Add git-write-blob.

A new command, git-write-blob, is introduced.  This registers
the contents of any file on the filesystem as a blob in the
object database and reports its SHA1 to the standard output.
To implement it, the patch promotes index_fd() from a static
function in update-cache.c to extern and moves it to a library
source, sha1_file.c.

This command is used to update git-merge-one-file-script so that
it does not smudge the work tree.

Signed-off-by: Junio C Hamano <junkio@cox.net>

Makefile

@@ -21,7 +21,7 @@ PROG=   git-update-cache git-diff-files git-init-db git-write-tree \
 	git-check-files git-ls-tree git-merge-base git-merge-cache \
 	git-unpack-file git-export git-diff-cache git-convert-cache \
 	git-http-pull git-rpush git-rpull git-rev-list git-mktag \
-	git-diff-tree-helper git-tar-tree git-local-pull
+	git-diff-tree-helper git-tar-tree git-local-pull git-write-blob
 
 all: $(PROG)
 
@@ -94,6 +94,7 @@ git-rev-list: rev-list.c
 git-mktag: mktag.c
 git-diff-tree-helper: diff-tree-helper.c
 git-tar-tree: tar-tree.c
+git-write-blob: write-blob.c
 
 git-http-pull: LIBS += -lcurl
 

cache.h

@@ -116,6 +116,7 @@ extern int remove_entry_at(int pos);
 extern int remove_file_from_cache(char *path);
 extern int same_name(struct cache_entry *a, struct cache_entry *b);
 extern int cache_match_stat(struct cache_entry *ce, struct stat *st);
+extern int index_fd(unsigned char *sha1, int fd, struct stat *st);
 
 #define MTIME_CHANGED	0x0001
 #define CTIME_CHANGED	0x0002

sha1_file.c

@@ -460,3 +460,54 @@ int has_sha1_file(const unsigned char *sha1)
 		return 1;
 	return 0;
 }
+
+int index_fd(unsigned char *sha1, int fd, struct stat *st)
+{
+	z_stream stream;
+	unsigned long size = st->st_size;
+	int max_out_bytes = size + 200;
+	void *out = xmalloc(max_out_bytes);
+	void *metadata = xmalloc(200);
+	int metadata_size;
+	void *in;
+	SHA_CTX c;
+
+	in = "";
+	if (size)
+		in = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+	close(fd);
+	if (!out || (int)(long)in == -1)
+		return -1;
+
+	metadata_size = 1+sprintf(metadata, "blob %lu", size);
+
+	SHA1_Init(&c);
+	SHA1_Update(&c, metadata, metadata_size);
+	SHA1_Update(&c, in, size);
+	SHA1_Final(sha1, &c);
+
+	memset(&stream, 0, sizeof(stream));
+	deflateInit(&stream, Z_BEST_COMPRESSION);
+
+	/*
+	 * ASCII size + nul byte
+	 */	
+	stream.next_in = metadata;
+	stream.avail_in = metadata_size;
+	stream.next_out = out;
+	stream.avail_out = max_out_bytes;
+	while (deflate(&stream, 0) == Z_OK)
+		/* nothing */;
+
+	/*
+	 * File content
+	 */
+	stream.next_in = in;
+	stream.avail_in = size;
+	while (deflate(&stream, Z_FINISH) == Z_OK)
+		/*nothing */;
+
+	deflateEnd(&stream);
+
+	return write_sha1_buffer(sha1, out, stream.total_out);
+}

update-cache.c

@@ -31,57 +31,6 @@ static inline long IS_ERR(const void *ptr)
 	return (unsigned long)ptr > (unsigned long)-1000L;
 }
 
-static int index_fd(unsigned char *sha1, int fd, struct stat *st)
-{
-	z_stream stream;
-	unsigned long size = st->st_size;
-	int max_out_bytes = size + 200;
-	void *out = xmalloc(max_out_bytes);
-	void *metadata = xmalloc(200);
-	int metadata_size;
-	void *in;
-	SHA_CTX c;
-
-	in = "";
-	if (size)
-		in = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
-	close(fd);
-	if (!out || (int)(long)in == -1)
-		return -1;
-
-	metadata_size = 1+sprintf(metadata, "blob %lu", size);
-
-	SHA1_Init(&c);
-	SHA1_Update(&c, metadata, metadata_size);
-	SHA1_Update(&c, in, size);
-	SHA1_Final(sha1, &c);
-
-	memset(&stream, 0, sizeof(stream));
-	deflateInit(&stream, Z_BEST_COMPRESSION);
-
-	/*
-	 * ASCII size + nul byte
-	 */	
-	stream.next_in = metadata;
-	stream.avail_in = metadata_size;
-	stream.next_out = out;
-	stream.avail_out = max_out_bytes;
-	while (deflate(&stream, 0) == Z_OK)
-		/* nothing */;
-
-	/*
-	 * File content
-	 */
-	stream.next_in = in;
-	stream.avail_in = size;
-	while (deflate(&stream, Z_FINISH) == Z_OK)
-		/*nothing */;
-
-	deflateEnd(&stream);
-
-	return write_sha1_buffer(sha1, out, stream.total_out);
-}
-
 /*
  * This only updates the "non-critical" parts of the directory
  * cache, ie the parts that aren't tracked by GIT, and only used

write-blob.c

@@ -0,0 +1,25 @@
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ */
+#include "cache.h"
+
+int main(int argc, char **argv)
+{
+	int i;
+
+	for (i = 1 ; i < argc; i++) {
+		char *path = argv[i];
+		int fd;
+		struct stat st;
+		unsigned char sha1[20];
+		fd = open(path, O_RDONLY);
+		if (fd < 0 ||
+		    fstat(fd, &st) < 0 ||
+		    index_fd(sha1, fd, &st) < 0)
+			die("Unable to add blob %s to database", path);
+		printf("%s\n", sha1_to_hex(sha1));
+	}
+	return 0;
+}