Merge branch 'jk/ident-ai-canonname-could-be-null'
[git] / patch-ids.c
1 #include "cache.h"
2 #include "diff.h"
3 #include "commit.h"
4 #include "sha1-lookup.h"
5 #include "patch-ids.h"
6
7 static int patch_id_defined(struct commit *commit)
8 {
9         /* must be 0 or 1 parents */
10         return !commit->parents || !commit->parents->next;
11 }
12
13 int commit_patch_id(struct commit *commit, struct diff_options *options,
14                     unsigned char *sha1, int diff_header_only)
15 {
16         if (!patch_id_defined(commit))
17                 return -1;
18
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);
26 }
27
28 /*
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.
37  */
38 static int patch_id_cmp(struct patch_id *a,
39                         struct patch_id *b,
40                         struct diff_options *opt)
41 {
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);
51 }
52
53 int init_patch_ids(struct patch_ids *ids)
54 {
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;
62 }
63
64 int free_patch_ids(struct patch_ids *ids)
65 {
66         hashmap_free(&ids->patches, 1);
67         return 0;
68 }
69
70 static int init_patch_id_entry(struct patch_id *patch,
71                                struct commit *commit,
72                                struct patch_ids *ids)
73 {
74         unsigned char header_only_patch_id[GIT_SHA1_RAWSZ];
75
76         patch->commit = commit;
77         if (commit_patch_id(commit, &ids->diffopts, header_only_patch_id, 1))
78                 return -1;
79
80         hashmap_entry_init(patch, sha1hash(header_only_patch_id));
81         return 0;
82 }
83
84 struct patch_id *has_commit_patch_id(struct commit *commit,
85                                      struct patch_ids *ids)
86 {
87         struct patch_id patch;
88
89         if (!patch_id_defined(commit))
90                 return NULL;
91
92         memset(&patch, 0, sizeof(patch));
93         if (init_patch_id_entry(&patch, commit, ids))
94                 return NULL;
95
96         return hashmap_get(&ids->patches, &patch, &ids->diffopts);
97 }
98
99 struct patch_id *add_commit_patch_id(struct commit *commit,
100                                      struct patch_ids *ids)
101 {
102         struct patch_id *key = xcalloc(1, sizeof(*key));
103
104         if (!patch_id_defined(commit))
105                 return NULL;
106
107         if (init_patch_id_entry(key, commit, ids)) {
108                 free(key);
109                 return NULL;
110         }
111
112         hashmap_add(&ids->patches, key);
113         return key;
114 }