ReactOS  0.4.14-dev-593-g1793dcc
jmemansi.c
Go to the documentation of this file.
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 *)
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 *)
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)
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)
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)
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)
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)
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)
159 {
160  return DEFAULT_MAX_MEM; /* default for max_memory_to_use */
161 }
162 
163 GLOBAL(void)
165 {
166  /* no work */
167 }
jpeg_get_small(j_common_ptr cinfo, size_t sizeofobject)
Definition: jmemansi.c:36
jpeg_get_large(j_common_ptr cinfo, size_t sizeofobject)
Definition: jmemansi.c:56
#define ERREXIT(msg)
Definition: rdjpgcom.c:72
long long max_bytes_needed
Definition: jmemsys.h:104
jpeg_mem_term(j_common_ptr cinfo)
Definition: jmemansi.c:164
void *malloc JPP((size_t size))
#define free
Definition: debug_ros.c:5
#define JFREAD(file, buf, sizeofbuf)
Definition: jinclude.h:92
#define JFWRITE(file, buf, sizeofbuf)
Definition: jinclude.h:94
size_t sizeofobject
Definition: jmemsys.h:47
write_backing_store(j_common_ptr cinfo, backing_store_ptr info, void FAR *buffer_address, long file_offset, long byte_count)
Definition: jmemansi.c:110
#define FAR
Definition: guiddef.h:36
static PVOID ptr
Definition: dispmode.c:27
smooth NULL
Definition: ftsmooth.c:416
_Check_return_opt_ _CRTIMP int __cdecl fseek(_Inout_ FILE *_File, _In_ long _Offset, _In_ int _Origin)
jpeg_open_backing_store(j_common_ptr cinfo, backing_store_ptr info, long total_bytes_needed)
Definition: jmemansi.c:141
backing_store_ptr long total_bytes_needed
Definition: jmemsys.h:181
_Check_return_ _CRTIMP FILE *__cdecl tmpfile(void)
Definition: file.c:3912
#define SEEK_SET
Definition: jmemansi.c:26
jpeg_free_large(j_common_ptr cinfo, void FAR *object, size_t sizeofobject)
Definition: jmemansi.c:62
GLsizeiptr size
Definition: glext.h:5919
long min_bytes_needed
Definition: jmemsys.h:104
close_backing_store(j_common_ptr cinfo, backing_store_ptr info)
Definition: jmemansi.c:123
long long long already_allocated
Definition: jmemsys.h:104
jpeg_mem_available(j_common_ptr cinfo, long min_bytes_needed, long max_bytes_needed, long already_allocated)
Definition: jmemansi.c:81
_Check_return_opt_ _CRTIMP int __cdecl fclose(_Inout_ FILE *_File)
#define GLOBAL(type)
Definition: jmorecfg.h:291
#define DEFAULT_MAX_MEM
Definition: jmemansi.c:77
#define METHODDEF(type)
Definition: jmorecfg.h:287
jpeg_mem_init(j_common_ptr cinfo)
Definition: jmemansi.c:158
jpeg_free_small(j_common_ptr cinfo, void *object, size_t sizeofobject)
Definition: jmemansi.c:42
read_backing_store(j_common_ptr cinfo, backing_store_ptr info, void FAR *buffer_address, long file_offset, long byte_count)
Definition: jmemansi.c:97
#define malloc
Definition: debug_ros.c:4
#define ERREXITS(cinfo, code, str)
Definition: jerror.h:243