jmemnobs.c 2.7 KB

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  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. #define JPEG_INTERNALS
  18. #include "jinclude.h"
  19. #include "jpeglib.h"
  20. #include "jmemsys.h" /* import the system-dependent declarations */
  21. #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc(),free() */
  22. extern void * malloc JPP((size_t size));
  23. extern void free JPP((void *ptr));
  24. #endif
  25. /*
  26. * Memory allocation and freeing are controlled by the regular library
  27. * routines malloc() and free().
  28. */
  29. GLOBAL(void *)
  30. jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
  31. {
  32. return (void *) malloc(sizeofobject);
  33. }
  34. GLOBAL(void)
  35. jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
  36. {
  37. free(object);
  38. }
  39. /*
  40. * "Large" objects are treated the same as "small" ones.
  41. * NB: although we include FAR keywords in the routine declarations,
  42. * this file won't actually work in 80x86 small/medium model; at least,
  43. * you probably won't be able to process useful-size images in only 64KB.
  44. */
  45. GLOBAL(void FAR *)
  46. jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
  47. {
  48. return (void FAR *) malloc(sizeofobject);
  49. }
  50. GLOBAL(void)
  51. jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
  52. {
  53. free(object);
  54. }
  55. /*
  56. * This routine computes the total memory space available for allocation.
  57. * Here we always say, "we got all you want bud!"
  58. */
  59. GLOBAL(long)
  60. jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
  61. long max_bytes_needed, long already_allocated)
  62. {
  63. return max_bytes_needed;
  64. }
  65. /*
  66. * Backing store (temporary file) management.
  67. * Since jpeg_mem_available always promised the moon,
  68. * this should never be called and we can just error out.
  69. */
  70. GLOBAL(void)
  71. jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
  72. long total_bytes_needed)
  73. {
  74. ERREXIT(cinfo, JERR_NO_BACKING_STORE);
  75. }
  76. /*
  77. * These routines take care of any system-dependent initialization and
  78. * cleanup required. Here, there isn't any.
  79. */
  80. GLOBAL(long)
  81. jpeg_mem_init (j_common_ptr cinfo)
  82. {
  83. return 0; /* just set max_memory_to_use to 0 */
  84. }
  85. GLOBAL(void)
  86. jpeg_mem_term (j_common_ptr cinfo)
  87. {
  88. /* no work */
  89. }