index-pack: smarter memory usage when appending objects

In the same spirit as commit 9892bebafe, let's avoid allocating the full buffer for the deflated data in write_compressed() in order to write it. Let's deflate and write the data in chunks instead to reduce memory usage. Signed-off-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Nicolas Pitre committed Apr 12, 2010 at 16:50 UTC 7734d7f2f6e57973bce3d7b2af815ac737f4637c

1 file changed +12 -12

builtin-index-pack.c

+12 -12

@@ -669,25 +669,25 @@ static void parse_pack_objects(unsigned char *sha1)

669 static int write_compressed(struct sha1file *f, void *in, unsigned int size)

670 {

671 z_stream stream;

672 - unsigned long maxsize;

673 - void *out;

672 + int status;

673 + unsigned char outbuf[4096];

674

675 memset(&stream, 0, sizeof(stream));

676 deflateInit(&stream, zlib_compression_level);

677 - maxsize = deflateBound(&stream, size);

678 - out = xmalloc(maxsize);

679 -

680 - /* Compress it */

677 stream.next_in = in;

678 stream.avail_in = size;

683 - stream.next_out = out;

684 - stream.avail_out = maxsize;

685 - while (deflate(&stream, Z_FINISH) == Z_OK);

686 - deflateEnd(&stream);

679

680 + do {

681 + stream.next_out = outbuf;

682 + stream.avail_out = sizeof(outbuf);

683 + status = deflate(&stream, Z_FINISH);

684 + sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);

685 + } while (status == Z_OK);

686 +

687 + if (status != Z_STREAM_END)

688 + die("unable to deflate appended object (%d)", status);

689 size = stream.total_out;

689 - sha1write(f, out, size);

690 - free(out);

690 + deflateEnd(&stream);

691 return size;

692 }

693