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2834bc27 VM |
1 | #include "cache.h" |
2 | #include "object.h" | |
3 | #include "pack.h" | |
4 | #include "pack-objects.h" | |
5 | ||
6 | static uint32_t locate_object_entry_hash(struct packing_data *pdata, | |
7 | const unsigned char *sha1, | |
8 | int *found) | |
9 | { | |
039dc71a | 10 | uint32_t i, mask = (pdata->index_size - 1); |
2834bc27 | 11 | |
039dc71a | 12 | i = sha1hash(sha1) & mask; |
2834bc27 VM |
13 | |
14 | while (pdata->index[i] > 0) { | |
15 | uint32_t pos = pdata->index[i] - 1; | |
16 | ||
17 | if (!hashcmp(sha1, pdata->objects[pos].idx.sha1)) { | |
18 | *found = 1; | |
19 | return i; | |
20 | } | |
21 | ||
22 | i = (i + 1) & mask; | |
23 | } | |
24 | ||
25 | *found = 0; | |
26 | return i; | |
27 | } | |
28 | ||
29 | static inline uint32_t closest_pow2(uint32_t v) | |
30 | { | |
31 | v = v - 1; | |
32 | v |= v >> 1; | |
33 | v |= v >> 2; | |
34 | v |= v >> 4; | |
35 | v |= v >> 8; | |
36 | v |= v >> 16; | |
37 | return v + 1; | |
38 | } | |
39 | ||
40 | static void rehash_objects(struct packing_data *pdata) | |
41 | { | |
42 | uint32_t i; | |
43 | struct object_entry *entry; | |
44 | ||
45 | pdata->index_size = closest_pow2(pdata->nr_objects * 3); | |
46 | if (pdata->index_size < 1024) | |
47 | pdata->index_size = 1024; | |
48 | ||
fb799474 RS |
49 | free(pdata->index); |
50 | pdata->index = xcalloc(pdata->index_size, sizeof(*pdata->index)); | |
2834bc27 VM |
51 | |
52 | entry = pdata->objects; | |
53 | ||
54 | for (i = 0; i < pdata->nr_objects; i++) { | |
55 | int found; | |
56 | uint32_t ix = locate_object_entry_hash(pdata, entry->idx.sha1, &found); | |
57 | ||
58 | if (found) | |
59 | die("BUG: Duplicate object in hash"); | |
60 | ||
61 | pdata->index[ix] = i + 1; | |
62 | entry++; | |
63 | } | |
64 | } | |
65 | ||
66 | struct object_entry *packlist_find(struct packing_data *pdata, | |
67 | const unsigned char *sha1, | |
68 | uint32_t *index_pos) | |
69 | { | |
70 | uint32_t i; | |
71 | int found; | |
72 | ||
73 | if (!pdata->index_size) | |
74 | return NULL; | |
75 | ||
76 | i = locate_object_entry_hash(pdata, sha1, &found); | |
77 | ||
78 | if (index_pos) | |
79 | *index_pos = i; | |
80 | ||
81 | if (!found) | |
82 | return NULL; | |
83 | ||
84 | return &pdata->objects[pdata->index[i] - 1]; | |
85 | } | |
86 | ||
87 | struct object_entry *packlist_alloc(struct packing_data *pdata, | |
88 | const unsigned char *sha1, | |
89 | uint32_t index_pos) | |
90 | { | |
91 | struct object_entry *new_entry; | |
92 | ||
93 | if (pdata->nr_objects >= pdata->nr_alloc) { | |
94 | pdata->nr_alloc = (pdata->nr_alloc + 1024) * 3 / 2; | |
2756ca43 | 95 | REALLOC_ARRAY(pdata->objects, pdata->nr_alloc); |
2834bc27 VM |
96 | } |
97 | ||
98 | new_entry = pdata->objects + pdata->nr_objects++; | |
99 | ||
100 | memset(new_entry, 0, sizeof(*new_entry)); | |
101 | hashcpy(new_entry->idx.sha1, sha1); | |
102 | ||
103 | if (pdata->index_size * 3 <= pdata->nr_objects * 4) | |
104 | rehash_objects(pdata); | |
105 | else | |
106 | pdata->index[index_pos] = pdata->nr_objects; | |
107 | ||
108 | return new_entry; | |
109 | } |