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) 2017-2018, 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
26 /*
27 * Memory allocation and freeing are controlled by the regular library
28 * routines malloc() and free().
29 */
30
31 GLOBAL(void *)
jpeg_get_small(j_common_ptr cinfo,size_t sizeofobject)32 jpeg_get_small(j_common_ptr cinfo, size_t sizeofobject)
33 {
34 return (void *)malloc(sizeofobject);
35 }
36
37 GLOBAL(void)
jpeg_free_small(j_common_ptr cinfo,void * object,size_t sizeofobject)38 jpeg_free_small(j_common_ptr cinfo, void *object, size_t sizeofobject)
39 {
40 free(object);
41 }
42
43
44 /*
45 * "Large" objects are treated the same as "small" ones.
46 */
47
48 GLOBAL(void *)
jpeg_get_large(j_common_ptr cinfo,size_t sizeofobject)49 jpeg_get_large(j_common_ptr cinfo, size_t sizeofobject)
50 {
51 return (void *)malloc(sizeofobject);
52 }
53
54 GLOBAL(void)
jpeg_free_large(j_common_ptr cinfo,void * object,size_t sizeofobject)55 jpeg_free_large(j_common_ptr cinfo, void *object, size_t sizeofobject)
56 {
57 free(object);
58 }
59
60
61 /*
62 * This routine computes the total memory space available for allocation.
63 */
64
65 GLOBAL(size_t)
jpeg_mem_available(j_common_ptr cinfo,size_t min_bytes_needed,size_t max_bytes_needed,size_t already_allocated)66 jpeg_mem_available(j_common_ptr cinfo, size_t min_bytes_needed,
67 size_t max_bytes_needed, size_t already_allocated)
68 {
69 if (cinfo->mem->max_memory_to_use) {
70 if ((size_t)cinfo->mem->max_memory_to_use > already_allocated)
71 return cinfo->mem->max_memory_to_use - already_allocated;
72 else
73 return 0;
74 } else {
75 /* Here we always say, "we got all you want bud!" */
76 return max_bytes_needed;
77 }
78 }
79
80
81 /*
82 * Backing store (temporary file) management.
83 * Since jpeg_mem_available always promised the moon,
84 * this should never be called and we can just error out.
85 */
86
87 GLOBAL(void)
jpeg_open_backing_store(j_common_ptr cinfo,backing_store_ptr info,long total_bytes_needed)88 jpeg_open_backing_store(j_common_ptr cinfo, backing_store_ptr info,
89 long total_bytes_needed)
90 {
91 ERREXIT(cinfo, JERR_NO_BACKING_STORE);
92 }
93
94
95 /*
96 * These routines take care of any system-dependent initialization and
97 * cleanup required. Here, there isn't any.
98 */
99
100 GLOBAL(long)
jpeg_mem_init(j_common_ptr cinfo)101 jpeg_mem_init(j_common_ptr cinfo)
102 {
103 return 0; /* just set max_memory_to_use to 0 */
104 }
105
106 GLOBAL(void)
jpeg_mem_term(j_common_ptr cinfo)107 jpeg_mem_term(j_common_ptr cinfo)
108 {
109 /* no work */
110 }
111