write_or_die.c

   1 #include "cache.h"
   2
   3 int read_in_full(int fd, void *buf, size_t count)
   4 {
   5         char *p = buf;
   6         ssize_t total = 0;
   7         ssize_t loaded = 0;
   8
   9         while (count > 0) {
  10                 loaded = xread(fd, p, count);
  11                 if (loaded <= 0) {
  12                         if (total)
  13                                 return total;
  14                         else
  15                                 return loaded;
  16                 }
  17                 count -= loaded;
  18                 p += loaded;
  19                 total += loaded;
  20         }
  21
  22         return total;
  23 }
  24
  25 void read_or_die(int fd, void *buf, size_t count)
  26 {
  27         ssize_t loaded;
  28
  29         loaded = read_in_full(fd, buf, count);
  30         if (loaded == 0)
  31                 die("unexpected end of file");
  32         else if (loaded < 0)
  33                 die("read error (%s)", strerror(errno));
  34 }
  35
  36 int write_in_full(int fd, const void *buf, size_t count)
  37 {
  38         const char *p = buf;
  39         ssize_t total = 0;
  40
  41         while (count > 0) {
  42                 size_t written = xwrite(fd, p, count);
  43                 if (written < 0)
  44                         return -1;
  45                 if (!written) {
  46                         errno = ENOSPC;
  47                         return -1;
  48                 }
  49                 count -= written;
  50                 p += written;
  51                 total += written;
  52         }
  53
  54         return total;
  55 }
  56
  57 void write_or_die(int fd, const void *buf, size_t count)
  58 {
  59         ssize_t written;
  60
  61         written = write_in_full(fd, buf, count);
  62         if (written == 0)
  63                 die("disk full?");
  64         else if (written < 0) {
  65                 if (errno == EPIPE)
  66                         exit(0);
  67                 die("write error (%s)", strerror(errno));
  68         }
  69 }
  70
  71 int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg)
  72 {
  73         ssize_t written;
  74
  75         written = write_in_full(fd, buf, count);
  76         if (written == 0) {
  77                 fprintf(stderr, "%s: disk full?\n", msg);
  78                 return 0;
  79         }
  80         else if (written < 0) {
  81                 if (errno == EPIPE)
  82                         exit(0);
  83                 fprintf(stderr, "%s: write error (%s)\n",
  84                         msg, strerror(errno));
  85                 return 0;
  86         }
  87
  88         return 1;
  89 }
  90
  91 int write_or_whine(int fd, const void *buf, size_t count, const char *msg)
  92 {
  93         ssize_t written;
  94
  95         written = write_in_full(fd, buf, count);
  96         if (written == 0) {
  97                 fprintf(stderr, "%s: disk full?\n", msg);
  98                 return 0;
  99         }
 100         else if (written < 0) {
 101                 fprintf(stderr, "%s: write error (%s)\n",
 102                         msg, strerror(errno));
 103                 return 0;
 104         }
 105
 106         return 1;
 107 }