src/common/files.c

   1 #include "files.h"
   2
   3 #include <stdio.h>
   4 #include <stdint.h>
   5 #include <assert.h>
   6
   7 static long FILE_Stream_GetPos (Stream *r) {
   8   FILE_Stream *rd = (FILE_Stream*)r;
   9   assert(rd != NULL);
  10   assert(rd->fp != NULL);
  11   long pos = ftell(rd->fp);
  12   assert(pos != -1); // fail
  13   return pos;
  14 }
  15
  16 static void FILE_Stream_SetPos (Stream *r, long pos) {
  17   FILE_Stream *rd = (FILE_Stream*)r;
  18   assert(rd != NULL);
  19   assert(rd->fp != NULL);
  20   assert(pos >= 0);
  21   int res = fseek(rd->fp, pos, SEEK_SET);
  22   assert(res == 0); // fail
  23 }
  24
  25 static long FILE_Stream_GetLen (Stream *r) {
  26   FILE_Stream *rd = (FILE_Stream*)r;
  27   assert(rd != NULL);
  28   assert(rd->fp != NULL);
  29   long pos = ftell(rd->fp);
  30   assert(pos != -1); // fail get cur pos
  31   int res = fseek(rd->fp, 0, SEEK_END);
  32   assert(res == 0); // fail jump to end
  33   long len = ftell(rd->fp);
  34   res = fseek(rd->fp, pos, SEEK_SET);
  35   assert(res == 0); // fail return
  36   assert(len != -1); // fail get length
  37   return len;
  38 }
  39
  40 static void FILE_Stream_Read (Stream *r, void *data, size_t size, size_t n) {
  41   FILE_Stream *rd = (FILE_Stream*)r;
  42   assert(rd != NULL);
  43   assert(rd->fp != NULL);
  44   size_t res = fread(data, size, n, rd->fp);
  45   assert(res == n); // fail
  46 }
  47
  48 static void FILE_Stream_Write (Stream *w, const void *data, size_t size, size_t n) {
  49   FILE_Stream *wr = (FILE_Stream*)w;
  50   assert(wr != NULL);
  51   assert(wr->fp != NULL);
  52   size_t res = fwrite(data, size, n, wr->fp);
  53   assert(res == n); // fail
  54 }
  55
  56 void FILE_Assign (FILE_Stream *r, FILE *fp) {
  57   assert(r != NULL);
  58   assert(fp != NULL);
  59   r->base.getpos = FILE_Stream_GetPos;
  60   r->base.setpos = FILE_Stream_SetPos;
  61   r->base.getlen = FILE_Stream_GetLen;
  62   r->base.read   = FILE_Stream_Read;
  63   r->base.write  = FILE_Stream_Write;
  64   r->fp = fp;
  65 }
  66
  67 int FILE_Open (FILE_Stream *r, const char *name, const char *mode) {
  68   assert(r != NULL);
  69   assert(name != NULL);
  70   FILE *fp = fopen(name, mode);
  71   if (fp) {
  72     FILE_Assign(r, fp);
  73   }
  74   return fp != NULL;
  75 }
  76
  77 void FILE_Close (FILE_Stream *r) {
  78   assert(r != NULL);
  79   if (r->fp != NULL) {
  80     fclose(r->fp);
  81   }
  82   r->base.getpos = NULL;
  83   r->base.setpos = NULL;
  84   r->base.getlen = NULL;
  85   r->base.read   = NULL;
  86   r->base.write  = NULL;
  87   r->fp = NULL;
  88 }