src/common/files.c

   1 #include "common/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   long pos;
   9   FILE_Stream *rd = (FILE_Stream*)r;
  10   assert(rd != NULL);
  11   assert(rd->fp != NULL);
  12   pos = ftell(rd->fp);
  13   assert(pos != -1); // fail
  14   return pos;
  15 }
  16
  17 static void FILE_Stream_SetPos (Stream *r, long pos) {
  18   int res;
  19   FILE_Stream *rd = (FILE_Stream*)r;
  20   assert(rd != NULL);
  21   assert(rd->fp != NULL);
  22   assert(pos >= 0);
  23   res = fseek(rd->fp, pos, SEEK_SET);
  24   assert(res == 0); // fail
  25 }
  26
  27 static long FILE_Stream_GetLen (Stream *r) {
  28   int res;
  29   long pos, len;
  30   FILE_Stream *rd = (FILE_Stream*)r;
  31   assert(rd != NULL);
  32   assert(rd->fp != NULL);
  33   pos = ftell(rd->fp);
  34   assert(pos != -1); // fail get cur pos
  35   res = fseek(rd->fp, 0, SEEK_END);
  36   assert(res == 0); // fail jump to end
  37   len = ftell(rd->fp);
  38   res = fseek(rd->fp, pos, SEEK_SET);
  39   assert(res == 0); // fail return
  40   assert(len != -1); // fail get length
  41   return len;
  42 }
  43
  44 static void FILE_Stream_Read (Stream *r, void *data, size_t size, size_t n) {
  45   size_t res;
  46   FILE_Stream *rd = (FILE_Stream*)r;
  47   assert(rd != NULL);
  48   assert(rd->fp != NULL);
  49   res = fread(data, size, n, rd->fp);
  50   assert(res == n); // fail
  51 }
  52
  53 static void FILE_Stream_Write (Stream *w, const void *data, size_t size, size_t n) {
  54   size_t res;
  55   FILE_Stream *wr = (FILE_Stream*)w;
  56   assert(wr != NULL);
  57   assert(wr->fp != NULL);
  58   res = fwrite(data, size, n, wr->fp);
  59   assert(res == n); // fail
  60 }
  61
  62 void FILE_Assign (FILE_Stream *r, FILE *fp) {
  63   assert(r != NULL);
  64   assert(fp != NULL);
  65   r->base.getpos = FILE_Stream_GetPos;
  66   r->base.setpos = FILE_Stream_SetPos;
  67   r->base.getlen = FILE_Stream_GetLen;
  68   r->base.read   = FILE_Stream_Read;
  69   r->base.write  = FILE_Stream_Write;
  70   r->fp = fp;
  71 }
  72
  73 int FILE_Open (FILE_Stream *r, const char *name, const char *mode) {
  74   FILE *fp;
  75   assert(r != NULL);
  76   assert(name != NULL);
  77   fp = fopen(name, mode);
  78   if (fp) {
  79     FILE_Assign(r, fp);
  80   }
  81   return fp != NULL;
  82 }
  83
  84 void FILE_Close (FILE_Stream *r) {
  85   assert(r != NULL);
  86   if (r->fp != NULL) {
  87     fclose(r->fp);
  88   }
  89   r->base.getpos = NULL;
  90   r->base.setpos = NULL;
  91   r->base.getlen = NULL;
  92   r->base.read   = NULL;
  93   r->base.write  = NULL;
  94   r->fp = NULL;
  95 }