From f0bca72dc77f62d61fc355bd6fe6e32b194950b8 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Wed, 8 Jun 2016 15:42:16 -0400 Subject: send-pack: use buffered I/O to talk to pack-objects We start a pack-objects process and then write all of the positive and negative sha1s to it over a pipe. We do so by formatting each item into a fixed-size buffer and then writing each individually. This has two drawbacks: 1. There's some manual computation of the buffer size, which is not immediately obvious is correct (though it is). 2. We write() once per sha1, which means a lot more system calls than are necessary. We can solve both by wrapping the pipe descriptor in a stdio handle; this is the same technique used by upload-pack when serving fetches. Note that we can also simplify and improve the error handling here. The original detected a single write error and broke out of the loop (presumably to avoid writing the error message over and over), but never actually acted on seeing an error; we just fed truncated input and took whatever pack-objects returned. In practice, this probably didn't matter, as the likely errors would be caused by pack-objects dying (and we'd probably just die with SIGPIPE anyway). But we can easily make this simpler and more robust; the stdio handle keeps an error flag, which we can check at the end. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano diff --git a/send-pack.c b/send-pack.c index 37ee04e..299d303 100644 --- a/send-pack.c +++ b/send-pack.c @@ -36,18 +36,15 @@ int option_parse_push_signed(const struct option *opt, die("bad %s argument: %s", opt->long_name, arg); } -static int feed_object(const unsigned char *sha1, int fd, int negative) +static void feed_object(const unsigned char *sha1, FILE *fh, int negative) { - char buf[42]; - if (negative && !has_sha1_file(sha1)) - return 1; + return; - memcpy(buf + negative, sha1_to_hex(sha1), 40); if (negative) - buf[0] = '^'; - buf[40 + negative] = '\n'; - return write_or_whine(fd, buf, 41 + negative, "send-pack: send refs"); + putc('^', fh); + fputs(sha1_to_hex(sha1), fh); + putc('\n', fh); } /* @@ -73,6 +70,7 @@ static int pack_objects(int fd, struct ref *refs, struct sha1_array *extra, stru NULL, }; struct child_process po = CHILD_PROCESS_INIT; + FILE *po_in; int i; i = 4; @@ -97,21 +95,22 @@ static int pack_objects(int fd, struct ref *refs, struct sha1_array *extra, stru * We feed the pack-objects we just spawned with revision * parameters by writing to the pipe. */ + po_in = xfdopen(po.in, "w"); for (i = 0; i < extra->nr; i++) - if (!feed_object(extra->sha1[i], po.in, 1)) - break; + feed_object(extra->sha1[i], po_in, 1); while (refs) { - if (!is_null_oid(&refs->old_oid) && - !feed_object(refs->old_oid.hash, po.in, 1)) - break; - if (!is_null_oid(&refs->new_oid) && - !feed_object(refs->new_oid.hash, po.in, 0)) - break; + if (!is_null_oid(&refs->old_oid)) + feed_object(refs->old_oid.hash, po_in, 1); + if (!is_null_oid(&refs->new_oid)) + feed_object(refs->new_oid.hash, po_in, 0); refs = refs->next; } - close(po.in); + fflush(po_in); + if (ferror(po_in)) + die_errno("error writing to pack-objects"); + fclose(po_in); if (args->stateless_rpc) { char *buf = xmalloc(LARGE_PACKET_MAX); -- cgit v0.10.2-6-g49f6 From b333d0d6f450d4f9c4535fd9fd6e0f4ef367507c Mon Sep 17 00:00:00 2001 From: Ramsay Jones Date: Thu, 9 Jun 2016 23:52:22 +0100 Subject: write_or_die: remove the unused write_or_whine() function Now the last caller of this function is gone, and new ones are unlikely to appear, because this function is doing very little that a regular if() does not besides obfuscating the error message (and if we ever did want something like it, we would probably prefer the function to come back with more "normal" return value semantics). Signed-off-by: Ramsay Jones Signed-off-by: Junio C Hamano diff --git a/cache.h b/cache.h index 4ff196c..5e5c1df 100644 --- a/cache.h +++ b/cache.h @@ -1715,7 +1715,6 @@ extern int copy_file(const char *dst, const char *src, int mode); extern int copy_file_with_time(const char *dst, const char *src, int mode); extern void write_or_die(int fd, const void *buf, size_t count); -extern int write_or_whine(int fd, const void *buf, size_t count, const char *msg); extern int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg); extern void fsync_or_die(int fd, const char *); diff --git a/write_or_die.c b/write_or_die.c index 49e80aa..9816879 100644 --- a/write_or_die.c +++ b/write_or_die.c @@ -94,14 +94,3 @@ int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg) return 1; } - -int write_or_whine(int fd, const void *buf, size_t count, const char *msg) -{ - if (write_in_full(fd, buf, count) < 0) { - fprintf(stderr, "%s: write error (%s)\n", - msg, strerror(errno)); - return 0; - } - - return 1; -} -- cgit v0.10.2-6-g49f6