Merge pull request #285 from dscho/readme
[git/mingw/4msysgit.git] / pack-objects.h
blobd1b98b30ffc468421a4eb82661d037f90cf580f2
1 #ifndef PACK_OBJECTS_H
2 #define PACK_OBJECTS_H
4 struct object_entry {
5 struct pack_idx_entry idx;
6 unsigned long size; /* uncompressed size */
7 struct packed_git *in_pack; /* already in pack */
8 off_t in_pack_offset;
9 struct object_entry *delta; /* delta base object */
10 struct object_entry *delta_child; /* deltified objects who bases me */
11 struct object_entry *delta_sibling; /* other deltified objects who
12 * uses the same base as me
14 void *delta_data; /* cached delta (uncompressed) */
15 unsigned long delta_size; /* delta data size (uncompressed) */
16 unsigned long z_delta_size; /* delta data size (compressed) */
17 enum object_type type;
18 enum object_type in_pack_type; /* could be delta */
19 uint32_t hash; /* name hint hash */
20 unsigned int in_pack_pos;
21 unsigned char in_pack_header_size;
22 unsigned preferred_base:1; /*
23 * we do not pack this, but is available
24 * to be used as the base object to delta
25 * objects against.
27 unsigned no_try_delta:1;
28 unsigned tagged:1; /* near the very tip of refs */
29 unsigned filled:1; /* assigned write-order */
32 struct packing_data {
33 struct object_entry *objects;
34 uint32_t nr_objects, nr_alloc;
36 int32_t *index;
37 uint32_t index_size;
40 struct object_entry *packlist_alloc(struct packing_data *pdata,
41 const unsigned char *sha1,
42 uint32_t index_pos);
44 struct object_entry *packlist_find(struct packing_data *pdata,
45 const unsigned char *sha1,
46 uint32_t *index_pos);
48 static inline uint32_t pack_name_hash(const char *name)
50 uint32_t c, hash = 0;
52 if (!name)
53 return 0;
56 * This effectively just creates a sortable number from the
57 * last sixteen non-whitespace characters. Last characters
58 * count "most", so things that end in ".c" sort together.
60 while ((c = *name++) != 0) {
61 if (isspace(c))
62 continue;
63 hash = (hash >> 2) + (c << 24);
65 return hash;
68 #endif