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[PATCH v1 1/2] string-list: use ALLOC_GROW macro when reallocing string_list

From
Ggit@jeffhostetler.com <git@jeffhostetler.com>
Date
Apr 5, 2017, 19:55 UTC
Message-ID
<20170405195600.54801-2-git@jeffhostetler.com>
In-Reply-To
<20170405195600.54801-1-git@jeffhostetler.com>
From: Jeff Hostetler <jeffhost@microsoft.com>

Use ALLOC_GROW() macro when reallocing a string_list array rather than simply increasing it by 32. This is a performance optimization.

During status on a very large repo and there are many changes, a significant percentage of the total run time was spent reallocing the wt_status.changes array.

This change decreased the time in wt_status_collect_changes_worktree() from 125 seconds to 45 seconds on my very large repository.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 string-list.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/string-list.c b/string-list.c
index 45016ad..cd4c4e0 100644
--- a/string-list.c
+++ b/string-list.c
@@ -41,10 +41,8 @@ static int add_entry(int insert_at, struct string_list *list, const char *string
 	if (exact_match)
 		return -1 - index;
 
-	if (list->nr + 1 >= list->alloc) {
-		list->alloc += 32;
-		REALLOC_ARRAY(list->items, list->alloc);
-	}
+	if (list->nr + 1 >= list->alloc)
+		ALLOC_GROW(list->items, list->nr+1, list->alloc);
 	if (index < list->nr)
 		memmove(list->items + index + 1, list->items + index,
 				(list->nr - index)
-- 
2.9.3
Previous: git@jeffhostetler.comNext: Stefan Beller
Message 2 of 10 in “string-list: use ALLOC_GROW macro when reallocing”
  1. 0/2 string-list: use ALLOC_GROW macro when reallocinggit@jeffhostetler.com, Apr 5, 2017
  2. 1/2 string-list: use ALLOC_GROW macro when reallocing string_listgit@jeffhostetler.com, Apr 5, 2017
  3. Stefan BellerApr 5, 2017
  4. Jeff KingApr 5, 2017
  5. Jeff HostetlerApr 5, 2017
  6. Jonathan NiederApr 5, 2017
  7. 2/2 p0005-status: time status on very large repogit@jeffhostetler.com, Apr 5, 2017
  8. Jonathan NiederApr 5, 2017
  9. Jeff HostetlerApr 6, 2017
  10. Jeff KingApr 7, 2017

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