Merge branch 'jc/rename-degrade-cc-to-c'
[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         if (diff_setup_done(&ids->diffopts) < 0)
43                 return error("diff_setup_done failed");
44         return 0;
45 }
46
47 int free_patch_ids(struct patch_ids *ids)
48 {
49         struct patch_id_bucket *next, *patches;
50
51         free(ids->table);
52         for (patches = ids->patches; patches; patches = next) {
53                 next = patches->next;
54                 free(patches);
55         }
56         return 0;
57 }
58
59 static struct patch_id *add_commit(struct commit *commit,
60                                    struct patch_ids *ids,
61                                    int no_add)
62 {
63         struct patch_id_bucket *bucket;
64         struct patch_id *ent;
65         unsigned char sha1[20];
66         int pos;
67
68         if (commit_patch_id(commit, &ids->diffopts, sha1))
69                 return NULL;
70         pos = patch_pos(ids->table, ids->nr, sha1);
71         if (0 <= pos)
72                 return ids->table[pos];
73         if (no_add)
74                 return NULL;
75
76         pos = -1 - pos;
77
78         bucket = ids->patches;
79         if (!bucket || (BUCKET_SIZE <= bucket->nr)) {
80                 bucket = xcalloc(1, sizeof(*bucket));
81                 bucket->next = ids->patches;
82                 ids->patches = bucket;
83         }
84         ent = &bucket->bucket[bucket->nr++];
85         hashcpy(ent->patch_id, sha1);
86
87         if (ids->alloc <= ids->nr) {
88                 ids->alloc = alloc_nr(ids->nr);
89                 ids->table = xrealloc(ids->table, sizeof(ent) * ids->alloc);
90         }
91         if (pos < ids->nr)
92                 memmove(ids->table + pos + 1, ids->table + pos,
93                         sizeof(ent) * (ids->nr - pos));
94         ids->nr++;
95         ids->table[pos] = ent;
96         return ids->table[pos];
97 }
98
99 struct patch_id *has_commit_patch_id(struct commit *commit,
100                                      struct patch_ids *ids)
101 {
102         return add_commit(commit, ids, 1);
103 }
104
105 struct patch_id *add_commit_patch_id(struct commit *commit,
106                                      struct patch_ids *ids)
107 {
108         return add_commit(commit, ids, 0);
109 }