Merge branch 'rs/blame-optim'
[git] / patch-ids.c
1 #include "cache.h"
2 #include "diff.h"
3 #include "commit.h"
4 #include "hash-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                     struct object_id *oid, int diff_header_only, int stable)
15 {
16         if (!patch_id_defined(commit))
17                 return -1;
18
19         if (commit->parents)
20                 diff_tree_oid(&commit->parents->item->object.oid,
21                               &commit->object.oid, "", options);
22         else
23                 diff_root_tree_oid(&commit->object.oid, "", options);
24         diffcore_std(options);
25         return diff_flush_patch_id(options, oid, diff_header_only, stable);
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 "neq" 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_neq(const void *cmpfn_data,
39                         const struct hashmap_entry *eptr,
40                         const struct hashmap_entry *entry_or_key,
41                         const void *unused_keydata)
42 {
43         /* NEEDSWORK: const correctness? */
44         struct diff_options *opt = (void *)cmpfn_data;
45         struct patch_id *a, *b;
46
47         a = container_of(eptr, struct patch_id, ent);
48         b = container_of(entry_or_key, struct patch_id, ent);
49
50         if (is_null_oid(&a->patch_id) &&
51             commit_patch_id(a->commit, opt, &a->patch_id, 0, 0))
52                 return error("Could not get patch ID for %s",
53                         oid_to_hex(&a->commit->object.oid));
54         if (is_null_oid(&b->patch_id) &&
55             commit_patch_id(b->commit, opt, &b->patch_id, 0, 0))
56                 return error("Could not get patch ID for %s",
57                         oid_to_hex(&b->commit->object.oid));
58         return !oideq(&a->patch_id, &b->patch_id);
59 }
60
61 int init_patch_ids(struct repository *r, struct patch_ids *ids)
62 {
63         memset(ids, 0, sizeof(*ids));
64         repo_diff_setup(r, &ids->diffopts);
65         ids->diffopts.detect_rename = 0;
66         ids->diffopts.flags.recursive = 1;
67         diff_setup_done(&ids->diffopts);
68         hashmap_init(&ids->patches, patch_id_neq, &ids->diffopts, 256);
69         return 0;
70 }
71
72 int free_patch_ids(struct patch_ids *ids)
73 {
74         hashmap_clear_and_free(&ids->patches, struct patch_id, ent);
75         return 0;
76 }
77
78 static int init_patch_id_entry(struct patch_id *patch,
79                                struct commit *commit,
80                                struct patch_ids *ids)
81 {
82         struct object_id header_only_patch_id;
83
84         patch->commit = commit;
85         if (commit_patch_id(commit, &ids->diffopts, &header_only_patch_id, 1, 0))
86                 return -1;
87
88         hashmap_entry_init(&patch->ent, oidhash(&header_only_patch_id));
89         return 0;
90 }
91
92 struct patch_id *patch_id_iter_first(struct commit *commit,
93                                      struct patch_ids *ids)
94 {
95         struct patch_id patch;
96
97         if (!patch_id_defined(commit))
98                 return NULL;
99
100         memset(&patch, 0, sizeof(patch));
101         if (init_patch_id_entry(&patch, commit, ids))
102                 return NULL;
103
104         return hashmap_get_entry(&ids->patches, &patch, ent, NULL);
105 }
106
107 struct patch_id *patch_id_iter_next(struct patch_id *cur,
108                                     struct patch_ids *ids)
109 {
110         return hashmap_get_next_entry(&ids->patches, cur, ent);
111 }
112
113 int has_commit_patch_id(struct commit *commit,
114                         struct patch_ids *ids)
115 {
116         return !!patch_id_iter_first(commit, ids);
117 }
118
119 struct patch_id *add_commit_patch_id(struct commit *commit,
120                                      struct patch_ids *ids)
121 {
122         struct patch_id *key;
123
124         if (!patch_id_defined(commit))
125                 return NULL;
126
127         key = xcalloc(1, sizeof(*key));
128         if (init_patch_id_entry(key, commit, ids)) {
129                 free(key);
130                 return NULL;
131         }
132
133         hashmap_add(&ids->patches, &key->ent);
134         return key;
135 }