threads / patch / 4150

patchpack-object: slightly more efficient

Subject: [PATCH] pack-object: slightly more efficient

## tl;dr

One message between May 15, 2006 and May 15, 2006. Diffs are folded; open one to read it.

replies: 0people: 1as markdown or json

Nicolas Pitre· May 15, 2006, 17:47 UTC · lore

Avoid creating a delta index for objects with maximum depth since they are not going to be used as delta base anyway. This also reduce peak memory usage slightly as the current object's delta index is not useful until the next object in the loop is considered for deltification. This saves a bit more than 1% on CPU usage.

Signed-off-by: Nicolas Pitre <nico@cam.org>
---
Show changes to 2 files +10 −7

delta.h, pack-objects.c

diff --git a/delta.h b/delta.h
index 727ae30..7b3f86d 100644
--- a/delta.h
+++ b/delta.h
@@ -18,6 +18,8 @@ create_delta_index(const void *buf, unsi
 
 /*
  * free_delta_index: free the index created by create_delta_index()
+ *
+ * Given pointer must be what create_delta_index() returned, or NULL.
  */
 extern void free_delta_index(struct delta_index *index);
 
diff --git a/pack-objects.c b/pack-objects.c
index b0388d7..9daf1c1 100644
--- a/pack-objects.c
+++ b/pack-objects.c
@@ -1104,17 +1104,14 @@ static void find_deltas(struct object_en
 
 		if (entry->size < 50)
 			continue;
-		if (n->index)
-			free_delta_index(n->index);
+		free_delta_index(n->index);
+		n->index = NULL;
 		free(n->data);
 		n->entry = entry;
 		n->data = read_sha1_file(entry->sha1, type, &size);
 		if (size != entry->size)
 			die("object %s inconsistent object length (%lu vs %lu)",
 			    sha1_to_hex(entry->sha1), size, entry->size);
-		n->index = create_delta_index(n->data, size);
-		if (!n->index)
-			die("out of memory");
 
 		j = window;
 		while (--j > 0) {
@@ -1134,6 +1131,11 @@ static void find_deltas(struct object_en
 		 */
 		if (entry->delta && depth <= entry->depth)
 			continue;
+
+		n->index = create_delta_index(n->data, size);
+		if (!n->index)
+			die("out of memory");
+
 		idx++;
 		if (idx >= window)
 			idx = 0;
@@ -1143,8 +1145,7 @@ static void find_deltas(struct object_en
 		fputc('\n', stderr);
 
 	for (i = 0; i < window; ++i) {
-		if (array[i].index)
-			free_delta_index(array[i].index);
+		free_delta_index(array[i].index);
 		free(array[i].data);
 	}
 	free(array);

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