mirror of
https://github.com/git/git.git
synced 2024-10-30 05:47:53 +01:00
9540ce5030
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 <peff@peff.net> Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
103 lines
2.1 KiB
C
103 lines
2.1 KiB
C
#include "cache.h"
|
|
|
|
static void check_pipe(int err)
|
|
{
|
|
if (err == EPIPE) {
|
|
signal(SIGPIPE, SIG_DFL);
|
|
raise(SIGPIPE);
|
|
/* Should never happen, but just in case... */
|
|
exit(141);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Some cases use stdio, but want to flush after the write
|
|
* to get error handling (and to get better interactive
|
|
* behaviour - not buffering excessively).
|
|
*
|
|
* Of course, if the flush happened within the write itself,
|
|
* we've already lost the error code, and cannot report it any
|
|
* more. So we just ignore that case instead (and hope we get
|
|
* the right error code on the flush).
|
|
*
|
|
* If the file handle is stdout, and stdout is a file, then skip the
|
|
* flush entirely since it's not needed.
|
|
*/
|
|
void maybe_flush_or_die(FILE *f, const char *desc)
|
|
{
|
|
static int skip_stdout_flush = -1;
|
|
struct stat st;
|
|
char *cp;
|
|
|
|
if (f == stdout) {
|
|
if (skip_stdout_flush < 0) {
|
|
cp = getenv("GIT_FLUSH");
|
|
if (cp)
|
|
skip_stdout_flush = (atoi(cp) == 0);
|
|
else if ((fstat(fileno(stdout), &st) == 0) &&
|
|
S_ISREG(st.st_mode))
|
|
skip_stdout_flush = 1;
|
|
else
|
|
skip_stdout_flush = 0;
|
|
}
|
|
if (skip_stdout_flush && !ferror(f))
|
|
return;
|
|
}
|
|
if (fflush(f)) {
|
|
check_pipe(errno);
|
|
die_errno("write failure on '%s'", 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) {
|
|
die_errno("fsync error on '%s'", msg);
|
|
}
|
|
}
|
|
|
|
void write_or_die(int fd, const void *buf, size_t count)
|
|
{
|
|
if (write_in_full(fd, buf, count) < 0) {
|
|
check_pipe(errno);
|
|
die_errno("write error");
|
|
}
|
|
}
|
|
|
|
int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg)
|
|
{
|
|
if (write_in_full(fd, buf, count) < 0) {
|
|
check_pipe(errno);
|
|
fprintf(stderr, "%s: write error (%s)\n",
|
|
msg, strerror(errno));
|
|
return 0;
|
|
}
|
|
|
|
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;
|
|
}
|