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-rw-r--r--refs.c1427
1 files changed, 1427 insertions, 0 deletions
diff --git a/refs.c b/refs.c
new file mode 100644
index 0000000000..89876bff87
--- /dev/null
+++ b/refs.c
@@ -0,0 +1,1427 @@
+#include "cache.h"
+#include "refs.h"
+#include "object.h"
+#include "tag.h"
+
+/* ISSYMREF=01 and ISPACKED=02 are public interfaces */
+#define REF_KNOWS_PEELED 04
+
+struct ref_list {
+ struct ref_list *next;
+ unsigned char flag; /* ISSYMREF? ISPACKED? */
+ unsigned char sha1[20];
+ unsigned char peeled[20];
+ char name[FLEX_ARRAY];
+};
+
+static const char *parse_ref_line(char *line, unsigned char *sha1)
+{
+ /*
+ * 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)
+ */
+ int len = strlen(line) - 42;
+
+ if (len <= 0)
+ return NULL;
+ if (get_sha1_hex(line, sha1) < 0)
+ return NULL;
+ if (!isspace(line[40]))
+ return NULL;
+ line += 41;
+ if (isspace(*line))
+ return NULL;
+ if (line[len] != '\n')
+ return NULL;
+ line[len] = 0;
+
+ return line;
+}
+
+static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
+ int flag, struct ref_list *list,
+ struct ref_list **new_entry)
+{
+ int len;
+ struct ref_list *entry;
+
+ /* Allocate it and add it in.. */
+ len = strlen(name) + 1;
+ entry = xmalloc(sizeof(struct ref_list) + len);
+ hashcpy(entry->sha1, sha1);
+ hashclr(entry->peeled);
+ memcpy(entry->name, name, len);
+ entry->flag = flag;
+ entry->next = list;
+ if (new_entry)
+ *new_entry = entry;
+ return entry;
+}
+
+/* merge sort the ref list */
+static struct ref_list *sort_ref_list(struct ref_list *list)
+{
+ int psize, qsize, last_merge_count, cmp;
+ struct ref_list *p, *q, *l, *e;
+ struct ref_list *new_list = list;
+ int k = 1;
+ int merge_count = 0;
+
+ if (!list)
+ return list;
+
+ do {
+ last_merge_count = merge_count;
+ merge_count = 0;
+
+ psize = 0;
+
+ p = new_list;
+ q = new_list;
+ new_list = NULL;
+ l = NULL;
+
+ while (p) {
+ merge_count++;
+
+ while (psize < k && q->next) {
+ q = q->next;
+ psize++;
+ }
+ qsize = k;
+
+ while ((psize > 0) || (qsize > 0 && q)) {
+ if (qsize == 0 || !q) {
+ e = p;
+ p = p->next;
+ psize--;
+ } else if (psize == 0) {
+ e = q;
+ q = q->next;
+ qsize--;
+ } else {
+ cmp = strcmp(q->name, p->name);
+ if (cmp < 0) {
+ e = q;
+ q = q->next;
+ qsize--;
+ } else if (cmp > 0) {
+ e = p;
+ p = p->next;
+ psize--;
+ } else {
+ if (hashcmp(q->sha1, p->sha1))
+ die("Duplicated ref, and SHA1s don't match: %s",
+ q->name);
+ warning("Duplicated ref: %s", q->name);
+ e = q;
+ q = q->next;
+ qsize--;
+ free(e);
+ e = p;
+ p = p->next;
+ psize--;
+ }
+ }
+
+ e->next = NULL;
+
+ if (l)
+ l->next = e;
+ if (!new_list)
+ new_list = e;
+ l = e;
+ }
+
+ p = q;
+ };
+
+ k = k * 2;
+ } while ((last_merge_count != merge_count) || (last_merge_count != 1));
+
+ return new_list;
+}
+
+/*
+ * Future: need to be in "struct repository"
+ * when doing a full libification.
+ */
+struct cached_refs {
+ char did_loose;
+ char did_packed;
+ struct ref_list *loose;
+ struct ref_list *packed;
+} cached_refs;
+
+static void free_ref_list(struct ref_list *list)
+{
+ struct ref_list *next;
+ for ( ; list; list = next) {
+ next = list->next;
+ free(list);
+ }
+}
+
+static void invalidate_cached_refs(void)
+{
+ struct cached_refs *ca = &cached_refs;
+
+ if (ca->did_loose && ca->loose)
+ free_ref_list(ca->loose);
+ if (ca->did_packed && ca->packed)
+ free_ref_list(ca->packed);
+ ca->loose = ca->packed = NULL;
+ ca->did_loose = ca->did_packed = 0;
+}
+
+static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
+{
+ struct ref_list *list = NULL;
+ struct ref_list *last = NULL;
+ char refline[PATH_MAX];
+ int flag = REF_ISPACKED;
+
+ while (fgets(refline, sizeof(refline), f)) {
+ unsigned char sha1[20];
+ const char *name;
+ static const char header[] = "# pack-refs with:";
+
+ if (!strncmp(refline, header, sizeof(header)-1)) {
+ const char *traits = refline + sizeof(header) - 1;
+ if (strstr(traits, " peeled "))
+ flag |= REF_KNOWS_PEELED;
+ /* perhaps other traits later as well */
+ continue;
+ }
+
+ name = parse_ref_line(refline, sha1);
+ if (name) {
+ list = add_ref(name, sha1, flag, list, &last);
+ continue;
+ }
+ if (last &&
+ refline[0] == '^' &&
+ strlen(refline) == 42 &&
+ refline[41] == '\n' &&
+ !get_sha1_hex(refline + 1, sha1))
+ hashcpy(last->peeled, sha1);
+ }
+ cached_refs->packed = sort_ref_list(list);
+}
+
+static struct ref_list *get_packed_refs(void)
+{
+ if (!cached_refs.did_packed) {
+ FILE *f = fopen(git_path("packed-refs"), "r");
+ cached_refs.packed = NULL;
+ if (f) {
+ read_packed_refs(f, &cached_refs);
+ fclose(f);
+ }
+ cached_refs.did_packed = 1;
+ }
+ return cached_refs.packed;
+}
+
+static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
+{
+ DIR *dir = opendir(git_path("%s", base));
+
+ if (dir) {
+ struct dirent *de;
+ int baselen = strlen(base);
+ char *ref = xmalloc(baselen + 257);
+
+ memcpy(ref, base, baselen);
+ if (baselen && base[baselen-1] != '/')
+ ref[baselen++] = '/';
+
+ while ((de = readdir(dir)) != NULL) {
+ unsigned char sha1[20];
+ struct stat st;
+ int flag;
+ int namelen;
+
+ if (de->d_name[0] == '.')
+ continue;
+ namelen = strlen(de->d_name);
+ if (namelen > 255)
+ continue;
+ if (has_extension(de->d_name, ".lock"))
+ continue;
+ memcpy(ref + baselen, de->d_name, namelen+1);
+ if (stat(git_path("%s", ref), &st) < 0)
+ continue;
+ if (S_ISDIR(st.st_mode)) {
+ list = get_ref_dir(ref, list);
+ continue;
+ }
+ if (!resolve_ref(ref, sha1, 1, &flag)) {
+ error("%s points nowhere!", ref);
+ continue;
+ }
+ list = add_ref(ref, sha1, flag, list, NULL);
+ }
+ free(ref);
+ closedir(dir);
+ }
+ return sort_ref_list(list);
+}
+
+static struct ref_list *get_loose_refs(void)
+{
+ if (!cached_refs.did_loose) {
+ cached_refs.loose = get_ref_dir("refs", NULL);
+ cached_refs.did_loose = 1;
+ }
+ return cached_refs.loose;
+}
+
+/* We allow "recursive" symbolic refs. Only within reason, though */
+#define MAXDEPTH 5
+#define MAXREFLEN (1024)
+
+static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
+{
+ FILE *f;
+ struct cached_refs refs;
+ struct ref_list *ref;
+ int retval;
+
+ strcpy(name + pathlen, "packed-refs");
+ f = fopen(name, "r");
+ if (!f)
+ return -1;
+ read_packed_refs(f, &refs);
+ fclose(f);
+ ref = refs.packed;
+ retval = -1;
+ while (ref) {
+ if (!strcmp(ref->name, refname)) {
+ retval = 0;
+ memcpy(result, ref->sha1, 20);
+ break;
+ }
+ ref = ref->next;
+ }
+ free_ref_list(refs.packed);
+ return retval;
+}
+
+static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
+{
+ int fd, len = strlen(refname);
+ char buffer[128], *p;
+
+ if (recursion > MAXDEPTH || len > MAXREFLEN)
+ return -1;
+ memcpy(name + pathlen, refname, len+1);
+ fd = open(name, O_RDONLY);
+ if (fd < 0)
+ return resolve_gitlink_packed_ref(name, pathlen, refname, result);
+
+ 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, result))
+ return 0;
+
+ /* Symref? */
+ if (strncmp(buffer, "ref:", 4))
+ return -1;
+ p = buffer + 4;
+ while (isspace(*p))
+ p++;
+
+ return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
+}
+
+int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
+{
+ int len = strlen(path), retval;
+ char *gitdir;
+
+ while (len && path[len-1] == '/')
+ len--;
+ if (!len)
+ return -1;
+ gitdir = xmalloc(len + MAXREFLEN + 8);
+ memcpy(gitdir, path, len);
+ memcpy(gitdir + len, "/.git/", 7);
+
+ retval = resolve_gitlink_ref_recursive(gitdir, len+6, refname, result, 0);
+ free(gitdir);
+ return retval;
+}
+
+const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
+{
+ int depth = MAXDEPTH, len;
+ char buffer[256];
+ static char ref_buffer[256];
+
+ if (flag)
+ *flag = 0;
+
+ for (;;) {
+ const char *path = git_path("%s", ref);
+ struct stat st;
+ char *buf;
+ int fd;
+
+ if (--depth < 0)
+ return NULL;
+
+ /* Special case: non-existing file.
+ * Not having the refs/heads/new-branch is OK
+ * if we are writing into it, so is .git/HEAD
+ * that points at refs/heads/master still to be
+ * born. It is NOT OK if we are resolving for
+ * reading.
+ */
+ if (lstat(path, &st) < 0) {
+ struct ref_list *list = get_packed_refs();
+ while (list) {
+ if (!strcmp(ref, list->name)) {
+ hashcpy(sha1, list->sha1);
+ if (flag)
+ *flag |= REF_ISPACKED;
+ return ref;
+ }
+ list = list->next;
+ }
+ if (reading || errno != ENOENT)
+ return NULL;
+ hashclr(sha1);
+ return ref;
+ }
+
+ /* Follow "normalized" - ie "refs/.." symlinks by hand */
+ if (S_ISLNK(st.st_mode)) {
+ len = readlink(path, buffer, sizeof(buffer)-1);
+ if (len >= 5 && !memcmp("refs/", buffer, 5)) {
+ buffer[len] = 0;
+ strcpy(ref_buffer, buffer);
+ ref = ref_buffer;
+ if (flag)
+ *flag |= REF_ISSYMREF;
+ 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)
+ return NULL;
+ len = read_in_full(fd, buffer, sizeof(buffer)-1);
+ close(fd);
+
+ /*
+ * Is it a symbolic ref?
+ */
+ if (len < 4 || memcmp("ref:", buffer, 4))
+ break;
+ buf = buffer + 4;
+ len -= 4;
+ while (len && isspace(*buf))
+ buf++, len--;
+ while (len && isspace(buf[len-1]))
+ len--;
+ buf[len] = 0;
+ memcpy(ref_buffer, buf, len + 1);
+ ref = ref_buffer;
+ if (flag)
+ *flag |= REF_ISSYMREF;
+ }
+ if (len < 40 || get_sha1_hex(buffer, sha1))
+ return NULL;
+ return ref;
+}
+
+int read_ref(const char *ref, unsigned char *sha1)
+{
+ if (resolve_ref(ref, sha1, 1, NULL))
+ return 0;
+ return -1;
+}
+
+static int do_one_ref(const char *base, each_ref_fn fn, int trim,
+ void *cb_data, struct ref_list *entry)
+{
+ if (strncmp(base, entry->name, trim))
+ return 0;
+ if (is_null_sha1(entry->sha1))
+ return 0;
+ if (!has_sha1_file(entry->sha1)) {
+ error("%s does not point to a valid object!", entry->name);
+ return 0;
+ }
+ return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
+}
+
+int peel_ref(const char *ref, unsigned char *sha1)
+{
+ int flag;
+ unsigned char base[20];
+ struct object *o;
+
+ if (!resolve_ref(ref, base, 1, &flag))
+ return -1;
+
+ if ((flag & REF_ISPACKED)) {
+ struct ref_list *list = get_packed_refs();
+
+ while (list) {
+ if (!strcmp(list->name, ref)) {
+ if (list->flag & REF_KNOWS_PEELED) {
+ hashcpy(sha1, list->peeled);
+ return 0;
+ }
+ /* older pack-refs did not leave peeled ones */
+ break;
+ }
+ list = list->next;
+ }
+ }
+
+ /* fallback - callers should not call this for unpacked refs */
+ o = parse_object(base);
+ if (o->type == OBJ_TAG) {
+ o = deref_tag(o, ref, 0);
+ if (o) {
+ hashcpy(sha1, o->sha1);
+ return 0;
+ }
+ }
+ return -1;
+}
+
+static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
+ void *cb_data)
+{
+ int retval;
+ struct ref_list *packed = get_packed_refs();
+ struct ref_list *loose = get_loose_refs();
+
+ while (packed && loose) {
+ struct ref_list *entry;
+ int cmp = strcmp(packed->name, loose->name);
+ if (!cmp) {
+ packed = packed->next;
+ continue;
+ }
+ if (cmp > 0) {
+ entry = loose;
+ loose = loose->next;
+ } else {
+ entry = packed;
+ packed = packed->next;
+ }
+ retval = do_one_ref(base, fn, trim, cb_data, entry);
+ if (retval)
+ return retval;
+ }
+
+ for (packed = packed ? packed : loose; packed; packed = packed->next) {
+ retval = do_one_ref(base, fn, trim, cb_data, packed);
+ if (retval)
+ return retval;
+ }
+ return 0;
+}
+
+int head_ref(each_ref_fn fn, void *cb_data)
+{
+ unsigned char sha1[20];
+ int flag;
+
+ if (resolve_ref("HEAD", sha1, 1, &flag))
+ return fn("HEAD", sha1, flag, cb_data);
+ return 0;
+}
+
+int for_each_ref(each_ref_fn fn, void *cb_data)
+{
+ return do_for_each_ref("refs/", fn, 0, cb_data);
+}
+
+int for_each_tag_ref(each_ref_fn fn, void *cb_data)
+{
+ return do_for_each_ref("refs/tags/", fn, 10, cb_data);
+}
+
+int for_each_branch_ref(each_ref_fn fn, void *cb_data)
+{
+ return do_for_each_ref("refs/heads/", fn, 11, cb_data);
+}
+
+int for_each_remote_ref(each_ref_fn fn, void *cb_data)
+{
+ return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
+}
+
+/* NEEDSWORK: This is only used by ssh-upload and it should go; the
+ * caller should do resolve_ref or read_ref like everybody else. Or
+ * maybe everybody else should use get_ref_sha1() instead of doing
+ * read_ref().
+ */
+int get_ref_sha1(const char *ref, unsigned char *sha1)
+{
+ if (check_ref_format(ref))
+ return -1;
+ return read_ref(mkpath("refs/%s", ref), sha1);
+}
+
+/*
+ * Make sure "ref" is something reasonable to have under ".git/refs/";
+ * We do not like it if:
+ *
+ * - any path component of it begins with ".", or
+ * - it has double dots "..", or
+ * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
+ * - it ends with a "/".
+ */
+
+static inline int bad_ref_char(int ch)
+{
+ return (((unsigned) ch) <= ' ' ||
+ ch == '~' || ch == '^' || ch == ':' ||
+ /* 2.13 Pattern Matching Notation */
+ ch == '?' || ch == '*' || ch == '[');
+}
+
+int check_ref_format(const char *ref)
+{
+ int ch, level;
+ const char *cp = ref;
+
+ level = 0;
+ while (1) {
+ while ((ch = *cp++) == '/')
+ ; /* tolerate duplicated slashes */
+ if (!ch)
+ return -1; /* should not end with slashes */
+
+ /* we are at the beginning of the path component */
+ if (ch == '.' || bad_ref_char(ch))
+ return -1;
+
+ /* scan the rest of the path component */
+ while ((ch = *cp++) != 0) {
+ if (bad_ref_char(ch))
+ return -1;
+ if (ch == '/')
+ break;
+ if (ch == '.' && *cp == '.')
+ return -1;
+ }
+ level++;
+ if (!ch) {
+ if (level < 2)
+ return -2; /* at least of form "heads/blah" */
+ return 0;
+ }
+ }
+}
+
+static struct ref_lock *verify_lock(struct ref_lock *lock,
+ const unsigned char *old_sha1, int mustexist)
+{
+ if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
+ error("Can't verify ref %s", lock->ref_name);
+ unlock_ref(lock);
+ return NULL;
+ }
+ if (hashcmp(lock->old_sha1, old_sha1)) {
+ error("Ref %s is at %s but expected %s", lock->ref_name,
+ sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
+ unlock_ref(lock);
+ return NULL;
+ }
+ return lock;
+}
+
+static int remove_empty_dir_recursive(char *path, int len)
+{
+ DIR *dir = opendir(path);
+ struct dirent *e;
+ int ret = 0;
+
+ if (!dir)
+ return -1;
+ if (path[len-1] != '/')
+ path[len++] = '/';
+ while ((e = readdir(dir)) != NULL) {
+ struct stat st;
+ int namlen;
+ if ((e->d_name[0] == '.') &&
+ ((e->d_name[1] == 0) ||
+ ((e->d_name[1] == '.') && e->d_name[2] == 0)))
+ continue; /* "." and ".." */
+
+ namlen = strlen(e->d_name);
+ if ((len + namlen < PATH_MAX) &&
+ strcpy(path + len, e->d_name) &&
+ !lstat(path, &st) &&
+ S_ISDIR(st.st_mode) &&
+ !remove_empty_dir_recursive(path, len + namlen))
+ continue; /* happy */
+
+ /* path too long, stat fails, or non-directory still exists */
+ ret = -1;
+ break;
+ }
+ closedir(dir);
+ if (!ret) {
+ path[len] = 0;
+ ret = rmdir(path);
+ }
+ return ret;
+}
+
+static int remove_empty_directories(char *file)
+{
+ /* 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.
+ */
+ char path[PATH_MAX];
+ int len = strlen(file);
+
+ if (len >= PATH_MAX) /* path too long ;-) */
+ return -1;
+ strcpy(path, file);
+ return remove_empty_dir_recursive(path, len);
+}
+
+static int is_refname_available(const char *ref, const char *oldref,
+ struct ref_list *list, int quiet)
+{
+ int namlen = strlen(ref); /* e.g. 'foo/bar' */
+ while (list) {
+ /* list->name could be 'foo' or 'foo/bar/baz' */
+ if (!oldref || strcmp(oldref, list->name)) {
+ int len = strlen(list->name);
+ int cmplen = (namlen < len) ? namlen : len;
+ const char *lead = (namlen < len) ? list->name : ref;
+ if (!strncmp(ref, list->name, cmplen) &&
+ lead[cmplen] == '/') {
+ if (!quiet)
+ error("'%s' exists; cannot create '%s'",
+ list->name, ref);
+ return 0;
+ }
+ }
+ list = list->next;
+ }
+ return 1;
+}
+
+static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int *flag)
+{
+ char *ref_file;
+ const char *orig_ref = ref;
+ struct ref_lock *lock;
+ struct stat st;
+ int last_errno = 0;
+ int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
+
+ lock = xcalloc(1, sizeof(struct ref_lock));
+ lock->lock_fd = -1;
+
+ ref = resolve_ref(ref, lock->old_sha1, mustexist, flag);
+ if (!ref && 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.
+ */
+ ref_file = git_path("%s", orig_ref);
+ if (remove_empty_directories(ref_file)) {
+ last_errno = errno;
+ error("there are still refs under '%s'", orig_ref);
+ goto error_return;
+ }
+ ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, flag);
+ }
+ if (!ref) {
+ last_errno = errno;
+ error("unable to resolve reference %s: %s",
+ orig_ref, strerror(errno));
+ goto error_return;
+ }
+ /* When the ref did not exist and we are creating it,
+ * make sure there is no existing ref that is packed
+ * whose name begins with our refname, nor a ref whose
+ * name is a proper prefix of our refname.
+ */
+ if (is_null_sha1(lock->old_sha1) &&
+ !is_refname_available(ref, NULL, get_packed_refs(), 0))
+ goto error_return;
+
+ lock->lk = xcalloc(1, sizeof(struct lock_file));
+
+ lock->ref_name = xstrdup(ref);
+ lock->orig_ref_name = xstrdup(orig_ref);
+ ref_file = git_path("%s", ref);
+ lock->force_write = lstat(ref_file, &st) && errno == ENOENT;
+
+ if (safe_create_leading_directories(ref_file)) {
+ last_errno = errno;
+ error("unable to create directory for %s", ref_file);
+ goto error_return;
+ }
+ lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
+
+ return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
+
+ error_return:
+ unlock_ref(lock);
+ errno = last_errno;
+ return NULL;
+}
+
+struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
+{
+ char refpath[PATH_MAX];
+ if (check_ref_format(ref))
+ return NULL;
+ strcpy(refpath, mkpath("refs/%s", ref));
+ return lock_ref_sha1_basic(refpath, old_sha1, NULL);
+}
+
+struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1)
+{
+ if (check_ref_format(ref) == -1)
+ return NULL;
+ return lock_ref_sha1_basic(ref, old_sha1, NULL);
+}
+
+static struct lock_file packlock;
+
+static int repack_without_ref(const char *refname)
+{
+ struct ref_list *list, *packed_ref_list;
+ int fd;
+ int found = 0;
+
+ packed_ref_list = get_packed_refs();
+ for (list = packed_ref_list; list; list = list->next) {
+ if (!strcmp(refname, list->name)) {
+ found = 1;
+ break;
+ }
+ }
+ if (!found)
+ return 0;
+ fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
+ if (fd < 0)
+ return error("cannot delete '%s' from packed refs", refname);
+
+ for (list = packed_ref_list; list; list = list->next) {
+ char line[PATH_MAX + 100];
+ int len;
+
+ if (!strcmp(refname, list->name))
+ continue;
+ len = snprintf(line, sizeof(line), "%s %s\n",
+ sha1_to_hex(list->sha1), list->name);
+ /* this should not happen but just being defensive */
+ if (len > sizeof(line))
+ die("too long a refname '%s'", list->name);
+ write_or_die(fd, line, len);
+ }
+ return commit_lock_file(&packlock);
+}
+
+int delete_ref(const char *refname, const unsigned char *sha1)
+{
+ struct ref_lock *lock;
+ int err, i, ret = 0, flag = 0;
+
+ lock = lock_ref_sha1_basic(refname, sha1, &flag);
+ if (!lock)
+ return 1;
+ if (!(flag & REF_ISPACKED)) {
+ /* loose */
+ i = strlen(lock->lk->filename) - 5; /* .lock */
+ lock->lk->filename[i] = 0;
+ err = unlink(lock->lk->filename);
+ if (err) {
+ ret = 1;
+ error("unlink(%s) failed: %s",
+ lock->lk->filename, strerror(errno));
+ }
+ lock->lk->filename[i] = '.';
+ }
+ /* removing the loose one could have resurrected an earlier
+ * packed one. Also, if it was not loose we need to repack
+ * without it.
+ */
+ ret |= repack_without_ref(refname);
+
+ err = unlink(git_path("logs/%s", lock->ref_name));
+ if (err && errno != ENOENT)
+ fprintf(stderr, "warning: unlink(%s) failed: %s",
+ git_path("logs/%s", lock->ref_name), strerror(errno));
+ invalidate_cached_refs();
+ unlock_ref(lock);
+ return ret;
+}
+
+int rename_ref(const char *oldref, const char *newref, const char *logmsg)
+{
+ static const char renamed_ref[] = "RENAMED-REF";
+ 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", oldref), &loginfo);
+
+ if (S_ISLNK(loginfo.st_mode))
+ return error("reflog for %s is a symlink", oldref);
+
+ if (!resolve_ref(oldref, orig_sha1, 1, &flag))
+ return error("refname %s not found", oldref);
+
+ if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
+ return 1;
+
+ if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
+ return 1;
+
+ lock = lock_ref_sha1_basic(renamed_ref, NULL, NULL);
+ if (!lock)
+ return error("unable to lock %s", renamed_ref);
+ lock->force_write = 1;
+ if (write_ref_sha1(lock, orig_sha1, logmsg))
+ return error("unable to save current sha1 in %s", renamed_ref);
+
+ if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
+ return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
+ oldref, strerror(errno));
+
+ if (delete_ref(oldref, orig_sha1)) {
+ error("unable to delete old %s", oldref);
+ goto rollback;
+ }
+
+ if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
+ if (errno==EISDIR) {
+ if (remove_empty_directories(git_path("%s", newref))) {
+ error("Directory not empty: %s", newref);
+ goto rollback;
+ }
+ } else {
+ error("unable to delete existing %s", newref);
+ goto rollback;
+ }
+ }
+
+ if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
+ error("unable to create directory for %s", newref);
+ goto rollback;
+ }
+
+ retry:
+ if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
+ if (errno==EISDIR || errno==ENOTDIR) {
+ /*
+ * 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(git_path("logs/%s", newref))) {
+ error("Directory not empty: logs/%s", newref);
+ goto rollback;
+ }
+ goto retry;
+ } else {
+ error("unable to move logfile tmp-renamed-log to logs/%s: %s",
+ newref, strerror(errno));
+ goto rollback;
+ }
+ }
+ logmoved = log;
+
+ lock = lock_ref_sha1_basic(newref, NULL, NULL);
+ if (!lock) {
+ error("unable to lock %s for update", newref);
+ goto rollback;
+ }
+
+ lock->force_write = 1;
+ hashcpy(lock->old_sha1, orig_sha1);
+ if (write_ref_sha1(lock, orig_sha1, logmsg)) {
+ error("unable to write current sha1 into %s", newref);
+ goto rollback;
+ }
+
+ return 0;
+
+ rollback:
+ lock = lock_ref_sha1_basic(oldref, NULL, NULL);
+ if (!lock) {
+ error("unable to lock %s for rollback", oldref);
+ goto rollbacklog;
+ }
+
+ lock->force_write = 1;
+ flag = log_all_ref_updates;
+ log_all_ref_updates = 0;
+ if (write_ref_sha1(lock, orig_sha1, NULL))
+ error("unable to write current sha1 into %s", oldref);
+ log_all_ref_updates = flag;
+
+ rollbacklog:
+ if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
+ error("unable to restore logfile %s from %s: %s",
+ oldref, newref, strerror(errno));
+ if (!logmoved && log &&
+ rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
+ error("unable to restore logfile %s from tmp-renamed-log: %s",
+ oldref, strerror(errno));
+
+ return 1;
+}
+
+void unlock_ref(struct ref_lock *lock)
+{
+ if (lock->lock_fd >= 0) {
+ close(lock->lock_fd);
+ /* 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);
+}
+
+static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
+ const unsigned char *new_sha1, const char *msg)
+{
+ int logfd, written, oflags = O_APPEND | O_WRONLY;
+ unsigned maxlen, len;
+ int msglen;
+ char *log_file, *logrec;
+ const char *committer;
+
+ if (log_all_ref_updates < 0)
+ log_all_ref_updates = !is_bare_repository();
+
+ log_file = git_path("logs/%s", ref_name);
+
+ if (log_all_ref_updates &&
+ (!prefixcmp(ref_name, "refs/heads/") ||
+ !prefixcmp(ref_name, "refs/remotes/") ||
+ !strcmp(ref_name, "HEAD"))) {
+ if (safe_create_leading_directories(log_file) < 0)
+ return error("unable to create directory for %s",
+ log_file);
+ oflags |= O_CREAT;
+ }
+
+ logfd = open(log_file, oflags, 0666);
+ if (logfd < 0) {
+ if (!(oflags & O_CREAT) && errno == ENOENT)
+ return 0;
+
+ if ((oflags & O_CREAT) && errno == EISDIR) {
+ if (remove_empty_directories(log_file)) {
+ return error("There are still logs under '%s'",
+ log_file);
+ }
+ logfd = open(log_file, oflags, 0666);
+ }
+
+ if (logfd < 0)
+ return error("Unable to append to %s: %s",
+ log_file, strerror(errno));
+ }
+
+ adjust_shared_perm(log_file);
+
+ msglen = 0;
+ if (msg) {
+ /* clean up the message and make sure it is a single line */
+ for ( ; *msg; msg++)
+ if (!isspace(*msg))
+ break;
+ if (*msg) {
+ const char *ep = strchr(msg, '\n');
+ if (ep)
+ msglen = ep - msg;
+ else
+ msglen = strlen(msg);
+ }
+ }
+
+ committer = git_committer_info(-1);
+ maxlen = strlen(committer) + msglen + 100;
+ logrec = xmalloc(maxlen);
+ len = sprintf(logrec, "%s %s %s\n",
+ sha1_to_hex(old_sha1),
+ sha1_to_hex(new_sha1),
+ committer);
+ if (msglen)
+ len += sprintf(logrec + len - 1, "\t%.*s\n", msglen, msg) - 1;
+ written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
+ free(logrec);
+ close(logfd);
+ if (written != len)
+ return error("Unable to append to %s", log_file);
+ return 0;
+}
+
+int write_ref_sha1(struct ref_lock *lock,
+ const unsigned char *sha1, const char *logmsg)
+{
+ static char term = '\n';
+
+ if (!lock)
+ return -1;
+ if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
+ unlock_ref(lock);
+ return 0;
+ }
+ if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
+ write_in_full(lock->lock_fd, &term, 1) != 1
+ || close(lock->lock_fd) < 0) {
+ error("Couldn't write %s", lock->lk->filename);
+ unlock_ref(lock);
+ return -1;
+ }
+ invalidate_cached_refs();
+ if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
+ (strcmp(lock->ref_name, lock->orig_ref_name) &&
+ log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
+ 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("HEAD", head_sha1, 1, &head_flag);
+ if (head_ref && (head_flag & REF_ISSYMREF) &&
+ !strcmp(head_ref, lock->ref_name))
+ log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
+ }
+ if (commit_lock_file(lock->lk)) {
+ error("Couldn't set %s", lock->ref_name);
+ unlock_ref(lock);
+ return -1;
+ }
+ lock->lock_fd = -1;
+ unlock_ref(lock);
+ return 0;
+}
+
+int create_symref(const char *ref_target, const char *refs_heads_master,
+ const char *logmsg)
+{
+ const char *lockpath;
+ char ref[1000];
+ int fd, len, written;
+ char *git_HEAD = xstrdup(git_path("%s", ref_target));
+ unsigned char old_sha1[20], new_sha1[20];
+
+ 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 = mkpath("%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);
+ close(fd);
+ if (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(lockpath);
+ error_free_return:
+ free(git_HEAD);
+ return -1;
+ }
+
+#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);
+
+ free(git_HEAD);
+ return 0;
+}
+
+static char *ref_msg(const char *line, const char *endp)
+{
+ const char *ep;
+ char *msg;
+
+ line += 82;
+ for (ep = line; ep < endp && *ep != '\n'; ep++)
+ ;
+ msg = xmalloc(ep - line + 1);
+ memcpy(msg, line, ep - line);
+ msg[ep - line] = 0;
+ return msg;
+}
+
+int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char *sha1, char **msg, unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
+{
+ const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
+ char *tz_c;
+ int logfd, tz, reccnt = 0;
+ struct stat st;
+ unsigned long date;
+ unsigned char logged_sha1[20];
+ void *log_mapped;
+ size_t mapsz;
+
+ logfile = git_path("logs/%s", ref);
+ logfd = open(logfile, O_RDONLY, 0);
+ if (logfd < 0)
+ die("Unable to read log %s: %s", logfile, strerror(errno));
+ fstat(logfd, &st);
+ if (!st.st_size)
+ die("Log %s is empty.", logfile);
+ mapsz = xsize_t(st.st_size);
+ log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
+ logdata = log_mapped;
+ close(logfd);
+
+ lastrec = NULL;
+ rec = logend = logdata + st.st_size;
+ while (logdata < rec) {
+ reccnt++;
+ if (logdata < rec && *(rec-1) == '\n')
+ rec--;
+ lastgt = NULL;
+ while (logdata < rec && *(rec-1) != '\n') {
+ rec--;
+ if (*rec == '>')
+ lastgt = rec;
+ }
+ if (!lastgt)
+ die("Log %s is corrupt.", logfile);
+ date = strtoul(lastgt + 1, &tz_c, 10);
+ if (date <= at_time || cnt == 0) {
+ tz = strtoul(tz_c, NULL, 10);
+ if (msg)
+ *msg = ref_msg(rec, logend);
+ if (cutoff_time)
+ *cutoff_time = date;
+ if (cutoff_tz)
+ *cutoff_tz = tz;
+ if (cutoff_cnt)
+ *cutoff_cnt = reccnt - 1;
+ if (lastrec) {
+ if (get_sha1_hex(lastrec, logged_sha1))
+ die("Log %s is corrupt.", logfile);
+ if (get_sha1_hex(rec + 41, sha1))
+ die("Log %s is corrupt.", logfile);
+ if (hashcmp(logged_sha1, sha1)) {
+ fprintf(stderr,
+ "warning: Log %s has gap after %s.\n",
+ logfile, show_rfc2822_date(date, tz));
+ }
+ }
+ else if (date == at_time) {
+ if (get_sha1_hex(rec + 41, sha1))
+ die("Log %s is corrupt.", logfile);
+ }
+ else {
+ if (get_sha1_hex(rec + 41, logged_sha1))
+ die("Log %s is corrupt.", logfile);
+ if (hashcmp(logged_sha1, sha1)) {
+ fprintf(stderr,
+ "warning: Log %s unexpectedly ended on %s.\n",
+ logfile, show_rfc2822_date(date, tz));
+ }
+ }
+ munmap(log_mapped, mapsz);
+ return 0;
+ }
+ lastrec = rec;
+ if (cnt > 0)
+ cnt--;
+ }
+
+ rec = logdata;
+ while (rec < logend && *rec != '>' && *rec != '\n')
+ rec++;
+ if (rec == logend || *rec == '\n')
+ die("Log %s is corrupt.", logfile);
+ date = strtoul(rec + 1, &tz_c, 10);
+ tz = strtoul(tz_c, NULL, 10);
+ if (get_sha1_hex(logdata, sha1))
+ die("Log %s is corrupt.", logfile);
+ if (msg)
+ *msg = ref_msg(logdata, logend);
+ munmap(log_mapped, mapsz);
+
+ if (cutoff_time)
+ *cutoff_time = date;
+ if (cutoff_tz)
+ *cutoff_tz = tz;
+ if (cutoff_cnt)
+ *cutoff_cnt = reccnt;
+ return 1;
+}
+
+int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
+{
+ const char *logfile;
+ FILE *logfp;
+ char buf[1024];
+ int ret = 0;
+
+ logfile = git_path("logs/%s", ref);
+ logfp = fopen(logfile, "r");
+ if (!logfp)
+ return -1;
+ while (fgets(buf, sizeof(buf), logfp)) {
+ unsigned char osha1[20], nsha1[20];
+ char *email_end, *message;
+ unsigned long timestamp;
+ int len, tz;
+
+ /* old SP new SP name <email> SP time TAB msg LF */
+ len = strlen(buf);
+ if (len < 83 || buf[len-1] != '\n' ||
+ get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
+ get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
+ !(email_end = strchr(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]))
+ continue; /* corrupt? */
+ email_end[1] = '\0';
+ tz = strtol(message + 1, NULL, 10);
+ if (message[6] != '\t')
+ message += 6;
+ else
+ message += 7;
+ ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
+ if (ret)
+ break;
+ }
+ fclose(logfp);
+ return ret;
+}
+
+static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
+{
+ DIR *dir = opendir(git_path("logs/%s", base));
+ int retval = 0;
+
+ if (dir) {
+ struct dirent *de;
+ int baselen = strlen(base);
+ char *log = xmalloc(baselen + 257);
+
+ memcpy(log, base, baselen);
+ if (baselen && base[baselen-1] != '/')
+ log[baselen++] = '/';
+
+ while ((de = readdir(dir)) != NULL) {
+ struct stat st;
+ int namelen;
+
+ if (de->d_name[0] == '.')
+ continue;
+ namelen = strlen(de->d_name);
+ if (namelen > 255)
+ continue;
+ if (has_extension(de->d_name, ".lock"))
+ continue;
+ memcpy(log + baselen, de->d_name, namelen+1);
+ if (stat(git_path("logs/%s", log), &st) < 0)
+ continue;
+ if (S_ISDIR(st.st_mode)) {
+ retval = do_for_each_reflog(log, fn, cb_data);
+ } else {
+ unsigned char sha1[20];
+ if (!resolve_ref(log, sha1, 0, NULL))
+ retval = error("bad ref for %s", log);
+ else
+ retval = fn(log, sha1, 0, cb_data);
+ }
+ if (retval)
+ break;
+ }
+ free(log);
+ closedir(dir);
+ }
+ else if (*base)
+ return errno;
+ return retval;
+}
+
+int for_each_reflog(each_ref_fn fn, void *cb_data)
+{
+ return do_for_each_reflog("", fn, cb_data);
+}