Merge branch 'jk/two-way-merge-corner-case-fix' into maint
[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 commit_patch_id(struct commit *commit, struct diff_options *options,
8                     unsigned char *sha1)
9 {
10         if (commit->parents)
11                 diff_tree_sha1(commit->parents->item->object.sha1,
12                                commit->object.sha1, "", options);
13         else
14                 diff_root_tree_sha1(commit->object.sha1, "", options);
15         diffcore_std(options);
16         return diff_flush_patch_id(options, sha1);
17 }
18
19 static const unsigned char *patch_id_access(size_t index, void *table)
20 {
21         struct patch_id **id_table = table;
22         return id_table[index]->patch_id;
23 }
24
25 static int patch_pos(struct patch_id **table, int nr, const unsigned char *id)
26 {
27         return sha1_pos(id, table, nr, patch_id_access);
28 }
29
30 #define BUCKET_SIZE 190 /* 190 * 21 = 3990, with slop close enough to 4K */
31 struct patch_id_bucket {
32         struct patch_id_bucket *next;
33         int nr;
34         struct patch_id bucket[BUCKET_SIZE];
35 };
36
37 int init_patch_ids(struct patch_ids *ids)
38 {
39         memset(ids, 0, sizeof(*ids));
40         diff_setup(&ids->diffopts);
41         DIFF_OPT_SET(&ids->diffopts, RECURSIVE);
42         diff_setup_done(&ids->diffopts);
43         return 0;
44 }
45
46 int free_patch_ids(struct patch_ids *ids)
47 {
48         struct patch_id_bucket *next, *patches;
49
50         free(ids->table);
51         for (patches = ids->patches; patches; patches = next) {
52                 next = patches->next;
53                 free(patches);
54         }
55         return 0;
56 }
57
58 static struct patch_id *add_commit(struct commit *commit,
59                                    struct patch_ids *ids,
60                                    int no_add)
61 {
62         struct patch_id_bucket *bucket;
63         struct patch_id *ent;
64         unsigned char sha1[20];
65         int pos;
66
67         if (commit_patch_id(commit, &ids->diffopts, sha1))
68                 return NULL;
69         pos = patch_pos(ids->table, ids->nr, sha1);
70         if (0 <= pos)
71                 return ids->table[pos];
72         if (no_add)
73                 return NULL;
74
75         pos = -1 - pos;
76
77         bucket = ids->patches;
78         if (!bucket || (BUCKET_SIZE <= bucket->nr)) {
79                 bucket = xcalloc(1, sizeof(*bucket));
80                 bucket->next = ids->patches;
81                 ids->patches = bucket;
82         }
83         ent = &bucket->bucket[bucket->nr++];
84         hashcpy(ent->patch_id, sha1);
85
86         if (ids->alloc <= ids->nr) {
87                 ids->alloc = alloc_nr(ids->nr);
88                 ids->table = xrealloc(ids->table, sizeof(ent) * ids->alloc);
89         }
90         if (pos < ids->nr)
91                 memmove(ids->table + pos + 1, ids->table + pos,
92                         sizeof(ent) * (ids->nr - pos));
93         ids->nr++;
94         ids->table[pos] = ent;
95         return ids->table[pos];
96 }
97
98 struct patch_id *has_commit_patch_id(struct commit *commit,
99                                      struct patch_ids *ids)
100 {
101         return add_commit(commit, ids, 1);
102 }
103
104 struct patch_id *add_commit_patch_id(struct commit *commit,
105                                      struct patch_ids *ids)
106 {
107         return add_commit(commit, ids, 0);
108 }