source: rtems-graphics-toolkit/jpeg-8d/jmemansi.c @ 86b99f7

Last change on this file since 86b99f7 was 86b99f7, checked in by Alexandru-Sever Horin <alex.sever.h@…>, on Aug 1, 2012 at 10:40:32 PM

Added jpeg-8d version. Made modifications to compile for RTEMS, without man or binaries

  • Property mode set to 100644
File size: 4.5 KB
RevLine 
[86b99f7]1/*
2 * jmemansi.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 simple generic implementation of the system-
9 * dependent portion of the JPEG memory manager.  This implementation
10 * assumes that you have the ANSI-standard library routine tmpfile().
11 * Also, the problem of determining the amount of memory available
12 * is shoved onto the user.
13 */
14
15#define JPEG_INTERNALS
16#include "jinclude.h"
17#include "jpeglib.h"
18#include "jmemsys.h"            /* import the system-dependent declarations */
19
20#ifndef HAVE_STDLIB_H           /* <stdlib.h> should declare malloc(),free() */
21extern void * malloc JPP((size_t size));
22extern void free JPP((void *ptr));
23#endif
24
25#ifndef SEEK_SET                /* pre-ANSI systems may not define this; */
26#define SEEK_SET  0             /* if not, assume 0 is correct */
27#endif
28
29
30/*
31 * Memory allocation and freeing are controlled by the regular library
32 * routines malloc() and free().
33 */
34
35GLOBAL(void *)
36jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
37{
38  return (void *) malloc(sizeofobject);
39}
40
41GLOBAL(void)
42jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
43{
44  free(object);
45}
46
47
48/*
49 * "Large" objects are treated the same as "small" ones.
50 * NB: although we include FAR keywords in the routine declarations,
51 * this file won't actually work in 80x86 small/medium model; at least,
52 * you probably won't be able to process useful-size images in only 64KB.
53 */
54
55GLOBAL(void FAR *)
56jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
57{
58  return (void FAR *) malloc(sizeofobject);
59}
60
61GLOBAL(void)
62jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
63{
64  free(object);
65}
66
67
68/*
69 * This routine computes the total memory space available for allocation.
70 * It's impossible to do this in a portable way; our current solution is
71 * to make the user tell us (with a default value set at compile time).
72 * If you can actually get the available space, it's a good idea to subtract
73 * a slop factor of 5% or so.
74 */
75
76#ifndef DEFAULT_MAX_MEM         /* so can override from makefile */
77#define DEFAULT_MAX_MEM         1000000L /* default: one megabyte */
78#endif
79
80GLOBAL(long)
81jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
82                    long max_bytes_needed, long already_allocated)
83{
84  return cinfo->mem->max_memory_to_use - already_allocated;
85}
86
87
88/*
89 * Backing store (temporary file) management.
90 * Backing store objects are only used when the value returned by
91 * jpeg_mem_available is less than the total space needed.  You can dispense
92 * with these routines if you have plenty of virtual memory; see jmemnobs.c.
93 */
94
95
96METHODDEF(void)
97read_backing_store (j_common_ptr cinfo, backing_store_ptr info,
98                    void FAR * buffer_address,
99                    long file_offset, long byte_count)
100{
101  if (fseek(info->temp_file, file_offset, SEEK_SET))
102    ERREXIT(cinfo, JERR_TFILE_SEEK);
103  if (JFREAD(info->temp_file, buffer_address, byte_count)
104      != (size_t) byte_count)
105    ERREXIT(cinfo, JERR_TFILE_READ);
106}
107
108
109METHODDEF(void)
110write_backing_store (j_common_ptr cinfo, backing_store_ptr info,
111                     void FAR * buffer_address,
112                     long file_offset, long byte_count)
113{
114  if (fseek(info->temp_file, file_offset, SEEK_SET))
115    ERREXIT(cinfo, JERR_TFILE_SEEK);
116  if (JFWRITE(info->temp_file, buffer_address, byte_count)
117      != (size_t) byte_count)
118    ERREXIT(cinfo, JERR_TFILE_WRITE);
119}
120
121
122METHODDEF(void)
123close_backing_store (j_common_ptr cinfo, backing_store_ptr info)
124{
125  fclose(info->temp_file);
126  /* Since this implementation uses tmpfile() to create the file,
127   * no explicit file deletion is needed.
128   */
129}
130
131
132/*
133 * Initial opening of a backing-store object.
134 *
135 * This version uses tmpfile(), which constructs a suitable file name
136 * behind the scenes.  We don't have to use info->temp_name[] at all;
137 * indeed, we can't even find out the actual name of the temp file.
138 */
139
140GLOBAL(void)
141jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
142                         long total_bytes_needed)
143{
144  if ((info->temp_file = tmpfile()) == NULL)
145    ERREXITS(cinfo, JERR_TFILE_CREATE, "");
146  info->read_backing_store = read_backing_store;
147  info->write_backing_store = write_backing_store;
148  info->close_backing_store = close_backing_store;
149}
150
151
152/*
153 * These routines take care of any system-dependent initialization and
154 * cleanup required.
155 */
156
157GLOBAL(long)
158jpeg_mem_init (j_common_ptr cinfo)
159{
160  return DEFAULT_MAX_MEM;       /* default for max_memory_to_use */
161}
162
163GLOBAL(void)
164jpeg_mem_term (j_common_ptr cinfo)
165{
166  /* no work */
167}
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