diff options
| -rw-r--r-- | fetch.c | 32 | ||||
| -rw-r--r-- | refs.c | 236 | ||||
| -rw-r--r-- | refs.h | 24 |
3 files changed, 144 insertions, 148 deletions
@@ -204,14 +204,14 @@ static int mark_complete(const char *path, const unsigned char *sha1) int pull(char *target) { + struct ref_lock *lock; unsigned char sha1[20]; - int fd = -1; save_commit_buffer = 0; track_object_refs = 0; - if (write_ref && current_ref) { - fd = lock_ref_sha1(write_ref, current_ref); - if (fd < 0) + if (write_ref) { + lock = lock_ref_sha1(write_ref, current_ref, 1); + if (!lock) return -1; } @@ -219,20 +219,22 @@ int pull(char *target) for_each_ref(mark_complete); } - if (interpret_target(target, sha1)) - return error("Could not interpret %s as something to pull", - target); - if (process(lookup_unknown_object(sha1))) + if (interpret_target(target, sha1)) { + error("Could not interpret %s as something to pull", target); + unlock_ref(lock); + return -1; + } + if (process(lookup_unknown_object(sha1))) { + unlock_ref(lock); return -1; - if (loop()) + } + if (loop()) { + unlock_ref(lock); return -1; - + } + if (write_ref) { - if (current_ref) { - write_ref_sha1(write_ref, fd, sha1); - } else { - write_ref_sha1_unlocked(write_ref, sha1); - } + return write_ref_sha1(lock, sha1, "git fetch"); } return 0; } @@ -198,26 +198,6 @@ int for_each_remote_ref(int (*fn)(const char *path, const unsigned char *sha1)) return do_for_each_ref("refs/remotes", fn, 13); } -static char *ref_file_name(const char *ref) -{ - char *base = get_refs_directory(); - int baselen = strlen(base); - int reflen = strlen(ref); - char *ret = xmalloc(baselen + 2 + reflen); - sprintf(ret, "%s/%s", base, ref); - return ret; -} - -static char *ref_lock_file_name(const char *ref) -{ - char *base = get_refs_directory(); - int baselen = strlen(base); - int reflen = strlen(ref); - char *ret = xmalloc(baselen + 7 + reflen); - sprintf(ret, "%s/%s.lock", base, ref); - return ret; -} - int get_ref_sha1(const char *ref, unsigned char *sha1) { if (check_ref_format(ref)) @@ -225,94 +205,6 @@ int get_ref_sha1(const char *ref, unsigned char *sha1) return read_ref(git_path("refs/%s", ref), sha1); } -static int lock_ref_file(const char *filename, const char *lock_filename, - const unsigned char *old_sha1) -{ - int fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666); - unsigned char current_sha1[20]; - int retval; - if (fd < 0) { - return error("Couldn't open lock file for %s: %s", - filename, strerror(errno)); - } - retval = read_ref(filename, current_sha1); - if (old_sha1) { - if (retval) { - close(fd); - unlink(lock_filename); - return error("Could not read the current value of %s", - filename); - } - if (memcmp(current_sha1, old_sha1, 20)) { - close(fd); - unlink(lock_filename); - error("The current value of %s is %s", - filename, sha1_to_hex(current_sha1)); - return error("Expected %s", - sha1_to_hex(old_sha1)); - } - } else { - if (!retval) { - close(fd); - unlink(lock_filename); - return error("Unexpectedly found a value of %s for %s", - sha1_to_hex(current_sha1), filename); - } - } - return fd; -} - -int lock_ref_sha1(const char *ref, const unsigned char *old_sha1) -{ - char *filename; - char *lock_filename; - int retval; - if (check_ref_format(ref)) - return -1; - filename = ref_file_name(ref); - lock_filename = ref_lock_file_name(ref); - retval = lock_ref_file(filename, lock_filename, old_sha1); - free(filename); - free(lock_filename); - return retval; -} - -static int write_ref_file(const char *filename, - const char *lock_filename, int fd, - const unsigned char *sha1) -{ - char *hex = sha1_to_hex(sha1); - char term = '\n'; - if (write(fd, hex, 40) < 40 || - write(fd, &term, 1) < 1) { - error("Couldn't write %s", filename); - close(fd); - return -1; - } - close(fd); - rename(lock_filename, filename); - return 0; -} - -int write_ref_sha1(const char *ref, int fd, const unsigned char *sha1) -{ - char *filename; - char *lock_filename; - int retval; - if (fd < 0) - return -1; - if (check_ref_format(ref)) - return -1; - filename = ref_file_name(ref); - lock_filename = ref_lock_file_name(ref); - if (safe_create_leading_directories(filename)) - die("unable to create leading directory for %s", filename); - retval = write_ref_file(filename, lock_filename, fd, sha1); - free(filename); - free(lock_filename); - return retval; -} - /* * Make sure "ref" is something reasonable to have under ".git/refs/"; * We do not like it if: @@ -365,25 +257,119 @@ int check_ref_format(const char *ref) } } -int write_ref_sha1_unlocked(const char *ref, const unsigned char *sha1) +static struct ref_lock* verify_lock(struct ref_lock *lock, + const unsigned char *old_sha1, int mustexist) +{ + char buf[40]; + int nr, fd = open(lock->ref_file, O_RDONLY); + if (fd < 0 && (mustexist || errno != ENOENT)) { + error("Can't verify ref %s", lock->ref_file); + unlock_ref(lock); + return NULL; + } + nr = read(fd, buf, 40); + close(fd); + if (nr != 40 || get_sha1_hex(buf, lock->old_sha1) < 0) { + error("Can't verify ref %s", lock->ref_file); + unlock_ref(lock); + return NULL; + } + if (memcmp(lock->old_sha1, old_sha1, 20)) { + error("Ref %s is at %s but expected %s", lock->ref_file, + sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1)); + unlock_ref(lock); + return NULL; + } + return lock; +} + +static struct ref_lock* lock_ref_sha1_basic(const char *path, + int plen, + const unsigned char *old_sha1, int mustexist) +{ + struct ref_lock *lock; + + lock = xcalloc(1, sizeof(struct ref_lock)); + lock->lock_fd = -1; + + plen = strlen(path) - plen; + path = resolve_ref(path, lock->old_sha1, mustexist); + if (!path) { + error("Can't read ref %s", path); + unlock_ref(lock); + return NULL; + } + + lock->ref_file = strdup(path); + lock->lock_file = strdup(mkpath("%s.lock", lock->ref_file)); + + if (safe_create_leading_directories(lock->lock_file)) + die("unable to create directory for %s", lock->lock_file); + lock->lock_fd = open(lock->lock_file, + O_WRONLY | O_CREAT | O_EXCL, 0666); + if (lock->lock_fd < 0) { + error("Couldn't open lock file %s: %s", + lock->lock_file, strerror(errno)); + unlock_ref(lock); + return NULL; + } + + return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock; +} + +struct ref_lock* lock_ref_sha1(const char *ref, + const unsigned char *old_sha1, int mustexist) { - char *filename; - char *lock_filename; - int fd; - int retval; if (check_ref_format(ref)) + return NULL; + return lock_ref_sha1_basic(git_path("refs/%s", ref), + strlen(ref), old_sha1, mustexist); +} + +struct ref_lock* lock_any_ref_for_update(const char *ref, + const unsigned char *old_sha1, int mustexist) +{ + return lock_ref_sha1_basic(git_path("%s", ref), + strlen(ref), old_sha1, mustexist); +} + +void unlock_ref (struct ref_lock *lock) +{ + if (lock->lock_fd >= 0) { + close(lock->lock_fd); + unlink(lock->lock_file); + } + if (lock->ref_file) + free(lock->ref_file); + if (lock->lock_file) + free(lock->lock_file); + free(lock); +} + +int write_ref_sha1(struct ref_lock *lock, + const unsigned char *sha1, const char *logmsg) +{ + static char term = '\n'; + + if (!lock) return -1; - filename = ref_file_name(ref); - lock_filename = ref_lock_file_name(ref); - if (safe_create_leading_directories(filename)) - die("unable to create leading directory for %s", filename); - fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666); - if (fd < 0) { - error("Writing %s", lock_filename); - perror("Open"); + if (!memcmp(lock->old_sha1, sha1, 20)) { + unlock_ref(lock); + return 0; } - retval = write_ref_file(filename, lock_filename, fd, sha1); - free(filename); - free(lock_filename); - return retval; + if (write(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 || + write(lock->lock_fd, &term, 1) != 1 + || close(lock->lock_fd) < 0) { + error("Couldn't write %s", lock->lock_file); + unlock_ref(lock); + return -1; + } + if (rename(lock->lock_file, lock->ref_file) < 0) { + error("Couldn't set %s", lock->ref_file); + unlock_ref(lock); + return -1; + } + lock->lock_fd = -1; + unlock_ref(lock); + return 0; } @@ -1,6 +1,13 @@ #ifndef REFS_H #define REFS_H +struct ref_lock { + char *ref_file; + char *lock_file; + unsigned char old_sha1[20]; + int lock_fd; +}; + /* * Calls the specified function for each ref file until it returns nonzero, * and returns the value @@ -14,16 +21,17 @@ extern int for_each_remote_ref(int (*fn)(const char *path, const unsigned char * /** Reads the refs file specified into sha1 **/ extern int get_ref_sha1(const char *ref, unsigned char *sha1); -/** Locks ref and returns the fd to give to write_ref_sha1() if the ref - * has the given value currently; otherwise, returns -1. - **/ -extern int lock_ref_sha1(const char *ref, const unsigned char *old_sha1); +/** Locks a "refs/" ref returning the lock on success and NULL on failure. **/ +extern struct ref_lock* lock_ref_sha1(const char *ref, const unsigned char *old_sha1, int mustexist); + +/** Locks any ref (for 'HEAD' type refs). */ +extern struct ref_lock* lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int mustexist); -/** Writes sha1 into the refs file specified, locked with the given fd. **/ -extern int write_ref_sha1(const char *ref, int fd, const unsigned char *sha1); +/** Release any lock taken but not written. **/ +extern void unlock_ref (struct ref_lock *lock); -/** Writes sha1 into the refs file specified. **/ -extern int write_ref_sha1_unlocked(const char *ref, const unsigned char *sha1); +/** Writes sha1 into the ref specified by the lock. **/ +extern int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1, const char *msg); /** Returns 0 if target has the right format for a ref. **/ extern int check_ref_format(const char *target); 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