write_or_die.c

   1 #include "cache.h"
   2
   3 static void check_pipe(int err)
   4 {
   5         if (err == EPIPE) {
   6                 signal(SIGPIPE, SIG_DFL);
   7                 raise(SIGPIPE);
   8                 /* Should never happen, but just in case... */
   9                 exit(141);
  10         }
  11 }
  12
  13 /*
  14  * Some cases use stdio, but want to flush after the write
  15  * to get error handling (and to get better interactive
  16  * behaviour - not buffering excessively).
  17  *
  18  * Of course, if the flush happened within the write itself,
  19  * we've already lost the error code, and cannot report it any
  20  * more. So we just ignore that case instead (and hope we get
  21  * the right error code on the flush).
  22  *
  23  * If the file handle is stdout, and stdout is a file, then skip the
  24  * flush entirely since it's not needed.
  25  */
  26 void maybe_flush_or_die(FILE *f, const char *desc)
  27 {
  28         static int skip_stdout_flush = -1;
  29         struct stat st;
  30         char *cp;
  31
  32         if (f == stdout) {
  33                 if (skip_stdout_flush < 0) {
  34                         cp = getenv("GIT_FLUSH");
  35                         if (cp)
  36                                 skip_stdout_flush = (atoi(cp) == 0);
  37                         else if ((fstat(fileno(stdout), &st) == 0) &&
  38                                  S_ISREG(st.st_mode))
  39                                 skip_stdout_flush = 1;
  40                         else
  41                                 skip_stdout_flush = 0;
  42                 }
  43                 if (skip_stdout_flush && !ferror(f))
  44                         return;
  45         }
  46         if (fflush(f)) {
  47                 check_pipe(errno);
  48                 die_errno("write failure on '%s'", desc);
  49         }
  50 }
  51
  52 void fprintf_or_die(FILE *f, const char *fmt, ...)
  53 {
  54         va_list ap;
  55         int ret;
  56
  57         va_start(ap, fmt);
  58         ret = vfprintf(f, fmt, ap);
  59         va_end(ap);
  60
  61         if (ret < 0) {
  62                 check_pipe(errno);
  63                 die_errno("write error");
  64         }
  65 }
  66
  67 void fsync_or_die(int fd, const char *msg)
  68 {
  69         if (fsync(fd) < 0) {
  70                 die_errno("fsync error on '%s'", msg);
  71         }
  72 }
  73
  74 void write_or_die(int fd, const void *buf, size_t count)
  75 {
  76         if (write_in_full(fd, buf, count) < 0) {
  77                 check_pipe(errno);
  78                 die_errno("write error");
  79         }
  80 }
  81
  82 int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg)
  83 {
  84         if (write_in_full(fd, buf, count) < 0) {
  85                 check_pipe(errno);
  86                 fprintf(stderr, "%s: write error (%s)\n",
  87                         msg, strerror(errno));
  88                 return 0;
  89         }
  90
  91         return 1;
  92 }
  93
  94 int write_or_whine(int fd, const void *buf, size_t count, const char *msg)
  95 {
  96         if (write_in_full(fd, buf, count) < 0) {
  97                 fprintf(stderr, "%s: write error (%s)\n",
  98                         msg, strerror(errno));
  99                 return 0;
 100         }
 101
 102         return 1;
 103 }