git/hash-lookup.h

33 строки
1.3 KiB
C

#ifndef HASH_LOOKUP_H
#define HASH_LOOKUP_H
typedef const unsigned char *hash_access_fn(size_t index, void *table);
int hash_pos(const unsigned char *hash,
void *table,
size_t nr,
hash_access_fn fn);
/*
* Searches for hash in table, using the given fanout table to determine the
* interval to search, then using binary search. Returns 1 if found, 0 if not.
*
* Takes the following parameters:
*
* - hash: the hash to search for
* - fanout_nbo: a 256-element array of NETWORK-order 32-bit integers; the
* integer at position i represents the number of elements in table whose
* first byte is less than or equal to i
* - table: a sorted list of hashes with optional extra information in between
* - stride: distance between two consecutive elements in table (should be
* GIT_MAX_RAWSZ or greater)
* - result: if not NULL, this function stores the element index of the
* position found (if the search is successful) or the index of the least
* element that is greater than hash (if the search is not successful)
*
* This function does not verify the validity of the fanout table.
*/
int bsearch_hash(const unsigned char *hash, const uint32_t *fanout_nbo,
const unsigned char *table, size_t stride, uint32_t *result);
#endif