Andrew's git - gitweb.git/blob

   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("write failure on %s: %s", desc, strerror(errno));
  45        }
  46}
  47
  48ssize_t read_in_full(int fd, void *buf, size_t count)
  49{
  50        char *p = buf;
  51        ssize_t total = 0;
  52
  53        while (count > 0) {
  54                ssize_t loaded = xread(fd, p, count);
  55                if (loaded <= 0)
  56                        return total ? total : loaded;
  57                count -= loaded;
  58                p += loaded;
  59                total += loaded;
  60        }
  61
  62        return total;
  63}
  64
  65ssize_t write_in_full(int fd, const void *buf, size_t count)
  66{
  67        const char *p = buf;
  68        ssize_t total = 0;
  69
  70        while (count > 0) {
  71                ssize_t written = xwrite(fd, p, count);
  72                if (written < 0)
  73                        return -1;
  74                if (!written) {
  75                        errno = ENOSPC;
  76                        return -1;
  77                }
  78                count -= written;
  79                p += written;
  80                total += written;
  81        }
  82
  83        return total;
  84}
  85
  86void fsync_or_die(int fd, const char *msg)
  87{
  88        if (fsync(fd) < 0) {
  89                die("%s: fsync error (%s)", msg, strerror(errno));
  90        }
  91}
  92
  93void write_or_die(int fd, const void *buf, size_t count)
  94{
  95        if (write_in_full(fd, buf, count) < 0) {
  96                if (errno == EPIPE)
  97                        exit(0);
  98                die("write error (%s)", strerror(errno));
  99        }
 100}
 101
 102int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg)
 103{
 104        if (write_in_full(fd, buf, count) < 0) {
 105                if (errno == EPIPE)
 106                        exit(0);
 107                fprintf(stderr, "%s: write error (%s)\n",
 108                        msg, strerror(errno));
 109                return 0;
 110        }
 111
 112        return 1;
 113}
 114
 115int write_or_whine(int fd, const void *buf, size_t count, const char *msg)
 116{
 117        if (write_in_full(fd, buf, count) < 0) {
 118                fprintf(stderr, "%s: write error (%s)\n",
 119                        msg, strerror(errno));
 120                return 0;
 121        }
 122
 123        return 1;
 124}