From 9540ce5030853ffbb7e11c30aa59a5e45095d32c Mon Sep 17 00:00:00 2001 From: Jeff King Date: Wed, 10 Sep 2014 06:03:52 -0400 Subject: refs: write packed_refs file using stdio We write each line of a new packed-refs file individually using a write() syscall (and sometimes 2, if the ref is peeled). Since each line is only about 50-100 bytes long, this creates a lot of system call overhead. We can instead open a stdio handle around our descriptor and use fprintf to write to it. The extra buffering is not a problem for us, because nobody will read our new packed-refs file until we call commit_lock_file (by which point we have flushed everything). On a pathological repository with 8.5 million refs, this dropped the time to run `git pack-refs` from 20s to 6s. Signed-off-by: Jeff King Reviewed-by: Michael Haggerty Signed-off-by: Junio C Hamano --- write_or_die.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'write_or_die.c') diff --git a/write_or_die.c b/write_or_die.c index b50f99a936..e7afe7a295 100644 --- a/write_or_die.c +++ b/write_or_die.c @@ -49,6 +49,21 @@ void maybe_flush_or_die(FILE *f, const char *desc) } } +void fprintf_or_die(FILE *f, const char *fmt, ...) +{ + va_list ap; + int ret; + + va_start(ap, fmt); + ret = vfprintf(f, fmt, ap); + va_end(ap); + + if (ret < 0) { + check_pipe(errno); + die_errno("write error"); + } +} + void fsync_or_die(int fd, const char *msg) { if (fsync(fd) < 0) { -- cgit v1.2.1