From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 2 Mar 2010 20:44:09 +0000 (-0800)
Subject: Merge branch 'np/compress-loose-object-memsave'
X-Git-Tag: v1.7.1-rc0~116
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/34c014d13e6b82fc3ae63d3657fcc6a6f367d760?ds=inline;hp=-c

Merge branch 'np/compress-loose-object-memsave'

* np/compress-loose-object-memsave:
sha1_file: be paranoid when creating loose objects
sha1_file: don't malloc the whole compressed result when writing out objects
---

34c014d13e6b82fc3ae63d3657fcc6a6f367d760
diff --combined sha1_file.c
index 0375159604,c0214d7946..006321e009
--- a/sha1_file.c
+++ b/sha1_file.c
@@@ -2281,9 -2281,10 +2281,10 @@@ static int write_loose_object(const uns
  			      void *buf, unsigned long len, time_t mtime)
  {
  	int fd, ret;
- 	size_t size;
- 	unsigned char *compressed;
+ 	unsigned char compressed[4096];
  	z_stream stream;
+ 	git_SHA_CTX c;
+ 	unsigned char parano_sha1[20];
  	char *filename;
  	static char tmpfile[PATH_MAX];
  
@@@ -2301,36 -2302,40 +2302,40 @@@
  	/* Set it up */
  	memset(&stream, 0, sizeof(stream));
  	deflateInit(&stream, zlib_compression_level);
- 	size = 8 + deflateBound(&stream, len+hdrlen);
- 	compressed = xmalloc(size);
- 
- 	/* Compress it */
  	stream.next_out = compressed;
- 	stream.avail_out = size;
+ 	stream.avail_out = sizeof(compressed);
+ 	git_SHA1_Init(&c);
  
  	/* First header.. */
  	stream.next_in = (unsigned char *)hdr;
  	stream.avail_in = hdrlen;
  	while (deflate(&stream, 0) == Z_OK)
  		/* nothing */;
+ 	git_SHA1_Update(&c, hdr, hdrlen);
  
  	/* Then the data itself.. */
  	stream.next_in = buf;
  	stream.avail_in = len;
- 	ret = deflate(&stream, Z_FINISH);
+ 	do {
+ 		unsigned char *in0 = stream.next_in;
+ 		ret = deflate(&stream, Z_FINISH);
+ 		git_SHA1_Update(&c, in0, stream.next_in - in0);
+ 		if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
+ 			die("unable to write sha1 file");
+ 		stream.next_out = compressed;
+ 		stream.avail_out = sizeof(compressed);
+ 	} while (ret == Z_OK);
+ 
  	if (ret != Z_STREAM_END)
  		die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
- 
  	ret = deflateEnd(&stream);
  	if (ret != Z_OK)
  		die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
+ 	git_SHA1_Final(parano_sha1, &c);
+ 	if (hashcmp(sha1, parano_sha1) != 0)
+ 		die("confused by unstable object source data for %s", sha1_to_hex(sha1));
  
- 	size = stream.total_out;
- 
- 	if (write_buffer(fd, compressed, size) < 0)
- 		die("unable to write sha1 file");
  	close_sha1_file(fd);
- 	free(compressed);
  
  	if (mtime) {
  		struct utimbuf utb;
@@@ -2434,8 -2439,6 +2439,8 @@@ static int index_mem(unsigned char *sha
  	return ret;
  }
  
 +#define SMALL_FILE_SIZE (32*1024)
 +
  int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
  	     enum object_type type, const char *path)
  {
@@@ -2450,14 -2453,6 +2455,14 @@@
  		else
  			ret = -1;
  		strbuf_release(&sbuf);
 +	} else if (size <= SMALL_FILE_SIZE) {
 +		char *buf = xmalloc(size);
 +		if (size == read_in_full(fd, buf, size))
 +			ret = index_mem(sha1, buf, size, write_object, type,
 +					path);
 +		else
 +			ret = error("short read %s", strerror(errno));
 +		free(buf);
  	} else if (size) {
  		void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
  		ret = index_mem(sha1, buf, size, write_object, type, path);