[PATCH] write_sha1_to_fd()

Add write_sha1_to_fd(), which writes an object to a file descriptor. This
includes support for unpacking it and recompressing it.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

cache.h

@@ -185,6 +185,7 @@ extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned l
 extern int read_tree(void *buffer, unsigned long size, int stage);
 
 extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
+extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
 
 extern int has_sha1_pack(const unsigned char *sha1);
 extern int has_sha1_file(const unsigned char *sha1);

sha1_file.c

@@ -1221,6 +1221,65 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
 	return 0;
 }
 
+int write_sha1_to_fd(int fd, const unsigned char *sha1)
+{
+	ssize_t size;
+	unsigned long objsize;
+	int posn = 0;
+	char *buf = map_sha1_file_internal(sha1, &objsize, 0);
+	z_stream stream;
+	if (!buf) {
+		unsigned char *unpacked;
+		unsigned long len;
+		char type[20];
+		char hdr[50];
+		int hdrlen;
+		// need to unpack and recompress it by itself
+		unpacked = read_packed_sha1(sha1, type, &len);
+
+		hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
+
+		/* Set it up */
+		memset(&stream, 0, sizeof(stream));
+		deflateInit(&stream, Z_BEST_COMPRESSION);
+		size = deflateBound(&stream, len + hdrlen);
+		buf = xmalloc(size);
+
+		/* Compress it */
+		stream.next_out = buf;
+		stream.avail_out = size;
+		
+		/* First header.. */
+		stream.next_in = hdr;
+		stream.avail_in = hdrlen;
+		while (deflate(&stream, 0) == Z_OK)
+			/* nothing */;
+
+		/* Then the data itself.. */
+		stream.next_in = unpacked;
+		stream.avail_in = len;
+		while (deflate(&stream, Z_FINISH) == Z_OK)
+			/* nothing */;
+		deflateEnd(&stream);
+		
+		objsize = stream.total_out;
+	}
+
+	do {
+		size = write(fd, buf + posn, objsize - posn);
+		if (size <= 0) {
+			if (!size) {
+				fprintf(stderr, "write closed");
+			} else {
+				perror("write ");
+			}
+			return -1;
+		}
+		posn += size;
+	} while (posn < objsize);
+	return 0;
+}
+
 int write_sha1_from_fd(const unsigned char *sha1, int fd)
 {
 	char *filename = sha1_file_name(sha1);

ssh-push.c

@@ -7,13 +7,13 @@
 static unsigned char local_version = 1;
 static unsigned char remote_version = 0;
 
+static int verbose = 0;
+
 static int serve_object(int fd_in, int fd_out) {
 	ssize_t size;
-	int posn = 0;
 	unsigned char sha1[20];
-	unsigned long objsize;
-	void *buf;
 	signed char remote;
+	int posn = 0;
 	do {
 		size = read(fd_in, sha1 + posn, 20 - posn);
 		if (size < 0) {
@@ -25,12 +25,12 @@ static int serve_object(int fd_in, int fd_out) {
 		posn += size;
 	} while (posn < 20);
 	
-	/* fprintf(stderr, "Serving %s\n", sha1_to_hex(sha1)); */
+	if (verbose)
+		fprintf(stderr, "Serving %s\n", sha1_to_hex(sha1));
+
 	remote = 0;
 	
-	buf = map_sha1_file(sha1, &objsize);
-	
-	if (!buf) {
+	if (!has_sha1_file(sha1)) {
 		fprintf(stderr, "git-ssh-push: could not find %s\n", 
 			sha1_to_hex(sha1));
 		remote = -1;
@@ -41,20 +41,7 @@ static int serve_object(int fd_in, int fd_out) {
 	if (remote < 0)
 		return 0;
 	
-	posn = 0;
-	do {
-		size = write(fd_out, buf + posn, objsize - posn);
-		if (size <= 0) {
-			if (!size) {
-				fprintf(stderr, "git-ssh-push: write closed");
-			} else {
-				perror("git-ssh-push: write ");
-			}
-			return -1;
-		}
-		posn += size;
-	} while (posn < objsize);
-	return 0;
+	return write_sha1_to_fd(fd_out, sha1);
 }
 
 static int serve_version(int fd_in, int fd_out)
@@ -76,6 +63,10 @@ static int serve_ref(int fd_in, int fd_out)
 			return -1;
 		posn++;
 	} while (ref[posn - 1]);
+
+	if (verbose)
+		fprintf(stderr, "Serving %s\n", ref);
+
 	if (get_ref_sha1(ref, sha1))
 		remote = -1;
 	write(fd_out, &remote, 1);