Documentation/stash: remove mention of git reset --hard
[git.git] / patch-ids.c
blobce285c2e0c552ecf725c87052846d755507bd9db
1 #include "cache.h"
2 #include "diff.h"
3 #include "commit.h"
4 #include "sha1-lookup.h"
5 #include "patch-ids.h"
7 static int patch_id_defined(struct commit *commit)
9 /* must be 0 or 1 parents */
10 return !commit->parents || !commit->parents->next;
13 int commit_patch_id(struct commit *commit, struct diff_options *options,
14 unsigned char *sha1, int diff_header_only)
16 if (!patch_id_defined(commit))
17 return -1;
19 if (commit->parents)
20 diff_tree_sha1(commit->parents->item->object.oid.hash,
21 commit->object.oid.hash, "", options);
22 else
23 diff_root_tree_sha1(commit->object.oid.hash, "", options);
24 diffcore_std(options);
25 return diff_flush_patch_id(options, sha1, diff_header_only);
29 * When we cannot load the full patch-id for both commits for whatever
30 * reason, the function returns -1 (i.e. return error(...)). Despite
31 * the "cmp" in the name of this function, the caller only cares about
32 * the return value being zero (a and b are equivalent) or non-zero (a
33 * and b are different), and returning non-zero would keep both in the
34 * result, even if they actually were equivalent, in order to err on
35 * the side of safety. The actual value being negative does not have
36 * any significance; only that it is non-zero matters.
38 static int patch_id_cmp(struct patch_id *a,
39 struct patch_id *b,
40 struct diff_options *opt)
42 if (is_null_sha1(a->patch_id) &&
43 commit_patch_id(a->commit, opt, a->patch_id, 0))
44 return error("Could not get patch ID for %s",
45 oid_to_hex(&a->commit->object.oid));
46 if (is_null_sha1(b->patch_id) &&
47 commit_patch_id(b->commit, opt, b->patch_id, 0))
48 return error("Could not get patch ID for %s",
49 oid_to_hex(&b->commit->object.oid));
50 return hashcmp(a->patch_id, b->patch_id);
53 int init_patch_ids(struct patch_ids *ids)
55 memset(ids, 0, sizeof(*ids));
56 diff_setup(&ids->diffopts);
57 ids->diffopts.detect_rename = 0;
58 DIFF_OPT_SET(&ids->diffopts, RECURSIVE);
59 diff_setup_done(&ids->diffopts);
60 hashmap_init(&ids->patches, (hashmap_cmp_fn)patch_id_cmp, 256);
61 return 0;
64 int free_patch_ids(struct patch_ids *ids)
66 hashmap_free(&ids->patches, 1);
67 return 0;
70 static int init_patch_id_entry(struct patch_id *patch,
71 struct commit *commit,
72 struct patch_ids *ids)
74 unsigned char header_only_patch_id[GIT_SHA1_RAWSZ];
76 patch->commit = commit;
77 if (commit_patch_id(commit, &ids->diffopts, header_only_patch_id, 1))
78 return -1;
80 hashmap_entry_init(patch, sha1hash(header_only_patch_id));
81 return 0;
84 struct patch_id *has_commit_patch_id(struct commit *commit,
85 struct patch_ids *ids)
87 struct patch_id patch;
89 if (!patch_id_defined(commit))
90 return NULL;
92 memset(&patch, 0, sizeof(patch));
93 if (init_patch_id_entry(&patch, commit, ids))
94 return NULL;
96 return hashmap_get(&ids->patches, &patch, &ids->diffopts);
99 struct patch_id *add_commit_patch_id(struct commit *commit,
100 struct patch_ids *ids)
102 struct patch_id *key = xcalloc(1, sizeof(*key));
104 if (!patch_id_defined(commit))
105 return NULL;
107 if (init_patch_id_entry(key, commit, ids)) {
108 free(key);
109 return NULL;
112 hashmap_add(&ids->patches, key);
113 return key;