pack_one_ref(): use write_packed_entry() to do the writing

Change pack_refs() to work with a file descriptor instead of a FILE*
(making the file-locking code less awkward) and use
write_packed_entry() to do the writing.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

refs.c

@@ -2001,7 +2001,7 @@ struct ref_to_prune {
 struct pack_refs_cb_data {
 	unsigned int flags;
 	struct ref_to_prune *ref_to_prune;
-	FILE *refs_file;
+	int fd;
 };
 
 static int pack_one_ref(struct ref_entry *entry, void *cb_data)
@@ -2020,15 +2020,13 @@ static int pack_one_ref(struct ref_entry *entry, void *cb_data)
 	    !(entry->flag & REF_ISPACKED))
 		return 0;
 
-	fprintf(cb->refs_file, "%s %s\n", sha1_to_hex(entry->u.value.sha1),
-		entry->name);
-
 	peel_status = peel_entry(entry, 1);
-	if (peel_status == PEEL_PEELED)
-		fprintf(cb->refs_file, "^%s\n", sha1_to_hex(entry->u.value.peeled));
-	else if (peel_status != PEEL_NON_TAG)
+	if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
 		die("internal error peeling reference %s (%s)",
 		    entry->name, sha1_to_hex(entry->u.value.sha1));
+	write_packed_entry(cb->fd, entry->name, entry->u.value.sha1,
+			   peel_status == PEEL_PEELED ?
+			   entry->u.value.peeled : NULL);
 
 	/* If the ref was already packed, there is no need to prune it. */
 	if ((cb->flags & PACK_REFS_PRUNE) && !(entry->flag & REF_ISPACKED)) {
@@ -2097,32 +2095,17 @@ static struct lock_file packlock;
 
 int pack_refs(unsigned int flags)
 {
-	int fd;
 	struct pack_refs_cb_data cbdata;
 
 	memset(&cbdata, 0, sizeof(cbdata));
 	cbdata.flags = flags;
 
-	fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"),
-				       LOCK_DIE_ON_ERROR);
-	cbdata.refs_file = fdopen(fd, "w");
-	if (!cbdata.refs_file)
-		die_errno("unable to create ref-pack file structure");
+	cbdata.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"),
+					      LOCK_DIE_ON_ERROR);
 
-	/* perhaps other traits later as well */
-	fprintf(cbdata.refs_file, "# pack-refs with: peeled fully-peeled \n");
+	write_or_die(cbdata.fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
 
 	do_for_each_entry(NULL, "", pack_one_ref, &cbdata);
-	if (ferror(cbdata.refs_file))
-		die("failed to write ref-pack file");
-	if (fflush(cbdata.refs_file) || fsync(fd) || fclose(cbdata.refs_file))
-		die_errno("failed to write ref-pack file");
-	/*
-	 * Since the lock file was fdopen()'ed and then fclose()'ed above,
-	 * assign -1 to the lock file descriptor so that commit_lock_file()
-	 * won't try to close() it.
-	 */
-	packlock.fd = -1;
 	if (commit_lock_file(&packlock) < 0)
 		die_errno("unable to overwrite old ref-pack file");
 	prune_refs(cbdata.ref_to_prune);