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 *)
jpeg_get_small(j_common_ptr cinfo,size_t sizeofobject)35 jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
36 {
37 (void) cinfo;
38
39 /*
40 return (void *) malloc(sizeofobject);
41 */
42 return (void *) calloc(sizeofobject, 1);
43 }
44
45 GLOBAL(void)
jpeg_free_small(j_common_ptr cinfo,void * object,size_t sizeofobject)46 jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
47 {
48 (void) cinfo;
49 (void) sizeofobject;
50
51 free(object);
52 }
53
54
55 /*
56 * "Large" objects are treated the same as "small" ones.
57 * NB: although we include FAR keywords in the routine declarations,
58 * this file won't actually work in 80x86 small/medium model; at least,
59 * you probably won't be able to process useful-size images in only 64KB.
60 */
61
62 GLOBAL(void FAR *)
jpeg_get_large(j_common_ptr cinfo,size_t sizeofobject)63 jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
64 {
65 (void) cinfo;
66
67 /*
68 return (void FAR *) malloc(sizeofobject);
69 */
70 return (void FAR *) calloc(sizeofobject, 1);
71 }
72
73 GLOBAL(void)
jpeg_free_large(j_common_ptr cinfo,void FAR * object,size_t sizeofobject)74 jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
75 {
76 (void) cinfo;
77 (void) sizeofobject;
78
79 free(object);
80 }
81
82
83 /*
84 * This routine computes the total memory space available for allocation.
85 * Here we always say, "we got all you want bud!"
86 */
87
88 GLOBAL(long)
jpeg_mem_available(j_common_ptr cinfo,long min_bytes_needed,long max_bytes_needed,long already_allocated)89 jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
90 long max_bytes_needed, long already_allocated)
91 {
92 (void) cinfo;
93 (void) min_bytes_needed;
94 (void) already_allocated;
95
96 return max_bytes_needed;
97 }
98
99
100 /*
101 * Backing store (temporary file) management.
102 * Since jpeg_mem_available always promised the moon,
103 * this should never be called and we can just error out.
104 */
105
106 GLOBAL(void)
jpeg_open_backing_store(j_common_ptr cinfo,backing_store_ptr info,long total_bytes_needed)107 jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
108 long total_bytes_needed)
109 {
110 (void) info;
111 (void) total_bytes_needed;
112
113 ERREXIT(cinfo, JERR_NO_BACKING_STORE);
114 }
115
116
117 /*
118 * These routines take care of any system-dependent initialization and
119 * cleanup required. Here, there isn't any.
120 */
121
122 GLOBAL(long)
jpeg_mem_init(j_common_ptr cinfo)123 jpeg_mem_init (j_common_ptr cinfo)
124 {
125 (void) cinfo;
126
127 return 0; /* just set max_memory_to_use to 0 */
128 }
129
130 GLOBAL(void)
jpeg_mem_term(j_common_ptr cinfo)131 jpeg_mem_term (j_common_ptr cinfo)
132 {
133 (void) cinfo;
134
135 /* no work */
136 }
137