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From: "René Scharfe" <l.s.r@web.de>
To: Git Mailing List <git@vger.kernel.org>
Cc: Junio C Hamano <gitster@pobox.com>
Subject: [PATCH] pack-write: use hashwrite_be32() instead of double-buffering array
Date: Sun, 1 Nov 2020 09:52:12 +0100	[thread overview]
Message-ID: <aec69531-d621-ab26-efd4-96e1ae0ed3a4@web.de> (raw)

hashwrite() already buffers writes, so pass the fanout table entries
individually via hashwrite_be32(), which also does the endianess
conversion for us.  This avoids a memory copy, shortens the code and
reduces the number of magic numbers.

Signed-off-by: René Scharfe <l.s.r@web.de>
---
Patch generated with -U8 for easier review.

 pack-write.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/pack-write.c b/pack-write.c
index a6cdb3c67c..23e19cc1ec 100644
--- a/pack-write.c
+++ b/pack-write.c
@@ -43,17 +43,16 @@ static int need_large_offset(off_t offset, const struct pack_idx_option *opts)
  */
 const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects,
 			   int nr_objects, const struct pack_idx_option *opts,
 			   const unsigned char *sha1)
 {
 	struct hashfile *f;
 	struct pack_idx_entry **sorted_by_sha, **list, **last;
 	off_t last_obj_offset = 0;
-	uint32_t array[256];
 	int i, fd;
 	uint32_t index_version;

 	if (nr_objects) {
 		sorted_by_sha = objects;
 		list = sorted_by_sha;
 		last = sorted_by_sha + nr_objects;
 		for (i = 0; i < nr_objects; ++i) {
@@ -101,20 +100,19 @@ const char *write_idx_file(const char *index_name, struct pack_idx_entry **objec
 	for (i = 0; i < 256; i++) {
 		struct pack_idx_entry **next = list;
 		while (next < last) {
 			struct pack_idx_entry *obj = *next;
 			if (obj->oid.hash[0] != i)
 				break;
 			next++;
 		}
-		array[i] = htonl(next - sorted_by_sha);
+		hashwrite_be32(f, next - sorted_by_sha);
 		list = next;
 	}
-	hashwrite(f, array, 256 * 4);

 	/*
 	 * Write the actual SHA1 entries..
 	 */
 	list = sorted_by_sha;
 	for (i = 0; i < nr_objects; i++) {
 		struct pack_idx_entry *obj = *list++;
 		if (index_version < 2)
--
2.29.2

             reply	other threads:[~2020-11-01  8:52 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-01  8:52 René Scharfe [this message]
2020-11-04 13:36 ` Jeff King
2020-11-04 16:23   ` Junio C Hamano

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