mirror of
https://github.com/git/git
synced 2024-11-05 18:59:29 +00:00
cff38a5e11
When receiving a push, we advertise ref tips from any alternate repositories, in case that helps the client send a smaller pack. Since these refs don't actually exist in the destination repository, we don't transmit the real ref names, but instead use the pseudo-ref ".have". If your alternate has a large number of duplicate refs (for example, because it is aggregating objects from many related repositories, some of which will have the same tags and branch tips), then we will send each ".have $sha1" line multiple times. This is a pointless waste of bandwidth, as we are simply repeating the same fact to the client over and over. This patch eliminates duplicate .have refs early on. It does so efficiently by sorting the complete list and skipping duplicates. This has the side effect of re-ordering the .have lines by ascending sha1; this isn't a problem, though, as the original order was meaningless. There is a similar .have system in fetch-pack, but it does not suffer from the same problem. For each alternate ref we consider in fetch-pack, we actually open the object and mark it with the SEEN flag, so duplicates are automatically culled. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
59 lines
1.2 KiB
C
59 lines
1.2 KiB
C
#include "cache.h"
|
|
#include "sha1-array.h"
|
|
#include "sha1-lookup.h"
|
|
|
|
void sha1_array_append(struct sha1_array *array, const unsigned char *sha1)
|
|
{
|
|
ALLOC_GROW(array->sha1, array->nr + 1, array->alloc);
|
|
hashcpy(array->sha1[array->nr++], sha1);
|
|
array->sorted = 0;
|
|
}
|
|
|
|
static int void_hashcmp(const void *a, const void *b)
|
|
{
|
|
return hashcmp(a, b);
|
|
}
|
|
|
|
void sha1_array_sort(struct sha1_array *array)
|
|
{
|
|
qsort(array->sha1, array->nr, sizeof(*array->sha1), void_hashcmp);
|
|
array->sorted = 1;
|
|
}
|
|
|
|
static const unsigned char *sha1_access(size_t index, void *table)
|
|
{
|
|
unsigned char (*array)[20] = table;
|
|
return array[index];
|
|
}
|
|
|
|
int sha1_array_lookup(struct sha1_array *array, const unsigned char *sha1)
|
|
{
|
|
if (!array->sorted)
|
|
sha1_array_sort(array);
|
|
return sha1_pos(sha1, array->sha1, array->nr, sha1_access);
|
|
}
|
|
|
|
void sha1_array_clear(struct sha1_array *array)
|
|
{
|
|
free(array->sha1);
|
|
array->sha1 = NULL;
|
|
array->nr = 0;
|
|
array->alloc = 0;
|
|
array->sorted = 0;
|
|
}
|
|
|
|
void sha1_array_for_each_unique(struct sha1_array *array,
|
|
for_each_sha1_fn fn,
|
|
void *data)
|
|
{
|
|
int i;
|
|
|
|
if (!array->sorted)
|
|
sha1_array_sort(array);
|
|
|
|
for (i = 0; i < array->nr; i++) {
|
|
if (i > 0 && !hashcmp(array->sha1[i], array->sha1[i-1]))
|
|
continue;
|
|
fn(array->sha1[i], data);
|
|
}
|
|
}
|