log_ref_setup(): improve robustness against races
[git/raj.git] / notes-cache.c
blob5dfc5cbd08e496748880bda6a67264c7d63f68b4
1 #include "cache.h"
2 #include "notes-cache.h"
3 #include "commit.h"
4 #include "refs.h"
6 static int notes_cache_match_validity(const char *ref, const char *validity)
8 unsigned char sha1[20];
9 struct commit *commit;
10 struct pretty_print_context pretty_ctx;
11 struct strbuf msg = STRBUF_INIT;
12 int ret;
14 if (read_ref(ref, sha1) < 0)
15 return 0;
17 commit = lookup_commit_reference_gently(sha1, 1);
18 if (!commit)
19 return 0;
21 memset(&pretty_ctx, 0, sizeof(pretty_ctx));
22 format_commit_message(commit, "%s", &msg, &pretty_ctx);
23 strbuf_trim(&msg);
25 ret = !strcmp(msg.buf, validity);
26 strbuf_release(&msg);
28 return ret;
31 void notes_cache_init(struct notes_cache *c, const char *name,
32 const char *validity)
34 struct strbuf ref = STRBUF_INIT;
35 int flags = NOTES_INIT_WRITABLE;
37 memset(c, 0, sizeof(*c));
38 c->validity = xstrdup(validity);
40 strbuf_addf(&ref, "refs/notes/%s", name);
41 if (!notes_cache_match_validity(ref.buf, validity))
42 flags |= NOTES_INIT_EMPTY;
43 init_notes(&c->tree, ref.buf, combine_notes_overwrite, flags);
44 strbuf_release(&ref);
47 int notes_cache_write(struct notes_cache *c)
49 unsigned char tree_sha1[20];
50 unsigned char commit_sha1[20];
52 if (!c || !c->tree.initialized || !c->tree.update_ref ||
53 !*c->tree.update_ref)
54 return -1;
55 if (!c->tree.dirty)
56 return 0;
58 if (write_notes_tree(&c->tree, tree_sha1))
59 return -1;
60 if (commit_tree(c->validity, strlen(c->validity), tree_sha1, NULL,
61 commit_sha1, NULL, NULL) < 0)
62 return -1;
63 if (update_ref("update notes cache", c->tree.update_ref, commit_sha1,
64 NULL, 0, UPDATE_REFS_QUIET_ON_ERR) < 0)
65 return -1;
67 return 0;
70 char *notes_cache_get(struct notes_cache *c, unsigned char key_sha1[20],
71 size_t *outsize)
73 const unsigned char *value_sha1;
74 enum object_type type;
75 char *value;
76 unsigned long size;
78 value_sha1 = get_note(&c->tree, key_sha1);
79 if (!value_sha1)
80 return NULL;
81 value = read_sha1_file(value_sha1, &type, &size);
83 *outsize = size;
84 return value;
87 int notes_cache_put(struct notes_cache *c, unsigned char key_sha1[20],
88 const char *data, size_t size)
90 unsigned char value_sha1[20];
92 if (write_sha1_file(data, size, "blob", value_sha1) < 0)
93 return -1;
94 return add_note(&c->tree, key_sha1, value_sha1, NULL);