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2834bc27 VM |
1 | #include "cache.h" |
2 | #include "object.h" | |
3 | #include "pack.h" | |
4 | #include "pack-objects.h" | |
43fa44fa NTND |
5 | #include "packfile.h" |
6 | #include "config.h" | |
2834bc27 VM |
7 | |
8 | static uint32_t locate_object_entry_hash(struct packing_data *pdata, | |
9 | const unsigned char *sha1, | |
10 | int *found) | |
11 | { | |
039dc71a | 12 | uint32_t i, mask = (pdata->index_size - 1); |
2834bc27 | 13 | |
039dc71a | 14 | i = sha1hash(sha1) & mask; |
2834bc27 VM |
15 | |
16 | while (pdata->index[i] > 0) { | |
17 | uint32_t pos = pdata->index[i] - 1; | |
18 | ||
e6a492b7 | 19 | if (!hashcmp(sha1, pdata->objects[pos].idx.oid.hash)) { |
2834bc27 VM |
20 | *found = 1; |
21 | return i; | |
22 | } | |
23 | ||
24 | i = (i + 1) & mask; | |
25 | } | |
26 | ||
27 | *found = 0; | |
28 | return i; | |
29 | } | |
30 | ||
31 | static inline uint32_t closest_pow2(uint32_t v) | |
32 | { | |
33 | v = v - 1; | |
34 | v |= v >> 1; | |
35 | v |= v >> 2; | |
36 | v |= v >> 4; | |
37 | v |= v >> 8; | |
38 | v |= v >> 16; | |
39 | return v + 1; | |
40 | } | |
41 | ||
42 | static void rehash_objects(struct packing_data *pdata) | |
43 | { | |
44 | uint32_t i; | |
45 | struct object_entry *entry; | |
46 | ||
47 | pdata->index_size = closest_pow2(pdata->nr_objects * 3); | |
48 | if (pdata->index_size < 1024) | |
49 | pdata->index_size = 1024; | |
50 | ||
fb799474 RS |
51 | free(pdata->index); |
52 | pdata->index = xcalloc(pdata->index_size, sizeof(*pdata->index)); | |
2834bc27 VM |
53 | |
54 | entry = pdata->objects; | |
55 | ||
56 | for (i = 0; i < pdata->nr_objects; i++) { | |
57 | int found; | |
e6a492b7 | 58 | uint32_t ix = locate_object_entry_hash(pdata, |
59 | entry->idx.oid.hash, | |
60 | &found); | |
2834bc27 VM |
61 | |
62 | if (found) | |
033abf97 | 63 | BUG("Duplicate object in hash"); |
2834bc27 VM |
64 | |
65 | pdata->index[ix] = i + 1; | |
66 | entry++; | |
67 | } | |
68 | } | |
69 | ||
70 | struct object_entry *packlist_find(struct packing_data *pdata, | |
71 | const unsigned char *sha1, | |
72 | uint32_t *index_pos) | |
73 | { | |
74 | uint32_t i; | |
75 | int found; | |
76 | ||
77 | if (!pdata->index_size) | |
78 | return NULL; | |
79 | ||
80 | i = locate_object_entry_hash(pdata, sha1, &found); | |
81 | ||
82 | if (index_pos) | |
83 | *index_pos = i; | |
84 | ||
85 | if (!found) | |
86 | return NULL; | |
87 | ||
88 | return &pdata->objects[pdata->index[i] - 1]; | |
89 | } | |
90 | ||
43fa44fa NTND |
91 | static void prepare_in_pack_by_idx(struct packing_data *pdata) |
92 | { | |
93 | struct packed_git **mapping, *p; | |
94 | int cnt = 0, nr = 1U << OE_IN_PACK_BITS; | |
95 | ||
96 | ALLOC_ARRAY(mapping, nr); | |
97 | /* | |
98 | * oe_in_pack() on an all-zero'd object_entry | |
99 | * (i.e. in_pack_idx also zero) should return NULL. | |
100 | */ | |
101 | mapping[cnt++] = NULL; | |
102 | for (p = get_packed_git(the_repository); p; p = p->next, cnt++) { | |
103 | if (cnt == nr) { | |
104 | free(mapping); | |
105 | return; | |
106 | } | |
107 | p->index = cnt; | |
108 | mapping[cnt] = p; | |
109 | } | |
110 | pdata->in_pack_by_idx = mapping; | |
111 | } | |
112 | ||
113 | /* | |
114 | * A new pack appears after prepare_in_pack_by_idx() has been | |
115 | * run. This is likely a race. | |
116 | * | |
117 | * We could map this new pack to in_pack_by_idx[] array, but then we | |
118 | * have to deal with full array anyway. And since it's hard to test | |
119 | * this fall back code, just stay simple and fall back to using | |
120 | * in_pack[] array. | |
121 | */ | |
122 | void oe_map_new_pack(struct packing_data *pack, | |
123 | struct packed_git *p) | |
124 | { | |
125 | uint32_t i; | |
126 | ||
127 | REALLOC_ARRAY(pack->in_pack, pack->nr_alloc); | |
128 | ||
129 | for (i = 0; i < pack->nr_objects; i++) | |
130 | pack->in_pack[i] = oe_in_pack(pack, pack->objects + i); | |
131 | ||
132 | FREE_AND_NULL(pack->in_pack_by_idx); | |
133 | } | |
134 | ||
135 | /* assume pdata is already zero'd by caller */ | |
136 | void prepare_packing_data(struct packing_data *pdata) | |
137 | { | |
138 | if (git_env_bool("GIT_TEST_FULL_IN_PACK_ARRAY", 0)) { | |
139 | /* | |
140 | * do not initialize in_pack_by_idx[] to force the | |
141 | * slow path in oe_in_pack() | |
142 | */ | |
143 | } else { | |
144 | prepare_in_pack_by_idx(pdata); | |
145 | } | |
ac77d0c3 NTND |
146 | |
147 | pdata->oe_size_limit = git_env_ulong("GIT_TEST_OE_SIZE", | |
148 | 1U << OE_SIZE_BITS); | |
43fa44fa NTND |
149 | } |
150 | ||
2834bc27 VM |
151 | struct object_entry *packlist_alloc(struct packing_data *pdata, |
152 | const unsigned char *sha1, | |
153 | uint32_t index_pos) | |
154 | { | |
155 | struct object_entry *new_entry; | |
156 | ||
157 | if (pdata->nr_objects >= pdata->nr_alloc) { | |
158 | pdata->nr_alloc = (pdata->nr_alloc + 1024) * 3 / 2; | |
2756ca43 | 159 | REALLOC_ARRAY(pdata->objects, pdata->nr_alloc); |
43fa44fa NTND |
160 | |
161 | if (!pdata->in_pack_by_idx) | |
162 | REALLOC_ARRAY(pdata->in_pack, pdata->nr_alloc); | |
2834bc27 VM |
163 | } |
164 | ||
165 | new_entry = pdata->objects + pdata->nr_objects++; | |
166 | ||
167 | memset(new_entry, 0, sizeof(*new_entry)); | |
e6a492b7 | 168 | hashcpy(new_entry->idx.oid.hash, sha1); |
2834bc27 VM |
169 | |
170 | if (pdata->index_size * 3 <= pdata->nr_objects * 4) | |
171 | rehash_objects(pdata); | |
172 | else | |
173 | pdata->index[index_pos] = pdata->nr_objects; | |
174 | ||
43fa44fa NTND |
175 | if (pdata->in_pack) |
176 | pdata->in_pack[pdata->nr_objects - 1] = NULL; | |
177 | ||
2834bc27 VM |
178 | return new_entry; |
179 | } |