[PATCH] connected: use buffered I/O to talk to rev-list

["René Scharfe" <l.s.r@web.de>]

Like f0bca72dc77 (send-pack: use buffered I/O to talk to pack-objects,
2016-06-08), significantly reduce the number of system calls and
simplify the code for sending object IDs to rev-list by using stdio's
buffering and handling errors after the loop.

Signed-off-by: René Scharfe <l.s.r@web.de>
---
 connected.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/connected.c b/connected.c
index 937b4bae387..05c2916f38d 100644
--- a/connected.c
+++ b/connected.c
@@ -22,14 +22,13 @@ int check_connected(oid_iterate_fn fn, void *cb_data,
 		    struct check_connected_options *opt)
 {
 	struct child_process rev_list = CHILD_PROCESS_INIT;
+	FILE *rev_list_in;
 	struct check_connected_options defaults = CHECK_CONNECTED_INIT;
-	char commit[GIT_MAX_HEXSZ + 1];
 	struct object_id oid;
 	int err = 0;
 	struct packed_git *new_pack = NULL;
 	struct transport *transport;
 	size_t base_len;
-	const unsigned hexsz = the_hash_algo->hexsz;

 	if (!opt)
 		opt = &defaults;
@@ -122,7 +121,8 @@ int check_connected(oid_iterate_fn fn, void *cb_data,

 	sigchain_push(SIGPIPE, SIG_IGN);

-	commit[hexsz] = '\n';
+	rev_list_in = xfdopen(rev_list.in, "w");
+
 	do {
 		/*
 		 * If index-pack already checked that:
@@ -135,16 +135,10 @@ int check_connected(oid_iterate_fn fn, void *cb_data,
 		if (new_pack && find_pack_entry_one(oid.hash, new_pack))
 			continue;

-		memcpy(commit, oid_to_hex(&oid), hexsz);
-		if (write_in_full(rev_list.in, commit, hexsz + 1) < 0) {
-			if (errno != EPIPE && errno != EINVAL)
-				error_errno(_("failed write to rev-list"));
-			err = -1;
-			break;
-		}
+		fprintf(rev_list_in, "%s\n", oid_to_hex(&oid));
 	} while (!fn(cb_data, &oid));

-	if (close(rev_list.in))
+	if (fclose(rev_list_in))
 		err = error_errno(_("failed to close rev-list's stdin"));

 	sigchain_pop(SIGPIPE);
--
2.28.0