Start preparing for 1.8.4.2
[alt-git.git] / decorate.c
blob7cb5d29a89a43ecf7e433db513b66184df3accb8
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"
9 static unsigned int hash_obj(const struct object *obj, unsigned int n)
11 unsigned int hash;
13 memcpy(&hash, obj->sha1, sizeof(unsigned int));
14 return hash % n;
17 static void *insert_decoration(struct decoration *n, const struct object *base, void *decoration)
19 int size = n->size;
20 struct object_decoration *hash = n->hash;
21 unsigned int j = hash_obj(base, size);
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;
29 if (++j >= size)
30 j = 0;
32 hash[j].base = base;
33 hash[j].decoration = decoration;
34 n->nr++;
35 return NULL;
38 static void grow_decoration(struct decoration *n)
40 int i;
41 int old_size = n->size;
42 struct object_decoration *old_hash = n->hash;
44 n->size = (old_size + 1000) * 3 / 2;
45 n->hash = xcalloc(n->size, sizeof(struct object_decoration));
46 n->nr = 0;
48 for (i = 0; i < old_size; i++) {
49 const struct object *base = old_hash[i].base;
50 void *decoration = old_hash[i].decoration;
52 if (!decoration)
53 continue;
54 insert_decoration(n, base, decoration);
56 free(old_hash);
59 /* Add a decoration pointer, return any old one */
60 void *add_decoration(struct decoration *n, const struct object *obj,
61 void *decoration)
63 int nr = n->nr + 1;
65 if (nr > n->size * 2 / 3)
66 grow_decoration(n);
67 return insert_decoration(n, obj, decoration);
70 /* Lookup a decoration pointer */
71 void *lookup_decoration(struct decoration *n, const struct object *obj)
73 unsigned int j;
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;