There is code in post_read_index_from() to catch out of order
entries when reading an index file. This order verification is ~13%
of the cost of every call to read_index_from().
Update check_ce_order() so that it skips this verification unless
the "verify_ce_order" global variable is set.
Teach fsck to force this verification.
The effect can be seen using t/perf/p0002-read-cache.sh:
Test HEAD HEAD~1
--------------------------------------------------------------------------------------
0002.1: read_cache/discard_cache 1000 times 0.41(0.04+0.04) 0.50(0.00+0.10) +22.0%
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
if (keep_cache_objects) {
verify_index_checksum = 1;
+ verify_ce_order = 1;
read_cache();
for (i = 0; i < active_nr; i++) {
unsigned int mode;
extern void set_alternate_index_output(const char *);
extern int verify_index_checksum;
+extern int verify_ce_order;
/* Environment bits from configuration mechanism */
extern int trust_executable_bit;
/* Allow fsck to force verification of the index checksum. */
int verify_index_checksum;
+/* Allow fsck to force verification of the cache entry order. */
+int verify_ce_order;
+
static int verify_hdr(struct cache_header *hdr, unsigned long size)
{
git_SHA_CTX c;
{
unsigned int i;
+ if (!verify_ce_order)
+ return;
+
for (i = 1; i < istate->cache_nr; i++) {
struct cache_entry *ce = istate->cache[i - 1];
struct cache_entry *next_ce = istate->cache[i];