pack-objects: improve path grouping heuristics.

[git.git] / refs.c

diff --git a/refs.c b/refs.c
index 4be75a5..eeb1196 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -142,6 +142,8 @@ static int do_for_each_ref(const char *base, int (*fn)(const char *path, const u
                        namelen = strlen(de->d_name);
                        if (namelen > 255)
                                continue;
+                       if (namelen>5 && !strcmp(de->d_name+namelen-5,".lock"))
+                               continue;
                        memcpy(path + baselen, de->d_name, namelen+1);
                        if (stat(git_path("%s", path), &st) < 0)
                                continue;
@@ -288,6 +290,7 @@ static struct ref_lock* lock_ref_sha1_basic(const char *path,
        const unsigned char *old_sha1, int mustexist)
 {
        struct ref_lock *lock;
+       struct stat st;
 
        lock = xcalloc(1, sizeof(struct ref_lock));
        lock->lock_fd = -1;
@@ -295,7 +298,6 @@ static struct ref_lock* lock_ref_sha1_basic(const char *path,
        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;
        }
@@ -303,6 +305,7 @@ static struct ref_lock* lock_ref_sha1_basic(const char *path,
        lock->ref_file = strdup(path);
        lock->lock_file = strdup(mkpath("%s.lock", lock->ref_file));
        lock->log_file = strdup(git_path("logs/%s", lock->ref_file + plen));
+       lock->force_write = lstat(lock->ref_file, &st) && errno == ENOENT;
 
        if (safe_create_leading_directories(lock->lock_file))
                die("unable to create directory for %s", lock->lock_file);
@@ -324,7 +327,7 @@ struct ref_lock* lock_ref_sha1(const char *ref,
        if (check_ref_format(ref))
                return NULL;
        return lock_ref_sha1_basic(git_path("refs/%s", ref),
-               strlen(ref), old_sha1, mustexist);
+               5 + strlen(ref), old_sha1, mustexist);
 }
 
 struct ref_lock* lock_any_ref_for_update(const char *ref,
@@ -405,7 +408,7 @@ int write_ref_sha1(struct ref_lock *lock,
 
        if (!lock)
                return -1;
-       if (!memcmp(lock->old_sha1, sha1, 20)) {
+       if (!lock->force_write && !memcmp(lock->old_sha1, sha1, 20)) {
                unlock_ref(lock);
                return 0;
        }
@@ -429,3 +432,82 @@ int write_ref_sha1(struct ref_lock *lock,
        unlock_ref(lock);
        return 0;
 }
+
+int read_ref_at(const char *ref, unsigned long at_time, unsigned char *sha1)
+{
+       const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
+       char *tz_c;
+       int logfd, tz;
+       struct stat st;
+       unsigned long date;
+       unsigned char logged_sha1[20];
+
+       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);
+       logdata = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, logfd, 0);
+       close(logfd);
+
+       lastrec = NULL;
+       rec = logend = logdata + st.st_size;
+       while (logdata < rec) {
+               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) {
+                       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 (memcmp(logged_sha1, sha1, 20)) {
+                                       tz = strtoul(tz_c, NULL, 10);
+                                       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 (memcmp(logged_sha1, sha1, 20)) {
+                                       tz = strtoul(tz_c, NULL, 10);
+                                       fprintf(stderr,
+                                               "warning: Log %s unexpectedly ended on %s.\n",
+                                               logfile, show_rfc2822_date(date, tz));
+                               }
+                       }
+                       munmap((void*)logdata, st.st_size);
+                       return 0;
+               }
+               lastrec = rec;
+       }
+
+       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);
+       munmap((void*)logdata, st.st_size);
+       fprintf(stderr, "warning: Log %s only goes back to %s.\n",
+               logfile, show_rfc2822_date(date, tz));
+       return 0;
+}