write-or-die.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "run-command.h"
   4
   5 /*
   6  * Some cases use stdio, but want to flush after the write
   7  * to get error handling (and to get better interactive
   8  * behaviour - not buffering excessively).
   9  *
  10  * Of course, if the flush happened within the write itself,
  11  * we've already lost the error code, and cannot report it any
  12  * more. So we just ignore that case instead (and hope we get
  13  * the right error code on the flush).
  14  *
  15  * If the file handle is stdout, and stdout is a file, then skip the
  16  * flush entirely since it's not needed.
  17  */
  18 void maybe_flush_or_die(FILE *f, const char *desc)
  19 {
  20         static int skip_stdout_flush = -1;
  21         struct stat st;
  22         char *cp;
  23
  24         if (f == stdout) {
  25                 if (skip_stdout_flush < 0) {
  26                         cp = getenv("GIT_FLUSH");
  27                         if (cp)
  28                                 skip_stdout_flush = (atoi(cp) == 0);
  29                         else if ((fstat(fileno(stdout), &st) == 0) &&
  30                                  S_ISREG(st.st_mode))
  31                                 skip_stdout_flush = 1;
  32                         else
  33                                 skip_stdout_flush = 0;
  34                 }
  35                 if (skip_stdout_flush && !ferror(f))
  36                         return;
  37         }
  38         if (fflush(f)) {
  39                 check_pipe(errno);
  40                 die_errno("write failure on '%s'", desc);
  41         }
  42 }
  43
  44 void fprintf_or_die(FILE *f, const char *fmt, ...)
  45 {
  46         va_list ap;
  47         int ret;
  48
  49         va_start(ap, fmt);
  50         ret = vfprintf(f, fmt, ap);
  51         va_end(ap);
  52
  53         if (ret < 0) {
  54                 check_pipe(errno);
  55                 die_errno("write error");
  56         }
  57 }
  58
  59 static int maybe_fsync(int fd)
  60 {
  61         if (use_fsync < 0)
  62                 use_fsync = git_env_bool("GIT_TEST_FSYNC", 1);
  63         if (!use_fsync)
  64                 return 0;
  65
  66         if (fsync_method == FSYNC_METHOD_WRITEOUT_ONLY &&
  67             git_fsync(fd, FSYNC_WRITEOUT_ONLY) >= 0)
  68                 return 0;
  69
  70         return git_fsync(fd, FSYNC_HARDWARE_FLUSH);
  71 }
  72
  73 void fsync_or_die(int fd, const char *msg)
  74 {
  75         if (maybe_fsync(fd) < 0)
  76                 die_errno("fsync error on '%s'", msg);
  77 }
  78
  79 int fsync_component(enum fsync_component component, int fd)
  80 {
  81         if (fsync_components & component)
  82                 return maybe_fsync(fd);
  83         return 0;
  84 }
  85
  86 void fsync_component_or_die(enum fsync_component component, int fd, const char *msg)
  87 {
  88         if (fsync_components & component)
  89                 fsync_or_die(fd, msg);
  90 }
  91
  92 void write_or_die(int fd, const void *buf, size_t count)
  93 {
  94         if (write_in_full(fd, buf, count) < 0) {
  95                 check_pipe(errno);
  96                 die_errno("write error");
  97         }
  98 }
  99
 100 void fwrite_or_die(FILE *f, const void *buf, size_t count)
 101 {
 102         if (fwrite(buf, 1, count, f) != count)
 103                 die_errno("fwrite error");
 104 }
 105
 106 void fflush_or_die(FILE *f)
 107 {
 108         if (fflush(f))
 109                 die_errno("fflush error");
 110 }