add a howto document about corrupted blob recovery
[git/jnareb-git/bp-gitweb.git] / builtin-pack-refs.c
bloba62f06bb89aa6ef035c26c4aad05c0fdbf0512de
1 #include "builtin.h"
2 #include "cache.h"
3 #include "refs.h"
4 #include "object.h"
5 #include "tag.h"
6 #include "parse-options.h"
8 struct ref_to_prune {
9 struct ref_to_prune *next;
10 unsigned char sha1[20];
11 char name[FLEX_ARRAY];
14 #define PACK_REFS_PRUNE 0x0001
15 #define PACK_REFS_ALL 0x0002
17 struct pack_refs_cb_data {
18 unsigned int flags;
19 struct ref_to_prune *ref_to_prune;
20 FILE *refs_file;
23 static int do_not_prune(int flags)
25 /* If it is already packed or if it is a symref,
26 * do not prune it.
28 return (flags & (REF_ISSYMREF|REF_ISPACKED));
31 static int handle_one_ref(const char *path, const unsigned char *sha1,
32 int flags, void *cb_data)
34 struct pack_refs_cb_data *cb = cb_data;
35 int is_tag_ref;
37 /* Do not pack the symbolic refs */
38 if ((flags & REF_ISSYMREF))
39 return 0;
40 is_tag_ref = !prefixcmp(path, "refs/tags/");
42 /* ALWAYS pack refs that were already packed or are tags */
43 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref && !(flags & REF_ISPACKED))
44 return 0;
46 fprintf(cb->refs_file, "%s %s\n", sha1_to_hex(sha1), path);
47 if (is_tag_ref) {
48 struct object *o = parse_object(sha1);
49 if (o->type == OBJ_TAG) {
50 o = deref_tag(o, path, 0);
51 if (o)
52 fprintf(cb->refs_file, "^%s\n",
53 sha1_to_hex(o->sha1));
57 if ((cb->flags & PACK_REFS_PRUNE) && !do_not_prune(flags)) {
58 int namelen = strlen(path) + 1;
59 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
60 hashcpy(n->sha1, sha1);
61 strcpy(n->name, path);
62 n->next = cb->ref_to_prune;
63 cb->ref_to_prune = n;
65 return 0;
68 /* make sure nobody touched the ref, and unlink */
69 static void prune_ref(struct ref_to_prune *r)
71 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
73 if (lock) {
74 unlink(git_path("%s", r->name));
75 unlock_ref(lock);
79 static void prune_refs(struct ref_to_prune *r)
81 while (r) {
82 prune_ref(r);
83 r = r->next;
87 static struct lock_file packed;
89 static int pack_refs(unsigned int flags)
91 int fd;
92 struct pack_refs_cb_data cbdata;
94 memset(&cbdata, 0, sizeof(cbdata));
95 cbdata.flags = flags;
97 fd = hold_lock_file_for_update(&packed, git_path("packed-refs"), 1);
98 cbdata.refs_file = fdopen(fd, "w");
99 if (!cbdata.refs_file)
100 die("unable to create ref-pack file structure (%s)",
101 strerror(errno));
103 /* perhaps other traits later as well */
104 fprintf(cbdata.refs_file, "# pack-refs with: peeled \n");
106 for_each_ref(handle_one_ref, &cbdata);
107 if (ferror(cbdata.refs_file))
108 die("failed to write ref-pack file");
109 if (fflush(cbdata.refs_file) || fsync(fd) || fclose(cbdata.refs_file))
110 die("failed to write ref-pack file (%s)", strerror(errno));
111 if (commit_lock_file(&packed) < 0)
112 die("unable to overwrite old ref-pack file (%s)", strerror(errno));
113 if (cbdata.flags & PACK_REFS_PRUNE)
114 prune_refs(cbdata.ref_to_prune);
115 return 0;
118 static char const * const pack_refs_usage[] = {
119 "git-pack-refs [options]",
120 NULL
123 int cmd_pack_refs(int argc, const char **argv, const char *prefix)
125 int all = 0, prune = 1;
126 unsigned int flags = 0;
127 struct option opts[] = {
128 OPT_BOOLEAN(0, "all", &all, "pack everything"),
129 OPT_BOOLEAN(0, "prune", &prune, "prune loose refs (default)"),
130 OPT_END(),
133 if (parse_options(argc, argv, opts, pack_refs_usage, 0))
134 usage_with_options(pack_refs_usage, opts);
135 if (prune)
136 flags |= PACK_REFS_PRUNE;
137 if (all)
138 flags |= PACK_REFS_ALL;
139 return pack_refs(flags);