write_or_die.con commit threaded delta search: refine work allocation (c2a3367)
   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                if (errno == EPIPE)
  38                        exit(0);
  39                die("write failure on %s: %s", desc, strerror(errno));
  40        }
  41}
  42
  43int read_in_full(int fd, void *buf, size_t count)
  44{
  45        char *p = buf;
  46        ssize_t total = 0;
  47
  48        while (count > 0) {
  49                ssize_t loaded = xread(fd, p, count);
  50                if (loaded <= 0)
  51                        return total ? total : loaded;
  52                count -= loaded;
  53                p += loaded;
  54                total += loaded;
  55        }
  56
  57        return total;
  58}
  59
  60int write_in_full(int fd, const void *buf, size_t count)
  61{
  62        const char *p = buf;
  63        ssize_t total = 0;
  64
  65        while (count > 0) {
  66                ssize_t written = xwrite(fd, p, count);
  67                if (written < 0)
  68                        return -1;
  69                if (!written) {
  70                        errno = ENOSPC;
  71                        return -1;
  72                }
  73                count -= written;
  74                p += written;
  75                total += written;
  76        }
  77
  78        return total;
  79}
  80
  81void write_or_die(int fd, const void *buf, size_t count)
  82{
  83        if (write_in_full(fd, buf, count) < 0) {
  84                if (errno == EPIPE)
  85                        exit(0);
  86                die("write error (%s)", strerror(errno));
  87        }
  88}
  89
  90int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg)
  91{
  92        if (write_in_full(fd, buf, count) < 0) {
  93                if (errno == EPIPE)
  94                        exit(0);
  95                fprintf(stderr, "%s: write error (%s)\n",
  96                        msg, strerror(errno));
  97                return 0;
  98        }
  99
 100        return 1;
 101}
 102
 103int write_or_whine(int fd, const void *buf, size_t count, const char *msg)
 104{
 105        if (write_in_full(fd, buf, count) < 0) {
 106                fprintf(stderr, "%s: write error (%s)\n",
 107                        msg, strerror(errno));
 108                return 0;
 109        }
 110
 111        return 1;
 112}