diff options
Diffstat (limited to 'refs/packed-backend.c')
| -rw-r--r-- | refs/packed-backend.c | 1045 |
1 files changed, 1045 insertions, 0 deletions
diff --git a/refs/packed-backend.c b/refs/packed-backend.c new file mode 100644 index 0000000000..3bc47ffd5e --- /dev/null +++ b/refs/packed-backend.c @@ -0,0 +1,1045 @@ +#include "../cache.h" +#include "../config.h" +#include "../refs.h" +#include "refs-internal.h" +#include "ref-cache.h" +#include "packed-backend.h" +#include "../iterator.h" +#include "../lockfile.h" + +struct packed_ref_cache { + struct ref_cache *cache; + + /* + * Count of references to the data structure in this instance, + * including the pointer from files_ref_store::packed if any. + * The data will not be freed as long as the reference count + * is nonzero. + */ + unsigned int referrers; + + /* The metadata from when this packed-refs cache was read */ + struct stat_validity validity; +}; + +/* + * 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_cache(packed_refs->cache); + stat_validity_clear(&packed_refs->validity); + free(packed_refs); + return 1; + } else { + return 0; + } +} + +/* + * A container for `packed-refs`-related data. It is not (yet) a + * `ref_store`. + */ +struct packed_ref_store { + struct ref_store base; + + unsigned int store_flags; + + /* The path of the "packed-refs" file: */ + char *path; + + /* + * A cache of the values read from the `packed-refs` file, if + * it might still be current; otherwise, NULL. + */ + struct packed_ref_cache *cache; + + /* + * Lock used for the "packed-refs" file. Note that this (and + * thus the enclosing `packed_ref_store`) must not be freed. + */ + struct lock_file lock; + + /* + * Temporary file used when rewriting new contents to the + * "packed-refs" file. Note that this (and thus the enclosing + * `packed_ref_store`) must not be freed. + */ + struct tempfile *tempfile; +}; + +struct ref_store *packed_ref_store_create(const char *path, + unsigned int store_flags) +{ + struct packed_ref_store *refs = xcalloc(1, sizeof(*refs)); + struct ref_store *ref_store = (struct ref_store *)refs; + + base_ref_store_init(ref_store, &refs_be_packed); + refs->store_flags = store_flags; + + refs->path = xstrdup(path); + return ref_store; +} + +/* + * Downcast `ref_store` to `packed_ref_store`. Die if `ref_store` is + * not a `packed_ref_store`. Also die if `packed_ref_store` doesn't + * support at least the flags specified in `required_flags`. `caller` + * is used in any necessary error messages. + */ +static struct packed_ref_store *packed_downcast(struct ref_store *ref_store, + unsigned int required_flags, + const char *caller) +{ + struct packed_ref_store *refs; + + if (ref_store->be != &refs_be_packed) + die("BUG: ref_store is type \"%s\" not \"packed\" in %s", + ref_store->be->name, caller); + + refs = (struct packed_ref_store *)ref_store; + + if ((refs->store_flags & required_flags) != required_flags) + die("BUG: unallowed operation (%s), requires %x, has %x\n", + caller, required_flags, refs->store_flags); + + return refs; +} + +static void clear_packed_ref_cache(struct packed_ref_store *refs) +{ + if (refs->cache) { + struct packed_ref_cache *cache = refs->cache; + + refs->cache = NULL; + release_packed_ref_cache(cache); + } +} + +/* The length of a peeled reference line in packed-refs, including EOL: */ +#define PEELED_LINE_LENGTH 42 + +/* + * 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, struct object_id *oid) +{ + const char *ref; + + if (parse_oid_hex(line->buf, oid, &ref) < 0) + return NULL; + if (!isspace(*ref++)) + return NULL; + + if (isspace(*ref)) + return NULL; + + if (line->buf[line->len - 1] != '\n') + return NULL; + line->buf[--line->len] = 0; + + return ref; +} + +/* + * Read from `packed_refs_file` into a newly-allocated + * `packed_ref_cache` and return it. The return value will already + * have its reference count incremented. + * + * 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 struct packed_ref_cache *read_packed_refs(const char *packed_refs_file) +{ + FILE *f; + struct packed_ref_cache *packed_refs = xcalloc(1, sizeof(*packed_refs)); + struct ref_entry *last = NULL; + struct strbuf line = STRBUF_INIT; + enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; + struct ref_dir *dir; + + acquire_packed_ref_cache(packed_refs); + packed_refs->cache = create_ref_cache(NULL, NULL); + packed_refs->cache->root->flag &= ~REF_INCOMPLETE; + + f = fopen(packed_refs_file, "r"); + if (!f) { + if (errno == ENOENT) { + /* + * This is OK; it just means that no + * "packed-refs" file has been written yet, + * which is equivalent to it being empty. + */ + return packed_refs; + } else { + die_errno("couldn't read %s", packed_refs_file); + } + } + + stat_validity_update(&packed_refs->validity, fileno(f)); + + dir = get_ref_dir(packed_refs->cache->root); + while (strbuf_getwholeline(&line, f, '\n') != EOF) { + struct object_id oid; + const char *refname; + const char *traits; + + if (!line.len || line.buf[line.len - 1] != '\n') + die("unterminated line in %s: %s", packed_refs_file, line.buf); + + 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, &oid); + 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); + oidclr(&oid); + flag |= REF_BAD_NAME | REF_ISBROKEN; + } + last = create_ref_entry(refname, &oid, flag); + if (peeled == PEELED_FULLY || + (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/"))) + last->flag |= REF_KNOWS_PEELED; + add_ref_entry(dir, last); + } else if (last && + line.buf[0] == '^' && + line.len == PEELED_LINE_LENGTH && + line.buf[PEELED_LINE_LENGTH - 1] == '\n' && + !get_oid_hex(line.buf + 1, &oid)) { + oidcpy(&last->u.value.peeled, &oid); + /* + * Regardless of what the file header said, + * we definitely know the value of *this* + * reference: + */ + last->flag |= REF_KNOWS_PEELED; + } else { + strbuf_setlen(&line, line.len - 1); + die("unexpected line in %s: %s", packed_refs_file, line.buf); + } + } + + fclose(f); + strbuf_release(&line); + + return packed_refs; +} + +/* + * Check that the packed refs cache (if any) still reflects the + * contents of the file. If not, clear the cache. + */ +static void validate_packed_ref_cache(struct packed_ref_store *refs) +{ + if (refs->cache && + !stat_validity_check(&refs->cache->validity, refs->path)) + clear_packed_ref_cache(refs); +} + +/* + * Get the packed_ref_cache for the specified packed_ref_store, + * creating and populating it if it hasn't been read before or if the + * file has been changed (according to its `validity` field) since it + * was last read. On the other hand, if we hold the lock, then assume + * that the file hasn't been changed out from under us, so skip the + * extra `stat()` call in `stat_validity_check()`. + */ +static struct packed_ref_cache *get_packed_ref_cache(struct packed_ref_store *refs) +{ + if (!is_lock_file_locked(&refs->lock)) + validate_packed_ref_cache(refs); + + if (!refs->cache) + refs->cache = read_packed_refs(refs->path); + + return refs->cache; +} + +static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache) +{ + return get_ref_dir(packed_ref_cache->cache->root); +} + +static struct ref_dir *get_packed_refs(struct packed_ref_store *refs) +{ + return get_packed_ref_dir(get_packed_ref_cache(refs)); +} + +/* + * 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(struct packed_ref_store *refs, + const char *refname) +{ + return find_ref_entry(get_packed_refs(refs), refname); +} + +static int packed_read_raw_ref(struct ref_store *ref_store, + const char *refname, unsigned char *sha1, + struct strbuf *referent, unsigned int *type) +{ + struct packed_ref_store *refs = + packed_downcast(ref_store, REF_STORE_READ, "read_raw_ref"); + + struct ref_entry *entry; + + *type = 0; + + entry = get_packed_ref(refs, refname); + if (!entry) { + errno = ENOENT; + return -1; + } + + hashcpy(sha1, entry->u.value.oid.hash); + *type = REF_ISPACKED; + return 0; +} + +static int packed_peel_ref(struct ref_store *ref_store, + const char *refname, unsigned char *sha1) +{ + struct packed_ref_store *refs = + packed_downcast(ref_store, REF_STORE_READ | REF_STORE_ODB, + "peel_ref"); + struct ref_entry *r = get_packed_ref(refs, refname); + + if (!r || peel_entry(r, 0)) + return -1; + + hashcpy(sha1, r->u.value.peeled.hash); + return 0; +} + +struct packed_ref_iterator { + struct ref_iterator base; + + struct packed_ref_cache *cache; + struct ref_iterator *iter0; + unsigned int flags; +}; + +static int packed_ref_iterator_advance(struct ref_iterator *ref_iterator) +{ + struct packed_ref_iterator *iter = + (struct packed_ref_iterator *)ref_iterator; + int ok; + + while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) { + if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY && + ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE) + continue; + + if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) && + !ref_resolves_to_object(iter->iter0->refname, + iter->iter0->oid, + iter->iter0->flags)) + continue; + + iter->base.refname = iter->iter0->refname; + iter->base.oid = iter->iter0->oid; + iter->base.flags = iter->iter0->flags; + return ITER_OK; + } + + iter->iter0 = NULL; + if (ref_iterator_abort(ref_iterator) != ITER_DONE) + ok = ITER_ERROR; + + return ok; +} + +static int packed_ref_iterator_peel(struct ref_iterator *ref_iterator, + struct object_id *peeled) +{ + struct packed_ref_iterator *iter = + (struct packed_ref_iterator *)ref_iterator; + + return ref_iterator_peel(iter->iter0, peeled); +} + +static int packed_ref_iterator_abort(struct ref_iterator *ref_iterator) +{ + struct packed_ref_iterator *iter = + (struct packed_ref_iterator *)ref_iterator; + int ok = ITER_DONE; + + if (iter->iter0) + ok = ref_iterator_abort(iter->iter0); + + release_packed_ref_cache(iter->cache); + base_ref_iterator_free(ref_iterator); + return ok; +} + +static struct ref_iterator_vtable packed_ref_iterator_vtable = { + packed_ref_iterator_advance, + packed_ref_iterator_peel, + packed_ref_iterator_abort +}; + +static struct ref_iterator *packed_ref_iterator_begin( + struct ref_store *ref_store, + const char *prefix, unsigned int flags) +{ + struct packed_ref_store *refs; + struct packed_ref_iterator *iter; + struct ref_iterator *ref_iterator; + unsigned int required_flags = REF_STORE_READ; + + if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) + required_flags |= REF_STORE_ODB; + refs = packed_downcast(ref_store, required_flags, "ref_iterator_begin"); + + iter = xcalloc(1, sizeof(*iter)); + ref_iterator = &iter->base; + base_ref_iterator_init(ref_iterator, &packed_ref_iterator_vtable); + + /* + * Note that get_packed_ref_cache() internally checks whether + * the packed-ref cache is up to date with what is on disk, + * and re-reads it if not. + */ + + iter->cache = get_packed_ref_cache(refs); + acquire_packed_ref_cache(iter->cache); + iter->iter0 = cache_ref_iterator_begin(iter->cache->cache, prefix, 0); + + iter->flags = flags; + + return ref_iterator; +} + +/* + * 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. On + * error, return a nonzero value and leave errno set at the value left + * by the failing call to `fprintf()`. + */ +static int write_packed_entry(FILE *fh, const char *refname, + const unsigned char *sha1, + const unsigned char *peeled) +{ + if (fprintf(fh, "%s %s\n", sha1_to_hex(sha1), refname) < 0 || + (peeled && fprintf(fh, "^%s\n", sha1_to_hex(peeled)) < 0)) + return -1; + + return 0; +} + +int packed_refs_lock(struct ref_store *ref_store, int flags, struct strbuf *err) +{ + struct packed_ref_store *refs = + packed_downcast(ref_store, REF_STORE_WRITE | REF_STORE_MAIN, + "packed_refs_lock"); + static int timeout_configured = 0; + static int timeout_value = 1000; + + if (!timeout_configured) { + git_config_get_int("core.packedrefstimeout", &timeout_value); + timeout_configured = 1; + } + + /* + * Note that we close the lockfile immediately because we + * don't write new content to it, but rather to a separate + * tempfile. + */ + if (hold_lock_file_for_update_timeout( + &refs->lock, + refs->path, + flags, timeout_value) < 0) { + unable_to_lock_message(refs->path, errno, err); + return -1; + } + + if (close_lock_file_gently(&refs->lock)) { + strbuf_addf(err, "unable to close %s: %s", refs->path, strerror(errno)); + rollback_lock_file(&refs->lock); + return -1; + } + + /* + * Now that we hold the `packed-refs` lock, make sure that our + * cache matches the current version of the file. Normally + * `get_packed_ref_cache()` does that for us, but that + * function assumes that when the file is locked, any existing + * cache is still valid. We've just locked the file, but it + * might have changed the moment *before* we locked it. + */ + validate_packed_ref_cache(refs); + + /* + * Now make sure that the packed-refs file as it exists in the + * locked state is loaded into the cache: + */ + get_packed_ref_cache(refs); + return 0; +} + +void packed_refs_unlock(struct ref_store *ref_store) +{ + struct packed_ref_store *refs = packed_downcast( + ref_store, + REF_STORE_READ | REF_STORE_WRITE, + "packed_refs_unlock"); + + if (!is_lock_file_locked(&refs->lock)) + die("BUG: packed_refs_unlock() called when not locked"); + rollback_lock_file(&refs->lock); +} + +int packed_refs_is_locked(struct ref_store *ref_store) +{ + struct packed_ref_store *refs = packed_downcast( + ref_store, + REF_STORE_READ | REF_STORE_WRITE, + "packed_refs_is_locked"); + + return is_lock_file_locked(&refs->lock); +} + +/* + * 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"; + +static int packed_init_db(struct ref_store *ref_store, struct strbuf *err) +{ + /* Nothing to do. */ + return 0; +} + +/* + * Write the packed-refs from the cache to the packed-refs tempfile, + * incorporating any changes from `updates`. `updates` must be a + * sorted string list whose keys are the refnames and whose util + * values are `struct ref_update *`. On error, rollback the tempfile, + * write an error message to `err`, and return a nonzero value. + * + * The packfile must be locked before calling this function and will + * remain locked when it is done. + */ +static int write_with_updates(struct packed_ref_store *refs, + struct string_list *updates, + struct strbuf *err) +{ + struct ref_iterator *iter = NULL; + size_t i; + int ok; + FILE *out; + struct strbuf sb = STRBUF_INIT; + char *packed_refs_path; + + if (!is_lock_file_locked(&refs->lock)) + die("BUG: write_with_updates() called while unlocked"); + + /* + * If packed-refs is a symlink, we want to overwrite the + * symlinked-to file, not the symlink itself. Also, put the + * staging file next to it: + */ + packed_refs_path = get_locked_file_path(&refs->lock); + strbuf_addf(&sb, "%s.new", packed_refs_path); + free(packed_refs_path); + refs->tempfile = create_tempfile(sb.buf); + if (!refs->tempfile) { + strbuf_addf(err, "unable to create file %s: %s", + sb.buf, strerror(errno)); + strbuf_release(&sb); + return -1; + } + strbuf_release(&sb); + + out = fdopen_tempfile(refs->tempfile, "w"); + if (!out) { + strbuf_addf(err, "unable to fdopen packed-refs tempfile: %s", + strerror(errno)); + goto error; + } + + if (fprintf(out, "%s", PACKED_REFS_HEADER) < 0) + goto write_error; + + /* + * We iterate in parallel through the current list of refs and + * the list of updates, processing an entry from at least one + * of the lists each time through the loop. When the current + * list of refs is exhausted, set iter to NULL. When the list + * of updates is exhausted, leave i set to updates->nr. + */ + iter = packed_ref_iterator_begin(&refs->base, "", + DO_FOR_EACH_INCLUDE_BROKEN); + if ((ok = ref_iterator_advance(iter)) != ITER_OK) + iter = NULL; + + i = 0; + + while (iter || i < updates->nr) { + struct ref_update *update = NULL; + int cmp; + + if (i >= updates->nr) { + cmp = -1; + } else { + update = updates->items[i].util; + + if (!iter) + cmp = +1; + else + cmp = strcmp(iter->refname, update->refname); + } + + if (!cmp) { + /* + * There is both an old value and an update + * for this reference. Check the old value if + * necessary: + */ + if ((update->flags & REF_HAVE_OLD)) { + if (is_null_oid(&update->old_oid)) { + strbuf_addf(err, "cannot update ref '%s': " + "reference already exists", + update->refname); + goto error; + } else if (oidcmp(&update->old_oid, iter->oid)) { + strbuf_addf(err, "cannot update ref '%s': " + "is at %s but expected %s", + update->refname, + oid_to_hex(iter->oid), + oid_to_hex(&update->old_oid)); + goto error; + } + } + + /* Now figure out what to use for the new value: */ + if ((update->flags & REF_HAVE_NEW)) { + /* + * The update takes precedence. Skip + * the iterator over the unneeded + * value. + */ + if ((ok = ref_iterator_advance(iter)) != ITER_OK) + iter = NULL; + cmp = +1; + } else { + /* + * The update doesn't actually want to + * change anything. We're done with it. + */ + i++; + cmp = -1; + } + } else if (cmp > 0) { + /* + * There is no old value but there is an + * update for this reference. Make sure that + * the update didn't expect an existing value: + */ + if ((update->flags & REF_HAVE_OLD) && + !is_null_oid(&update->old_oid)) { + strbuf_addf(err, "cannot update ref '%s': " + "reference is missing but expected %s", + update->refname, + oid_to_hex(&update->old_oid)); + goto error; + } + } + + if (cmp < 0) { + /* Pass the old reference through. */ + + struct object_id peeled; + int peel_error = ref_iterator_peel(iter, &peeled); + + if (write_packed_entry(out, iter->refname, + iter->oid->hash, + peel_error ? NULL : peeled.hash)) + goto write_error; + + if ((ok = ref_iterator_advance(iter)) != ITER_OK) + iter = NULL; + } else if (is_null_oid(&update->new_oid)) { + /* + * The update wants to delete the reference, + * and the reference either didn't exist or we + * have already skipped it. So we're done with + * the update (and don't have to write + * anything). + */ + i++; + } else { + struct object_id peeled; + int peel_error = peel_object(update->new_oid.hash, + peeled.hash); + + if (write_packed_entry(out, update->refname, + update->new_oid.hash, + peel_error ? NULL : peeled.hash)) + goto write_error; + + i++; + } + } + + if (ok != ITER_DONE) { + strbuf_addf(err, "unable to write packed-refs file: " + "error iterating over old contents"); + goto error; + } + + if (close_tempfile_gently(refs->tempfile)) { + strbuf_addf(err, "error closing file %s: %s", + get_tempfile_path(refs->tempfile), + strerror(errno)); + strbuf_release(&sb); + delete_tempfile(&refs->tempfile); + return -1; + } + + return 0; + +write_error: + strbuf_addf(err, "error writing to %s: %s", + get_tempfile_path(refs->tempfile), strerror(errno)); + +error: + if (iter) + ref_iterator_abort(iter); + + delete_tempfile(&refs->tempfile); + return -1; +} + +struct packed_transaction_backend_data { + /* True iff the transaction owns the packed-refs lock. */ + int own_lock; + + struct string_list updates; +}; + +static void packed_transaction_cleanup(struct packed_ref_store *refs, + struct ref_transaction *transaction) +{ + struct packed_transaction_backend_data *data = transaction->backend_data; + + if (data) { + string_list_clear(&data->updates, 0); + + if (is_tempfile_active(refs->tempfile)) + delete_tempfile(&refs->tempfile); + + if (data->own_lock && is_lock_file_locked(&refs->lock)) { + packed_refs_unlock(&refs->base); + data->own_lock = 0; + } + + free(data); + transaction->backend_data = NULL; + } + + transaction->state = REF_TRANSACTION_CLOSED; +} + +static int packed_transaction_prepare(struct ref_store *ref_store, + struct ref_transaction *transaction, + struct strbuf *err) +{ + struct packed_ref_store *refs = packed_downcast( + ref_store, + REF_STORE_READ | REF_STORE_WRITE | REF_STORE_ODB, + "ref_transaction_prepare"); + struct packed_transaction_backend_data *data; + size_t i; + int ret = TRANSACTION_GENERIC_ERROR; + + /* + * Note that we *don't* skip transactions with zero updates, + * because such a transaction might be executed for the side + * effect of ensuring that all of the references are peeled. + * If the caller wants to optimize away empty transactions, it + * should do so itself. + */ + + data = xcalloc(1, sizeof(*data)); + string_list_init(&data->updates, 0); + + transaction->backend_data = data; + + /* + * Stick the updates in a string list by refname so that we + * can sort them: + */ + for (i = 0; i < transaction->nr; i++) { + struct ref_update *update = transaction->updates[i]; + struct string_list_item *item = + string_list_append(&data->updates, update->refname); + + /* Store a pointer to update in item->util: */ + item->util = update; + } + string_list_sort(&data->updates); + + if (ref_update_reject_duplicates(&data->updates, err)) + goto failure; + + if (!is_lock_file_locked(&refs->lock)) { + if (packed_refs_lock(ref_store, 0, err)) + goto failure; + data->own_lock = 1; + } + + if (write_with_updates(refs, &data->updates, err)) + goto failure; + + transaction->state = REF_TRANSACTION_PREPARED; + return 0; + +failure: + packed_transaction_cleanup(refs, transaction); + return ret; +} + +static int packed_transaction_abort(struct ref_store *ref_store, + struct ref_transaction *transaction, + struct strbuf *err) +{ + struct packed_ref_store *refs = packed_downcast( + ref_store, + REF_STORE_READ | REF_STORE_WRITE | REF_STORE_ODB, + "ref_transaction_abort"); + + packed_transaction_cleanup(refs, transaction); + return 0; +} + +static int packed_transaction_finish(struct ref_store *ref_store, + struct ref_transaction *transaction, + struct strbuf *err) +{ + struct packed_ref_store *refs = packed_downcast( + ref_store, + REF_STORE_READ | REF_STORE_WRITE | REF_STORE_ODB, + "ref_transaction_finish"); + int ret = TRANSACTION_GENERIC_ERROR; + char *packed_refs_path; + + packed_refs_path = get_locked_file_path(&refs->lock); + if (rename_tempfile(&refs->tempfile, packed_refs_path)) { + strbuf_addf(err, "error replacing %s: %s", + refs->path, strerror(errno)); + goto cleanup; + } + + clear_packed_ref_cache(refs); + ret = 0; + +cleanup: + free(packed_refs_path); + packed_transaction_cleanup(refs, transaction); + return ret; +} + +static int packed_initial_transaction_commit(struct ref_store *ref_store, + struct ref_transaction *transaction, + struct strbuf *err) +{ + return ref_transaction_commit(transaction, err); +} + +static int packed_delete_refs(struct ref_store *ref_store, const char *msg, + struct string_list *refnames, unsigned int flags) +{ + struct packed_ref_store *refs = + packed_downcast(ref_store, REF_STORE_WRITE, "delete_refs"); + struct strbuf err = STRBUF_INIT; + struct ref_transaction *transaction; + struct string_list_item *item; + int ret; + + (void)refs; /* We need the check above, but don't use the variable */ + + if (!refnames->nr) + return 0; + + /* + * Since we don't check the references' old_oids, the + * individual updates can't fail, so we can pack all of the + * updates into a single transaction. + */ + + transaction = ref_store_transaction_begin(ref_store, &err); + if (!transaction) + return -1; + + for_each_string_list_item(item, refnames) { + if (ref_transaction_delete(transaction, item->string, NULL, + flags, msg, &err)) { + warning(_("could not delete reference %s: %s"), + item->string, err.buf); + strbuf_reset(&err); + } + } + + ret = ref_transaction_commit(transaction, &err); + + if (ret) { + 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); + } + + ref_transaction_free(transaction); + strbuf_release(&err); + return ret; +} + +static int packed_pack_refs(struct ref_store *ref_store, unsigned int flags) +{ + /* + * Packed refs are already packed. It might be that loose refs + * are packed *into* a packed refs store, but that is done by + * updating the packed references via a transaction. + */ + return 0; +} + +static int packed_create_symref(struct ref_store *ref_store, + const char *refname, const char *target, + const char *logmsg) +{ + die("BUG: packed reference store does not support symrefs"); +} + +static int packed_rename_ref(struct ref_store *ref_store, + const char *oldrefname, const char *newrefname, + const char *logmsg) +{ + die("BUG: packed reference store does not support renaming references"); +} + +static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_store) +{ + return empty_ref_iterator_begin(); +} + +static int packed_for_each_reflog_ent(struct ref_store *ref_store, + const char *refname, + each_reflog_ent_fn fn, void *cb_data) +{ + return 0; +} + +static int packed_for_each_reflog_ent_reverse(struct ref_store *ref_store, + const char *refname, + each_reflog_ent_fn fn, + void *cb_data) +{ + return 0; +} + +static int packed_reflog_exists(struct ref_store *ref_store, + const char *refname) +{ + return 0; +} + +static int packed_create_reflog(struct ref_store *ref_store, + const char *refname, int force_create, + struct strbuf *err) +{ + die("BUG: packed reference store does not support reflogs"); +} + +static int packed_delete_reflog(struct ref_store *ref_store, + const char *refname) +{ + return 0; +} + +static int packed_reflog_expire(struct ref_store *ref_store, + 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) +{ + return 0; +} + +struct ref_storage_be refs_be_packed = { + NULL, + "packed", + packed_ref_store_create, + packed_init_db, + packed_transaction_prepare, + packed_transaction_finish, + packed_transaction_abort, + packed_initial_transaction_commit, + + packed_pack_refs, + packed_peel_ref, + packed_create_symref, + packed_delete_refs, + packed_rename_ref, + + packed_ref_iterator_begin, + packed_read_raw_ref, + + packed_reflog_iterator_begin, + packed_for_each_reflog_ent, + packed_for_each_reflog_ent_reverse, + packed_reflog_exists, + packed_create_reflog, + packed_delete_reflog, + packed_reflog_expire +}; |