jpeg/jmemnobs.c

   1 /*
   2  * jmemnobs.c
   3  *
   4  * Copyright (C) 1992-1996, Thomas G. Lane.
   5  * This file is part of the Independent JPEG Group's software.
   6  * For conditions of distribution and use, see the accompanying README file.
   7  *
   8  * This file provides a really simple implementation of the system-
   9  * dependent portion of the JPEG memory manager.  This implementation
  10  * assumes that no backing-store files are needed: all required space
  11  * can be obtained from malloc().
  12  * This is very portable in the sense that it'll compile on almost anything,
  13  * but you'd better have lots of main memory (or virtual memory) if you want
  14  * to process big images.
  15  * Note that the max_memory_to_use option is ignored by this implementation.
  16  */
  17
  18 #define JPEG_INTERNALS
  19 #include "jinclude.h"
  20 #include "jpeglib.h"
  21 #include "jmemsys.h"            /* import the system-dependent declarations */
  22
  23 #ifndef HAVE_STDLIB_H           /* <stdlib.h> should declare malloc(),free() */
  24 extern void * malloc JPP((size_t size));
  25 extern void free JPP((void *ptr));
  26 #endif
  27
  28
  29 /*
  30  * Memory allocation and freeing are controlled by the regular library
  31  * routines malloc() and free().
  32  */
  33
  34 GLOBAL(void *)
  35 jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
  36 {
  37   return (void *) malloc(sizeofobject);
  38 }
  39
  40 GLOBAL(void)
  41 jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
  42 {
  43   free(object);
  44 }
  45
  46
  47 /*
  48  * "Large" objects are treated the same as "small" ones.
  49  * NB: although we include FAR keywords in the routine declarations,
  50  * this file won't actually work in 80x86 small/medium model; at least,
  51  * you probably won't be able to process useful-size images in only 64KB.
  52  */
  53
  54 GLOBAL(void FAR *)
  55 jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
  56 {
  57   return (void FAR *) malloc(sizeofobject);
  58 }
  59
  60 GLOBAL(void)
  61 jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
  62 {
  63   free(object);
  64 }
  65
  66
  67 /*
  68  * This routine computes the total memory space available for allocation.
  69  * Here we always say, "we got all you want bud!"
  70  */
  71
  72 GLOBAL(long)
  73 jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
  74                     long max_bytes_needed, long already_allocated)
  75 {
  76   return max_bytes_needed;
  77 }
  78
  79
  80 /*
  81  * Backing store (temporary file) management.
  82  * Since jpeg_mem_available always promised the moon,
  83  * this should never be called and we can just error out.
  84  */
  85
  86 GLOBAL(void)
  87 jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
  88                          long total_bytes_needed)
  89 {
  90   ERREXIT(cinfo, JERR_NO_BACKING_STORE);
  91 }
  92
  93
  94 /*
  95  * These routines take care of any system-dependent initialization and
  96  * cleanup required.  Here, there isn't any.
  97  */
  98
  99 GLOBAL(long)
 100 jpeg_mem_init (j_common_ptr cinfo)
 101 {
 102   return 0;                     /* just set max_memory_to_use to 0 */
 103 }
 104
 105 GLOBAL(void)
 106 jpeg_mem_term (j_common_ptr cinfo)
 107 {
 108   /* no work */
 109 }