blob: 7678b23b36c291c7b1b6656e0c42fc14ea12da15 [file] [log] [blame]
Junio C Hamano628522e2007-12-29 02:05:47 -08001#ifndef SHA1_LOOKUP_H
2#define SHA1_LOOKUP_H
3
Christian Couder96beef82009-04-04 22:59:26 +02004typedef const unsigned char *sha1_access_fn(size_t index, void *table);
5
6extern int sha1_pos(const unsigned char *sha1,
7 void *table,
8 size_t nr,
9 sha1_access_fn fn);
Jonathan Tanb4e00f72018-02-13 10:39:39 -080010
11/*
12 * Searches for sha1 in table, using the given fanout table to determine the
13 * interval to search, then using binary search. Returns 1 if found, 0 if not.
14 *
15 * Takes the following parameters:
16 *
17 * - sha1: the hash to search for
18 * - fanout_nbo: a 256-element array of NETWORK-order 32-bit integers; the
19 * integer at position i represents the number of elements in table whose
20 * first byte is less than or equal to i
21 * - table: a sorted list of hashes with optional extra information in between
22 * - stride: distance between two consecutive elements in table (should be
23 * GIT_MAX_RAWSZ or greater)
24 * - result: if not NULL, this function stores the element index of the
25 * position found (if the search is successful) or the index of the least
26 * element that is greater than sha1 (if the search is not successful)
27 *
28 * This function does not verify the validity of the fanout table.
29 */
30int bsearch_hash(const unsigned char *sha1, const uint32_t *fanout_nbo,
31 const unsigned char *table, size_t stride, uint32_t *result);
Junio C Hamano628522e2007-12-29 02:05:47 -080032#endif