archive: stop passing "stage" through read_tree_recursive()
[git] / pack-objects.c
1 #include "cache.h"
2 #include "object.h"
3 #include "pack.h"
4 #include "pack-objects.h"
5 #include "packfile.h"
6 #include "config.h"
7
8 static uint32_t locate_object_entry_hash(struct packing_data *pdata,
9                                          const struct object_id *oid,
10                                          int *found)
11 {
12         uint32_t i, mask = (pdata->index_size - 1);
13
14         i = oidhash(oid) & mask;
15
16         while (pdata->index[i] > 0) {
17                 uint32_t pos = pdata->index[i] - 1;
18
19                 if (oideq(oid, &pdata->objects[pos].idx.oid)) {
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
51         free(pdata->index);
52         pdata->index = xcalloc(pdata->index_size, sizeof(*pdata->index));
53
54         entry = pdata->objects;
55
56         for (i = 0; i < pdata->nr_objects; i++) {
57                 int found;
58                 uint32_t ix = locate_object_entry_hash(pdata,
59                                                        &entry->idx.oid,
60                                                        &found);
61
62                 if (found)
63                         BUG("Duplicate object in hash");
64
65                 pdata->index[ix] = i + 1;
66                 entry++;
67         }
68 }
69
70 struct object_entry *packlist_find(struct packing_data *pdata,
71                                    const struct object_id *oid)
72 {
73         uint32_t i;
74         int found;
75
76         if (!pdata->index_size)
77                 return NULL;
78
79         i = locate_object_entry_hash(pdata, oid, &found);
80
81         if (!found)
82                 return NULL;
83
84         return &pdata->objects[pdata->index[i] - 1];
85 }
86
87 static void prepare_in_pack_by_idx(struct packing_data *pdata)
88 {
89         struct packed_git **mapping, *p;
90         int cnt = 0, nr = 1U << OE_IN_PACK_BITS;
91
92         ALLOC_ARRAY(mapping, nr);
93         /*
94          * oe_in_pack() on an all-zero'd object_entry
95          * (i.e. in_pack_idx also zero) should return NULL.
96          */
97         mapping[cnt++] = NULL;
98         for (p = get_all_packs(pdata->repo); p; p = p->next, cnt++) {
99                 if (cnt == nr) {
100                         free(mapping);
101                         return;
102                 }
103                 p->index = cnt;
104                 mapping[cnt] = p;
105         }
106         pdata->in_pack_by_idx = mapping;
107 }
108
109 /*
110  * A new pack appears after prepare_in_pack_by_idx() has been
111  * run. This is likely a race.
112  *
113  * We could map this new pack to in_pack_by_idx[] array, but then we
114  * have to deal with full array anyway. And since it's hard to test
115  * this fall back code, just stay simple and fall back to using
116  * in_pack[] array.
117  */
118 void oe_map_new_pack(struct packing_data *pack)
119 {
120         uint32_t i;
121
122         if (pack->in_pack)
123                 BUG("packing_data has already been converted to pack array");
124
125         ALLOC_ARRAY(pack->in_pack, pack->nr_alloc);
126
127         for (i = 0; i < pack->nr_objects; i++)
128                 pack->in_pack[i] = oe_in_pack(pack, pack->objects + i);
129
130         FREE_AND_NULL(pack->in_pack_by_idx);
131 }
132
133 /* assume pdata is already zero'd by caller */
134 void prepare_packing_data(struct repository *r, struct packing_data *pdata)
135 {
136         pdata->repo = r;
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         }
146
147         pdata->oe_size_limit = git_env_ulong("GIT_TEST_OE_SIZE",
148                                              1U << OE_SIZE_BITS);
149         pdata->oe_delta_size_limit = git_env_ulong("GIT_TEST_OE_DELTA_SIZE",
150                                                    1UL << OE_DELTA_SIZE_BITS);
151         init_recursive_mutex(&pdata->odb_lock);
152 }
153
154 struct object_entry *packlist_alloc(struct packing_data *pdata,
155                                     const struct object_id *oid)
156 {
157         struct object_entry *new_entry;
158
159         if (pdata->nr_objects >= pdata->nr_alloc) {
160                 pdata->nr_alloc = (pdata->nr_alloc  + 1024) * 3 / 2;
161                 REALLOC_ARRAY(pdata->objects, pdata->nr_alloc);
162
163                 if (!pdata->in_pack_by_idx)
164                         REALLOC_ARRAY(pdata->in_pack, pdata->nr_alloc);
165                 if (pdata->delta_size)
166                         REALLOC_ARRAY(pdata->delta_size, pdata->nr_alloc);
167
168                 if (pdata->tree_depth)
169                         REALLOC_ARRAY(pdata->tree_depth, pdata->nr_alloc);
170
171                 if (pdata->layer)
172                         REALLOC_ARRAY(pdata->layer, pdata->nr_alloc);
173         }
174
175         new_entry = pdata->objects + pdata->nr_objects++;
176
177         memset(new_entry, 0, sizeof(*new_entry));
178         oidcpy(&new_entry->idx.oid, oid);
179
180         if (pdata->index_size * 3 <= pdata->nr_objects * 4)
181                 rehash_objects(pdata);
182         else {
183                 int found;
184                 uint32_t pos = locate_object_entry_hash(pdata,
185                                                         &new_entry->idx.oid,
186                                                         &found);
187                 if (found)
188                         BUG("duplicate object inserted into hash");
189                 pdata->index[pos] = pdata->nr_objects;
190         }
191
192         if (pdata->in_pack)
193                 pdata->in_pack[pdata->nr_objects - 1] = NULL;
194
195         if (pdata->tree_depth)
196                 pdata->tree_depth[pdata->nr_objects - 1] = 0;
197
198         if (pdata->layer)
199                 pdata->layer[pdata->nr_objects - 1] = 0;
200
201         return new_entry;
202 }
203
204 void oe_set_delta_ext(struct packing_data *pdata,
205                       struct object_entry *delta,
206                       const struct object_id *oid)
207 {
208         struct object_entry *base;
209
210         ALLOC_GROW(pdata->ext_bases, pdata->nr_ext + 1, pdata->alloc_ext);
211         base = &pdata->ext_bases[pdata->nr_ext++];
212         memset(base, 0, sizeof(*base));
213         oidcpy(&base->idx.oid, oid);
214
215         /* These flags mark that we are not part of the actual pack output. */
216         base->preferred_base = 1;
217         base->filled = 1;
218
219         delta->ext_base = 1;
220         delta->delta_idx = base - pdata->ext_bases + 1;
221 }