From: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
Teach add_index_entry_with_check() to see if the path
of the new item is greater than the last path in the
index array before attempting to search for it.
During checkout, merge_working_tree() populates the new
index in sorted order, so this change will save a binary
lookups per file. This preserves the original behavior
but simply checks the last element before starting the
search.
This helps performance on very large repositories.
Signed-off-by: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
---
read-cache.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/read-cache.c b/read-cache.c
index 97f13a1..6a27688 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1021,7 +1021,16 @@ static int add_index_entry_with_check(struct index_state *istate, struct cache_e
if (!(option & ADD_CACHE_KEEP_CACHE_TREE))
cache_tree_invalidate_path(istate, ce->name);
- pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce));
+
+ /*
+ * If this entry's path sorts after the last entry in the index,
+ * we can avoid searching for it.
+ */
+ if (istate->cache_nr > 0 &&
+ strcmp(ce->name, istate->cache[istate->cache_nr - 1]->name) > 0)
+ pos = -istate->cache_nr - 1;
+ else
+ pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce));
/* existing match? Just replace it. */
if (pos >= 0) {
--
2.9.3