From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 5 Mar 2010 06:26:17 +0000 (-0800)
Subject: Merge branch 'dp/read-not-mmap-small-loose-object' into maint
X-Git-Tag: v1.7.0.2~10
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/780fc9a0a6d13f667bb012621692107d244998a8?ds=inline;hp=-c

Merge branch 'dp/read-not-mmap-small-loose-object' into maint

* dp/read-not-mmap-small-loose-object:
hash-object: don't use mmap() for small files
---

780fc9a0a6d13f667bb012621692107d244998a8
diff --combined sha1_file.c
index c0214d7946,0375159604..006321e009
--- a/sha1_file.c
+++ b/sha1_file.c
@@@ -2281,10 -2281,9 +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];
  
@@@ -2302,40 -2301,36 +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;
@@@ -2439,6 -2434,8 +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)
  {
@@@ -2453,6 -2450,14 +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);