mirrors/git
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

packfile: refactor hash search with fanout table

Browse Source 
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>
This commit is contained in:
Jonathan Tan
2018-02-13 10:39:39 -08:00
committed by Junio C Hamano
parent 4669e7d68e
commit b4e00f7306
3 changed files with 54 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
packfile.c
View File

@ -1712,7 +1712,8 @@ off_t find_pack_entry_one(const unsigned char *sha1,
{
const uint32_t *level1_ofs = p->index_data;
const unsigned char *index = p->index_data;
unsigned hi, lo, stride;
unsigned stride;
uint32_t result;
if (!index) {
if (open_pack_index(p))
@ -1725,8 +1726,6 @@ off_t find_pack_entry_one(const unsigned char *sha1,
index += 8;
}
index += 4 * 256;
hi = ntohl(level1_ofs[*sha1]);
lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
if (p->index_version > 1) {
stride = 20;
} else {
@ -1734,17 +1733,8 @@ off_t find_pack_entry_one(const unsigned char *sha1,
index += 4;
}
while (lo < hi) {
unsigned mi = lo + (hi - lo) / 2;
int cmp = hashcmp(index + mi * stride, sha1);
if (!cmp)
return nth_packed_object_offset(p, mi);
if (cmp > 0)
hi = mi;
else
lo = mi+1;
}
if (bsearch_hash(sha1, level1_ofs, index, stride, &result))
return nth_packed_object_offset(p, result);
return 0;
}