diff options
Diffstat (limited to 'refs.c')
| -rw-r--r-- | refs.c | 1558 |
1 files changed, 1558 insertions, 0 deletions
diff --git a/refs.c b/refs.c new file mode 100644 index 0000000000..9e8e8581ba --- /dev/null +++ b/refs.c @@ -0,0 +1,1558 @@ +#include "cache.h" +#include "refs.h" +#include "object.h" +#include "tag.h" +#include "dir.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. + */ +static struct cached_refs { + char did_loose; + char did_packed; + struct ref_list *loose; + struct ref_list *packed; +} cached_refs; +static struct ref_list *current_ref; + +static struct ref_list *extra_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); +} + +void add_extra_ref(const char *name, const unsigned char *sha1, int flag) +{ + extra_refs = add_ref(name, sha1, flag, extra_refs, NULL); +} + +void clear_extra_refs(void) +{ + free_ref_list(extra_refs); + extra_refs = NULL; +} + +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; + const char *tmp; + + while (len && path[len-1] == '/') + len--; + if (!len) + return -1; + gitdir = xmalloc(len + MAXREFLEN + 8); + memcpy(gitdir, path, len); + memcpy(gitdir + len, "/.git", 6); + len += 5; + + tmp = read_gitfile_gently(gitdir); + if (tmp) { + free(gitdir); + len = strlen(tmp); + gitdir = xmalloc(len + MAXREFLEN + 3); + memcpy(gitdir, tmp, len); + } + gitdir[len] = '/'; + gitdir[++len] = '\0'; + retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0); + free(gitdir); + return retval; +} + +const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag) +{ + int depth = MAXDEPTH; + ssize_t 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; + } + current_ref = entry; + 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 (current_ref && (current_ref->name == ref + || !strcmp(current_ref->name, ref))) { + if (current_ref->flag & REF_KNOWS_PEELED) { + hashcpy(sha1, current_ref->peeled); + return 0; + } + hashcpy(base, current_ref->sha1); + goto fallback; + } + + 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: + o = parse_object(base); + if (o && 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 = 0; + struct ref_list *packed = get_packed_refs(); + struct ref_list *loose = get_loose_refs(); + + struct ref_list *extra; + + for (extra = extra_refs; extra; extra = extra->next) + retval = do_one_ref(base, fn, trim, cb_data, extra); + + 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) + goto end_each; + } + + for (packed = packed ? packed : loose; packed; packed = packed->next) { + retval = do_one_ref(base, fn, trim, cb_data, packed); + if (retval) + goto end_each; + } + +end_each: + current_ref = NULL; + return retval; +} + +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); +} + +/* + * 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) +{ + if (((unsigned) ch) <= ' ' || + ch == '~' || ch == '^' || ch == ':') + return 1; + /* 2.13 Pattern Matching Notation */ + if (ch == '?' || ch == '[') /* Unsupported */ + return 1; + if (ch == '*') /* Supported at the end */ + return 2; + return 0; +} + +int check_ref_format(const char *ref) +{ + int ch, level, bad_type; + const char *cp = ref; + + level = 0; + while (1) { + while ((ch = *cp++) == '/') + ; /* tolerate duplicated slashes */ + if (!ch) + /* should not end with slashes */ + return CHECK_REF_FORMAT_ERROR; + + /* we are at the beginning of the path component */ + if (ch == '.') + return CHECK_REF_FORMAT_ERROR; + bad_type = bad_ref_char(ch); + if (bad_type) { + return (bad_type == 2 && !*cp) + ? CHECK_REF_FORMAT_WILDCARD + : CHECK_REF_FORMAT_ERROR; + } + + /* scan the rest of the path component */ + while ((ch = *cp++) != 0) { + bad_type = bad_ref_char(ch); + if (bad_type) { + return (bad_type == 2 && !*cp) + ? CHECK_REF_FORMAT_WILDCARD + : CHECK_REF_FORMAT_ERROR; + } + if (ch == '/') + break; + if (ch == '.' && *cp == '.') + return CHECK_REF_FORMAT_ERROR; + } + level++; + if (!ch) { + if (level < 2) + return CHECK_REF_FORMAT_ONELEVEL; + return CHECK_REF_FORMAT_OK; + } + } +} + +const char *ref_rev_parse_rules[] = { + "%.*s", + "refs/%.*s", + "refs/tags/%.*s", + "refs/heads/%.*s", + "refs/remotes/%.*s", + "refs/remotes/%.*s/HEAD", + NULL +}; + +const char *ref_fetch_rules[] = { + "%.*s", + "refs/%.*s", + "refs/heads/%.*s", + NULL +}; + +int refname_match(const char *abbrev_name, const char *full_name, const char **rules) +{ + const char **p; + const int abbrev_name_len = strlen(abbrev_name); + + for (p = rules; *p; p++) { + if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) { + return 1; + } + } + + 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_directories(const 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. + */ + struct strbuf path; + int result; + + strbuf_init(&path, 20); + strbuf_addstr(&path, file); + + result = remove_dir_recursively(&path, 1); + + strbuf_release(&path); + + return result; +} + +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 flags, int *type_p) +{ + char *ref_file; + const char *orig_ref = ref; + struct ref_lock *lock; + struct stat st; + int last_errno = 0; + int type; + 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, &type); + 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, &type); + } + if (type_p) + *type_p = type; + 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)); + + if (flags & REF_NODEREF) + ref = orig_ref; + lock->ref_name = xstrdup(ref); + lock->orig_ref_name = xstrdup(orig_ref); + ref_file = git_path("%s", ref); + if (lstat(ref_file, &st) && errno == ENOENT) + lock->force_write = 1; + if ((flags & REF_NODEREF) && (type & REF_ISSYMREF)) + lock->force_write = 1; + + 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, 0, NULL); +} + +struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags) +{ + switch (check_ref_format(ref)) { + default: + return NULL; + case 0: + case CHECK_REF_FORMAT_ONELEVEL: + return lock_ref_sha1_basic(ref, old_sha1, flags, 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, 0, &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, 0, 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, 0, 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, 0, 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; +} + +int close_ref(struct ref_lock *lock) +{ + if (close_lock_file(lock->lk)) + return -1; + lock->lock_fd = -1; + return 0; +} + +int commit_ref(struct ref_lock *lock) +{ + if (commit_lock_file(lock->lk)) + return -1; + lock->lock_fd = -1; + return 0; +} + +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); +} + +/* + * 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_msg(char *buf, const char *msg) +{ + char *cp = buf; + char c; + int wasspace = 1; + + *cp++ = '\t'; + while ((c = *msg++)) { + if (wasspace && isspace(c)) + continue; + wasspace = isspace(c); + if (wasspace) + c = ' '; + *cp++ = c; + } + while (buf < cp && isspace(cp[-1])) + cp--; + *cp++ = '\n'; + return cp - buf; +} + +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 = msg ? strlen(msg) : 0; + committer = git_committer_info(0); + 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 += copy_msg(logrec + len - 1, msg) - 1; + written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1; + free(logrec); + if (close(logfd) != 0 || written != len) + return error("Unable to append to %s", log_file); + return 0; +} + +static int is_branch(const char *refname) +{ + return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/"); +} + +int write_ref_sha1(struct ref_lock *lock, + const unsigned char *sha1, const char *logmsg) +{ + static char term = '\n'; + struct object *o; + + if (!lock) + return -1; + if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) { + unlock_ref(lock); + return 0; + } + o = parse_object(sha1); + if (!o) { + error("Trying to write ref %s with nonexistant object %s", + lock->ref_name, sha1_to_hex(sha1)); + unlock_ref(lock); + return -1; + } + if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) { + error("Trying to write non-commit object %s to branch %s", + sha1_to_hex(sha1), lock->ref_name); + unlock_ref(lock); + return -1; + } + if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 || + write_in_full(lock->lock_fd, &term, 1) != 1 + || close_ref(lock) < 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_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) +{ + 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); + 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(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; + line += 82; + ep = memchr(line, '\n', endp - line); + if (!ep) + ep = endp; + return xmemdupz(line, ep - line); +} + +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_date(date, tz, DATE_RFC2822)); + } + } + 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_date(date, tz, DATE_RFC2822)); + } + } + 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); +} + +int update_ref(const char *action, const char *refname, + const unsigned char *sha1, const unsigned char *oldval, + int flags, enum action_on_err onerr) +{ + static struct ref_lock *lock; + lock = lock_any_ref_for_update(refname, oldval, flags); + if (!lock) { + const char *str = "Cannot lock the ref '%s'."; + switch (onerr) { + case MSG_ON_ERR: error(str, refname); break; + case DIE_ON_ERR: die(str, refname); break; + case QUIET_ON_ERR: break; + } + return 1; + } + if (write_ref_sha1(lock, sha1, action) < 0) { + const char *str = "Cannot update the ref '%s'."; + switch (onerr) { + case MSG_ON_ERR: error(str, refname); break; + case DIE_ON_ERR: die(str, refname); break; + case QUIET_ON_ERR: break; + } + return 1; + } + return 0; +} + +struct ref *find_ref_by_name(struct ref *list, const char *name) +{ + for ( ; list; list = list->next) + if (!strcmp(list->name, name)) + return list; + return NULL; +} |