1/*
2 * Copyright (C) 2010 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/**
18 * @addtogroup Asset
19 * @{
20 */
21
22/**
23 * @file asset_manager.h
24 */
25
26#ifndef ANDROID_ASSET_MANAGER_H
27#define ANDROID_ASSET_MANAGER_H
28
29#include <sys/cdefs.h>
30#include <sys/types.h>
31
32#ifdef __cplusplus
33extern "C" {
34#endif
35
36struct AAssetManager;
37/**
38 * {@link AAssetManager} provides access to an application's raw assets by
39 * creating {@link AAsset} objects.
40 *
41 * AAssetManager is a wrapper to the low-level native implementation
42 * of the java {@link AAssetManager}, a pointer can be obtained using
43 * AAssetManager_fromJava().
44 *
45 * The asset hierarchy may be examined like a filesystem, using
46 * {@link AAssetDir} objects to peruse a single directory.
47 *
48 * A native {@link AAssetManager} pointer may be shared across multiple threads.
49 */
50typedef struct AAssetManager AAssetManager;
51
52struct AAssetDir;
53/**
54 * {@link AAssetDir} provides access to a chunk of the asset hierarchy as if
55 * it were a single directory. The contents are populated by the
56 * {@link AAssetManager}.
57 *
58 * The list of files will be sorted in ascending order by ASCII value.
59 */
60typedef struct AAssetDir AAssetDir;
61
62struct AAsset;
63/**
64 * {@link AAsset} provides access to a read-only asset.
65 *
66 * {@link AAsset} objects are NOT thread-safe, and should not be shared across
67 * threads.
68 */
69typedef struct AAsset AAsset;
70
71/** Available access modes for opening assets with {@link AAssetManager_open} */
72enum {
73    /** No specific information about how data will be accessed. **/
74    AASSET_MODE_UNKNOWN      = 0,
75    /** Read chunks, and seek forward and backward. */
76    AASSET_MODE_RANDOM       = 1,
77    /** Read sequentially, with an occasional forward seek. */
78    AASSET_MODE_STREAMING    = 2,
79    /** Caller plans to ask for a read-only buffer with all data. */
80    AASSET_MODE_BUFFER       = 3
81};
82
83
84/**
85 * Open the named directory within the asset hierarchy.  The directory can then
86 * be inspected with the AAssetDir functions.  To open the top-level directory,
87 * pass in "" as the dirName.
88 *
89 * The object returned here should be freed by calling AAssetDir_close().
90 */
91AAssetDir* AAssetManager_openDir(AAssetManager* mgr, const char* dirName);
92
93/**
94 * Open an asset.
95 *
96 * The object returned here should be freed by calling AAsset_close().
97 */
98AAsset* AAssetManager_open(AAssetManager* mgr, const char* filename, int mode);
99
100/**
101 * Iterate over the files in an asset directory.  A NULL string is returned
102 * when all the file names have been returned.
103 *
104 * The returned file name is suitable for passing to AAssetManager_open().
105 *
106 * The string returned here is owned by the AssetDir implementation and is not
107 * guaranteed to remain valid if any other calls are made on this AAssetDir
108 * instance.
109 */
110const char* AAssetDir_getNextFileName(AAssetDir* assetDir);
111
112/**
113 * Reset the iteration state of AAssetDir_getNextFileName() to the beginning.
114 */
115void AAssetDir_rewind(AAssetDir* assetDir);
116
117/**
118 * Close an opened AAssetDir, freeing any related resources.
119 */
120void AAssetDir_close(AAssetDir* assetDir);
121
122/**
123 * Attempt to read 'count' bytes of data from the current offset.
124 *
125 * Returns the number of bytes read, zero on EOF, or < 0 on error.
126 */
127int AAsset_read(AAsset* asset, void* buf, size_t count);
128
129/**
130 * Seek to the specified offset within the asset data.  'whence' uses the
131 * same constants as lseek()/fseek().
132 *
133 * Returns the new position on success, or (off_t) -1 on error.
134 */
135off_t AAsset_seek(AAsset* asset, off_t offset, int whence);
136
137#if __ANDROID_API__ >= 13
138/**
139 * Seek to the specified offset within the asset data.  'whence' uses the
140 * same constants as lseek()/fseek().
141 *
142 * Uses 64-bit data type for large files as opposed to the 32-bit type used
143 * by AAsset_seek.
144 *
145 * Returns the new position on success, or (off64_t) -1 on error.
146 */
147off64_t AAsset_seek64(AAsset* asset, off64_t offset, int whence);
148#endif
149
150/**
151 * Close the asset, freeing all associated resources.
152 */
153void AAsset_close(AAsset* asset);
154
155/**
156 * Get a pointer to a buffer holding the entire contents of the assset.
157 *
158 * Returns NULL on failure.
159 */
160const void* AAsset_getBuffer(AAsset* asset);
161
162/**
163 * Report the total size of the asset data.
164 */
165off_t AAsset_getLength(AAsset* asset);
166
167#if __ANDROID_API__ >= 13
168/**
169 * Report the total size of the asset data. Reports the size using a 64-bit
170 * number insted of 32-bit as AAsset_getLength.
171 */
172off64_t AAsset_getLength64(AAsset* asset);
173#endif
174
175/**
176 * Report the total amount of asset data that can be read from the current position.
177 */
178off_t AAsset_getRemainingLength(AAsset* asset);
179
180#if __ANDROID_API__ >= 13
181/**
182 * Report the total amount of asset data that can be read from the current position.
183 *
184 * Uses a 64-bit number instead of a 32-bit number as AAsset_getRemainingLength does.
185 */
186off64_t AAsset_getRemainingLength64(AAsset* asset);
187#endif
188
189/**
190 * Open a new file descriptor that can be used to read the asset data. If the
191 * start or length cannot be represented by a 32-bit number, it will be
192 * truncated. If the file is large, use AAsset_openFileDescriptor64 instead.
193 *
194 * Returns < 0 if direct fd access is not possible (for example, if the asset is
195 * compressed).
196 */
197int AAsset_openFileDescriptor(AAsset* asset, off_t* outStart, off_t* outLength);
198
199#if __ANDROID_API__ >= 13
200/**
201 * Open a new file descriptor that can be used to read the asset data.
202 *
203 * Uses a 64-bit number for the offset and length instead of 32-bit instead of
204 * as AAsset_openFileDescriptor does.
205 *
206 * Returns < 0 if direct fd access is not possible (for example, if the asset is
207 * compressed).
208 */
209int AAsset_openFileDescriptor64(AAsset* asset, off64_t* outStart, off64_t* outLength);
210#endif
211
212/**
213 * Returns whether this asset's internal buffer is allocated in ordinary RAM (i.e. not
214 * mmapped).
215 */
216int AAsset_isAllocated(AAsset* asset);
217
218
219
220#ifdef __cplusplus
221};
222#endif
223
224#endif      // ANDROID_ASSET_MANAGER_H
225
226/** @} */
227