - - } - if (!ret && sb.len) - die("BUG: reverse reflog parser had leftover data"); - - fclose(logfp); - strbuf_release(&sb); - return ret; -} - -int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data) -{ - FILE *logfp; - struct strbuf sb = STRBUF_INIT; - int ret = 0; - - logfp = fopen(git_path("logs/%s", refname), "r"); - if (!logfp) - return -1; - - while (!ret && !strbuf_getwholeline(&sb, logfp, '\n')) - ret = show_one_reflog_ent(&sb, fn, cb_data); - fclose(logfp); - strbuf_release(&sb); - return ret; -} -/* - * Call fn for each reflog in the namespace indicated by name. name - * must be empty or end with '/'. Name will be used as a scratch - * space, but its contents will be restored before return. - */ -static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data) -{ - DIR *d = opendir(git_path("logs/%s", name->buf)); - int retval = 0; - struct dirent *de; - int oldlen = name->len; - - if (!d) - return name->len ? errno : 0; - - while ((de = readdir(d)) != NULL) { - struct stat st; - - if (de->d_name[0] == '.') - continue; - if (ends_with(de->d_name, ".lock")) - continue; - strbuf_addstr(name, de->d_name); - if (stat(git_path("logs/%s", name->buf), &st) < 0) { - ; /* silently ignore */ - } else { - if (S_ISDIR(st.st_mode)) { - strbuf_addch(name, '/'); - retval = do_for_each_reflog(name, fn, cb_data); - } else { - struct object_id oid; - - if (read_ref_full(name->buf, 0, oid.hash, NULL)) - retval = error("bad ref for %s", name->buf); - else - retval = fn(name->buf, &oid, 0, cb_data); - } - if (retval) - break; - } - strbuf_setlen(name, oldlen); - } - closedir(d); - return retval; -} - -int for_each_reflog(each_ref_fn fn, void *cb_data) -{ - int retval; - struct strbuf name; - strbuf_init(&name, PATH_MAX); - retval = do_for_each_reflog(&name, fn, cb_data); - strbuf_release(&name); - return retval; -} - struct ref_transaction *ref_transaction_begin(struct strbuf *err) { assert(err); @@ -4012,269 +886,6 @@ int update_ref(const char *msg, const char *refname, return 0; } -static int ref_update_reject_duplicates(struct string_list *refnames, - struct strbuf *err) -{ - int i, n = refnames->nr; - - assert(err); - - for (i = 1; i < n; i++) - if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) { - strbuf_addf(err, - "Multiple updates for ref '%s' not allowed.", - refnames->items[i].string); - return 1; - } - return 0; -} - -int ref_transaction_commit(struct ref_transaction *transaction, - struct strbuf *err) -{ - int ret = 0, i; - int n = transaction->nr; - struct ref_update **updates = transaction->updates; - struct string_list refs_to_delete = STRING_LIST_INIT_NODUP; - struct string_list_item *ref_to_delete; - struct string_list affected_refnames = STRING_LIST_INIT_NODUP; - - assert(err); - - if (transaction->state != REF_TRANSACTION_OPEN) - die("BUG: commit called for transaction that is not open"); - - if (!n) { - transaction->state = REF_TRANSACTION_CLOSED; - return 0; - } - - /* Fail if a refname appears more than once in the transaction: */ - for (i = 0; i < n; i++) - string_list_append(&affected_refnames, updates[i]->refname); - string_list_sort(&affected_refnames); - if (ref_update_reject_duplicates(&affected_refnames, err)) { - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - - /* - * Acquire all locks, verify old values if provided, check - * that new values are valid, and write new values to the - * lockfiles, ready to be activated. Only keep one lockfile - * open at a time to avoid running out of file descriptors. - */ - for (i = 0; i < n; i++) { - struct ref_update *update = updates[i]; - - if ((update->flags & REF_HAVE_NEW) && - is_null_sha1(update->new_sha1)) - update->flags |= REF_DELETING; - update->lock = lock_ref_sha1_basic( - update->refname, - ((update->flags & REF_HAVE_OLD) ? - update->old_sha1 : NULL), - &affected_refnames, NULL, - update->flags, - &update->type, - err); - if (!update->lock) { - char *reason; - - ret = (errno == ENOTDIR) - ? TRANSACTION_NAME_CONFLICT - : TRANSACTION_GENERIC_ERROR; - reason = strbuf_detach(err, NULL); - strbuf_addf(err, "cannot lock ref '%s': %s", - update->refname, reason); - free(reason); - goto cleanup; - } - if ((update->flags & REF_HAVE_NEW) && - !(update->flags & REF_DELETING)) { - int overwriting_symref = ((update->type & REF_ISSYMREF) && - (update->flags & REF_NODEREF)); - - if (!overwriting_symref && - !hashcmp(update->lock->old_oid.hash, update->new_sha1)) { - /* - * The reference already has the desired - * value, so we don't need to write it. - */ - } else if (write_ref_to_lockfile(update->lock, - update->new_sha1, - err)) { - char *write_err = strbuf_detach(err, NULL); - - /* - * The lock was freed upon failure of - * write_ref_to_lockfile(): - */ - update->lock = NULL; - strbuf_addf(err, - "cannot update the ref '%s': %s", - update->refname, write_err); - free(write_err); - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } else { - update->flags |= REF_NEEDS_COMMIT; - } - } - if (!(update->flags & REF_NEEDS_COMMIT)) { - /* - * We didn't have to write anything to the lockfile. - * Close it to free up the file descriptor: - */ - if (close_ref(update->lock)) { - strbuf_addf(err, "Couldn't close %s.lock", - update->refname); - goto cleanup; - } - } - } - - /* Perform updates first so live commits remain referenced */ - for (i = 0; i < n; i++) { - struct ref_update *update = updates[i]; - - if (update->flags & REF_NEEDS_COMMIT) { - if (commit_ref_update(update->lock, - update->new_sha1, update->msg, - update->flags, err)) { - /* freed by commit_ref_update(): */ - update->lock = NULL; - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } else { - /* freed by commit_ref_update(): */ - update->lock = NULL; - } - } - } - - /* Perform deletes now that updates are safely completed */ - for (i = 0; i < n; i++) { - struct ref_update *update = updates[i]; - - if (update->flags & REF_DELETING) { - if (delete_ref_loose(update->lock, update->type, err)) { - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - - if (!(update->flags & REF_ISPRUNING)) - string_list_append(&refs_to_delete, - update->lock->ref_name); - } - } - - if (repack_without_refs(&refs_to_delete, err)) { - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - for_each_string_list_item(ref_to_delete, &refs_to_delete) - unlink_or_warn(git_path("logs/%s", ref_to_delete->string)); - clear_loose_ref_cache(&ref_cache); - -cleanup: - transaction->state = REF_TRANSACTION_CLOSED; - - for (i = 0; i < n; i++) - if (updates[i]->lock) - unlock_ref(updates[i]->lock); - string_list_clear(&refs_to_delete, 0); - string_list_clear(&affected_refnames, 0); - return ret; -} - -static int ref_present(const char *refname, - const struct object_id *oid, int flags, void *cb_data) -{ - struct string_list *affected_refnames = cb_data; - - return string_list_has_string(affected_refnames, refname); -} - -int initial_ref_transaction_commit(struct ref_transaction *transaction, - struct strbuf *err) -{ - int ret = 0, i; - int n = transaction->nr; - struct ref_update **updates = transaction->updates; - struct string_list affected_refnames = STRING_LIST_INIT_NODUP; - - assert(err); - - if (transaction->state != REF_TRANSACTION_OPEN) - die("BUG: commit called for transaction that is not open"); - - /* Fail if a refname appears more than once in the transaction: */ - for (i = 0; i < n; i++) - string_list_append(&affected_refnames, updates[i]->refname); - string_list_sort(&affected_refnames); - if (ref_update_reject_duplicates(&affected_refnames, err)) { - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - - /* - * It's really undefined to call this function in an active - * repository or when there are existing references: we are - * only locking and changing packed-refs, so (1) any - * simultaneous processes might try to change a reference at - * the same time we do, and (2) any existing loose versions of - * the references that we are setting would have precedence - * over our values. But some remote helpers create the remote - * "HEAD" and "master" branches before calling this function, - * so here we really only check that none of the references - * that we are creating already exists. - */ - if (for_each_rawref(ref_present, &affected_refnames)) - die("BUG: initial ref transaction called with existing refs"); - - for (i = 0; i < n; i++) { - struct ref_update *update = updates[i]; - - if ((update->flags & REF_HAVE_OLD) && - !is_null_sha1(update->old_sha1)) - die("BUG: initial ref transaction with old_sha1 set"); - if (verify_refname_available(update->refname, - &affected_refnames, NULL, - err)) { - ret = TRANSACTION_NAME_CONFLICT; - goto cleanup; - } - } - - if (lock_packed_refs(0)) { - strbuf_addf(err, "unable to lock packed-refs file: %s", - strerror(errno)); - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - - for (i = 0; i < n; i++) { - struct ref_update *update = updates[i]; - - if ((update->flags & REF_HAVE_NEW) && - !is_null_sha1(update->new_sha1)) - add_packed_ref(update->refname, update->new_sha1); - } - - if (commit_packed_refs()) { - strbuf_addf(err, "unable to commit packed-refs file: %s", - strerror(errno)); - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - -cleanup: - transaction->state = REF_TRANSACTION_CLOSED; - string_list_clear(&affected_refnames, 0); - return ret; -} - char *shorten_unambiguous_ref(const char *refname, int strict) { int i; @@ -4418,145 +1029,3 @@ int ref_is_hidden(const char *refname) } return 0; } - -struct expire_reflog_cb { - unsigned int flags; - reflog_expiry_should_prune_fn *should_prune_fn; - void *policy_cb; - FILE *newlog; - unsigned char last_kept_sha1[20]; -}; - -static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1, - const char *email, unsigned long timestamp, int tz, - const char *message, void *cb_data) -{ - struct expire_reflog_cb *cb = cb_data; - struct expire_reflog_policy_cb *policy_cb = cb->policy_cb; - - if (cb->flags & EXPIRE_REFLOGS_REWRITE) - osha1 = cb->last_kept_sha1; - - if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz, - message, policy_cb)) { - if (!cb->newlog) - printf("would prune %s", message); - else if (cb->flags & EXPIRE_REFLOGS_VERBOSE) - printf("prune %s", message); - } else { - if (cb->newlog) { - fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s", - sha1_to_hex(osha1), sha1_to_hex(nsha1), - email, timestamp, tz, message); - hashcpy(cb->last_kept_sha1, nsha1); - } - if (cb->flags & EXPIRE_REFLOGS_VERBOSE) - printf("keep %s", message); - } - return 0; -} - -int reflog_expire(const char *refname, const unsigned char *sha1, - unsigned int flags, - reflog_expiry_prepare_fn prepare_fn, - reflog_expiry_should_prune_fn should_prune_fn, - reflog_expiry_cleanup_fn cleanup_fn, - void *policy_cb_data) -{ - static struct lock_file reflog_lock; - struct expire_reflog_cb cb; - struct ref_lock *lock; - char *log_file; - int status = 0; - int type; - struct strbuf err = STRBUF_INIT; - - memset(&cb, 0, sizeof(cb)); - cb.flags = flags; - cb.policy_cb = policy_cb_data; - cb.should_prune_fn = should_prune_fn; - - /* - * The reflog file is locked by holding the lock on the - * reference itself, plus we might need to update the - * reference if --updateref was specified: - */ - lock = lock_ref_sha1_basic(refname, sha1, NULL, NULL, 0, &type, &err); - if (!lock) { - error("cannot lock ref '%s': %s", refname, err.buf); - strbuf_release(&err); - return -1; - } - if (!reflog_exists(refname)) { - unlock_ref(lock); - return 0; - } - - log_file = git_pathdup("logs/%s", refname); - if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) { - /* - * Even though holding $GIT_DIR/logs/$reflog.lock has - * no locking implications, we use the lock_file - * machinery here anyway because it does a lot of the - * work we need, including cleaning up if the program - * exits unexpectedly. - */ - if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) { - struct strbuf err = STRBUF_INIT; - unable_to_lock_message(log_file, errno, &err); - error("%s", err.buf); - strbuf_release(&err); - goto failure; - } - cb.newlog = fdopen_lock_file(&reflog_lock, "w"); - if (!cb.newlog) { - error("cannot fdopen %s (%s)", - get_lock_file_path(&reflog_lock), strerror(errno)); - goto failure; - } - } - - (*prepare_fn)(refname, sha1, cb.policy_cb); - for_each_reflog_ent(refname, expire_reflog_ent, &cb); - (*cleanup_fn)(cb.policy_cb); - - if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) { - /* - * It doesn't make sense to adjust a reference pointed - * to by a symbolic ref based on expiring entries in - * the symbolic reference's reflog. Nor can we update - * a reference if there are no remaining reflog - * entries. - */ - int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) && - !(type & REF_ISSYMREF) && - !is_null_sha1(cb.last_kept_sha1); - - if (close_lock_file(&reflog_lock)) { - status |= error("couldn't write %s: %s", log_file, - strerror(errno)); - } else if (update && - (write_in_full(get_lock_file_fd(lock->lk), - sha1_to_hex(cb.last_kept_sha1), 40) != 40 || - write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 || - close_ref(lock) < 0)) { - status |= error("couldn't write %s", - get_lock_file_path(lock->lk)); - rollback_lock_file(&reflog_lock); - } else if (commit_lock_file(&reflog_lock)) { - status |= error("unable to commit reflog '%s' (%s)", - log_file, strerror(errno)); - } else if (update && commit_ref(lock)) { - status |= error("couldn't set %s", lock->ref_name); - } - } - free(log_file); - unlock_ref(lock); - return status; - - failure: - rollback_lock_file(&reflog_lock); - free(log_file); - unlock_ref(lock); - return -1; -} diff --git a/refs/files-backend.c b/refs/files-backend.c new file mode 100644 index 0000000000..14ec506c17 --- /dev/null +++ b/refs/files-backend.c @@ -0,0 +1,3539 @@ +#include "../cache.h" +#include "../refs.h" +#include "refs-internal.h" +#include "../lockfile.h" +#include "../object.h" +#include "../dir.h" + +struct ref_lock { + char *ref_name; + char *orig_ref_name; + struct lock_file *lk; + struct object_id old_oid; +}; + +struct ref_entry; + +/* + * Information used (along with the information in ref_entry) to + * describe a single cached reference. This data structure only + * occurs embedded in a union in struct ref_entry, and only when + * (ref_entry->flag & REF_DIR) is zero. + */ +struct ref_value { + /* + * The name of the object to which this reference resolves + * (which may be a tag object). If REF_ISBROKEN, this is + * null. If REF_ISSYMREF, then this is the name of the object + * referred to by the last reference in the symlink chain. + */ + struct object_id oid; + + /* + * If REF_KNOWS_PEELED, then this field holds the peeled value + * of this reference, or null if the reference is known not to + * be peelable. See the documentation for peel_ref() for an + * exact definition of "peelable". + */ + struct object_id peeled; +}; + +struct ref_cache; + +/* + * Information used (along with the information in ref_entry) to + * describe a level in the hierarchy of references. This data + * structure only occurs embedded in a union in struct ref_entry, and + * only when (ref_entry.flag & REF_DIR) is set. In that case, + * (ref_entry.flag & REF_INCOMPLETE) determines whether the references + * in the directory have already been read: + * + * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose + * or packed references, already read. + * + * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose + * references that hasn't been read yet (nor has any of its + * subdirectories). + * + * Entries within a directory are stored within a growable array of + * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < + * sorted are sorted by their component name in strcmp() order and the + * remaining entries are unsorted. + * + * Loose references are read lazily, one directory at a time. When a + * directory of loose references is read, then all of the references + * in that directory are stored, and REF_INCOMPLETE stubs are created + * for any subdirectories, but the subdirectories themselves are not + * read. The reading is triggered by get_ref_dir(). + */ +struct ref_dir { + int nr, alloc; + + /* + * Entries with index 0 <= i < sorted are sorted by name. New + * entries are appended to the list unsorted, and are sorted + * only when required; thus we avoid the need to sort the list + * after the addition of every reference. + */ + int sorted; + + /* A pointer to the ref_cache that contains this ref_dir. */ + struct ref_cache *ref_cache; + + struct ref_entry **entries; +}; + +/* + * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, + * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are + * public values; see refs.h. + */ + +/* + * The field ref_entry->u.value.peeled of this value entry contains + * the correct peeled value for the reference, which might be + * null_sha1 if the reference is not a tag or if it is broken. + */ +#define REF_KNOWS_PEELED 0x10 + +/* ref_entry represents a directory of references */ +#define REF_DIR 0x20 + +/* + * Entry has not yet been read from disk (used only for REF_DIR + * entries representing loose references) + */ +#define REF_INCOMPLETE 0x40 + +/* + * A ref_entry represents either a reference or a "subdirectory" of + * references. + * + * Each directory in the reference namespace is represented by a + * ref_entry with (flags & REF_DIR) set and containing a subdir member + * that holds the entries in that directory that have been read so + * far. If (flags & REF_INCOMPLETE) is set, then the directory and + * its subdirectories haven't been read yet. REF_INCOMPLETE is only + * used for loose reference directories. + * + * References are represented by a ref_entry with (flags & REF_DIR) + * unset and a value member that describes the reference's value. The + * flag member is at the ref_entry level, but it is also needed to + * interpret the contents of the value field (in other words, a + * ref_value object is not very much use without the enclosing + * ref_entry). + * + * Reference names cannot end with slash and directories' names are + * always stored with a trailing slash (except for the top-level + * directory, which is always denoted by ""). This has two nice + * consequences: (1) when the entries in each subdir are sorted + * lexicographically by name (as they usually are), the references in + * a whole tree can be generated in lexicographic order by traversing + * the tree in left-to-right, depth-first order; (2) the names of + * references and subdirectories cannot conflict, and therefore the + * presence of an empty subdirectory does not block the creation of a + * similarly-named reference. (The fact that reference names with the + * same leading components can conflict *with each other* is a + * separate issue that is regulated by verify_refname_available().) + * + * Please note that the name field contains the fully-qualified + * reference (or subdirectory) name. Space could be saved by only + * storing the relative names. But that would require the full names + * to be generated on the fly when iterating in do_for_each_ref(), and + * would break callback functions, who have always been able to assume + * that the name strings that they are passed will not be freed during + * the iteration. + */ +struct ref_entry { + unsigned char flag; /* ISSYMREF? ISPACKED? */ + union { + struct ref_value value; /* if not (flags&REF_DIR) */ + struct ref_dir subdir; /* if (flags&REF_DIR) */ + } u; + /* + * The full name of the reference (e.g., "refs/heads/master") + * or the full name of the directory with a trailing slash + * (e.g., "refs/heads/"): + */ + char name[FLEX_ARRAY]; +}; + +static void read_loose_refs(const char *dirname, struct ref_dir *dir); +static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len); +static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, + const char *dirname, size_t len, + int incomplete); +static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry); + +static struct ref_dir *get_ref_dir(struct ref_entry *entry) +{ + struct ref_dir *dir; + assert(entry->flag & REF_DIR); + dir = &entry->u.subdir; + if (entry->flag & REF_INCOMPLETE) { + read_loose_refs(entry->name, dir); + + /* + * Manually add refs/bisect, which, being + * per-worktree, might not appear in the directory + * listing for refs/ in the main repo. + */ + if (!strcmp(entry->name, "refs/")) { + int pos = search_ref_dir(dir, "refs/bisect/", 12); + if (pos < 0) { + struct ref_entry *child_entry; + child_entry = create_dir_entry(dir->ref_cache, + "refs/bisect/", + 12, 1); + add_entry_to_dir(dir, child_entry); + read_loose_refs("refs/bisect", + &child_entry->u.subdir); + } + } + entry->flag &= ~REF_INCOMPLETE; + } + return dir; +} + +static struct ref_entry *create_ref_entry(const char *refname, + const unsigned char *sha1, int flag, + int check_name) +{ + int len; + struct ref_entry *ref; + + if (check_name && + check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) + die("Reference has invalid format: '%s'", refname); + len = strlen(refname) + 1; + ref = xmalloc(sizeof(struct ref_entry) + len); + hashcpy(ref->u.value.oid.hash, sha1); + oidclr(&ref->u.value.peeled); + memcpy(ref->name, refname, len); + ref->flag = flag; + return ref; +} + +static void clear_ref_dir(struct ref_dir *dir); + +static void free_ref_entry(struct ref_entry *entry) +{ + if (entry->flag & REF_DIR) { + /* + * Do not use get_ref_dir() here, as that might + * trigger the reading of loose refs. + */ + clear_ref_dir(&entry->u.subdir); + } + free(entry); +} + +/* + * Add a ref_entry to the end of dir (unsorted). Entry is always + * stored directly in dir; no recursion into subdirectories is + * done. + */ +static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry) +{ + ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc); + dir->entries[dir->nr++] = entry; + /* optimize for the case that entries are added in order */ + if (dir->nr == 1 || + (dir->nr == dir->sorted + 1 && + strcmp(dir->entries[dir->nr - 2]->name, + dir->entries[dir->nr - 1]->name) < 0)) + dir->sorted = dir->nr; +} + +/* + * Clear and free all entries in dir, recursively. + */ +static void clear_ref_dir(struct ref_dir *dir) +{ + int i; + for (i = 0; i < dir->nr; i++) + free_ref_entry(dir->entries[i]); + free(dir->entries); + dir->sorted = dir->nr = dir->alloc = 0; + dir->entries = NULL; +} + +/* + * Create a struct ref_entry object for the specified dirname. + * dirname is the name of the directory with a trailing slash (e.g., + * "refs/heads/") or "" for the top-level directory. + */ +static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, + const char *dirname, size_t len, + int incomplete) +{ + struct ref_entry *direntry; + direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1); + memcpy(direntry->name, dirname, len); + direntry->name[len] = '\0'; + direntry->u.subdir.ref_cache = ref_cache; + direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0); + return direntry; +} + +static int ref_entry_cmp(const void *a, const void *b) +{ + struct ref_entry *one = *(struct ref_entry **)a; + struct ref_entry *two = *(struct ref_entry **)b; + return strcmp(one->name, two->name); +} + +static void sort_ref_dir(struct ref_dir *dir); + +struct string_slice { + size_t len; + const char *str; +}; + +static int ref_entry_cmp_sslice(const void *key_, const void *ent_) +{ + const struct string_slice *key = key_; + const struct ref_entry *ent = *(const struct ref_entry * const *)ent_; + int cmp = strncmp(key->str, ent->name, key->len); + if (cmp) + return cmp; + return '\0' - (unsigned char)ent->name[key->len]; +} + +/* + * Return the index of the entry with the given refname from the + * ref_dir (non-recursively), sorting dir if necessary. Return -1 if + * no such entry is found. dir must already be complete. + */ +static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len) +{ + struct ref_entry **r; + struct string_slice key; + + if (refname == NULL || !dir->nr) + return -1; + + sort_ref_dir(dir); + key.len = len; + key.str = refname; + r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries), + ref_entry_cmp_sslice); + + if (r == NULL) + return -1; + + return r - dir->entries; +} + +/* + * Search for a directory entry directly within dir (without + * recursing). Sort dir if necessary. subdirname must be a directory + * name (i.e., end in '/'). If mkdir is set, then create the + * directory if it is missing; otherwise, return NULL if the desired + * directory cannot be found. dir must already be complete. + */ +static struct ref_dir *search_for_subdir(struct ref_dir *dir, + const char *subdirname, size_t len, + int mkdir) +{ + int entry_index = search_ref_dir(dir, subdirname, len); + struct ref_entry *entry; + if (entry_index == -1) { + if (!mkdir) + return NULL; + /* + * Since dir is complete, the absence of a subdir + * means that the subdir really doesn't exist; + * therefore, create an empty record for it but mark + * the record complete. + */ + entry = create_dir_entry(dir->ref_cache, subdirname, len, 0); + add_entry_to_dir(dir, entry); + } else { + entry = dir->entries[entry_index]; + } + return get_ref_dir(entry); +} + +/* + * If refname is a reference name, find the ref_dir within the dir + * tree that should hold refname. If refname is a directory name + * (i.e., ends in '/'), then return that ref_dir itself. dir must + * represent the top-level directory and must already be complete. + * Sort ref_dirs and recurse into subdirectories as necessary. If + * mkdir is set, then create any missing directories; otherwise, + * return NULL if the desired directory cannot be found. + */ +static struct ref_dir *find_containing_dir(struct ref_dir *dir, + const char *refname, int mkdir) +{ + const char *slash; + for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { + size_t dirnamelen = slash - refname + 1; + struct ref_dir *subdir; + subdir = search_for_subdir(dir, refname, dirnamelen, mkdir); + if (!subdir) { + dir = NULL; + break; + } + dir = subdir; + } + + return dir; +} + +/* + * Find the value entry with the given name in dir, sorting ref_dirs + * and recursing into subdirectories as necessary. If the name is not + * found or it corresponds to a directory entry, return NULL. + */ +static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname) +{ + int entry_index; + struct ref_entry *entry; + dir = find_containing_dir(dir, refname, 0); + if (!dir) + return NULL; + entry_index = search_ref_dir(dir, refname, strlen(refname)); + if (entry_index == -1) + return NULL; + entry = dir->entries[entry_index]; + return (entry->flag & REF_DIR) ? NULL : entry; +} + +/* + * Remove the entry with the given name from dir, recursing into + * subdirectories as necessary. If refname is the name of a directory + * (i.e., ends with '/'), then remove the directory and its contents. + * If the removal was successful, return the number of entries + * remaining in the directory entry that contained the deleted entry. + * If the name was not found, return -1. Please note that this + * function only deletes the entry from the cache; it does not delete + * it from the filesystem or ensure that other cache entries (which + * might be symbolic references to the removed entry) are updated. + * Nor does it remove any containing dir entries that might be made + * empty by the removal. dir must represent the top-level directory + * and must already be complete. + */ +static int remove_entry(struct ref_dir *dir, const char *refname) +{ + int refname_len = strlen(refname); + int entry_index; + struct ref_entry *entry; + int is_dir = refname[refname_len - 1] == '/'; + if (is_dir) { + /* + * refname represents a reference directory. Remove + * the trailing slash; otherwise we will get the + * directory *representing* refname rather than the + * one *containing* it. + */ + char *dirname = xmemdupz(refname, refname_len - 1); + dir = find_containing_dir(dir, dirname, 0); + free(dirname); + } else { + dir = find_containing_dir(dir, refname, 0); + } + if (!dir) + return -1; + entry_index = search_ref_dir(dir, refname, refname_len); + if (entry_index == -1) + return -1; + entry = dir->entries[entry_index]; + + memmove(&dir->entries[entry_index], + &dir->entries[entry_index + 1], + (dir->nr - entry_index - 1) * sizeof(*dir->entries) + ); + dir->nr--; + if (dir->sorted > entry_index) + dir->sorted--; + free_ref_entry(entry); + return dir->nr; +} + +/* + * Add a ref_entry to the ref_dir (unsorted), recursing into + * subdirectories as necessary. dir must represent the top-level + * directory. Return 0 on success. + */ +static int add_ref(struct ref_dir *dir, struct ref_entry *ref) +{ + dir = find_containing_dir(dir, ref->name, 1); + if (!dir) + return -1; + add_entry_to_dir(dir, ref); + return 0; +} + +/* + * Emit a warning and return true iff ref1 and ref2 have the same name + * and the same sha1. Die if they have the same name but different + * sha1s. + */ +static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2) +{ + if (strcmp(ref1->name, ref2->name)) + return 0; + + /* Duplicate name; make sure that they don't conflict: */ + + if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) + /* This is impossible by construction */ + die("Reference directory conflict: %s", ref1->name); + + if (oidcmp(&ref1->u.value.oid, &ref2->u.value.oid)) + die("Duplicated ref, and SHA1s don't match: %s", ref1->name); + + warning("Duplicated ref: %s", ref1->name); + return 1; +} + +/* + * Sort the entries in dir non-recursively (if they are not already + * sorted) and remove any duplicate entries. + */ +static void sort_ref_dir(struct ref_dir *dir) +{ + int i, j; + struct ref_entry *last = NULL; + + /* + * This check also prevents passing a zero-length array to qsort(), + * which is a problem on some platforms. + */ + if (dir->sorted == dir->nr) + return; + + qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp); + + /* Remove any duplicates: */ + for (i = 0, j = 0; j < dir->nr; j++) { + struct ref_entry *entry = dir->entries[j]; + if (last && is_dup_ref(last, entry)) + free_ref_entry(entry); + else + last = dir->entries[i++] = entry; + } + dir->sorted = dir->nr = i; +} + +/* Include broken references in a do_for_each_ref*() iteration: */ +#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 + +/* + * Return true iff the reference described by entry can be resolved to + * an object in the database. Emit a warning if the referred-to + * object does not exist. + */ +static int ref_resolves_to_object(struct ref_entry *entry) +{ + if (entry->flag & REF_ISBROKEN) + return 0; + if (!has_sha1_file(entry->u.value.oid.hash)) { + error("%s does not point to a valid object!", entry->name); + return 0; + } + return 1; +} + +/* + * current_ref is a performance hack: when iterating over references + * using the for_each_ref*() functions, current_ref is set to the + * current reference's entry before calling the callback function. If + * the callback function calls peel_ref(), then peel_ref() first + * checks whether the reference to be peeled is the current reference + * (it usually is) and if so, returns that reference's peeled version + * if it is available. This avoids a refname lookup in a common case. + */ +static struct ref_entry *current_ref; + +typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data); + +struct ref_entry_cb { + const char *base; + int trim; + int flags; + each_ref_fn *fn; + void *cb_data; +}; + +/* + * Handle one reference in a do_for_each_ref*()-style iteration, + * calling an each_ref_fn for each entry. + */ +static int do_one_ref(struct ref_entry *entry, void *cb_data) +{ + struct ref_entry_cb *data = cb_data; + struct ref_entry *old_current_ref; + int retval; + + if (!starts_with(entry->name, data->base)) + return 0; + + if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && + !ref_resolves_to_object(entry)) + return 0; + + /* Store the old value, in case this is a recursive call: */ + old_current_ref = current_ref; + current_ref = entry; + retval = data->fn(entry->name + data->trim, &entry->u.value.oid, + entry->flag, data->cb_data); + current_ref = old_current_ref; + return retval; +} + +/* + * Call fn for each reference in dir that has index in the range + * offset <= index < dir->nr. Recurse into subdirectories that are in + * that index range, sorting them before iterating. This function + * does not sort dir itself; it should be sorted beforehand. fn is + * called for all references, including broken ones. + */ +static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset, + each_ref_entry_fn fn, void *cb_data) +{ + int i; + assert(dir->sorted == dir->nr); + for (i = offset; i < dir->nr; i++) { + struct ref_entry *entry = dir->entries[i]; + int retval; + if (entry->flag & REF_DIR) { + struct ref_dir *subdir = get_ref_dir(entry); + sort_ref_dir(subdir); + retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data); + } else { + retval = fn(entry, cb_data); + } + if (retval) + return retval; + } + return 0; +} + +/* + * Call fn for each reference in the union of dir1 and dir2, in order + * by refname. Recurse into subdirectories. If a value entry appears + * in both dir1 and dir2, then only process the version that is in + * dir2. The input dirs must already be sorted, but subdirs will be + * sorted as needed. fn is called for all references, including + * broken ones. + */ +static int do_for_each_entry_in_dirs(struct ref_dir *dir1, + struct ref_dir *dir2, + each_ref_entry_fn fn, void *cb_data) +{ + int retval; + int i1 = 0, i2 = 0; + + assert(dir1->sorted == dir1->nr); + assert(dir2->sorted == dir2->nr); + while (1) { + struct ref_entry *e1, *e2; + int cmp; + if (i1 == dir1->nr) { + return do_for_each_entry_in_dir(dir2, i2, fn, cb_data); + } + if (i2 == dir2->nr) { + return do_for_each_entry_in_dir(dir1, i1, fn, cb_data); + } + e1 = dir1->entries[i1]; + e2 = dir2->entries[i2]; + cmp = strcmp(e1->name, e2->name); + if (cmp == 0) { + if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { + /* Both are directories; descend them in parallel. */ + struct ref_dir *subdir1 = get_ref_dir(e1); + struct ref_dir *subdir2 = get_ref_dir(e2); + sort_ref_dir(subdir1); + sort_ref_dir(subdir2); + retval = do_for_each_entry_in_dirs( + subdir1, subdir2, fn, cb_data); + i1++; + i2++; + } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { + /* Both are references; ignore the one from dir1. */ + retval = fn(e2, cb_data); + i1++; + i2++; + } else { + die("conflict between reference and directory: %s", + e1->name); + } + } else { + struct ref_entry *e; + if (cmp < 0) { + e = e1; + i1++; + } else { + e = e2; + i2++; + } + if (e->flag & REF_DIR) { + struct ref_dir *subdir = get_ref_dir(e); + sort_ref_dir(subdir); + retval = do_for_each_entry_in_dir( + subdir, 0, fn, cb_data); + } else { + retval = fn(e, cb_data); + } + } + if (retval) + return retval; + } +} + +/* + * Load all of the refs from the dir into our in-memory cache. The hard work + * of loading loose refs is done by get_ref_dir(), so we just need to recurse + * through all of the sub-directories. We do not even need to care about + * sorting, as traversal order does not matter to us. + */ +static void prime_ref_dir(struct ref_dir *dir) +{ + int i; + for (i = 0; i < dir->nr; i++) { + struct ref_entry *entry = dir->entries[i]; + if (entry->flag & REF_DIR) + prime_ref_dir(get_ref_dir(entry)); + } +} + +struct nonmatching_ref_data { + const struct string_list *skip; + const char *conflicting_refname; +}; + +static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata) +{ + struct nonmatching_ref_data *data = vdata; + + if (data->skip && string_list_has_string(data->skip, entry->name)) + return 0; + + data->conflicting_refname = entry->name; + return 1; +} + +/* + * Return 0 if a reference named refname could be created without + * conflicting with the name of an existing reference in dir. + * See verify_refname_available for more information. + */ +static int verify_refname_available_dir(const char *refname, + const struct string_list *extras, + const struct string_list *skip, + struct ref_dir *dir, + struct strbuf *err) +{ + const char *slash; + int pos; + struct strbuf dirname = STRBUF_INIT; + int ret = -1; + + /* + * For the sake of comments in this function, suppose that + * refname is "refs/foo/bar". + */ + + assert(err); + + strbuf_grow(&dirname, strlen(refname) + 1); + for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { + /* Expand dirname to the new prefix, not including the trailing slash: */ + strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len); + + /* + * We are still at a leading dir of the refname (e.g., + * "refs/foo"; if there is a reference with that name, + * it is a conflict, *unless* it is in skip. + */ + if (dir) { + pos = search_ref_dir(dir, dirname.buf, dirname.len); + if (pos >= 0 && + (!skip || !string_list_has_string(skip, dirname.buf))) { + /* + * We found a reference whose name is + * a proper prefix of refname; e.g., + * "refs/foo", and is not in skip. + */ + strbuf_addf(err, "'%s' exists; cannot create '%s'", + dirname.buf, refname); + goto cleanup; + } + } + + if (extras && string_list_has_string(extras, dirname.buf) && + (!skip || !string_list_has_string(skip, dirname.buf))) { + strbuf_addf(err, "cannot process '%s' and '%s' at the same time", + refname, dirname.buf); + goto cleanup; + } + + /* + * Otherwise, we can try to continue our search with + * the next component. So try to look up the + * directory, e.g., "refs/foo/". If we come up empty, + * we know there is nothing under this whole prefix, + * but even in that case we still have to continue the + * search for conflicts with extras. + */ + strbuf_addch(&dirname, '/'); + if (dir) { + pos = search_ref_dir(dir, dirname.buf, dirname.len); + if (pos < 0) { + /* + * There was no directory "refs/foo/", + * so there is nothing under this + * whole prefix. So there is no need + * to continue looking for conflicting + * references. But we need to continue + * looking for conflicting extras. + */ + dir = NULL; + } else { + dir = get_ref_dir(dir->entries[pos]); + } + } + } + + /* + * We are at the leaf of our refname (e.g., "refs/foo/bar"). + * There is no point in searching for a reference with that + * name, because a refname isn't considered to conflict with + * itself. But we still need to check for references whose + * names are in the "refs/foo/bar/" namespace, because they + * *do* conflict. + */ + strbuf_addstr(&dirname, refname + dirname.len); + strbuf_addch(&dirname, '/'); + + if (dir) { + pos = search_ref_dir(dir, dirname.buf, dirname.len); + + if (pos >= 0) { + /* + * We found a directory named "$refname/" + * (e.g., "refs/foo/bar/"). It is a problem + * iff it contains any ref that is not in + * "skip". + */ + struct nonmatching_ref_data data; + + data.skip = skip; + data.conflicting_refname = NULL; + dir = get_ref_dir(dir->entries[pos]); + sort_ref_dir(dir); + if (do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) { + strbuf_addf(err, "'%s' exists; cannot create '%s'", + data.conflicting_refname, refname); + goto cleanup; + } + } + } + + if (extras) { + /* + * Check for entries in extras that start with + * "$refname/". We do that by looking for the place + * where "$refname/" would be inserted in extras. If + * there is an entry at that position that starts with + * "$refname/" and is not in skip, then we have a + * conflict. + */ + for (pos = string_list_find_insert_index(extras, dirname.buf, 0); + pos < extras->nr; pos++) { + const char *extra_refname = extras->items[pos].string; + + if (!starts_with(extra_refname, dirname.buf)) + break; + + if (!skip || !string_list_has_string(skip, extra_refname)) { + strbuf_addf(err, "cannot process '%s' and '%s' at the same time", + refname, extra_refname); + goto cleanup; + } + } + } + + /* No conflicts were found */ + ret = 0; + +cleanup: + strbuf_release(&dirname); + return ret; +} + +struct packed_ref_cache { + struct ref_entry *root; + + /* + * Count of references to the data structure in this instance, + * including the pointer from ref_cache::packed if any. The + * data will not be freed as long as the reference count is + * nonzero. + */ + unsigned int referrers; + + /* + * Iff the packed-refs file associated with this instance is + * currently locked for writing, this points at the associated + * lock (which is owned by somebody else). The referrer count + * is also incremented when the file is locked and decremented + * when it is unlocked. + */ + struct lock_file *lock; + + /* The metadata from when this packed-refs cache was read */ + struct stat_validity validity; +}; + +/* + * Future: need to be in "struct repository" + * when doing a full libification. + */ +static struct ref_cache { + struct ref_cache *next; + struct ref_entry *loose; + struct packed_ref_cache *packed; + /* + * The submodule name, or "" for the main repo. We allocate + * length 1 rather than FLEX_ARRAY so that the main ref_cache + * is initialized correctly. + */ + char name[1]; +} ref_cache, *submodule_ref_caches; + +/* Lock used for the main packed-refs file: */ +static struct lock_file packlock; + +/* + * Increment the reference count of *packed_refs. + */ +static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) +{ + packed_refs->referrers++; +} + +/* + * Decrease the reference count of *packed_refs. If it goes to zero, + * free *packed_refs and return true; otherwise return false. + */ +static int release_packed_ref_cache(struct packed_ref_cache *packed_refs) +{ + if (!--packed_refs->referrers) { + free_ref_entry(packed_refs->root); + stat_validity_clear(&packed_refs->validity); + free(packed_refs); + return 1; + } else { + return 0; + } +} + +static void clear_packed_ref_cache(struct ref_cache *refs) +{ + if (refs->packed) { + struct packed_ref_cache *packed_refs = refs->packed; + + if (packed_refs->lock) + die("internal error: packed-ref cache cleared while locked"); + refs->packed = NULL; + release_packed_ref_cache(packed_refs); + } +} + +static void clear_loose_ref_cache(struct ref_cache *refs) +{ + if (refs->loose) { + free_ref_entry(refs->loose); + refs->loose = NULL; + } +} + +static struct ref_cache *create_ref_cache(const char *submodule) +{ + int len; + struct ref_cache *refs; + if (!submodule) + submodule = ""; + len = strlen(submodule) + 1; + refs = xcalloc(1, sizeof(struct ref_cache) + len); + memcpy(refs->name, submodule, len); + return refs; +} + +/* + * Return a pointer to a ref_cache for the specified submodule. For + * the main repository, use submodule==NULL. The returned structure + * will be allocated and initialized but not necessarily populated; it + * should not be freed. + */ +static struct ref_cache *get_ref_cache(const char *submodule) +{ + struct ref_cache *refs; + + if (!submodule || !*submodule) + return &ref_cache; + + for (refs = submodule_ref_caches; refs; refs = refs->next) + if (!strcmp(submodule, refs->name)) + return refs; + + refs = create_ref_cache(submodule); + refs->next = submodule_ref_caches; + submodule_ref_caches = refs; + return refs; +} + +/* The length of a peeled reference line in packed-refs, including EOL: */ +#define PEELED_LINE_LENGTH 42 + +/* + * The packed-refs header line that we write out. Perhaps other + * traits will be added later. The trailing space is required. + */ +static const char PACKED_REFS_HEADER[] = + "# pack-refs with: peeled fully-peeled \n"; + +/* + * Parse one line from a packed-refs file. Write the SHA1 to sha1. + * Return a pointer to the refname within the line (null-terminated), + * or NULL if there was a problem. + */ +static const char *parse_ref_line(struct strbuf *line, unsigned char *sha1) +{ + const char *ref; + + /* + * 42: the answer to everything. + * + * In this case, it happens to be the answer to + * 40 (length of sha1 hex representation) + * +1 (space in between hex and name) + * +1 (newline at the end of the line) + */ + if (line->len <= 42) + return NULL; + + if (get_sha1_hex(line->buf, sha1) < 0) + return NULL; + if (!isspace(line->buf[40])) + return NULL; + + ref = line->buf + 41; + if (isspace(*ref)) + return NULL; + + if (line->buf[line->len - 1] != '\n') + return NULL; + line->buf[--line->len] = 0; + + return ref; +} + +/* + * Read f, which is a packed-refs file, into dir. + * + * A comment line of the form "# pack-refs with: " may contain zero or + * more traits. We interpret the traits as follows: + * + * No traits: + * + * Probably no references are peeled. But if the file contains a + * peeled value for a reference, we will use it. + * + * peeled: + * + * References under "refs/tags/", if they *can* be peeled, *are* + * peeled in this file. References outside of "refs/tags/" are + * probably not peeled even if they could have been, but if we find + * a peeled value for such a reference we will use it. + * + * fully-peeled: + * + * All references in the file that can be peeled are peeled. + * Inversely (and this is more important), any references in the + * file for which no peeled value is recorded is not peelable. This + * trait should typically be written alongside "peeled" for + * compatibility with older clients, but we do not require it + * (i.e., "peeled" is a no-op if "fully-peeled" is set). + */ +static void read_packed_refs(FILE *f, struct ref_dir *dir) +{ + struct ref_entry *last = NULL; + struct strbuf line = STRBUF_INIT; + enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; + + while (strbuf_getwholeline(&line, f, '\n') != EOF) { + unsigned char sha1[20]; + const char *refname; + const char *traits; + + if (skip_prefix(line.buf, "# pack-refs with:", &traits)) { + if (strstr(traits, " fully-peeled ")) + peeled = PEELED_FULLY; + else if (strstr(traits, " peeled ")) + peeled = PEELED_TAGS; + /* perhaps other traits later as well */ + continue; + } + + refname = parse_ref_line(&line, sha1); + if (refname) { + int flag = REF_ISPACKED; + + if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { + if (!refname_is_safe(refname)) + die("packed refname is dangerous: %s", refname); + hashclr(sha1); + flag |= REF_BAD_NAME | REF_ISBROKEN; + } + last = create_ref_entry(refname, sha1, flag, 0); + if (peeled == PEELED_FULLY || + (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/"))) + last->flag |= REF_KNOWS_PEELED; + add_ref(dir, last); + continue; + } + if (last && + line.buf[0] == '^' && + line.len == PEELED_LINE_LENGTH && + line.buf[PEELED_LINE_LENGTH - 1] == '\n' && + !get_sha1_hex(line.buf + 1, sha1)) { + hashcpy(last->u.value.peeled.hash, sha1); + /* + * Regardless of what the file header said, + * we definitely know the value of *this* + * reference: + */ + last->flag |= REF_KNOWS_PEELED; + } + } + + strbuf_release(&line); +} + +/* + * Get the packed_ref_cache for the specified ref_cache, creating it + * if necessary. + */ +static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs) +{ + char *packed_refs_file; + + if (*refs->name) + packed_refs_file = git_pathdup_submodule(refs->name, "packed-refs"); + else + packed_refs_file = git_pathdup("packed-refs"); + + if (refs->packed && + !stat_validity_check(&refs->packed->validity, packed_refs_file)) + clear_packed_ref_cache(refs); + + if (!refs->packed) { + FILE *f; + + refs->packed = xcalloc(1, sizeof(*refs->packed)); + acquire_packed_ref_cache(refs->packed); + refs->packed->root = create_dir_entry(refs, "", 0, 0); + f = fopen(packed_refs_file, "r"); + if (f) { + stat_validity_update(&refs->packed->validity, fileno(f)); + read_packed_refs(f, get_ref_dir(refs->packed->root)); + fclose(f); + } + } + free(packed_refs_file); + return refs->packed; +} + +static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache) +{ + return get_ref_dir(packed_ref_cache->root); +} + +static struct ref_dir *get_packed_refs(struct ref_cache *refs) +{ + return get_packed_ref_dir(get_packed_ref_cache(refs)); +} + +/* + * Add a reference to the in-memory packed reference cache. This may + * only be called while the packed-refs file is locked (see + * lock_packed_refs()). To actually write the packed-refs file, call + * commit_packed_refs(). + */ +static void add_packed_ref(const char *refname, const unsigned char *sha1) +{ + struct packed_ref_cache *packed_ref_cache = + get_packed_ref_cache(&ref_cache); + + if (!packed_ref_cache->lock) + die("internal error: packed refs not locked"); + add_ref(get_packed_ref_dir(packed_ref_cache), + create_ref_entry(refname, sha1, REF_ISPACKED, 1)); +} + +/* + * Read the loose references from the namespace dirname into dir + * (without recursing). dirname must end with '/'. dir must be the + * directory entry corresponding to dirname. + */ +static void read_loose_refs(const char *dirname, struct ref_dir *dir) +{ + struct ref_cache *refs = dir->ref_cache; + DIR *d; + struct dirent *de; + int dirnamelen = strlen(dirname); + struct strbuf refname; + struct strbuf path = STRBUF_INIT; + size_t path_baselen; + + if (*refs->name) + strbuf_git_path_submodule(&path, refs->name, "%s", dirname); + else + strbuf_git_path(&path, "%s", dirname); + path_baselen = path.len; + + d = opendir(path.buf); + if (!d) { + strbuf_release(&path); + return; + } + + strbuf_init(&refname, dirnamelen + 257); + strbuf_add(&refname, dirname, dirnamelen); + + while ((de = readdir(d)) != NULL) { + unsigned char sha1[20]; + struct stat st; + int flag; + + if (de->d_name[0] == '.') + continue; + if (ends_with(de->d_name, ".lock")) + continue; + strbuf_addstr(&refname, de->d_name); + strbuf_addstr(&path, de->d_name); + if (stat(path.buf, &st) < 0) { + ; /* silently ignore */ + } else if (S_ISDIR(st.st_mode)) { + strbuf_addch(&refname, '/'); + add_entry_to_dir(dir, + create_dir_entry(refs, refname.buf, + refname.len, 1)); + } else { + int read_ok; + + if (*refs->name) { + hashclr(sha1); + flag = 0; + read_ok = !resolve_gitlink_ref(refs->name, + refname.buf, sha1); + } else { + read_ok = !read_ref_full(refname.buf, + RESOLVE_REF_READING, + sha1, &flag); + } + + if (!read_ok) { + hashclr(sha1); + flag |= REF_ISBROKEN; + } else if (is_null_sha1(sha1)) { + /* + * It is so astronomically unlikely + * that NULL_SHA1 is the SHA-1 of an + * actual object that we consider its + * appearance in a loose reference + * file to be repo corruption + * (probably due to a software bug). + */ + flag |= REF_ISBROKEN; + } + + if (check_refname_format(refname.buf, + REFNAME_ALLOW_ONELEVEL)) { + if (!refname_is_safe(refname.buf)) + die("loose refname is dangerous: %s", refname.buf); + hashclr(sha1); + flag |= REF_BAD_NAME | REF_ISBROKEN; + } + add_entry_to_dir(dir, + create_ref_entry(refname.buf, sha1, flag, 0)); + } + strbuf_setlen(&refname, dirnamelen); + strbuf_setlen(&path, path_baselen); + } + strbuf_release(&refname); + strbuf_release(&path); + closedir(d); +} + +static struct ref_dir *get_loose_refs(struct ref_cache *refs) +{ + if (!refs->loose) { + /* + * Mark the top-level directory complete because we + * are about to read the only subdirectory that can + * hold references: + */ + refs->loose = create_dir_entry(refs, "", 0, 0); + /* + * Create an incomplete entry for "refs/": + */ + add_entry_to_dir(get_ref_dir(refs->loose), + create_dir_entry(refs, "refs/", 5, 1)); + } + return get_ref_dir(refs->loose); +} + +/* We allow "recursive" symbolic refs. Only within reason, though */ +#define MAXDEPTH 5 +#define MAXREFLEN (1024) + +/* + * Called by resolve_gitlink_ref_recursive() after it failed to read + * from the loose refs in ref_cache refs. Find in the + * packed-refs file for the submodule. + */ +static int resolve_gitlink_packed_ref(struct ref_cache *refs, + const char *refname, unsigned char *sha1) +{ + struct ref_entry *ref; + struct ref_dir *dir = get_packed_refs(refs); + + ref = find_ref(dir, refname); + if (ref == NULL) + return -1; + + hashcpy(sha1, ref->u.value.oid.hash); + return 0; +} + +static int resolve_gitlink_ref_recursive(struct ref_cache *refs, + const char *refname, unsigned char *sha1, + int recursion) +{ + int fd, len; + char buffer[128], *p; + char *path; + + if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN) + return -1; + path = *refs->name + ? git_pathdup_submodule(refs->name, "%s", refname) + : git_pathdup("%s", refname); + fd = open(path, O_RDONLY); + free(path); + if (fd < 0) + return resolve_gitlink_packed_ref(refs, refname, sha1); + + len = read(fd, buffer, sizeof(buffer)-1); + close(fd); + if (len < 0) + return -1; + while (len && isspace(buffer[len-1])) + len--; + buffer[len] = 0; + + /* Was it a detached head or an old-fashioned symlink? */ + if (!get_sha1_hex(buffer, sha1)) + return 0; + + /* Symref? */ + if (strncmp(buffer, "ref:", 4)) + return -1; + p = buffer + 4; + while (isspace(*p)) + p++; + + return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1); +} + +int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1) +{ + int len = strlen(path), retval; + char *submodule; + struct ref_cache *refs; + + while (len && path[len-1] == '/') + len--; + if (!len) + return -1; + submodule = xstrndup(path, len); + refs = get_ref_cache(submodule); + free(submodule); + + retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0); + return retval; +} + +/* + * Return the ref_entry for the given refname from the packed + * references. If it does not exist, return NULL. + */ +static struct ref_entry *get_packed_ref(const char *refname) +{ + return find_ref(get_packed_refs(&ref_cache), refname); +} + +/* + * A loose ref file doesn't exist; check for a packed ref. The + * options are forwarded from resolve_safe_unsafe(). + */ +static int resolve_missing_loose_ref(const char *refname, + int resolve_flags, + unsigned char *sha1, + int *flags) +{ + struct ref_entry *entry; + + /* + * The loose reference file does not exist; check for a packed + * reference. + */ + entry = get_packed_ref(refname); + if (entry) { + hashcpy(sha1, entry->u.value.oid.hash); + if (flags) + *flags |= REF_ISPACKED; + return 0; + } + /* The reference is not a packed reference, either. */ + if (resolve_flags & RESOLVE_REF_READING) { + errno = ENOENT; + return -1; + } else { + hashclr(sha1); + return 0; + } +} + +/* This function needs to return a meaningful errno on failure */ +static const char *resolve_ref_1(const char *refname, + int resolve_flags, + unsigned char *sha1, + int *flags, + struct strbuf *sb_refname, + struct strbuf *sb_path, + struct strbuf *sb_contents) +{ + int depth = MAXDEPTH; + int bad_name = 0; + + if (flags) + *flags = 0; + + if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { + if (flags) + *flags |= REF_BAD_NAME; + + if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) || + !refname_is_safe(refname)) { + errno = EINVAL; + return NULL; + } + /* + * dwim_ref() uses REF_ISBROKEN to distinguish between + * missing refs and refs that were present but invalid, + * to complain about the latter to stderr. + * + * We don't know whether the ref exists, so don't set + * REF_ISBROKEN yet. + */ + bad_name = 1; + } + for (;;) { + const char *path; + struct stat st; + char *buf; + int fd; + + if (--depth < 0) { + errno = ELOOP; + return NULL; + } + + strbuf_reset(sb_path); + strbuf_git_path(sb_path, "%s", refname); + path = sb_path->buf; + + /* + * We might have to loop back here to avoid a race + * condition: first we lstat() the file, then we try + * to read it as a link or as a file. But if somebody + * changes the type of the file (file <-> directory + * <-> symlink) between the lstat() and reading, then + * we don't want to report that as an error but rather + * try again starting with the lstat(). + */ + stat_ref: + if (lstat(path, &st) < 0) { + if (errno != ENOENT) + return NULL; + if (resolve_missing_loose_ref(refname, resolve_flags, + sha1, flags)) + return NULL; + if (bad_name) { + hashclr(sha1); + if (flags) + *flags |= REF_ISBROKEN; + } + return refname; + } + + /* Follow "normalized" - ie "refs/.." symlinks by hand */ + if (S_ISLNK(st.st_mode)) { + strbuf_reset(sb_contents); + if (strbuf_readlink(sb_contents, path, 0) < 0) { + if (errno == ENOENT || errno == EINVAL) + /* inconsistent with lstat; retry */ + goto stat_ref; + else + return NULL; + } + if (starts_with(sb_contents->buf, "refs/") && + !check_refname_format(sb_contents->buf, 0)) { + strbuf_swap(sb_refname, sb_contents); + refname = sb_refname->buf; + if (flags) + *flags |= REF_ISSYMREF; + if (resolve_flags & RESOLVE_REF_NO_RECURSE) { + hashclr(sha1); + return refname; + } + continue; + } + } + + /* Is it a directory? */ + if (S_ISDIR(st.st_mode)) { + errno = EISDIR; + return NULL; + } + + /* + * Anything else, just open it and try to use it as + * a ref + */ + fd = open(path, O_RDONLY); + if (fd < 0) { + if (errno == ENOENT) + /* inconsistent with lstat; retry */ + goto stat_ref; + else + return NULL; + } + strbuf_reset(sb_contents); + if (strbuf_read(sb_contents, fd, 256) < 0) { + int save_errno = errno; + close(fd); + errno = save_errno; + return NULL; + } + close(fd); + strbuf_rtrim(sb_contents); + + /* + * Is it a symbolic ref? + */ + if (!starts_with(sb_contents->buf, "ref:")) { + /* + * Please note that FETCH_HEAD has a second + * line containing other data. + */ + if (get_sha1_hex(sb_contents->buf, sha1) || + (sb_contents->buf[40] != '\0' && !isspace(sb_contents->buf[40]))) { + if (flags) + *flags |= REF_ISBROKEN; + errno = EINVAL; + return NULL; + } + if (bad_name) { + hashclr(sha1); + if (flags) + *flags |= REF_ISBROKEN; + } + return refname; + } + if (flags) + *flags |= REF_ISSYMREF; + buf = sb_contents->buf + 4; + while (isspace(*buf)) + buf++; + strbuf_reset(sb_refname); + strbuf_addstr(sb_refname, buf); + refname = sb_refname->buf; + if (resolve_flags & RESOLVE_REF_NO_RECURSE) { + hashclr(sha1); + return refname; + } + if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) { + if (flags) + *flags |= REF_ISBROKEN; + + if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) || + !refname_is_safe(buf)) { + errno = EINVAL; + return NULL; + } + bad_name = 1; + } + } +} + +const char *resolve_ref_unsafe(const char *refname, int resolve_flags, + unsigned char *sha1, int *flags) +{ + static struct strbuf sb_refname = STRBUF_INIT; + struct strbuf sb_contents = STRBUF_INIT; + struct strbuf sb_path = STRBUF_INIT; + const char *ret; + + ret = resolve_ref_1(refname, resolve_flags, sha1, flags, + &sb_refname, &sb_path, &sb_contents); + strbuf_release(&sb_path); + strbuf_release(&sb_contents); + return ret; +} + +/* + * Peel the entry (if possible) and return its new peel_status. If + * repeel is true, re-peel the entry even if there is an old peeled + * value that is already stored in it. + * + * It is OK to call this function with a packed reference entry that + * might be stale and might even refer to an object that has since + * been garbage-collected. In such a case, if the entry has + * REF_KNOWS_PEELED then leave the status unchanged and return + * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID. + */ +static enum peel_status peel_entry(struct ref_entry *entry, int repeel) +{ + enum peel_status status; + + if (entry->flag & REF_KNOWS_PEELED) { + if (repeel) { + entry->flag &= ~REF_KNOWS_PEELED; + oidclr(&entry->u.value.peeled); + } else { + return is_null_oid(&entry->u.value.peeled) ? + PEEL_NON_TAG : PEEL_PEELED; + } + } + if (entry->flag & REF_ISBROKEN) + return PEEL_BROKEN; + if (entry->flag & REF_ISSYMREF) + return PEEL_IS_SYMREF; + + status = peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash); + if (status == PEEL_PEELED || status == PEEL_NON_TAG) + entry->flag |= REF_KNOWS_PEELED; + return status; +} + +int peel_ref(const char *refname, unsigned char *sha1) +{ + int flag; + unsigned char base[20]; + + if (current_ref && (current_ref->name == refname + || !strcmp(current_ref->name, refname))) { + if (peel_entry(current_ref, 0)) + return -1; + hashcpy(sha1, current_ref->u.value.peeled.hash); + return 0; + } + + if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag)) + return -1; + + /* + * If the reference is packed, read its ref_entry from the + * cache in the hope that we already know its peeled value. + * We only try this optimization on packed references because + * (a) forcing the filling of the loose reference cache could + * be expensive and (b) loose references anyway usually do not + * have REF_KNOWS_PEELED. + */ + if (flag & REF_ISPACKED) { + struct ref_entry *r = get_packed_ref(refname); + if (r) { + if (peel_entry(r, 0)) + return -1; + hashcpy(sha1, r->u.value.peeled.hash); + return 0; + } + } + + return peel_object(base, sha1); +} + +/* + * Call fn for each reference in the specified ref_cache, omitting + * references not in the containing_dir of base. fn is called for all + * references, including broken ones. If fn ever returns a non-zero + * value, stop the iteration and return that value; otherwise, return + * 0. + */ +static int do_for_each_entry(struct ref_cache *refs, const char *base, + each_ref_entry_fn fn, void *cb_data) +{ + struct packed_ref_cache *packed_ref_cache; + struct ref_dir *loose_dir; + struct ref_dir *packed_dir; + int retval = 0; + + /* + * We must make sure that all loose refs are read before accessing the + * packed-refs file; this avoids a race condition in which loose refs + * are migrated to the packed-refs file by a simultaneous process, but + * our in-memory view is from before the migration. get_packed_ref_cache() + * takes care of making sure our view is up to date with what is on + * disk. + */ + loose_dir = get_loose_refs(refs); + if (base && *base) { + loose_dir = find_containing_dir(loose_dir, base, 0); + } + if (loose_dir) + prime_ref_dir(loose_dir); + + packed_ref_cache = get_packed_ref_cache(refs); + acquire_packed_ref_cache(packed_ref_cache); + packed_dir = get_packed_ref_dir(packed_ref_cache); + if (base && *base) { + packed_dir = find_containing_dir(packed_dir, base, 0); + } + + if (packed_dir && loose_dir) { + sort_ref_dir(packed_dir); + sort_ref_dir(loose_dir); + retval = do_for_each_entry_in_dirs( + packed_dir, loose_dir, fn, cb_data); + } else if (packed_dir) { + sort_ref_dir(packed_dir); + retval = do_for_each_entry_in_dir( + packed_dir, 0, fn, cb_data); + } else if (loose_dir) { + sort_ref_dir(loose_dir); + retval = do_for_each_entry_in_dir( + loose_dir, 0, fn, cb_data); + } + + release_packed_ref_cache(packed_ref_cache); + return retval; +} + +/* + * Call fn for each reference in the specified ref_cache for which the + * refname begins with base. If trim is non-zero, then trim that many + * characters off the beginning of each refname before passing the + * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include + * broken references in the iteration. If fn ever returns a non-zero + * value, stop the iteration and return that value; otherwise, return + * 0. + */ +static int do_for_each_ref(struct ref_cache *refs, const char *base, + each_ref_fn fn, int trim, int flags, void *cb_data) +{ + struct ref_entry_cb data; + data.base = base; + data.trim = trim; + data.flags = flags; + data.fn = fn; + data.cb_data = cb_data; + + if (ref_paranoia < 0) + ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0); + if (ref_paranoia) + data.flags |= DO_FOR_EACH_INCLUDE_BROKEN; + + return do_for_each_entry(refs, base, do_one_ref, &data); +} + +static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data) +{ + struct object_id oid; + int flag; + + if (submodule) { + if (resolve_gitlink_ref(submodule, "HEAD", oid.hash) == 0) + return fn("HEAD", &oid, 0, cb_data); + + return 0; + } + + if (!read_ref_full("HEAD", RESOLVE_REF_READING, oid.hash, &flag)) + return fn("HEAD", &oid, flag, cb_data); + + return 0; +} + +int head_ref(each_ref_fn fn, void *cb_data) +{ + return do_head_ref(NULL, fn, cb_data); +} + +int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) +{ + return do_head_ref(submodule, fn, cb_data); +} + +int for_each_ref(each_ref_fn fn, void *cb_data) +{ + return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data); +} + +int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) +{ + return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data); +} + +int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data) +{ + return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data); +} + +int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken) +{ + unsigned int flag = 0; + + if (broken) + flag = DO_FOR_EACH_INCLUDE_BROKEN; + return do_for_each_ref(&ref_cache, prefix, fn, 0, flag, cb_data); +} + +int for_each_ref_in_submodule(const char *submodule, const char *prefix, + each_ref_fn fn, void *cb_data) +{ + return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data); +} + +int for_each_replace_ref(each_ref_fn fn, void *cb_data) +{ + return do_for_each_ref(&ref_cache, git_replace_ref_base, fn, + strlen(git_replace_ref_base), 0, cb_data); +} + +int for_each_namespaced_ref(each_ref_fn fn, void *cb_data) +{ + struct strbuf buf = STRBUF_INIT; + int ret; + strbuf_addf(&buf, "%srefs/", get_git_namespace()); + ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data); + strbuf_release(&buf); + return ret; +} + +int for_each_rawref(each_ref_fn fn, void *cb_data) +{ + return do_for_each_ref(&ref_cache, "", fn, 0, + DO_FOR_EACH_INCLUDE_BROKEN, cb_data); +} + +static void unlock_ref(struct ref_lock *lock) +{ + /* Do not free lock->lk -- atexit() still looks at them */ + if (lock->lk) + rollback_lock_file(lock->lk); + free(lock->ref_name); + free(lock->orig_ref_name); + free(lock); +} + +/* + * Verify that the reference locked by lock has the value old_sha1. + * Fail if the reference doesn't exist and mustexist is set. Return 0 + * on success. On error, write an error message to err, set errno, and + * return a negative value. + */ +static int verify_lock(struct ref_lock *lock, + const unsigned char *old_sha1, int mustexist, + struct strbuf *err) +{ + assert(err); + + if (read_ref_full(lock->ref_name, + mustexist ? RESOLVE_REF_READING : 0, + lock->old_oid.hash, NULL)) { + int save_errno = errno; + strbuf_addf(err, "can't verify ref %s", lock->ref_name); + errno = save_errno; + return -1; + } + if (hashcmp(lock->old_oid.hash, old_sha1)) { + strbuf_addf(err, "ref %s is at %s but expected %s", + lock->ref_name, + sha1_to_hex(lock->old_oid.hash), + sha1_to_hex(old_sha1)); + errno = EBUSY; + return -1; + } + return 0; +} + +static int remove_empty_directories(struct strbuf *path) +{ + /* + * we want to create a file but there is a directory there; + * if that is an empty directory (or a directory that contains + * only empty directories), remove them. + */ + return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY); +} + +/* + * Locks a ref returning the lock on success and NULL on failure. + * On failure errno is set to something meaningful. + */ +static struct ref_lock *lock_ref_sha1_basic(const char *refname, + const unsigned char *old_sha1, + const struct string_list *extras, + const struct string_list *skip, + unsigned int flags, int *type_p, + struct strbuf *err) +{ + struct strbuf ref_file = STRBUF_INIT; + struct strbuf orig_ref_file = STRBUF_INIT; + const char *orig_refname = refname; + struct ref_lock *lock; + int last_errno = 0; + int type, lflags; + int mustexist = (old_sha1 && !is_null_sha1(old_sha1)); + int resolve_flags = 0; + int attempts_remaining = 3; + + assert(err); + + lock = xcalloc(1, sizeof(struct ref_lock)); + + if (mustexist) + resolve_flags |= RESOLVE_REF_READING; + if (flags & REF_DELETING) { + resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME; + if (flags & REF_NODEREF) + resolve_flags |= RESOLVE_REF_NO_RECURSE; + } + + refname = resolve_ref_unsafe(refname, resolve_flags, + lock->old_oid.hash, &type); + if (!refname && errno == EISDIR) { + /* + * we are trying to lock foo but we used to + * have foo/bar which now does not exist; + * it is normal for the empty directory 'foo' + * to remain. + */ + strbuf_git_path(&orig_ref_file, "%s", orig_refname); + if (remove_empty_directories(&orig_ref_file)) { + last_errno = errno; + if (!verify_refname_available_dir(orig_refname, extras, skip, + get_loose_refs(&ref_cache), err)) + strbuf_addf(err, "there are still refs under '%s'", + orig_refname); + goto error_return; + } + refname = resolve_ref_unsafe(orig_refname, resolve_flags, + lock->old_oid.hash, &type); + } + if (type_p) + *type_p = type; + if (!refname) { + last_errno = errno; + if (last_errno != ENOTDIR || + !verify_refname_available_dir(orig_refname, extras, skip, + get_loose_refs(&ref_cache), err)) + strbuf_addf(err, "unable to resolve reference %s: %s", + orig_refname, strerror(last_errno)); + + goto error_return; + } + /* + * If the ref did not exist and we are creating it, make sure + * there is no existing packed ref whose name begins with our + * refname, nor a packed ref whose name is a proper prefix of + * our refname. + */ + if (is_null_oid(&lock->old_oid) && + verify_refname_available_dir(refname, extras, skip, + get_packed_refs(&ref_cache), err)) { + last_errno = ENOTDIR; + goto error_return; + } + + lock->lk = xcalloc(1, sizeof(struct lock_file)); + + lflags = 0; + if (flags & REF_NODEREF) { + refname = orig_refname; + lflags |= LOCK_NO_DEREF; + } + lock->ref_name = xstrdup(refname); + lock->orig_ref_name = xstrdup(orig_refname); + strbuf_git_path(&ref_file, "%s", refname); + + retry: + switch (safe_create_leading_directories_const(ref_file.buf)) { + case SCLD_OK: + break; /* success */ + case SCLD_VANISHED: + if (--attempts_remaining > 0) + goto retry; + /* fall through */ + default: + last_errno = errno; + strbuf_addf(err, "unable to create directory for %s", + ref_file.buf); + goto error_return; + } + + if (hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) < 0) { + last_errno = errno; + if (errno == ENOENT && --attempts_remaining > 0) + /* + * Maybe somebody just deleted one of the + * directories leading to ref_file. Try + * again: + */ + goto retry; + else { + unable_to_lock_message(ref_file.buf, errno, err); + goto error_return; + } + } + if (old_sha1 && verify_lock(lock, old_sha1, mustexist, err)) { + last_errno = errno; + goto error_return; + } + goto out; + + error_return: + unlock_ref(lock); + lock = NULL; + + out: + strbuf_release(&ref_file); + strbuf_release(&orig_ref_file); + errno = last_errno; + return lock; +} + +/* + * Write an entry to the packed-refs file for the specified refname. + * If peeled is non-NULL, write it as the entry's peeled value. + */ +static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1, + unsigned char *peeled) +{ + fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname); + if (peeled) + fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled)); +} + +/* + * An each_ref_entry_fn that writes the entry to a packed-refs file. + */ +static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data) +{ + enum peel_status peel_status = peel_entry(entry, 0); + + if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG) + error("internal error: %s is not a valid packed reference!", + entry->name); + write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash, + peel_status == PEEL_PEELED ? + entry->u.value.peeled.hash : NULL); + return 0; +} + +/* + * Lock the packed-refs file for writing. Flags is passed to + * hold_lock_file_for_update(). Return 0 on success. On errors, set + * errno appropriately and return a nonzero value. + */ +static int lock_packed_refs(int flags) +{ + static int timeout_configured = 0; + static int timeout_value = 1000; + + struct packed_ref_cache *packed_ref_cache; + + if (!timeout_configured) { + git_config_get_int("core.packedrefstimeout", &timeout_value); + timeout_configured = 1; + } + + if (hold_lock_file_for_update_timeout( + &packlock, git_path("packed-refs"), + flags, timeout_value) < 0) + return -1; + /* + * Get the current packed-refs while holding the lock. If the + * packed-refs file has been modified since we last read it, + * this will automatically invalidate the cache and re-read + * the packed-refs file. + */ + packed_ref_cache = get_packed_ref_cache(&ref_cache); + packed_ref_cache->lock = &packlock; + /* Increment the reference count to prevent it from being freed: */ + acquire_packed_ref_cache(packed_ref_cache); + return 0; +} + +/* + * Write the current version of the packed refs cache from memory to + * disk. The packed-refs file must already be locked for writing (see + * lock_packed_refs()). Return zero on success. On errors, set errno + * and return a nonzero value + */ +static int commit_packed_refs(void) +{ + struct packed_ref_cache *packed_ref_cache = + get_packed_ref_cache(&ref_cache); + int error = 0; + int save_errno = 0; + FILE *out; + + if (!packed_ref_cache->lock) + die("internal error: packed-refs not locked"); + + out = fdopen_lock_file(packed_ref_cache->lock, "w"); + if (!out) + die_errno("unable to fdopen packed-refs descriptor"); + + fprintf_or_die(out, "%s", PACKED_REFS_HEADER); + do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache), + 0, write_packed_entry_fn, out); + + if (commit_lock_file(packed_ref_cache->lock)) { + save_errno = errno; + error = -1; + } + packed_ref_cache->lock = NULL; + release_packed_ref_cache(packed_ref_cache); + errno = save_errno; + return error; +} + +/* + * Rollback the lockfile for the packed-refs file, and discard the + * in-memory packed reference cache. (The packed-refs file will be + * read anew if it is needed again after this function is called.) + */ +static void rollback_packed_refs(void) +{ + struct packed_ref_cache *packed_ref_cache = + get_packed_ref_cache(&ref_cache); + + if (!packed_ref_cache->lock) + die("internal error: packed-refs not locked"); + rollback_lock_file(packed_ref_cache->lock); + packed_ref_cache->lock = NULL; + release_packed_ref_cache(packed_ref_cache); + clear_packed_ref_cache(&ref_cache); +} + +struct ref_to_prune { + struct ref_to_prune *next; + unsigned char sha1[20]; + char name[FLEX_ARRAY]; +}; + +struct pack_refs_cb_data { + unsigned int flags; + struct ref_dir *packed_refs; + struct ref_to_prune *ref_to_prune; +}; + +/* + * An each_ref_entry_fn that is run over loose references only. If + * the loose reference can be packed, add an entry in the packed ref + * cache. If the reference should be pruned, also add it to + * ref_to_prune in the pack_refs_cb_data. + */ +static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data) +{ + struct pack_refs_cb_data *cb = cb_data; + enum peel_status peel_status; + struct ref_entry *packed_entry; + int is_tag_ref = starts_with(entry->name, "refs/tags/"); + + /* Do not pack per-worktree refs: */ + if (ref_type(entry->name) != REF_TYPE_NORMAL) + return 0; + + /* ALWAYS pack tags */ + if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref) + return 0; + + /* Do not pack symbolic or broken refs: */ + if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry)) + return 0; + + /* Add a packed ref cache entry equivalent to the loose entry. */ + peel_status = peel_entry(entry, 1); + if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG) + die("internal error peeling reference %s (%s)", + entry->name, oid_to_hex(&entry->u.value.oid)); + packed_entry = find_ref(cb->packed_refs, entry->name); + if (packed_entry) { + /* Overwrite existing packed entry with info from loose entry */ + packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED; + oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid); + } else { + packed_entry = create_ref_entry(entry->name, entry->u.value.oid.hash, + REF_ISPACKED | REF_KNOWS_PEELED, 0); + add_ref(cb->packed_refs, packed_entry); + } + oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled); + + /* Schedule the loose reference for pruning if requested. */ + if ((cb->flags & PACK_REFS_PRUNE)) { + int namelen = strlen(entry->name) + 1; + struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen); + hashcpy(n->sha1, entry->u.value.oid.hash); + memcpy(n->name, entry->name, namelen); /* includes NUL */ + n->next = cb->ref_to_prune; + cb->ref_to_prune = n; + } + return 0; +} + +/* + * Remove empty parents, but spare refs/ and immediate subdirs. + * Note: munges *name. + */ +static void try_remove_empty_parents(char *name) +{ + char *p, *q; + int i; + p = name; + for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */ + while (*p && *p != '/') + p++; + /* tolerate duplicate slashes; see check_refname_format() */ + while (*p == '/') + p++; + } + for (q = p; *q; q++) + ; + while (1) { + while (q > p && *q != '/') + q--; + while (q > p && *(q-1) == '/') + q--; + if (q == p) + break; + *q = '\0'; + if (rmdir(git_path("%s", name))) + break; + } +} + +/* make sure nobody touched the ref, and unlink */ +static void prune_ref(struct ref_to_prune *r) +{ + struct ref_transaction *transaction; + struct strbuf err = STRBUF_INIT; + + if (check_refname_format(r->name, 0)) + return; + + transaction = ref_transaction_begin(&err); + if (!transaction || + ref_transaction_delete(transaction, r->name, r->sha1, + REF_ISPRUNING, NULL, &err) || + ref_transaction_commit(transaction, &err)) { + ref_transaction_free(transaction); + error("%s", err.buf); + strbuf_release(&err); + return; + } + ref_transaction_free(transaction); + strbuf_release(&err); + try_remove_empty_parents(r->name); +} + +static void prune_refs(struct ref_to_prune *r) +{ + while (r) { + prune_ref(r); + r = r->next; + } +} + +int pack_refs(unsigned int flags) +{ + struct pack_refs_cb_data cbdata; + + memset(&cbdata, 0, sizeof(cbdata)); + cbdata.flags = flags; + + lock_packed_refs(LOCK_DIE_ON_ERROR); + cbdata.packed_refs = get_packed_refs(&ref_cache); + + do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0, + pack_if_possible_fn, &cbdata); + + if (commit_packed_refs()) + die_errno("unable to overwrite old ref-pack file"); + + prune_refs(cbdata.ref_to_prune); + return 0; +} + +/* + * Rewrite the packed-refs file, omitting any refs listed in + * 'refnames'. On error, leave packed-refs unchanged, write an error + * message to 'err', and return a nonzero value. + * + * The refs in 'refnames' needn't be sorted. `err` must not be NULL. + */ +static int repack_without_refs(struct string_list *refnames, struct strbuf *err) +{ + struct ref_dir *packed; + struct string_list_item *refname; + int ret, needs_repacking = 0, removed = 0; + + assert(err); + + /* Look for a packed ref */ + for_each_string_list_item(refname, refnames) { + if (get_packed_ref(refname->string)) { + needs_repacking = 1; + break; + } + } + + /* Avoid locking if we have nothing to do */ + if (!needs_repacking) + return 0; /* no refname exists in packed refs */ + + if (lock_packed_refs(0)) { + unable_to_lock_message(git_path("packed-refs"), errno, err); + return -1; + } + packed = get_packed_refs(&ref_cache); + + /* Remove refnames from the cache */ + for_each_string_list_item(refname, refnames) + if (remove_entry(packed, refname->string) != -1) + removed = 1; + if (!removed) { + /* + * All packed entries disappeared while we were + * acquiring the lock. + */ + rollback_packed_refs(); + return 0; + } + + /* Write what remains */ + ret = commit_packed_refs(); + if (ret) + strbuf_addf(err, "unable to overwrite old ref-pack file: %s", + strerror(errno)); + return ret; +} + +static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err) +{ + assert(err); + + if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) { + /* + * loose. The loose file name is the same as the + * lockfile name, minus ".lock": + */ + char *loose_filename = get_locked_file_path(lock->lk); + int res = unlink_or_msg(loose_filename, err); + free(loose_filename); + if (res) + return 1; + } + return 0; +} + +int delete_refs(struct string_list *refnames) +{ + struct strbuf err = STRBUF_INIT; + int i, result = 0; + + if (!refnames->nr) + return 0; + + result = repack_without_refs(refnames, &err); + if (result) { + /* + * If we failed to rewrite the packed-refs file, then + * it is unsafe to try to remove loose refs, because + * doing so might expose an obsolete packed value for + * a reference that might even point at an object that + * has been garbage collected. + */ + if (refnames->nr == 1) + error(_("could not delete reference %s: %s"), + refnames->items[0].string, err.buf); + else + error(_("could not delete references: %s"), err.buf); + + goto out; + } + + for (i = 0; i < refnames->nr; i++) { + const char *refname = refnames->items[i].string; + + if (delete_ref(refname, NULL, 0)) + result |= error(_("could not remove reference %s"), refname); + } + +out: + strbuf_release(&err); + return result; +} + +/* + * People using contrib's git-new-workdir have .git/logs/refs -> + * /some/other/path/.git/logs/refs, and that may live on another device. + * + * IOW, to avoid cross device rename errors, the temporary renamed log must + * live into logs/refs. + */ +#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log" + +static int rename_tmp_log(const char *newrefname) +{ + int attempts_remaining = 4; + struct strbuf path = STRBUF_INIT; + int ret = -1; + + retry: + strbuf_reset(&path); + strbuf_git_path(&path, "logs/%s", newrefname); + switch (safe_create_leading_directories_const(path.buf)) { + case SCLD_OK: + break; /* success */ + case SCLD_VANISHED: + if (--attempts_remaining > 0) + goto retry; + /* fall through */ + default: + error("unable to create directory for %s", newrefname); + goto out; + } + + if (rename(git_path(TMP_RENAMED_LOG), path.buf)) { + if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) { + /* + * rename(a, b) when b is an existing + * directory ought to result in ISDIR, but + * Solaris 5.8 gives ENOTDIR. Sheesh. + */ + if (remove_empty_directories(&path)) { + error("Directory not empty: logs/%s", newrefname); + goto out; + } + goto retry; + } else if (errno == ENOENT && --attempts_remaining > 0) { + /* + * Maybe another process just deleted one of + * the directories in the path to newrefname. + * Try again from the beginning. + */ + goto retry; + } else { + error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s", + newrefname, strerror(errno)); + goto out; + } + } + ret = 0; +out: + strbuf_release(&path); + return ret; +} + +int verify_refname_available(const char *newname, + struct string_list *extras, + struct string_list *skip, + struct strbuf *err) +{ + struct ref_dir *packed_refs = get_packed_refs(&ref_cache); + struct ref_dir *loose_refs = get_loose_refs(&ref_cache); + + if (verify_refname_available_dir(newname, extras, skip, + packed_refs, err) || + verify_refname_available_dir(newname, extras, skip, + loose_refs, err)) + return -1; + + return 0; +} + +static int rename_ref_available(const char *oldname, const char *newname) +{ + struct string_list skip = STRING_LIST_INIT_NODUP; + struct strbuf err = STRBUF_INIT; + int ret; + + string_list_insert(&skip, oldname); + ret = !verify_refname_available(newname, NULL, &skip, &err); + if (!ret) + error("%s", err.buf); + + string_list_clear(&skip, 0); + strbuf_release(&err); + return ret; +} + +static int write_ref_to_lockfile(struct ref_lock *lock, + const unsigned char *sha1, struct strbuf *err); +static int commit_ref_update(struct ref_lock *lock, + const unsigned char *sha1, const char *logmsg, + int flags, struct strbuf *err); + +int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg) +{ + unsigned char sha1[20], orig_sha1[20]; + int flag = 0, logmoved = 0; + struct ref_lock *lock; + struct stat loginfo; + int log = !lstat(git_path("logs/%s", oldrefname), &loginfo); + const char *symref = NULL; + struct strbuf err = STRBUF_INIT; + + if (log && S_ISLNK(loginfo.st_mode)) + return error("reflog for %s is a symlink", oldrefname); + + symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING, + orig_sha1, &flag); + if (flag & REF_ISSYMREF) + return error("refname %s is a symbolic ref, renaming it is not supported", + oldrefname); + if (!symref) + return error("refname %s not found", oldrefname); + + if (!rename_ref_available(oldrefname, newrefname)) + return 1; + + if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG))) + return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s", + oldrefname, strerror(errno)); + + if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) { + error("unable to delete old %s", oldrefname); + goto rollback; + } + + if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) && + delete_ref(newrefname, sha1, REF_NODEREF)) { + if (errno==EISDIR) { + struct strbuf path = STRBUF_INIT; + int result; + + strbuf_git_path(&path, "%s", newrefname); + result = remove_empty_directories(&path); + strbuf_release(&path); + + if (result) { + error("Directory not empty: %s", newrefname); + goto rollback; + } + } else { + error("unable to delete existing %s", newrefname); + goto rollback; + } + } + + if (log && rename_tmp_log(newrefname)) + goto rollback; + + logmoved = log; + + lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, 0, NULL, &err); + if (!lock) { + error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf); + strbuf_release(&err); + goto rollback; + } + hashcpy(lock->old_oid.hash, orig_sha1); + + if (write_ref_to_lockfile(lock, orig_sha1, &err) || + commit_ref_update(lock, orig_sha1, logmsg, 0, &err)) { + error("unable to write current sha1 into %s: %s", newrefname, err.buf); + strbuf_release(&err); + goto rollback; + } + + return 0; + + rollback: + lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, 0, NULL, &err); + if (!lock) { + error("unable to lock %s for rollback: %s", oldrefname, err.buf); + strbuf_release(&err); + goto rollbacklog; + } + + flag = log_all_ref_updates; + log_all_ref_updates = 0; + if (write_ref_to_lockfile(lock, orig_sha1, &err) || + commit_ref_update(lock, orig_sha1, NULL, 0, &err)) { + error("unable to write current sha1 into %s: %s", oldrefname, err.buf); + strbuf_release(&err); + } + log_all_ref_updates = flag; + + rollbacklog: + if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname))) + error("unable to restore logfile %s from %s: %s", + oldrefname, newrefname, strerror(errno)); + if (!logmoved && log && + rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname))) + error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s", + oldrefname, strerror(errno)); + + return 1; +} + +static int close_ref(struct ref_lock *lock) +{ + if (close_lock_file(lock->lk)) + return -1; + return 0; +} + +static int commit_ref(struct ref_lock *lock) +{ + if (commit_lock_file(lock->lk)) + return -1; + return 0; +} + +/* + * Create a reflog for a ref. If force_create = 0, the reflog will + * only be created for certain refs (those for which + * should_autocreate_reflog returns non-zero. Otherwise, create it + * regardless of the ref name. Fill in *err and return -1 on failure. + */ +static int log_ref_setup(const char *refname, struct strbuf *logfile, struct strbuf *err, int force_create) +{ + int logfd, oflags = O_APPEND | O_WRONLY; + + strbuf_git_path(logfile, "logs/%s", refname); + if (force_create || should_autocreate_reflog(refname)) { + if (safe_create_leading_directories(logfile->buf) < 0) { + strbuf_addf(err, "unable to create directory for %s: " + "%s", logfile->buf, strerror(errno)); + return -1; + } + oflags |= O_CREAT; + } + + logfd = open(logfile->buf, oflags, 0666); + if (logfd < 0) { + if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR)) + return 0; + + if (errno == EISDIR) { + if (remove_empty_directories(logfile)) { + strbuf_addf(err, "There are still logs under " + "'%s'", logfile->buf); + return -1; + } + logfd = open(logfile->buf, oflags, 0666); + } + + if (logfd < 0) { + strbuf_addf(err, "unable to append to %s: %s", + logfile->buf, strerror(errno)); + return -1; + } + } + + adjust_shared_perm(logfile->buf); + close(logfd); + return 0; +} + + +int safe_create_reflog(const char *refname, int force_create, struct strbuf *err) +{ + int ret; + struct strbuf sb = STRBUF_INIT; + + ret = log_ref_setup(refname, &sb, err, force_create); + strbuf_release(&sb); + return ret; +} + +static int log_ref_write_fd(int fd, const unsigned char *old_sha1, + const unsigned char *new_sha1, + const char *committer, const char *msg) +{ + int msglen, written; + unsigned maxlen, len; + char *logrec; + + msglen = msg ? strlen(msg) : 0; + maxlen = strlen(committer) + msglen + 100; + logrec = xmalloc(maxlen); + len = xsnprintf(logrec, maxlen, "%s %s %s\n", + sha1_to_hex(old_sha1), + sha1_to_hex(new_sha1), + committer); + if (msglen) + len += copy_reflog_msg(logrec + len - 1, msg) - 1; + + written = len <= maxlen ? write_in_full(fd, logrec, len) : -1; + free(logrec); + if (written != len) + return -1; + + return 0; +} + +static int log_ref_write_1(const char *refname, const unsigned char *old_sha1, + const unsigned char *new_sha1, const char *msg, + struct strbuf *logfile, int flags, + struct strbuf *err) +{ + int logfd, result, oflags = O_APPEND | O_WRONLY; + + if (log_all_ref_updates < 0) + log_all_ref_updates = !is_bare_repository(); + + result = log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG); + + if (result) + return result; + + logfd = open(logfile->buf, oflags); + if (logfd < 0) + return 0; + result = log_ref_write_fd(logfd, old_sha1, new_sha1, + git_committer_info(0), msg); + if (result) { + strbuf_addf(err, "unable to append to %s: %s", logfile->buf, + strerror(errno)); + close(logfd); + return -1; + } + if (close(logfd)) { + strbuf_addf(err, "unable to append to %s: %s", logfile->buf, + strerror(errno)); + return -1; + } + return 0; +} + +static int log_ref_write(const char *refname, const unsigned char *old_sha1, + const unsigned char *new_sha1, const char *msg, + int flags, struct strbuf *err) +{ + struct strbuf sb = STRBUF_INIT; + int ret = log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags, + err); + strbuf_release(&sb); + return ret; +} + +/* + * Write sha1 into the open lockfile, then close the lockfile. On + * errors, rollback the lockfile, fill in *err and + * return -1. + */ +static int write_ref_to_lockfile(struct ref_lock *lock, + const unsigned char *sha1, struct strbuf *err) +{ + static char term = '\n'; + struct object *o; + int fd; + + o = parse_object(sha1); + if (!o) { + strbuf_addf(err, + "Trying to write ref %s with nonexistent object %s", + lock->ref_name, sha1_to_hex(sha1)); + unlock_ref(lock); + return -1; + } + if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) { + strbuf_addf(err, + "Trying to write non-commit object %s to branch %s", + sha1_to_hex(sha1), lock->ref_name); + unlock_ref(lock); + return -1; + } + fd = get_lock_file_fd(lock->lk); + if (write_in_full(fd, sha1_to_hex(sha1), 40) != 40 || + write_in_full(fd, &term, 1) != 1 || + close_ref(lock) < 0) { + strbuf_addf(err, + "Couldn't write %s", get_lock_file_path(lock->lk)); + unlock_ref(lock); + return -1; + } + return 0; +} + +/* + * Commit a change to a loose reference that has already been written + * to the loose reference lockfile. Also update the reflogs if + * necessary, using the specified lockmsg (which can be NULL). + */ +static int commit_ref_update(struct ref_lock *lock, + const unsigned char *sha1, const char *logmsg, + int flags, struct strbuf *err) +{ + clear_loose_ref_cache(&ref_cache); + if (log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, flags, err) < 0 || + (strcmp(lock->ref_name, lock->orig_ref_name) && + log_ref_write(lock->orig_ref_name, lock->old_oid.hash, sha1, logmsg, flags, err) < 0)) { + char *old_msg = strbuf_detach(err, NULL); + strbuf_addf(err, "Cannot update the ref '%s': %s", + lock->ref_name, old_msg); + free(old_msg); + unlock_ref(lock); + return -1; + } + if (strcmp(lock->orig_ref_name, "HEAD") != 0) { + /* + * Special hack: If a branch is updated directly and HEAD + * points to it (may happen on the remote side of a push + * for example) then logically the HEAD reflog should be + * updated too. + * A generic solution implies reverse symref information, + * but finding all symrefs pointing to the given branch + * would be rather costly for this rare event (the direct + * update of a branch) to be worth it. So let's cheat and + * check with HEAD only which should cover 99% of all usage + * scenarios (even 100% of the default ones). + */ + unsigned char head_sha1[20]; + int head_flag; + const char *head_ref; + head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, + head_sha1, &head_flag); + if (head_ref && (head_flag & REF_ISSYMREF) && + !strcmp(head_ref, lock->ref_name)) { + struct strbuf log_err = STRBUF_INIT; + if (log_ref_write("HEAD", lock->old_oid.hash, sha1, + logmsg, 0, &log_err)) { + error("%s", log_err.buf); + strbuf_release(&log_err); + } + } + } + if (commit_ref(lock)) { + error("Couldn't set %s", lock->ref_name); + unlock_ref(lock); + return -1; + } + + unlock_ref(lock); + return 0; +} + +int create_symref(const char *ref_target, const char *refs_heads_master, + const char *logmsg) +{ + char *lockpath = NULL; + char ref[1000]; + int fd, len, written; + char *git_HEAD = git_pathdup("%s", ref_target); + unsigned char old_sha1[20], new_sha1[20]; + struct strbuf err = STRBUF_INIT; + + if (logmsg && read_ref(ref_target, old_sha1)) + hashclr(old_sha1); + + if (safe_create_leading_directories(git_HEAD) < 0) + return error("unable to create directory for %s", git_HEAD); + +#ifndef NO_SYMLINK_HEAD + if (prefer_symlink_refs) { + unlink(git_HEAD); + if (!symlink(refs_heads_master, git_HEAD)) + goto done; + fprintf(stderr, "no symlink - falling back to symbolic ref\n"); + } +#endif + + len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master); + if (sizeof(ref) <= len) { + error("refname too long: %s", refs_heads_master); + goto error_free_return; + } + lockpath = mkpathdup("%s.lock", git_HEAD); + fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666); + if (fd < 0) { + error("Unable to open %s for writing", lockpath); + goto error_free_return; + } + written = write_in_full(fd, ref, len); + if (close(fd) != 0 || written != len) { + error("Unable to write to %s", lockpath); + goto error_unlink_return; + } + if (rename(lockpath, git_HEAD) < 0) { + error("Unable to create %s", git_HEAD); + goto error_unlink_return; + } + if (adjust_shared_perm(git_HEAD)) { + error("Unable to fix permissions on %s", lockpath); + error_unlink_return: + unlink_or_warn(lockpath); + error_free_return: + free(lockpath); + free(git_HEAD); + return -1; + } + free(lockpath); + +#ifndef NO_SYMLINK_HEAD + done: +#endif + if (logmsg && !read_ref(refs_heads_master, new_sha1) && + log_ref_write(ref_target, old_sha1, new_sha1, logmsg, 0, &err)) { + error("%s", err.buf); + strbuf_release(&err); + } + + free(git_HEAD); + return 0; +} + +int reflog_exists(const char *refname) +{ + struct stat st; + + return !lstat(git_path("logs/%s", refname), &st) && + S_ISREG(st.st_mode); +} + +int delete_reflog(const char *refname) +{ + return remove_path(git_path("logs/%s", refname)); +} + +static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data) +{ + unsigned char osha1[20], nsha1[20]; + char *email_end, *message; + unsigned long timestamp; + int tz; + + /* old SP new SP name SP time TAB msg LF */ + if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' || + get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' || + get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' || + !(email_end = strchr(sb->buf + 82, '>')) || + email_end[1] != ' ' || + !(timestamp = strtoul(email_end + 2, &message, 10)) || + !message || message[0] != ' ' || + (message[1] != '+' && message[1] != '-') || + !isdigit(message[2]) || !isdigit(message[3]) || + !isdigit(message[4]) || !isdigit(message[5])) + return 0; /* corrupt? */ + email_end[1] = '\0'; + tz = strtol(message + 1, NULL, 10); + if (message[6] != '\t') + message += 6; + else + message += 7; + return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data); +} + +static char *find_beginning_of_line(char *bob, char *scan) +{ + while (bob < scan && *(--scan) != '\n') + ; /* keep scanning backwards */ + /* + * Return either beginning of the buffer, or LF at the end of + * the previous line. + */ + return scan; +} + +int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data) +{ + struct strbuf sb = STRBUF_INIT; + FILE *logfp; + long pos; + int ret = 0, at_tail = 1; + + logfp = fopen(git_path("logs/%s", refname), "r"); + if (!logfp) + return -1; + + /* Jump to the end */ + if (fseek(logfp, 0, SEEK_END) < 0) + return error("cannot seek back reflog for %s: %s", + refname, strerror(errno)); + pos = ftell(logfp); + while (!ret && 0 < pos) { + int cnt; + size_t nread; + char buf[BUFSIZ]; + char *endp, *scanp; + + /* Fill next block from the end */ + cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos; + if (fseek(logfp, pos - cnt, SEEK_SET)) + return error("cannot seek back reflog for %s: %s", + refname, strerror(errno)); + nread = fread(buf, cnt, 1, logfp); + if (nread != 1) + return error("cannot read %d bytes from reflog for %s: %s", + cnt, refname, strerror(errno)); + pos -= cnt; + + scanp = endp = buf + cnt; + if (at_tail && scanp[-1] == '\n') + /* Looking at the final LF at the end of the file */ + scanp--; + at_tail = 0; + + while (buf < scanp) { + /* + * terminating LF of the previous line, or the beginning + * of the buffer. + */ + char *bp; + + bp = find_beginning_of_line(buf, scanp); + + if (*bp == '\n') { + /* + * The newline is the end of the previous line, + * so we know we have complete line starting + * at (bp + 1). Prefix it onto any prior data + * we collected for the line and process it. + */ + strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1)); + scanp = bp; + endp = bp + 1; + ret = show_one_reflog_ent(&sb, fn, cb_data); + strbuf_reset(&sb); + if (ret) + break; + } else if (!pos) { + /* + * We are at the start of the buffer, and the + * start of the file; there is no previous + * line, and we have everything for this one. + * Process it, and we can end the loop. + */ + strbuf_splice(&sb, 0, 0, buf, endp - buf); + ret = show_one_reflog_ent(&sb, fn, cb_data); + strbuf_reset(&sb); + break; + } + + if (bp == buf) { + /* + * We are at the start of the buffer, and there + * is more file to read backwards. Which means + * we are in the middle of a line. Note that we + * may get here even if *bp was a newline; that + * just means we are at the exact end of the + * previous line, rather than some spot in the + * middle. + * + * Save away what we have to be combined with + * the data from the next read. + */ + strbuf_splice(&sb, 0, 0, buf, endp - buf); + break; + } + } + + } + if (!ret && sb.len) + die("BUG: reverse reflog parser had leftover data"); + + fclose(logfp); + strbuf_release(&sb); + return ret; +} + +int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data) +{ + FILE *logfp; + struct strbuf sb = STRBUF_INIT; + int ret = 0; + + logfp = fopen(git_path("logs/%s", refname), "r"); + if (!logfp) + return -1; + + while (!ret && !strbuf_getwholeline(&sb, logfp, '\n')) + ret = show_one_reflog_ent(&sb, fn, cb_data); + fclose(logfp); + strbuf_release(&sb); + return ret; +} +/* + * Call fn for each reflog in the namespace indicated by name. name + * must be empty or end with '/'. Name will be used as a scratch + * space, but its contents will be restored before return. + */ +static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data) +{ + DIR *d = opendir(git_path("logs/%s", name->buf)); + int retval = 0; + struct dirent *de; + int oldlen = name->len; + + if (!d) + return name->len ? errno : 0; + + while ((de = readdir(d)) != NULL) { + struct stat st; + + if (de->d_name[0] == '.') + continue; + if (ends_with(de->d_name, ".lock")) + continue; + strbuf_addstr(name, de->d_name); + if (stat(git_path("logs/%s", name->buf), &st) < 0) { + ; /* silently ignore */ + } else { + if (S_ISDIR(st.st_mode)) { + strbuf_addch(name, '/'); + retval = do_for_each_reflog(name, fn, cb_data); + } else { + struct object_id oid; + + if (read_ref_full(name->buf, 0, oid.hash, NULL)) + retval = error("bad ref for %s", name->buf); + else + retval = fn(name->buf, &oid, 0, cb_data); + } + if (retval) + break; + } + strbuf_setlen(name, oldlen); + } + closedir(d); + return retval; +} + +int for_each_reflog(each_ref_fn fn, void *cb_data) +{ + int retval; + struct strbuf name; + strbuf_init(&name, PATH_MAX); + retval = do_for_each_reflog(&name, fn, cb_data); + strbuf_release(&name); + return retval; +} + +static int ref_update_reject_duplicates(struct string_list *refnames, + struct strbuf *err) +{ + int i, n = refnames->nr; + + assert(err); + + for (i = 1; i < n; i++) + if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) { + strbuf_addf(err, + "Multiple updates for ref '%s' not allowed.", + refnames->items[i].string); + return 1; + } + return 0; +} + +int ref_transaction_commit(struct ref_transaction *transaction, + struct strbuf *err) +{ + int ret = 0, i; + int n = transaction->nr; + struct ref_update **updates = transaction->updates; + struct string_list refs_to_delete = STRING_LIST_INIT_NODUP; + struct string_list_item *ref_to_delete; + struct string_list affected_refnames = STRING_LIST_INIT_NODUP; + + assert(err); + + if (transaction->state != REF_TRANSACTION_OPEN) + die("BUG: commit called for transaction that is not open"); + + if (!n) { + transaction->state = REF_TRANSACTION_CLOSED; + return 0; + } + + /* Fail if a refname appears more than once in the transaction: */ + for (i = 0; i < n; i++) + string_list_append(&affected_refnames, updates[i]->refname); + string_list_sort(&affected_refnames); + if (ref_update_reject_duplicates(&affected_refnames, err)) { + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } + + /* + * Acquire all locks, verify old values if provided, check + * that new values are valid, and write new values to the + * lockfiles, ready to be activated. Only keep one lockfile + * open at a time to avoid running out of file descriptors. + */ + for (i = 0; i < n; i++) { + struct ref_update *update = updates[i]; + + if ((update->flags & REF_HAVE_NEW) && + is_null_sha1(update->new_sha1)) + update->flags |= REF_DELETING; + update->lock = lock_ref_sha1_basic( + update->refname, + ((update->flags & REF_HAVE_OLD) ? + update->old_sha1 : NULL), + &affected_refnames, NULL, + update->flags, + &update->type, + err); + if (!update->lock) { + char *reason; + + ret = (errno == ENOTDIR) + ? TRANSACTION_NAME_CONFLICT + : TRANSACTION_GENERIC_ERROR; + reason = strbuf_detach(err, NULL); + strbuf_addf(err, "cannot lock ref '%s': %s", + update->refname, reason); + free(reason); + goto cleanup; + } + if ((update->flags & REF_HAVE_NEW) && + !(update->flags & REF_DELETING)) { + int overwriting_symref = ((update->type & REF_ISSYMREF) && + (update->flags & REF_NODEREF)); + + if (!overwriting_symref && + !hashcmp(update->lock->old_oid.hash, update->new_sha1)) { + /* + * The reference already has the desired + * value, so we don't need to write it. + */ + } else if (write_ref_to_lockfile(update->lock, + update->new_sha1, + err)) { + char *write_err = strbuf_detach(err, NULL); + + /* + * The lock was freed upon failure of + * write_ref_to_lockfile(): + */ + update->lock = NULL; + strbuf_addf(err, + "cannot update the ref '%s': %s", + update->refname, write_err); + free(write_err); + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } else { + update->flags |= REF_NEEDS_COMMIT; + } + } + if (!(update->flags & REF_NEEDS_COMMIT)) { + /* + * We didn't have to write anything to the lockfile. + * Close it to free up the file descriptor: + */ + if (close_ref(update->lock)) { + strbuf_addf(err, "Couldn't close %s.lock", + update->refname); + goto cleanup; + } + } + } + + /* Perform updates first so live commits remain referenced */ + for (i = 0; i < n; i++) { + struct ref_update *update = updates[i]; + + if (update->flags & REF_NEEDS_COMMIT) { + if (commit_ref_update(update->lock, + update->new_sha1, update->msg, + update->flags, err)) { + /* freed by commit_ref_update(): */ + update->lock = NULL; + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } else { + /* freed by commit_ref_update(): */ + update->lock = NULL; + } + } + } + + /* Perform deletes now that updates are safely completed */ + for (i = 0; i < n; i++) { + struct ref_update *update = updates[i]; + + if (update->flags & REF_DELETING) { + if (delete_ref_loose(update->lock, update->type, err)) { + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } + + if (!(update->flags & REF_ISPRUNING)) + string_list_append(&refs_to_delete, + update->lock->ref_name); + } + } + + if (repack_without_refs(&refs_to_delete, err)) { + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } + for_each_string_list_item(ref_to_delete, &refs_to_delete) + unlink_or_warn(git_path("logs/%s", ref_to_delete->string)); + clear_loose_ref_cache(&ref_cache); + +cleanup: + transaction->state = REF_TRANSACTION_CLOSED; + + for (i = 0; i < n; i++) + if (updates[i]->lock) + unlock_ref(updates[i]->lock); + string_list_clear(&refs_to_delete, 0); + string_list_clear(&affected_refnames, 0); + return ret; +} + +static int ref_present(const char *refname, + const struct object_id *oid, int flags, void *cb_data) +{ + struct string_list *affected_refnames = cb_data; + + return string_list_has_string(affected_refnames, refname); +} + +int initial_ref_transaction_commit(struct ref_transaction *transaction, + struct strbuf *err) +{ + int ret = 0, i; + int n = transaction->nr; + struct ref_update **updates = transaction->updates; + struct string_list affected_refnames = STRING_LIST_INIT_NODUP; + + assert(err); + + if (transaction->state != REF_TRANSACTION_OPEN) + die("BUG: commit called for transaction that is not open"); + + /* Fail if a refname appears more than once in the transaction: */ + for (i = 0; i < n; i++) + string_list_append(&affected_refnames, updates[i]->refname); + string_list_sort(&affected_refnames); + if (ref_update_reject_duplicates(&affected_refnames, err)) { + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } + + /* + * It's really undefined to call this function in an active + * repository or when there are existing references: we are + * only locking and changing packed-refs, so (1) any + * simultaneous processes might try to change a reference at + * the same time we do, and (2) any existing loose versions of + * the references that we are setting would have precedence + * over our values. But some remote helpers create the remote + * "HEAD" and "master" branches before calling this function, + * so here we really only check that none of the references + * that we are creating already exists. + */ + if (for_each_rawref(ref_present, &affected_refnames)) + die("BUG: initial ref transaction called with existing refs"); + + for (i = 0; i < n; i++) { + struct ref_update *update = updates[i]; + + if ((update->flags & REF_HAVE_OLD) && + !is_null_sha1(update->old_sha1)) + die("BUG: initial ref transaction with old_sha1 set"); + if (verify_refname_available(update->refname, + &affected_refnames, NULL, + err)) { + ret = TRANSACTION_NAME_CONFLICT; + goto cleanup; + } + } + + if (lock_packed_refs(0)) { + strbuf_addf(err, "unable to lock packed-refs file: %s", + strerror(errno)); + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } + + for (i = 0; i < n; i++) { + struct ref_update *update = updates[i]; + + if ((update->flags & REF_HAVE_NEW) && + !is_null_sha1(update->new_sha1)) + add_packed_ref(update->refname, update->new_sha1); + } + + if (commit_packed_refs()) { + strbuf_addf(err, "unable to commit packed-refs file: %s", + strerror(errno)); + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } + +cleanup: + transaction->state = REF_TRANSACTION_CLOSED; + string_list_clear(&affected_refnames, 0); + return ret; +} + +struct expire_reflog_cb { + unsigned int flags; + reflog_expiry_should_prune_fn *should_prune_fn; + void *policy_cb; + FILE *newlog; + unsigned char last_kept_sha1[20]; +}; + +static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1, + const char *email, unsigned long timestamp, int tz, + const char *message, void *cb_data) +{ + struct expire_reflog_cb *cb = cb_data; + struct expire_reflog_policy_cb *policy_cb = cb->policy_cb; + + if (cb->flags & EXPIRE_REFLOGS_REWRITE) + osha1 = cb->last_kept_sha1; + + if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz, + message, policy_cb)) { + if (!cb->newlog) + printf("would prune %s", message); + else if (cb->flags & EXPIRE_REFLOGS_VERBOSE) + printf("prune %s", message); + } else { + if (cb->newlog) { + fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s", + sha1_to_hex(osha1), sha1_to_hex(nsha1), + email, timestamp, tz, message); + hashcpy(cb->last_kept_sha1, nsha1); + } + if (cb->flags & EXPIRE_REFLOGS_VERBOSE) + printf("keep %s", message); + } + return 0; +} + +int reflog_expire(const char *refname, const unsigned char *sha1, + unsigned int flags, + reflog_expiry_prepare_fn prepare_fn, + reflog_expiry_should_prune_fn should_prune_fn, + reflog_expiry_cleanup_fn cleanup_fn, + void *policy_cb_data) +{ + static struct lock_file reflog_lock; + struct expire_reflog_cb cb; + struct ref_lock *lock; + char *log_file; + int status = 0; + int type; + struct strbuf err = STRBUF_INIT; + + memset(&cb, 0, sizeof(cb)); + cb.flags = flags; + cb.policy_cb = policy_cb_data; + cb.should_prune_fn = should_prune_fn; + + /* + * The reflog file is locked by holding the lock on the + * reference itself, plus we might need to update the + * reference if --updateref was specified: + */ + lock = lock_ref_sha1_basic(refname, sha1, NULL, NULL, 0, &type, &err); + if (!lock) { + error("cannot lock ref '%s': %s", refname, err.buf); + strbuf_release(&err); + return -1; + } + if (!reflog_exists(refname)) { + unlock_ref(lock); + return 0; + } + + log_file = git_pathdup("logs/%s", refname); + if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) { + /* + * Even though holding $GIT_DIR/logs/$reflog.lock has + * no locking implications, we use the lock_file + * machinery here anyway because it does a lot of the + * work we need, including cleaning up if the program + * exits unexpectedly. + */ + if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) { + struct strbuf err = STRBUF_INIT; + unable_to_lock_message(log_file, errno, &err); + error("%s", err.buf); + strbuf_release(&err); + goto failure; + } + cb.newlog = fdopen_lock_file(&reflog_lock, "w"); + if (!cb.newlog) { + error("cannot fdopen %s (%s)", + get_lock_file_path(&reflog_lock), strerror(errno)); + goto failure; + } + } + + (*prepare_fn)(refname, sha1, cb.policy_cb); + for_each_reflog_ent(refname, expire_reflog_ent, &cb); + (*cleanup_fn)(cb.policy_cb); + + if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) { + /* + * It doesn't make sense to adjust a reference pointed + * to by a symbolic ref based on expiring entries in + * the symbolic reference's reflog. Nor can we update + * a reference if there are no remaining reflog + * entries. + */ + int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) && + !(type & REF_ISSYMREF) && + !is_null_sha1(cb.last_kept_sha1); + + if (close_lock_file(&reflog_lock)) { + status |= error("couldn't write %s: %s", log_file, + strerror(errno)); + } else if (update && + (write_in_full(get_lock_file_fd(lock->lk), + sha1_to_hex(cb.last_kept_sha1), 40) != 40 || + write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 || + close_ref(lock) < 0)) { + status |= error("couldn't write %s", + get_lock_file_path(lock->lk)); + rollback_lock_file(&reflog_lock); + } else if (commit_lock_file(&reflog_lock)) { + status |= error("unable to commit reflog '%s' (%s)", + log_file, strerror(errno)); + } else if (update && commit_ref(lock)) { + status |= error("couldn't set %s", lock->ref_name); + } + } + free(log_file); + unlock_ref(lock); + return status; + + failure: + rollback_lock_file(&reflog_lock); + free(log_file); + unlock_ref(lock); + return -1; +} -- cgit v1.2.3 From eb33876c262bec79a127b82a3a853ad00665d894 Mon Sep 17 00:00:00 2001 From: David Turner Date: Tue, 10 Nov 2015 12:42:38 +0100 Subject: initdb: make safe_create_dir public Soon we will want to create initdb functions for ref backends, and code from initdb that calls this function needs to move into the files backend. So this function needs to be public. Signed-off-by: David Turner Signed-off-by: Junio C Hamano Signed-off-by: Michael Haggerty Signed-off-by: Jeff King --- builtin/init-db.c | 12 ------------ cache.h | 8 ++++++++ path.c | 12 ++++++++++++ 3 files changed, 20 insertions(+), 12 deletions(-) diff --git a/builtin/init-db.c b/builtin/init-db.c index f59f40768e..07229d60f1 100644 --- a/builtin/init-db.c +++ b/builtin/init-db.c @@ -24,18 +24,6 @@ static int init_shared_repository = -1; static const char *init_db_template_dir; static const char *git_link; -static void safe_create_dir(const char *dir, int share) -{ - if (mkdir(dir, 0777) < 0) { - if (errno != EEXIST) { - perror(dir); - exit(1); - } - } - else if (share && adjust_shared_perm(dir)) - die(_("Could not make %s writable by group"), dir); -} - static void copy_templates_1(struct strbuf *path, struct strbuf *template, DIR *dir) { diff --git a/cache.h b/cache.h index 3ba0b8f3d7..4e13ddb193 100644 --- a/cache.h +++ b/cache.h @@ -1747,4 +1747,12 @@ void stat_validity_update(struct stat_validity *sv, int fd); int versioncmp(const char *s1, const char *s2); void sleep_millisec(int millisec); +/* + * Create a directory and (if share is nonzero) adjust its permissions + * according to the shared_repository setting. Only use this for + * directories under $GIT_DIR. Don't use it for working tree + * directories. + */ +void safe_create_dir(const char *dir, int share); + #endif /* CACHE_H */ diff --git a/path.c b/path.c index c740c4ff94..9d1ab1f69e 100644 --- a/path.c +++ b/path.c @@ -740,6 +740,18 @@ int adjust_shared_perm(const char *path) return 0; } +void safe_create_dir(const char *dir, int share) +{ + if (mkdir(dir, 0777) < 0) { + if (errno != EEXIST) { + perror(dir); + exit(1); + } + } + else if (share && adjust_shared_perm(dir)) + die(_("Could not make %s writable by group"), dir); +} + static int have_same_root(const char *path1, const char *path2) { int is_abs1, is_abs2; -- cgit v1.2.3 From 5f3c3a4e6f11dedad93d9f5bb2caa85c684db54a Mon Sep 17 00:00:00 2001 From: David Turner Date: Tue, 10 Nov 2015 12:42:39 +0100 Subject: files_log_ref_write: new function Because HEAD and stash are per-worktree, every refs backend needs to go through the files backend to write these refs. So create a new function, files_log_ref_write, and add it to refs/refs-internal.h. Later, we will use this to handle reflog updates for per-worktree symbolic refs (HEAD). Signed-off-by: David Turner Signed-off-by: Junio C Hamano Signed-off-by: Michael Haggerty Signed-off-by: Jeff King --- refs/files-backend.c | 8 ++++++++ refs/refs-internal.h | 4 ++++ 2 files changed, 12 insertions(+) diff --git a/refs/files-backend.c b/refs/files-backend.c index 14ec506c17..aaf263956c 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -2733,6 +2733,14 @@ static int log_ref_write_1(const char *refname, const unsigned char *old_sha1, static int log_ref_write(const char *refname, const unsigned char *old_sha1, const unsigned char *new_sha1, const char *msg, int flags, struct strbuf *err) +{ + return files_log_ref_write(refname, old_sha1, new_sha1, msg, flags, + err); +} + +int files_log_ref_write(const char *refname, const unsigned char *old_sha1, + const unsigned char *new_sha1, const char *msg, + int flags, struct strbuf *err) { struct strbuf sb = STRBUF_INIT; int ret = log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags, diff --git a/refs/refs-internal.h b/refs/refs-internal.h index 9077c114d0..7b6c8bcb74 100644 --- a/refs/refs-internal.h +++ b/refs/refs-internal.h @@ -177,4 +177,8 @@ struct ref_transaction { enum ref_transaction_state state; }; +int files_log_ref_write(const char *refname, const unsigned char *old_sha1, + const unsigned char *new_sha1, const char *msg, + int flags, struct strbuf *err); + #endif /* REFS_REFS_INTERNAL_H */ -- cgit v1.2.3 From 0845122c39c415fa50904ee94c6b60e4e722466b Mon Sep 17 00:00:00 2001 From: David Turner Date: Tue, 10 Nov 2015 12:42:40 +0100 Subject: refs: break out ref conflict checks Create new function find_descendant_ref, to hold one of the ref conflict checks used in verify_refname_available. Multiple backends will need this function, so move it to the common code. Also move rename_ref_available to the common code, because alternate backends might need it and it has no files-backend-specific code. Signed-off-by: David Turner Signed-off-by: Junio C Hamano Signed-off-by: Michael Haggerty Signed-off-by: Jeff King --- refs.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ refs/files-backend.c | 49 +++++++------------------------------------------ refs/refs-internal.h | 16 ++++++++++++++++ 3 files changed, 67 insertions(+), 42 deletions(-) diff --git a/refs.c b/refs.c index 1620a53c48..ad883ec4d9 100644 --- a/refs.c +++ b/refs.c @@ -1029,3 +1029,47 @@ int ref_is_hidden(const char *refname) } return 0; } + +const char *find_descendant_ref(const char *dirname, + const struct string_list *extras, + const struct string_list *skip) +{ + int pos; + + if (!extras) + return NULL; + + /* + * Look at the place where dirname would be inserted into + * extras. If there is an entry at that position that starts + * with dirname (remember, dirname includes the trailing + * slash) and is not in skip, then we have a conflict. + */ + for (pos = string_list_find_insert_index(extras, dirname, 0); + pos < extras->nr; pos++) { + const char *extra_refname = extras->items[pos].string; + + if (!starts_with(extra_refname, dirname)) + break; + + if (!skip || !string_list_has_string(skip, extra_refname)) + return extra_refname; + } + return NULL; +} + +int rename_ref_available(const char *oldname, const char *newname) +{ + struct string_list skip = STRING_LIST_INIT_NODUP; + struct strbuf err = STRBUF_INIT; + int ret; + + string_list_insert(&skip, oldname); + ret = !verify_refname_available(newname, NULL, &skip, &err); + if (!ret) + error("%s", err.buf); + + string_list_clear(&skip, 0); + strbuf_release(&err); + return ret; +} diff --git a/refs/files-backend.c b/refs/files-backend.c index aaf263956c..4db3e36f89 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -728,6 +728,7 @@ static int verify_refname_available_dir(const char *refname, struct strbuf *err) { const char *slash; + const char *extra_refname; int pos; struct strbuf dirname = STRBUF_INIT; int ret = -1; @@ -833,32 +834,12 @@ static int verify_refname_available_dir(const char *refname, } } - if (extras) { - /* - * Check for entries in extras that start with - * "$refname/". We do that by looking for the place - * where "$refname/" would be inserted in extras. If - * there is an entry at that position that starts with - * "$refname/" and is not in skip, then we have a - * conflict. - */ - for (pos = string_list_find_insert_index(extras, dirname.buf, 0); - pos < extras->nr; pos++) { - const char *extra_refname = extras->items[pos].string; - - if (!starts_with(extra_refname, dirname.buf)) - break; - - if (!skip || !string_list_has_string(skip, extra_refname)) { - strbuf_addf(err, "cannot process '%s' and '%s' at the same time", - refname, extra_refname); - goto cleanup; - } - } - } - - /* No conflicts were found */ - ret = 0; + extra_refname = find_descendant_ref(dirname.buf, extras, skip); + if (extra_refname) + strbuf_addf(err, "cannot process '%s' and '%s' at the same time", + refname, extra_refname); + else + ret = 0; cleanup: strbuf_release(&dirname); @@ -2473,22 +2454,6 @@ int verify_refname_available(const char *newname, return 0; } -static int rename_ref_available(const char *oldname, const char *newname) -{ - struct string_list skip = STRING_LIST_INIT_NODUP; - struct strbuf err = STRBUF_INIT; - int ret; - - string_list_insert(&skip, oldname); - ret = !verify_refname_available(newname, NULL, &skip, &err); - if (!ret) - error("%s", err.buf); - - string_list_clear(&skip, 0); - strbuf_release(&err); - return ret; -} - static int write_ref_to_lockfile(struct ref_lock *lock, const unsigned char *sha1, struct strbuf *err); static int commit_ref_update(struct ref_lock *lock, diff --git a/refs/refs-internal.h b/refs/refs-internal.h index 7b6c8bcb74..c7dded35f4 100644 --- a/refs/refs-internal.h +++ b/refs/refs-internal.h @@ -181,4 +181,20 @@ int files_log_ref_write(const char *refname, const unsigned char *old_sha1, const unsigned char *new_sha1, const char *msg, int flags, struct strbuf *err); +/* + * Check for entries in extras that are within the specified + * directory, where dirname is a reference directory name including + * the trailing slash (e.g., "refs/heads/foo/"). Ignore any + * conflicting references that are found in skip. If there is a + * conflicting reference, return its name. + * + * extras and skip must be sorted lists of reference names. Either one + * can be NULL, signifying the empty list. + */ +const char *find_descendant_ref(const char *dirname, + const struct string_list *extras, + const struct string_list *skip); + +int rename_ref_available(const char *oldname, const char *newname); + #endif /* REFS_REFS_INTERNAL_H */ -- cgit v1.2.3