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 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc(),free() */
26 extern void *malloc(size_t size);
27 extern 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
36 GLOBAL(void *)
jpeg_get_small(j_common_ptr cinfo,size_t sizeofobject)37 jpeg_get_small(j_common_ptr cinfo, size_t sizeofobject)
38 {
39 return (void *)malloc(sizeofobject);
40 }
41
42 GLOBAL(void)
jpeg_free_small(j_common_ptr cinfo,void * object,size_t sizeofobject)43 jpeg_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
53 GLOBAL(void *)
jpeg_get_large(j_common_ptr cinfo,size_t sizeofobject)54 jpeg_get_large(j_common_ptr cinfo, size_t sizeofobject)
55 {
56 return (void *)malloc(sizeofobject);
57 }
58
59 GLOBAL(void)
jpeg_free_large(j_common_ptr cinfo,void * object,size_t sizeofobject)60 jpeg_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
70 GLOBAL(size_t)
jpeg_mem_available(j_common_ptr cinfo,size_t min_bytes_needed,size_t max_bytes_needed,size_t already_allocated)71 jpeg_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 ((size_t)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
92 GLOBAL(void)
jpeg_open_backing_store(j_common_ptr cinfo,backing_store_ptr info,long total_bytes_needed)93 jpeg_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
105 GLOBAL(long)
jpeg_mem_init(j_common_ptr cinfo)106 jpeg_mem_init(j_common_ptr cinfo)
107 {
108 return 0; /* just set max_memory_to_use to 0 */
109 }
110
111 GLOBAL(void)
jpeg_mem_term(j_common_ptr cinfo)112 jpeg_mem_term(j_common_ptr cinfo)
113 {
114 /* no work */
115 }
116