From 776ea3707a0248b9d36d696ee92beeeac5ccf1a1 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Mon, 12 Apr 2010 12:11:07 -0400 Subject: [PATCH] index-pack: smarter memory usage when resolving deltas In the same spirit as commit 9892bebafe, let's avoid allocating the full buffer for the deflated data in get_data_from_pack() in order to inflate it. Let's read and inflate the data in chunks instead to reduce memory usage. Signed-off-by: Nicolas Pitre Signed-off-by: Junio C Hamano --- builtin-index-pack.c | 46 ++++++++++++++++++++++++-------------------- 1 file changed, 25 insertions(+), 21 deletions(-) diff --git a/builtin-index-pack.c b/builtin-index-pack.c index b4cf8c53e0..127e713dde 100644 --- a/builtin-index-pack.c +++ b/builtin-index-pack.c @@ -359,34 +359,38 @@ static void *get_data_from_pack(struct object_entry *obj) { off_t from = obj[0].idx.offset + obj[0].hdr_size; unsigned long len = obj[1].idx.offset - from; - unsigned long rdy = 0; - unsigned char *src, *data; + unsigned char *data, *inbuf; z_stream stream; - int st; + int status; + + data = xmalloc(obj->size); + inbuf = xmalloc((len < 64*1024) ? len : 64*1024); + + memset(&stream, 0, sizeof(stream)); + git_inflate_init(&stream); + stream.next_out = data; + stream.avail_out = obj->size; - src = xmalloc(len); - data = src; do { - ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy); + ssize_t n = (len < 64*1024) ? len : 64*1024; + n = pread(pack_fd, inbuf, n, from); if (n < 0) die_errno("cannot pread pack file"); if (!n) - die("premature end of pack file, %lu bytes missing", - len - rdy); - rdy += n; - } while (rdy < len); - data = xmalloc(obj->size); - memset(&stream, 0, sizeof(stream)); - stream.next_out = data; - stream.avail_out = obj->size; - stream.next_in = src; - stream.avail_in = len; - git_inflate_init(&stream); - while ((st = git_inflate(&stream, Z_FINISH)) == Z_OK); - git_inflate_end(&stream); - if (st != Z_STREAM_END || stream.total_out != obj->size) + die("premature end of pack file, %lu bytes missing", len); + from += n; + len -= n; + stream.next_in = inbuf; + stream.avail_in = n; + status = git_inflate(&stream, 0); + } while (len && status == Z_OK && !stream.avail_in); + + /* This has been inflated OK when first encountered, so... */ + if (status != Z_STREAM_END || stream.total_out != obj->size) die("serious inflate inconsistency"); - free(src); + + git_inflate_end(&stream); + free(inbuf); return data; }