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b4e00f7306
Subsequent patches will introduce file formats that make use of a fanout array and a sorted table containing hashes, just like packfiles. Refactor the hash search in packfile.c into its own function, so that those patches can make use of it as well. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
32 lines
1.3 KiB
C
32 lines
1.3 KiB
C
#ifndef SHA1_LOOKUP_H
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#define SHA1_LOOKUP_H
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typedef const unsigned char *sha1_access_fn(size_t index, void *table);
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extern int sha1_pos(const unsigned char *sha1,
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void *table,
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size_t nr,
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sha1_access_fn fn);
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/*
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* Searches for sha1 in table, using the given fanout table to determine the
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* interval to search, then using binary search. Returns 1 if found, 0 if not.
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*
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* Takes the following parameters:
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*
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* - sha1: the hash to search for
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* - fanout_nbo: a 256-element array of NETWORK-order 32-bit integers; the
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* integer at position i represents the number of elements in table whose
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* first byte is less than or equal to i
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* - table: a sorted list of hashes with optional extra information in between
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* - stride: distance between two consecutive elements in table (should be
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* GIT_MAX_RAWSZ or greater)
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* - result: if not NULL, this function stores the element index of the
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* position found (if the search is successful) or the index of the least
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* element that is greater than sha1 (if the search is not successful)
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*
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* This function does not verify the validity of the fanout table.
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*/
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int bsearch_hash(const unsigned char *sha1, const uint32_t *fanout_nbo,
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const unsigned char *table, size_t stride, uint32_t *result);
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#endif
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