git/write-or-die.c
Eric Wong 412e4caee3 tests: disable fsync everywhere
The "GIT_TEST_FSYNC" environment variable now exists for
disabling fsync() even on packfiles and other "critical" data.

Running "make test -j8 NO_SVN_TESTS=1" on a noisy 8-core system
on an HDD, test runtime drops from ~4 minutes down to ~3 minutes.
Using "GIT_TEST_FSYNC=1" re-enables fsync() for comparison
purposes.

SVN interopability tests are minimally affected since SVN will
still use fsync in various places.

This will also be useful for 3rd-party tools which create
throwaway git repositories of temporary data, but remains
undocumented for end users.

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-29 10:22:40 -07:00

78 lines
1.7 KiB
C

#include "cache.h"
#include "config.h"
#include "run-command.h"
/*
* 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 (use_fsync < 0)
use_fsync = git_env_bool("GIT_TEST_FSYNC", 1);
if (!use_fsync)
return;
while (fsync(fd) < 0) {
if (errno != EINTR)
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");
}
}