1 /* 2 * Copyright (C) 2006 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 // Asset management class. AssetManager objects are thread-safe. 19 // 20 #ifndef __LIBS_ASSETMANAGER_H 21 #define __LIBS_ASSETMANAGER_H 22 23 #include <utils/Asset.h> 24 #include <utils/AssetDir.h> 25 #include <utils/KeyedVector.h> 26 #include <utils/String8.h> 27 #include <utils/Vector.h> 28 #include <utils/String16.h> 29 #include <utils/ZipFileRO.h> 30 #include <utils/threads.h> 31 32 /* 33 * Native-app access is via the opaque typedef struct AAssetManager in the C namespace. 34 */ 35 #ifdef __cplusplus 36 extern "C" { 37 #endif 38 39 struct AAssetManager { }; 40 41 #ifdef __cplusplus 42 }; 43 #endif 44 45 46 /* 47 * Now the proper C++ android-namespace definitions 48 */ 49 50 namespace android { 51 52 class Asset; // fwd decl for things that include Asset.h first 53 class ResTable; 54 struct ResTable_config; 55 56 /* 57 * Every application that uses assets needs one instance of this. A 58 * single instance may be shared across multiple threads, and a single 59 * thread may have more than one instance (the latter is discouraged). 60 * 61 * The purpose of the AssetManager is to create Asset objects. To do 62 * this efficiently it may cache information about the locations of 63 * files it has seen. This can be controlled with the "cacheMode" 64 * argument. 65 * 66 * The asset hierarchy may be examined like a filesystem, using 67 * AssetDir objects to peruse a single directory. 68 */ 69 class AssetManager : public AAssetManager { 70 public: 71 typedef enum CacheMode { 72 CACHE_UNKNOWN = 0, 73 CACHE_OFF, // don't try to cache file locations 74 CACHE_DEFER, // construct cache as pieces are needed 75 //CACHE_SCAN, // scan full(!) asset hierarchy at init() time 76 } CacheMode; 77 78 AssetManager(CacheMode cacheMode = CACHE_OFF); 79 virtual ~AssetManager(void); 80 81 static int32_t getGlobalCount(); 82 83 /* 84 * Add a new source for assets. This can be called multiple times to 85 * look in multiple places for assets. It can be either a directory (for 86 * finding assets as raw files on the disk) or a ZIP file. This newly 87 * added asset path will be examined first when searching for assets, 88 * before any that were previously added. 89 * 90 * Returns "true" on success, "false" on failure. If 'cookie' is non-NULL, 91 * then on success, *cookie is set to the value corresponding to the 92 * newly-added asset source. 93 */ 94 bool addAssetPath(const String8& path, void** cookie); 95 96 /* 97 * Convenience for adding the standard system assets. Uses the 98 * ANDROID_ROOT environment variable to find them. 99 */ 100 bool addDefaultAssets(); 101 102 /* 103 * Iterate over the asset paths in this manager. (Previously 104 * added via addAssetPath() and addDefaultAssets().) On first call, 105 * 'cookie' must be NULL, resulting in the first cookie being returned. 106 * Each next cookie will be returned there-after, until NULL indicating 107 * the end has been reached. 108 */ 109 void* nextAssetPath(void* cookie) const; 110 111 /* 112 * Return an asset path in the manager. 'which' must be between 0 and 113 * countAssetPaths(). 114 */ 115 String8 getAssetPath(void* cookie) const; 116 117 /* 118 * Set the current locale and vendor. The locale can change during 119 * the lifetime of an AssetManager if the user updates the device's 120 * language setting. The vendor is less likely to change. 121 * 122 * Pass in NULL to indicate no preference. 123 */ 124 void setLocale(const char* locale); 125 void setVendor(const char* vendor); 126 127 /* 128 * Choose screen orientation for resources values returned. 129 */ 130 void setConfiguration(const ResTable_config& config, const char* locale = NULL); 131 132 void getConfiguration(ResTable_config* outConfig) const; 133 134 typedef Asset::AccessMode AccessMode; // typing shortcut 135 136 /* 137 * Open an asset. 138 * 139 * This will search through locale-specific and vendor-specific 140 * directories and packages to find the file. 141 * 142 * The object returned does not depend on the AssetManager. It should 143 * be freed by calling Asset::close(). 144 */ 145 Asset* open(const char* fileName, AccessMode mode); 146 147 /* 148 * Open a non-asset file as an asset. 149 * 150 * This is for opening files that are included in an asset package 151 * but aren't assets. These sit outside the usual "locale/vendor" 152 * path hierarchy, and will not be seen by "AssetDir" or included 153 * in our filename cache. 154 */ 155 Asset* openNonAsset(const char* fileName, AccessMode mode); 156 157 /* 158 * Explicit non-asset file. The file explicitly named by the cookie (the 159 * resource set to look in) and fileName will be opened and returned. 160 */ 161 Asset* openNonAsset(void* cookie, const char* fileName, AccessMode mode); 162 163 /* 164 * Open a directory within the asset hierarchy. 165 * 166 * The contents of the directory are an amalgam of vendor-specific, 167 * locale-specific, and generic assets stored loosely or in asset 168 * packages. Depending on the cache setting and previous accesses, 169 * this call may incur significant disk overhead. 170 * 171 * To open the top-level directory, pass in "". 172 */ 173 AssetDir* openDir(const char* dirName); 174 175 /* 176 * Open a directory within a particular path of the asset manager. 177 * 178 * The contents of the directory are an amalgam of vendor-specific, 179 * locale-specific, and generic assets stored loosely or in asset 180 * packages. Depending on the cache setting and previous accesses, 181 * this call may incur significant disk overhead. 182 * 183 * To open the top-level directory, pass in "". 184 */ 185 AssetDir* openNonAssetDir(void* cookie, const char* dirName); 186 187 /* 188 * Get the type of a file in the asset hierarchy. They will either 189 * be "regular" or "directory". [Currently only works for "regular".] 190 * 191 * Can also be used as a quick test for existence of a file. 192 */ 193 FileType getFileType(const char* fileName); 194 195 /* 196 * Return the complete resource table to find things in the package. 197 */ 198 const ResTable& getResources(bool required = true) const; 199 200 /* 201 * Discard cached filename information. This only needs to be called 202 * if somebody has updated the set of "loose" files, and we want to 203 * discard our cached notion of what's where. 204 */ purge(void)205 void purge(void) { purgeFileNameCacheLocked(); } 206 207 /* 208 * Return true if the files this AssetManager references are all 209 * up-to-date (have not been changed since it was created). If false 210 * is returned, you will need to create a new AssetManager to get 211 * the current data. 212 */ 213 bool isUpToDate(); 214 215 /** 216 * Get the known locales for this asset manager object. 217 */ 218 void getLocales(Vector<String8>* locales) const; 219 220 private: 221 struct asset_path 222 { 223 String8 path; 224 FileType type; 225 }; 226 227 Asset* openInPathLocked(const char* fileName, AccessMode mode, 228 const asset_path& path); 229 Asset* openNonAssetInPathLocked(const char* fileName, AccessMode mode, 230 const asset_path& path); 231 Asset* openInLocaleVendorLocked(const char* fileName, AccessMode mode, 232 const asset_path& path, const char* locale, const char* vendor); 233 String8 createPathNameLocked(const asset_path& path, const char* locale, 234 const char* vendor); 235 String8 createPathNameLocked(const asset_path& path, const char* rootDir); 236 String8 createZipSourceNameLocked(const String8& zipFileName, 237 const String8& dirName, const String8& fileName); 238 239 ZipFileRO* getZipFileLocked(const asset_path& path); 240 Asset* openAssetFromFileLocked(const String8& fileName, AccessMode mode); 241 Asset* openAssetFromZipLocked(const ZipFileRO* pZipFile, 242 const ZipEntryRO entry, AccessMode mode, const String8& entryName); 243 244 bool scanAndMergeDirLocked(SortedVector<AssetDir::FileInfo>* pMergedInfo, 245 const asset_path& path, const char* rootDir, const char* dirName); 246 SortedVector<AssetDir::FileInfo>* scanDirLocked(const String8& path); 247 bool scanAndMergeZipLocked(SortedVector<AssetDir::FileInfo>* pMergedInfo, 248 const asset_path& path, const char* rootDir, const char* dirName); 249 void mergeInfoLocked(SortedVector<AssetDir::FileInfo>* pMergedInfo, 250 const SortedVector<AssetDir::FileInfo>* pContents); 251 252 void loadFileNameCacheLocked(void); 253 void fncScanLocked(SortedVector<AssetDir::FileInfo>* pMergedInfo, 254 const char* dirName); 255 bool fncScanAndMergeDirLocked( 256 SortedVector<AssetDir::FileInfo>* pMergedInfo, 257 const asset_path& path, const char* locale, const char* vendor, 258 const char* dirName); 259 void purgeFileNameCacheLocked(void); 260 261 const ResTable* getResTable(bool required = true) const; 262 void setLocaleLocked(const char* locale); 263 void updateResourceParamsLocked() const; 264 265 class SharedZip : public RefBase { 266 public: 267 static sp<SharedZip> get(const String8& path); 268 269 ZipFileRO* getZip(); 270 271 Asset* getResourceTableAsset(); 272 Asset* setResourceTableAsset(Asset* asset); 273 274 ResTable* getResourceTable(); 275 ResTable* setResourceTable(ResTable* res); 276 277 bool isUpToDate(); 278 279 protected: 280 ~SharedZip(); 281 282 private: 283 SharedZip(const String8& path, time_t modWhen); 284 SharedZip(); // <-- not implemented 285 286 String8 mPath; 287 ZipFileRO* mZipFile; 288 time_t mModWhen; 289 290 Asset* mResourceTableAsset; 291 ResTable* mResourceTable; 292 293 static Mutex gLock; 294 static DefaultKeyedVector<String8, wp<SharedZip> > gOpen; 295 }; 296 297 /* 298 * Manage a set of Zip files. For each file we need a pointer to the 299 * ZipFile and a time_t with the file's modification date. 300 * 301 * We currently only have two zip files (current app, "common" app). 302 * (This was originally written for 8, based on app/locale/vendor.) 303 */ 304 class ZipSet { 305 public: 306 ZipSet(void); 307 ~ZipSet(void); 308 309 /* 310 * Return a ZipFileRO structure for a ZipFileRO with the specified 311 * parameters. 312 */ 313 ZipFileRO* getZip(const String8& path); 314 315 Asset* getZipResourceTableAsset(const String8& path); 316 Asset* setZipResourceTableAsset(const String8& path, Asset* asset); 317 318 ResTable* getZipResourceTable(const String8& path); 319 ResTable* setZipResourceTable(const String8& path, ResTable* res); 320 321 // generate path, e.g. "common/en-US-noogle.zip" 322 static String8 getPathName(const char* path); 323 324 bool isUpToDate(); 325 326 private: 327 void closeZip(int idx); 328 329 int getIndex(const String8& zip) const; 330 mutable Vector<String8> mZipPath; 331 mutable Vector<sp<SharedZip> > mZipFile; 332 }; 333 334 // Protect all internal state. 335 mutable Mutex mLock; 336 337 ZipSet mZipSet; 338 339 Vector<asset_path> mAssetPaths; 340 char* mLocale; 341 char* mVendor; 342 343 mutable ResTable* mResources; 344 ResTable_config* mConfig; 345 346 /* 347 * Cached data for "loose" files. This lets us avoid poking at the 348 * filesystem when searching for loose assets. Each entry is the 349 * "extended partial" path, e.g. "default/default/foo/bar.txt". The 350 * full set of files is present, including ".EXCLUDE" entries. 351 * 352 * We do not cache directory names. We don't retain the ".gz", 353 * because to our clients "foo" and "foo.gz" both look like "foo". 354 */ 355 CacheMode mCacheMode; // is the cache enabled? 356 bool mCacheValid; // clear when locale or vendor changes 357 SortedVector<AssetDir::FileInfo> mCache; 358 }; 359 360 }; // namespace android 361 362 #endif // __LIBS_ASSETMANAGER_H 363