write_or_die.con commit cherry-pick: handle root commits with external strategies (1618073)
   1#include "cache.h"
   2
   3/*
   4 * Some cases use stdio, but want to flush after the write
   5 * to get error handling (and to get better interactive
   6 * behaviour - not buffering excessively).
   7 *
   8 * Of course, if the flush happened within the write itself,
   9 * we've already lost the error code, and cannot report it any
  10 * more. So we just ignore that case instead (and hope we get
  11 * the right error code on the flush).
  12 *
  13 * If the file handle is stdout, and stdout is a file, then skip the
  14 * flush entirely since it's not needed.
  15 */
  16void maybe_flush_or_die(FILE *f, const char *desc)
  17{
  18        static int skip_stdout_flush = -1;
  19        struct stat st;
  20        char *cp;
  21
  22        if (f == stdout) {
  23                if (skip_stdout_flush < 0) {
  24                        cp = getenv("GIT_FLUSH");
  25                        if (cp)
  26                                skip_stdout_flush = (atoi(cp) == 0);
  27                        else if ((fstat(fileno(stdout), &st) == 0) &&
  28                                 S_ISREG(st.st_mode))
  29                                skip_stdout_flush = 1;
  30                        else
  31                                skip_stdout_flush = 0;
  32                }
  33                if (skip_stdout_flush && !ferror(f))
  34                        return;
  35        }
  36        if (fflush(f)) {
  37                /*
  38                 * On Windows, EPIPE is returned only by the first write()
  39                 * after the reading end has closed its handle; subsequent
  40                 * write()s return EINVAL.
  41                 */
  42                if (errno == EPIPE || errno == EINVAL)
  43                        exit(0);
  44                die_errno("write failure on '%s'", desc);
  45        }
  46}
  47
  48void fsync_or_die(int fd, const char *msg)
  49{
  50        if (fsync(fd) < 0) {
  51                die_errno("fsync error on '%s'", msg);
  52        }
  53}
  54
  55void write_or_die(int fd, const void *buf, size_t count)
  56{
  57        if (write_in_full(fd, buf, count) < 0) {
  58                if (errno == EPIPE)
  59                        exit(0);
  60                die_errno("write error");
  61        }
  62}
  63
  64int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg)
  65{
  66        if (write_in_full(fd, buf, count) < 0) {
  67                if (errno == EPIPE)
  68                        exit(0);
  69                fprintf(stderr, "%s: write error (%s)\n",
  70                        msg, strerror(errno));
  71                return 0;
  72        }
  73
  74        return 1;
  75}
  76
  77int write_or_whine(int fd, const void *buf, size_t count, const char *msg)
  78{
  79        if (write_in_full(fd, buf, count) < 0) {
  80                fprintf(stderr, "%s: write error (%s)\n",
  81                        msg, strerror(errno));
  82                return 0;
  83        }
  84
  85        return 1;
  86}