builtin-pack-refs.c

   1 #include "cache.h"
   2 #include "refs.h"
   3
   4 static const char *result_path, *lock_path;
   5 static const char builtin_pack_refs_usage[] =
   6 "git-pack-refs [--prune]";
   7
   8 struct ref_to_prune {
   9         struct ref_to_prune *next;
  10         unsigned char sha1[20];
  11         char name[FLEX_ARRAY];
  12 };
  13
  14 struct pack_refs_cb_data {
  15         int prune;
  16         struct ref_to_prune *ref_to_prune;
  17         FILE *refs_file;
  18 };
  19
  20 static void remove_lock_file(void)
  21 {
  22         if (lock_path)
  23                 unlink(lock_path);
  24 }
  25
  26 static int do_not_prune(int flags)
  27 {
  28         /* If it is already packed or if it is a symref,
  29          * do not prune it.
  30          */
  31         return (flags & (REF_ISSYMREF|REF_ISPACKED));
  32 }
  33
  34 static int handle_one_ref(const char *path, const unsigned char *sha1,
  35                           int flags, void *cb_data)
  36 {
  37         struct pack_refs_cb_data *cb = cb_data;
  38
  39         /* Do not pack the symbolic refs */
  40         if (!(flags & REF_ISSYMREF))
  41                 fprintf(cb->refs_file, "%s %s\n", sha1_to_hex(sha1), path);
  42         if (cb->prune && !do_not_prune(flags)) {
  43                 int namelen = strlen(path) + 1;
  44                 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
  45                 hashcpy(n->sha1, sha1);
  46                 strcpy(n->name, path);
  47                 n->next = cb->ref_to_prune;
  48                 cb->ref_to_prune = n;
  49         }
  50         return 0;
  51 }
  52
  53 /* make sure nobody touched the ref, and unlink */
  54 static void prune_ref(struct ref_to_prune *r)
  55 {
  56         struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1, 1);
  57
  58         if (lock) {
  59                 unlink(git_path(r->name));
  60                 unlock_ref(lock);
  61         }
  62 }
  63
  64 static void prune_refs(struct ref_to_prune *r)
  65 {
  66         while (r) {
  67                 prune_ref(r);
  68                 r = r->next;
  69         }
  70 }
  71
  72 int cmd_pack_refs(int argc, const char **argv, const char *prefix)
  73 {
  74         int fd, i;
  75         struct pack_refs_cb_data cbdata;
  76
  77         memset(&cbdata, 0, sizeof(cbdata));
  78
  79         for (i = 1; i < argc; i++) {
  80                 const char *arg = argv[i];
  81                 if (!strcmp(arg, "--prune")) {
  82                         cbdata.prune = 1;
  83                         continue;
  84                 }
  85                 /* perhaps other parameters later... */
  86                 break;
  87         }
  88         if (i != argc)
  89                 usage(builtin_pack_refs_usage);
  90
  91         result_path = xstrdup(git_path("packed-refs"));
  92         lock_path = xstrdup(mkpath("%s.lock", result_path));
  93
  94         fd = open(lock_path, O_CREAT | O_EXCL | O_WRONLY, 0666);
  95         if (fd < 0)
  96                 die("unable to create new ref-pack file (%s)", strerror(errno));
  97         atexit(remove_lock_file);
  98
  99         cbdata.refs_file = fdopen(fd, "w");
 100         if (!cbdata.refs_file)
 101                 die("unable to create ref-pack file structure (%s)",
 102                     strerror(errno));
 103         for_each_ref(handle_one_ref, &cbdata);
 104         fsync(fd);
 105         fclose(cbdata.refs_file);
 106         if (rename(lock_path, result_path) < 0)
 107                 die("unable to overwrite old ref-pack file (%s)", strerror(errno));
 108         lock_path = NULL;
 109         if (cbdata.prune)
 110                 prune_refs(cbdata.ref_to_prune);
 111         return 0;
 112 }