http.c: die if curl_*_init fails
[git] / pack-objects.c
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 {
10         uint32_t i, hash, mask = (pdata->index_size - 1);
11
12         memcpy(&hash, sha1, sizeof(uint32_t));
13         i = hash & mask;
14
15         while (pdata->index[i] > 0) {
16                 uint32_t pos = pdata->index[i] - 1;
17
18                 if (!hashcmp(sha1, pdata->objects[pos].idx.sha1)) {
19                         *found = 1;
20                         return i;
21                 }
22
23                 i = (i + 1) & mask;
24         }
25
26         *found = 0;
27         return i;
28 }
29
30 static inline uint32_t closest_pow2(uint32_t v)
31 {
32         v = v - 1;
33         v |= v >> 1;
34         v |= v >> 2;
35         v |= v >> 4;
36         v |= v >> 8;
37         v |= v >> 16;
38         return v + 1;
39 }
40
41 static void rehash_objects(struct packing_data *pdata)
42 {
43         uint32_t i;
44         struct object_entry *entry;
45
46         pdata->index_size = closest_pow2(pdata->nr_objects * 3);
47         if (pdata->index_size < 1024)
48                 pdata->index_size = 1024;
49
50         free(pdata->index);
51         pdata->index = xcalloc(pdata->index_size, sizeof(*pdata->index));
52
53         entry = pdata->objects;
54
55         for (i = 0; i < pdata->nr_objects; i++) {
56                 int found;
57                 uint32_t ix = locate_object_entry_hash(pdata, entry->idx.sha1, &found);
58
59                 if (found)
60                         die("BUG: Duplicate object in hash");
61
62                 pdata->index[ix] = i + 1;
63                 entry++;
64         }
65 }
66
67 struct object_entry *packlist_find(struct packing_data *pdata,
68                                    const unsigned char *sha1,
69                                    uint32_t *index_pos)
70 {
71         uint32_t i;
72         int found;
73
74         if (!pdata->index_size)
75                 return NULL;
76
77         i = locate_object_entry_hash(pdata, sha1, &found);
78
79         if (index_pos)
80                 *index_pos = i;
81
82         if (!found)
83                 return NULL;
84
85         return &pdata->objects[pdata->index[i] - 1];
86 }
87
88 struct object_entry *packlist_alloc(struct packing_data *pdata,
89                                     const unsigned char *sha1,
90                                     uint32_t index_pos)
91 {
92         struct object_entry *new_entry;
93
94         if (pdata->nr_objects >= pdata->nr_alloc) {
95                 pdata->nr_alloc = (pdata->nr_alloc  + 1024) * 3 / 2;
96                 pdata->objects = xrealloc(pdata->objects,
97                                           pdata->nr_alloc * sizeof(*new_entry));
98         }
99
100         new_entry = pdata->objects + pdata->nr_objects++;
101
102         memset(new_entry, 0, sizeof(*new_entry));
103         hashcpy(new_entry->idx.sha1, sha1);
104
105         if (pdata->index_size * 3 <= pdata->nr_objects * 4)
106                 rehash_objects(pdata);
107         else
108                 pdata->index[index_pos] = pdata->nr_objects;
109
110         return new_entry;
111 }