3rdparty/libjpeg/jmemansi.c

/*
 * jmemansi.c
 *
 * Copyright (C) 1992-1996, Thomas G. Lane.
 * This file is part of the Independent JPEG Group's software.
 * For conditions of distribution and use, see the accompanying README file.
 *
 * This file provides a simple generic implementation of the system-
 * dependent portion of the JPEG memory manager.  This implementation
 * assumes that you have the ANSI-standard library routine tmpfile().
 * Also, the problem of determining the amount of memory available
 * is shoved onto the user.
 */

#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jmemsys.h"            /* import the system-dependent declarations */

#ifndef HAVE_STDLIB_H           /* <stdlib.h> should declare malloc(),free() */
extern void * malloc JPP((size_t size));
extern void free JPP((void *ptr));
#endif

#ifndef SEEK_SET                /* pre-ANSI systems may not define this; */
#define SEEK_SET  0             /* if not, assume 0 is correct */
#endif


/*
 * Memory allocation and freeing are controlled by the regular library
 * routines malloc() and free().
 */

GLOBAL(void *)
jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
{
  return (void *) malloc(sizeofobject);
}

GLOBAL(void)
jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
{
  free(object);
}


/*
 * "Large" objects are treated the same as "small" ones.
 * NB: although we include FAR keywords in the routine declarations,
 * this file won't actually work in 80x86 small/medium model; at least,
 * you probably won't be able to process useful-size images in only 64KB.
 */

GLOBAL(void FAR *)
jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
{
  return (void FAR *) malloc(sizeofobject);
}

GLOBAL(void)
jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
{
  free(object);
}


/*
 * This routine computes the total memory space available for allocation.
 * It's impossible to do this in a portable way; our current solution is
 * to make the user tell us (with a default value set at compile time).
 * If you can actually get the available space, it's a good idea to subtract
 * a slop factor of 5% or so.
 */

#ifndef DEFAULT_MAX_MEM         /* so can override from makefile */
#define DEFAULT_MAX_MEM         1000000L /* default: one megabyte */
#endif

GLOBAL(long)
jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
                    long max_bytes_needed, long already_allocated)
{
  return cinfo->mem->max_memory_to_use - already_allocated;
}


/*
 * Backing store (temporary file) management.
 * Backing store objects are only used when the value returned by
 * jpeg_mem_available is less than the total space needed.  You can dispense
 * with these routines if you have plenty of virtual memory; see jmemnobs.c.
 */


METHODDEF(void)
read_backing_store (j_common_ptr cinfo, backing_store_ptr info,
                    void FAR * buffer_address,
                    long file_offset, long byte_count)
{
  if (fseek(info->temp_file, file_offset, SEEK_SET))
    ERREXIT(cinfo, JERR_TFILE_SEEK);
  if (JFREAD(info->temp_file, buffer_address, byte_count)
      != (size_t) byte_count)
    ERREXIT(cinfo, JERR_TFILE_READ);
}


METHODDEF(void)
write_backing_store (j_common_ptr cinfo, backing_store_ptr info,
                     void FAR * buffer_address,
                     long file_offset, long byte_count)
{
  if (fseek(info->temp_file, file_offset, SEEK_SET))
    ERREXIT(cinfo, JERR_TFILE_SEEK);
  if (JFWRITE(info->temp_file, buffer_address, byte_count)
      != (size_t) byte_count)
    ERREXIT(cinfo, JERR_TFILE_WRITE);
}


METHODDEF(void)
close_backing_store (j_common_ptr cinfo, backing_store_ptr info)
{
  fclose(info->temp_file);
  /* Since this implementation uses tmpfile() to create the file,
   * no explicit file deletion is needed.
   */
}


/*
 * Initial opening of a backing-store object.
 *
 * This version uses tmpfile(), which constructs a suitable file name
 * behind the scenes.  We don't have to use info->temp_name[] at all;
 * indeed, we can't even find out the actual name of the temp file.
 */

GLOBAL(void)
jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
                         long total_bytes_needed)
{
  if ((info->temp_file = tmpfile()) == NULL)
    ERREXITS(cinfo, JERR_TFILE_CREATE, "");
  info->read_backing_store = read_backing_store;
  info->write_backing_store = write_backing_store;
  info->close_backing_store = close_backing_store;
}


/*
 * These routines take care of any system-dependent initialization and
 * cleanup required.
 */

GLOBAL(long)
jpeg_mem_init (j_common_ptr cinfo)
{
  return DEFAULT_MAX_MEM;       /* default for max_memory_to_use */
}

GLOBAL(void)
jpeg_mem_term (j_common_ptr cinfo)
{
  /* no work */
}
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() */
21	extern void * malloc JPP((size_t size));
22	extern 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
35	GLOBAL(void *)
36	jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
37	{
38	return (void *) malloc(sizeofobject);
39	}
40
41	GLOBAL(void)
42	jpeg_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
55	GLOBAL(void FAR *)
56	jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
57	{
58	return (void FAR *) malloc(sizeofobject);
59	}
60
61	GLOBAL(void)
62	jpeg_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
80	GLOBAL(long)
81	jpeg_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
96	METHODDEF(void)
97	read_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
109	METHODDEF(void)
110	write_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
122	METHODDEF(void)
123	close_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
140	GLOBAL(void)
141	jpeg_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
157	GLOBAL(long)
158	jpeg_mem_init (j_common_ptr cinfo)
159	{
160	return DEFAULT_MAX_MEM; /* default for max_memory_to_use */
161	}
162
163	GLOBAL(void)
164	jpeg_mem_term (j_common_ptr cinfo)
165	{
166	/* no work */
167	}