root/write_or_die.c

DEFINITIONS

1. check_pipe
2. maybe_flush_or_die
3. fprintf_or_die
4. fsync_or_die
5. write_or_die
6. write_or_whine_pipe
7. write_or_whine

#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;
}