1 /*
2 * Copyright (C) 2007-2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define JPEG_INTERNALS
18 #include "jinclude.h"
19 #include "jpeglib.h"
20 #include "jmemsys.h" /* import the system-dependent declarations */
21
22 #include <unistd.h>
23 #include <sys/mman.h>
24
25 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc(),free() */
26 extern void * malloc JPP((size_t size));
27 extern void free JPP((void *ptr));
28 #endif
29
30 /*
31 * Memory allocation and freeing are controlled by the regular library
32 * routines malloc() and free().
33 */
34
35 GLOBAL(void *)
jpeg_get_small(j_common_ptr cinfo,size_t sizeofobject)36 jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
37 {
38 return (void *) malloc(sizeofobject);
39 }
40
41 GLOBAL(void)
jpeg_free_small(j_common_ptr cinfo,void * object,size_t sizeofobject)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 *)
jpeg_get_large(j_common_ptr cinfo,size_t sizeofobject)56 jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
57 {
58 return (void FAR *) malloc(sizeofobject);
59 }
60
61 GLOBAL(void)
jpeg_free_large(j_common_ptr cinfo,void FAR * object,size_t sizeofobject)62 jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
63 {
64 free(object);
65 }
66
67 /*
68 * This routine computes the total memory space available for allocation.
69 * It's impossible to do this in a portable way; our current solution is
70 * to make the user tell us (with a default value set at compile time).
71 * If you can actually get the available space, it's a good idea to subtract
72 * a slop factor of 5% or so.
73 */
74
75 #ifndef DEFAULT_MAX_MEM /* so can override from makefile */
76 #define DEFAULT_MAX_MEM 10000000L /* default: ten megabyte */
77 #endif
78
79 GLOBAL(long)
jpeg_mem_available(j_common_ptr cinfo,long min_bytes_needed,long max_bytes_needed,long already_allocated)80 jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
81 long max_bytes_needed, long already_allocated)
82 {
83 return cinfo->mem->max_memory_to_use - already_allocated;
84 }
85
86
87 /*
88 * Backing store (temporary file) management.
89 * Backing store objects are only used when the value returned by
90 * jpeg_mem_available is less than the total space needed. You can dispense
91 * with these routines if you have plenty of virtual memory; see jmemnobs.c.
92 */
93
94 METHODDEF(void)
read_backing_store(j_common_ptr cinfo,backing_store_ptr info,void FAR * buffer_address,long file_offset,long byte_count)95 read_backing_store (j_common_ptr cinfo, backing_store_ptr info,
96 void FAR * buffer_address,
97 long file_offset, long byte_count)
98 {
99 memmove(buffer_address, info->addr + file_offset, byte_count);
100 }
101
102
103 METHODDEF(void)
write_backing_store(j_common_ptr cinfo,backing_store_ptr info,void FAR * buffer_address,long file_offset,long byte_count)104 write_backing_store (j_common_ptr cinfo, backing_store_ptr info,
105 void FAR * buffer_address,
106 long file_offset, long byte_count)
107 {
108 memmove(info->addr + file_offset, buffer_address, byte_count);
109 }
110
111
112 METHODDEF(void)
close_backing_store(j_common_ptr cinfo,backing_store_ptr info)113 close_backing_store (j_common_ptr cinfo, backing_store_ptr info)
114 {
115 munmap(info->addr, info->size);
116 close(info->temp_file);
117 }
118
119 LOCAL(int)
get_ashmem(backing_store_ptr info,long total_bytes_needed)120 get_ashmem(backing_store_ptr info, long total_bytes_needed)
121 {
122 char path[1024];
123 snprintf(path, 1023, "%d.tmp.ashmem", getpid());
124 int fd = ashmem_create_region(path, total_bytes_needed);
125 if (fd == -1) {
126 return -1;
127 }
128 int err = ashmem_set_prot_region(fd, PROT_READ | PROT_WRITE);
129 if (err) {
130 return -1;
131 }
132 info->addr = mmap(NULL, total_bytes_needed, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
133 info->size = total_bytes_needed;
134 info->temp_file = fd;
135 return fd;
136 }
137
138 /*
139 * Initial opening of a backing-store object.
140 * This version uses ashmem to get a shared memory of total-bytes_needed.
141 */
142
143 GLOBAL(void)
jpeg_open_backing_store(j_common_ptr cinfo,backing_store_ptr info,long total_bytes_needed)144 jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
145 long total_bytes_needed)
146 {
147 if (get_ashmem(info, total_bytes_needed) == -1)
148 ERREXITS(cinfo, JERR_TFILE_CREATE, "");
149 info->read_backing_store = read_backing_store;
150 info->write_backing_store = write_backing_store;
151 info->close_backing_store = close_backing_store;
152 }
153
154 /*
155 * These routines take care of any system-dependent initialization and
156 * cleanup required.
157 */
158
159 GLOBAL(long)
jpeg_mem_init(j_common_ptr cinfo)160 jpeg_mem_init (j_common_ptr cinfo)
161 {
162 return DEFAULT_MAX_MEM; /* default for max_memory_to_use */
163 }
164
165 GLOBAL(void)
jpeg_mem_term(j_common_ptr cinfo)166 jpeg_mem_term (j_common_ptr cinfo)
167 {
168 /* no work */
169 }
170