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Commit | Line | Data |
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1 | /* | |
2 | * decorate.c - decorate a git object with some arbitrary | |
3 | * data. | |
4 | */ | |
5 | #include "cache.h" | |
6 | #include "object.h" | |
7 | #include "decorate.h" | |
8 | ||
9 | static unsigned int hash_obj(const struct object *obj, unsigned int n) | |
10 | { | |
11 | unsigned int hash; | |
12 | ||
13 | memcpy(&hash, obj->sha1, sizeof(unsigned int)); | |
14 | return hash % n; | |
15 | } | |
16 | ||
17 | static void *insert_decoration(struct decoration *n, const struct object *base, void *decoration) | |
18 | { | |
19 | int size = n->size; | |
20 | struct object_decoration *hash = n->hash; | |
21 | unsigned int j = hash_obj(base, size); | |
22 | ||
23 | while (hash[j].base) { | |
24 | if (hash[j].base == base) { | |
25 | void *old = hash[j].decoration; | |
26 | hash[j].decoration = decoration; | |
27 | return old; | |
28 | } | |
29 | if (++j >= size) | |
30 | j = 0; | |
31 | } | |
32 | hash[j].base = base; | |
33 | hash[j].decoration = decoration; | |
34 | n->nr++; | |
35 | return NULL; | |
36 | } | |
37 | ||
38 | static void grow_decoration(struct decoration *n) | |
39 | { | |
40 | int i; | |
41 | int old_size = n->size; | |
42 | struct object_decoration *old_hash = n->hash; | |
43 | ||
44 | n->size = (old_size + 1000) * 3 / 2; | |
45 | n->hash = xcalloc(n->size, sizeof(struct object_decoration)); | |
46 | n->nr = 0; | |
47 | ||
48 | for (i = 0; i < old_size; i++) { | |
49 | const struct object *base = old_hash[i].base; | |
50 | void *decoration = old_hash[i].decoration; | |
51 | ||
52 | if (!base) | |
53 | continue; | |
54 | insert_decoration(n, base, decoration); | |
55 | } | |
56 | free(old_hash); | |
57 | } | |
58 | ||
59 | /* Add a decoration pointer, return any old one */ | |
60 | void *add_decoration(struct decoration *n, const struct object *obj, | |
61 | void *decoration) | |
62 | { | |
63 | int nr = n->nr + 1; | |
64 | ||
65 | if (nr > n->size * 2 / 3) | |
66 | grow_decoration(n); | |
67 | return insert_decoration(n, obj, decoration); | |
68 | } | |
69 | ||
70 | /* Lookup a decoration pointer */ | |
71 | void *lookup_decoration(struct decoration *n, const struct object *obj) | |
72 | { | |
73 | unsigned int j; | |
74 | ||
75 | /* nothing to lookup */ | |
76 | if (!n->size) | |
77 | return NULL; | |
78 | j = hash_obj(obj, n->size); | |
79 | for (;;) { | |
80 | struct object_decoration *ref = n->hash + j; | |
81 | if (ref->base == obj) | |
82 | return ref->decoration; | |
83 | if (!ref->base) | |
84 | return NULL; | |
85 | if (++j == n->size) | |
86 | j = 0; | |
87 | } | |
88 | } |