1/*
2 * jmemnobs.c
3 *
4 * This file was part of the Independent JPEG Group's software:
5 * Copyright (C) 1992-1996, Thomas G. Lane.
6 * libjpeg-turbo Modifications:
7 * Copyright (C) 2017, D. R. Commander.
8 * For conditions of distribution and use, see the accompanying README.ijg
9 * file.
10 *
11 * This file provides a really simple implementation of the system-
12 * dependent portion of the JPEG memory manager.  This implementation
13 * assumes that no backing-store files are needed: all required space
14 * can be obtained from malloc().
15 * This is very portable in the sense that it'll compile on almost anything,
16 * but you'd better have lots of main memory (or virtual memory) if you want
17 * to process big images.
18 */
19
20#define JPEG_INTERNALS
21#include "jinclude.h"
22#include "jpeglib.h"
23#include "jmemsys.h"            /* import the system-dependent declarations */
24
25#ifndef HAVE_STDLIB_H           /* <stdlib.h> should declare malloc(),free() */
26extern void *malloc (size_t size);
27extern void free (void *ptr);
28#endif
29
30
31/*
32 * Memory allocation and freeing are controlled by the regular library
33 * routines malloc() and free().
34 */
35
36GLOBAL(void *)
37jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
38{
39  return (void *) malloc(sizeofobject);
40}
41
42GLOBAL(void)
43jpeg_free_small (j_common_ptr cinfo, void *object, size_t sizeofobject)
44{
45  free(object);
46}
47
48
49/*
50 * "Large" objects are treated the same as "small" ones.
51 */
52
53GLOBAL(void *)
54jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
55{
56  return (void *) malloc(sizeofobject);
57}
58
59GLOBAL(void)
60jpeg_free_large (j_common_ptr cinfo, void *object, size_t sizeofobject)
61{
62  free(object);
63}
64
65
66/*
67 * This routine computes the total memory space available for allocation.
68 */
69
70GLOBAL(size_t)
71jpeg_mem_available (j_common_ptr cinfo, size_t min_bytes_needed,
72                    size_t max_bytes_needed, size_t already_allocated)
73{
74  if (cinfo->mem->max_memory_to_use) {
75    if (cinfo->mem->max_memory_to_use > already_allocated)
76      return cinfo->mem->max_memory_to_use - already_allocated;
77    else
78      return 0;
79  } else {
80    /* Here we always say, "we got all you want bud!" */
81    return max_bytes_needed;
82  }
83}
84
85
86/*
87 * Backing store (temporary file) management.
88 * Since jpeg_mem_available always promised the moon,
89 * this should never be called and we can just error out.
90 */
91
92GLOBAL(void)
93jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
94                         long total_bytes_needed)
95{
96  ERREXIT(cinfo, JERR_NO_BACKING_STORE);
97}
98
99
100/*
101 * These routines take care of any system-dependent initialization and
102 * cleanup required.  Here, there isn't any.
103 */
104
105GLOBAL(long)
106jpeg_mem_init (j_common_ptr cinfo)
107{
108  return 0;                     /* just set max_memory_to_use to 0 */
109}
110
111GLOBAL(void)
112jpeg_mem_term (j_common_ptr cinfo)
113{
114  /* no work */
115}
116