root/ext/gd/libgd/gd_io_file.c

DEFINITIONS

1. gdNewFileCtx
2. gdFreeFileCtx
3. filePutbuf
4. fileGetbuf
5. filePutchar
6. fileGetchar
7. fileSeek
8. fileTell

   1 
   2 /*
   3    * io_file.c
   4    *
   5    * Implements the file interface.
   6    *
   7    * As will all I/O modules, most functions are for local use only (called
   8    * via function pointers in the I/O context).
   9    *
  10    * Most functions are just 'wrappers' for standard file functions.
  11    *
  12    * Written/Modified 1999, Philip Warner.
  13    *
  14  */
  15 
  16 /* For platforms with incomplete ANSI defines. Fortunately,
  17    SEEK_SET is defined to be zero by the standard. */
  18 
  19 #ifndef SEEK_SET
  20 #define SEEK_SET 0
  21 #endif /* SEEK_SET */
  22 
  23 #include <math.h>
  24 #include <string.h>
  25 #include <stdlib.h>
  26 #include "gd.h"
  27 #include "gdhelpers.h"
  28 
  29 /* this is used for creating images in main memory */
  30 
  31 typedef struct fileIOCtx
  32 {
  33         gdIOCtx ctx;
  34         FILE *f;
  35 } fileIOCtx;
  36 
  37 gdIOCtx *newFileCtx (FILE * f);
  38 
  39 static int fileGetbuf (gdIOCtx *, void *, int);
  40 static int filePutbuf (gdIOCtx *, const void *, int);
  41 static void filePutchar (gdIOCtx *, int);
  42 static int fileGetchar (gdIOCtx * ctx);
  43 
  44 static int fileSeek (struct gdIOCtx *, const int);
  45 static long fileTell (struct gdIOCtx *);
  46 static void gdFreeFileCtx (gdIOCtx * ctx);
  47 
  48 /* return data as a dynamic pointer */
  49 gdIOCtx * gdNewFileCtx (FILE * f)
  50 {
  51         fileIOCtx *ctx;
  52 
  53         ctx = (fileIOCtx *) gdMalloc(sizeof (fileIOCtx));
  54 
  55         ctx->f = f;
  56 
  57         ctx->ctx.getC = fileGetchar;
  58         ctx->ctx.putC = filePutchar;
  59 
  60         ctx->ctx.getBuf = fileGetbuf;
  61         ctx->ctx.putBuf = filePutbuf;
  62 
  63         ctx->ctx.tell = fileTell;
  64         ctx->ctx.seek = fileSeek;
  65 
  66         ctx->ctx.gd_free = gdFreeFileCtx;
  67 
  68         return (gdIOCtx *) ctx;
  69 }
  70 
  71 static void gdFreeFileCtx (gdIOCtx * ctx)
  72 {
  73         gdFree(ctx);
  74 }
  75 
  76 
  77 static int filePutbuf (gdIOCtx * ctx, const void *buf, int size)
  78 {
  79         fileIOCtx *fctx;
  80         fctx = (fileIOCtx *) ctx;
  81 
  82         return fwrite(buf, 1, size, fctx->f);
  83 
  84 }
  85 
  86 static int fileGetbuf (gdIOCtx * ctx, void *buf, int size)
  87 {
  88         fileIOCtx *fctx;
  89         fctx = (fileIOCtx *) ctx;
  90 
  91         return fread(buf, 1, size, fctx->f);
  92 }
  93 
  94 static void filePutchar (gdIOCtx * ctx, int a)
  95 {
  96         unsigned char b;
  97         fileIOCtx *fctx;
  98         fctx = (fileIOCtx *) ctx;
  99 
 100         b = a;
 101 
 102         putc (b, fctx->f);
 103 }
 104 
 105 static int fileGetchar (gdIOCtx * ctx)
 106 {
 107         fileIOCtx *fctx;
 108         fctx = (fileIOCtx *) ctx;
 109 
 110         return getc (fctx->f);
 111 }
 112 
 113 
 114 static int fileSeek (struct gdIOCtx *ctx, const int pos)
 115 {
 116         fileIOCtx *fctx;
 117         fctx = (fileIOCtx *) ctx;
 118 
 119         return (fseek (fctx->f, pos, SEEK_SET) == 0);
 120 }
 121 
 122 static long fileTell (struct gdIOCtx *ctx)
 123 {
 124         fileIOCtx *fctx;
 125         fctx = (fileIOCtx *) ctx;
 126 
 127         return ftell (fctx->f);
 128 }