write-or-die.c

   1 #include "git-compat-util.h"
   2 #include "config.h"
   3 #include "run-command.h"
   4 #include "wrapper.h"
   5 #include "write-or-die.h"
   6
   7 /*
   8  * Some cases use stdio, but want to flush after the write
   9  * to get error handling (and to get better interactive
  10  * behaviour - not buffering excessively).
  11  *
  12  * Of course, if the flush happened within the write itself,
  13  * we've already lost the error code, and cannot report it any
  14  * more. So we just ignore that case instead (and hope we get
  15  * the right error code on the flush).
  16  *
  17  * If the file handle is stdout, and stdout is a file, then skip the
  18  * flush entirely since it's not needed.
  19  */
  20 void maybe_flush_or_die(FILE *f, const char *desc)
  21 {
  22         static int skip_stdout_flush = -1;
  23         struct stat st;
  24         char *cp;
  25
  26         if (f == stdout) {
  27                 if (skip_stdout_flush < 0) {
  28                         /* NEEDSWORK: make this a normal Boolean */
  29                         cp = getenv("GIT_FLUSH");
  30                         if (cp)
  31                                 skip_stdout_flush = (atoi(cp) == 0);
  32                         else if ((fstat(fileno(stdout), &st) == 0) &&
  33                                  S_ISREG(st.st_mode))
  34                                 skip_stdout_flush = 1;
  35                         else
  36                                 skip_stdout_flush = 0;
  37                 }
  38                 if (skip_stdout_flush && !ferror(f))
  39                         return;
  40         }
  41         if (fflush(f)) {
  42                 check_pipe(errno);
  43                 die_errno("write failure on '%s'", desc);
  44         }
  45 }
  46
  47 void fprintf_or_die(FILE *f, const char *fmt, ...)
  48 {
  49         va_list ap;
  50         int ret;
  51
  52         va_start(ap, fmt);
  53         ret = vfprintf(f, fmt, ap);
  54         va_end(ap);
  55
  56         if (ret < 0) {
  57                 check_pipe(errno);
  58                 die_errno("write error");
  59         }
  60 }
  61
  62 static int maybe_fsync(int fd)
  63 {
  64         if (use_fsync < 0)
  65                 use_fsync = git_env_bool("GIT_TEST_FSYNC", 1);
  66         if (!use_fsync)
  67                 return 0;
  68
  69         if (fsync_method == FSYNC_METHOD_WRITEOUT_ONLY &&
  70             git_fsync(fd, FSYNC_WRITEOUT_ONLY) >= 0)
  71                 return 0;
  72
  73         return git_fsync(fd, FSYNC_HARDWARE_FLUSH);
  74 }
  75
  76 void fsync_or_die(int fd, const char *msg)
  77 {
  78         if (maybe_fsync(fd) < 0)
  79                 die_errno("fsync error on '%s'", msg);
  80 }
  81
  82 int fsync_component(enum fsync_component component, int fd)
  83 {
  84         if (fsync_components & component)
  85                 return maybe_fsync(fd);
  86         return 0;
  87 }
  88
  89 void fsync_component_or_die(enum fsync_component component, int fd, const char *msg)
  90 {
  91         if (fsync_components & component)
  92                 fsync_or_die(fd, msg);
  93 }
  94
  95 void write_or_die(int fd, const void *buf, size_t count)
  96 {
  97         if (write_in_full(fd, buf, count) < 0) {
  98                 check_pipe(errno);
  99                 die_errno("write error");
 100         }
 101 }
 102
 103 void fwrite_or_die(FILE *f, const void *buf, size_t count)
 104 {
 105         if (fwrite(buf, 1, count, f) != count)
 106                 die_errno("fwrite error");
 107 }
 108
 109 void fflush_or_die(FILE *f)
 110 {
 111         if (fflush(f))
 112                 die_errno("fflush error");
 113 }