[PATCH] index-pack: smarter memory usage when appending objects
From: Nicolas Pitre <nico@fluxnic.net>
Date: 2016-06-15 22:48:36
Subsystem:
the rest · Maintainer:
Linus Torvalds
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>
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 4308abb..c1e0394 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c@@ -669,25 +669,25 @@ static void parse_pack_objects(unsigned char *sha1) static int write_compressed(struct sha1file *f, void *in, unsigned int size) { z_stream stream; - unsigned long maxsize; - void *out; + int status; + unsigned char outbuf[4096]; memset(&stream, 0, sizeof(stream)); deflateInit(&stream, zlib_compression_level); - maxsize = deflateBound(&stream, size); - out = xmalloc(maxsize); - - /* Compress it */ stream.next_in = in; stream.avail_in = size; - stream.next_out = out; - stream.avail_out = maxsize; - while (deflate(&stream, Z_FINISH) == Z_OK); - deflateEnd(&stream); + do { + stream.next_out = outbuf; + stream.avail_out = sizeof(outbuf); + status = deflate(&stream, Z_FINISH); + sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out); + } while (status == Z_OK); + + if (status != Z_STREAM_END) + die("unable to deflate appended object (%d)", status); size = stream.total_out; - sha1write(f, out, size); - free(out); + deflateEnd(&stream); return size; }