The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 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 | package android.webkit; |
| 18 | |
| 19 | import android.content.Context; |
| 20 | import android.net.http.Headers; |
| 21 | import android.os.FileUtils; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 22 | import android.util.Log; |
| 23 | import java.io.File; |
| 24 | import java.io.FileInputStream; |
| 25 | import java.io.FileNotFoundException; |
| 26 | import java.io.FileOutputStream; |
| 27 | import java.io.IOException; |
| 28 | import java.io.InputStream; |
| 29 | import java.io.OutputStream; |
| 30 | import java.util.ArrayList; |
| 31 | import java.util.Map; |
| 32 | |
| 33 | import org.bouncycastle.crypto.Digest; |
| 34 | import org.bouncycastle.crypto.digests.SHA1Digest; |
| 35 | |
| 36 | /** |
| 37 | * The class CacheManager provides the persistent cache of content that is |
| 38 | * received over the network. The component handles parsing of HTTP headers and |
| 39 | * utilizes the relevant cache headers to determine if the content should be |
| 40 | * stored and if so, how long it is valid for. Network requests are provided to |
| 41 | * this component and if they can not be resolved by the cache, the HTTP headers |
| 42 | * are attached, as appropriate, to the request for revalidation of content. The |
| 43 | * class also manages the cache size. |
| 44 | */ |
| 45 | public final class CacheManager { |
| 46 | |
| 47 | private static final String LOGTAG = "cache"; |
| 48 | |
| 49 | static final String HEADER_KEY_IFMODIFIEDSINCE = "if-modified-since"; |
| 50 | static final String HEADER_KEY_IFNONEMATCH = "if-none-match"; |
| 51 | |
| 52 | private static final String NO_STORE = "no-store"; |
| 53 | private static final String NO_CACHE = "no-cache"; |
The Android Open Source Project | ba87e3e | 2009-03-13 13:04:22 -0700 | [diff] [blame] | 54 | private static final String PRIVATE = "private"; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 55 | private static final String MAX_AGE = "max-age"; |
| 56 | |
| 57 | private static long CACHE_THRESHOLD = 6 * 1024 * 1024; |
| 58 | private static long CACHE_TRIM_AMOUNT = 2 * 1024 * 1024; |
| 59 | |
| 60 | private static boolean mDisabled; |
| 61 | |
| 62 | // Reference count the enable/disable transaction |
| 63 | private static int mRefCount; |
| 64 | |
| 65 | // trimCacheIfNeeded() is called when a page is fully loaded. But JavaScript |
| 66 | // can load the content, e.g. in a slideshow, continuously, so we need to |
| 67 | // trim the cache on a timer base too. endCacheTransaction() is called on a |
| 68 | // timer base. We share the same timer with less frequent update. |
| 69 | private static int mTrimCacheCount = 0; |
| 70 | private static final int TRIM_CACHE_INTERVAL = 5; |
| 71 | |
| 72 | private static WebViewDatabase mDataBase; |
| 73 | private static File mBaseDir; |
| 74 | |
| 75 | // Flag to clear the cache when the CacheManager is initialized |
| 76 | private static boolean mClearCacheOnInit = false; |
| 77 | |
| 78 | public static class CacheResult { |
| 79 | // these fields are saved to the database |
| 80 | int httpStatusCode; |
| 81 | long contentLength; |
| 82 | long expires; |
| 83 | String localPath; |
| 84 | String lastModified; |
| 85 | String etag; |
| 86 | String mimeType; |
| 87 | String location; |
| 88 | String encoding; |
| 89 | |
| 90 | // these fields are NOT saved to the database |
| 91 | InputStream inStream; |
| 92 | OutputStream outStream; |
| 93 | File outFile; |
| 94 | |
| 95 | public int getHttpStatusCode() { |
| 96 | return httpStatusCode; |
| 97 | } |
| 98 | |
| 99 | public long getContentLength() { |
| 100 | return contentLength; |
| 101 | } |
| 102 | |
| 103 | public String getLocalPath() { |
| 104 | return localPath; |
| 105 | } |
| 106 | |
| 107 | public long getExpires() { |
| 108 | return expires; |
| 109 | } |
| 110 | |
| 111 | public String getLastModified() { |
| 112 | return lastModified; |
| 113 | } |
| 114 | |
| 115 | public String getETag() { |
| 116 | return etag; |
| 117 | } |
| 118 | |
| 119 | public String getMimeType() { |
| 120 | return mimeType; |
| 121 | } |
| 122 | |
| 123 | public String getLocation() { |
| 124 | return location; |
| 125 | } |
| 126 | |
| 127 | public String getEncoding() { |
| 128 | return encoding; |
| 129 | } |
| 130 | |
| 131 | // For out-of-package access to the underlying streams. |
| 132 | public InputStream getInputStream() { |
| 133 | return inStream; |
| 134 | } |
| 135 | |
| 136 | public OutputStream getOutputStream() { |
| 137 | return outStream; |
| 138 | } |
| 139 | |
| 140 | // These fields can be set manually. |
| 141 | public void setInputStream(InputStream stream) { |
| 142 | this.inStream = stream; |
| 143 | } |
| 144 | |
| 145 | public void setEncoding(String encoding) { |
| 146 | this.encoding = encoding; |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | /** |
| 151 | * initialize the CacheManager. WebView should handle this for each process. |
| 152 | * |
| 153 | * @param context The application context. |
| 154 | */ |
| 155 | static void init(Context context) { |
| 156 | mDataBase = WebViewDatabase.getInstance(context); |
| 157 | mBaseDir = new File(context.getCacheDir(), "webviewCache"); |
| 158 | if (createCacheDirectory() && mClearCacheOnInit) { |
| 159 | removeAllCacheFiles(); |
| 160 | mClearCacheOnInit = false; |
| 161 | } |
| 162 | } |
| 163 | |
| 164 | /** |
| 165 | * Create the cache directory if it does not already exist. |
| 166 | * |
| 167 | * @return true if the cache directory didn't exist and was created. |
| 168 | */ |
| 169 | static private boolean createCacheDirectory() { |
| 170 | if (!mBaseDir.exists()) { |
| 171 | if(!mBaseDir.mkdirs()) { |
| 172 | Log.w(LOGTAG, "Unable to create webviewCache directory"); |
| 173 | return false; |
| 174 | } |
| 175 | FileUtils.setPermissions( |
| 176 | mBaseDir.toString(), |
| 177 | FileUtils.S_IRWXU|FileUtils.S_IRWXG|FileUtils.S_IXOTH, |
| 178 | -1, -1); |
| 179 | // If we did create the directory, we need to flush |
| 180 | // the cache database. The directory could be recreated |
| 181 | // because the system flushed all the data/cache directories |
| 182 | // to free up disk space. |
| 183 | WebViewCore.endCacheTransaction(); |
| 184 | mDataBase.clearCache(); |
| 185 | WebViewCore.startCacheTransaction(); |
| 186 | return true; |
| 187 | } |
| 188 | return false; |
| 189 | } |
| 190 | |
| 191 | /** |
| 192 | * get the base directory of the cache. With localPath of the CacheResult, |
| 193 | * it identifies the cache file. |
| 194 | * |
| 195 | * @return File The base directory of the cache. |
| 196 | */ |
| 197 | public static File getCacheFileBaseDir() { |
| 198 | return mBaseDir; |
| 199 | } |
| 200 | |
| 201 | /** |
| 202 | * set the flag to control whether cache is enabled or disabled |
| 203 | * |
| 204 | * @param disabled true to disable the cache |
| 205 | */ |
| 206 | // only called from WebCore thread |
| 207 | static void setCacheDisabled(boolean disabled) { |
| 208 | if (disabled == mDisabled) { |
| 209 | return; |
| 210 | } |
| 211 | mDisabled = disabled; |
| 212 | if (mDisabled) { |
| 213 | removeAllCacheFiles(); |
| 214 | } |
| 215 | } |
| 216 | |
| 217 | /** |
| 218 | * get the state of the current cache, enabled or disabled |
| 219 | * |
| 220 | * @return return if it is disabled |
| 221 | */ |
| 222 | public static boolean cacheDisabled() { |
| 223 | return mDisabled; |
| 224 | } |
| 225 | |
| 226 | // only called from WebCore thread |
| 227 | // make sure to call enableTransaction/disableTransaction in pair |
| 228 | static boolean enableTransaction() { |
| 229 | if (++mRefCount == 1) { |
| 230 | mDataBase.startCacheTransaction(); |
| 231 | return true; |
| 232 | } |
| 233 | return false; |
| 234 | } |
| 235 | |
| 236 | // only called from WebCore thread |
| 237 | // make sure to call enableTransaction/disableTransaction in pair |
| 238 | static boolean disableTransaction() { |
| 239 | if (mRefCount == 0) { |
| 240 | Log.e(LOGTAG, "disableTransaction is out of sync"); |
| 241 | } |
| 242 | if (--mRefCount == 0) { |
| 243 | mDataBase.endCacheTransaction(); |
| 244 | return true; |
| 245 | } |
| 246 | return false; |
| 247 | } |
| 248 | |
| 249 | // only called from WebCore thread |
| 250 | // make sure to call startCacheTransaction/endCacheTransaction in pair |
| 251 | public static boolean startCacheTransaction() { |
| 252 | return mDataBase.startCacheTransaction(); |
| 253 | } |
| 254 | |
| 255 | // only called from WebCore thread |
| 256 | // make sure to call startCacheTransaction/endCacheTransaction in pair |
| 257 | public static boolean endCacheTransaction() { |
| 258 | boolean ret = mDataBase.endCacheTransaction(); |
| 259 | if (++mTrimCacheCount >= TRIM_CACHE_INTERVAL) { |
| 260 | mTrimCacheCount = 0; |
| 261 | trimCacheIfNeeded(); |
| 262 | } |
| 263 | return ret; |
| 264 | } |
| 265 | |
| 266 | /** |
| 267 | * Given a url, returns the CacheResult if exists. Otherwise returns null. |
| 268 | * If headers are provided and a cache needs validation, |
| 269 | * HEADER_KEY_IFNONEMATCH or HEADER_KEY_IFMODIFIEDSINCE will be set in the |
| 270 | * cached headers. |
| 271 | * |
| 272 | * @return the CacheResult for a given url |
| 273 | */ |
| 274 | // only called from WebCore thread |
| 275 | public static CacheResult getCacheFile(String url, |
| 276 | Map<String, String> headers) { |
| 277 | if (mDisabled) { |
| 278 | return null; |
| 279 | } |
| 280 | |
| 281 | CacheResult result = mDataBase.getCache(url); |
| 282 | if (result != null) { |
| 283 | if (result.contentLength == 0) { |
The Android Open Source Project | 1059253 | 2009-03-18 17:39:46 -0700 | [diff] [blame] | 284 | if (!checkCacheRedirect(result.httpStatusCode)) { |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 285 | // this should not happen. If it does, remove it. |
| 286 | mDataBase.removeCache(url); |
| 287 | return null; |
| 288 | } |
| 289 | } else { |
| 290 | File src = new File(mBaseDir, result.localPath); |
| 291 | try { |
| 292 | // open here so that even the file is deleted, the content |
| 293 | // is still readable by the caller until close() is called |
| 294 | result.inStream = new FileInputStream(src); |
| 295 | } catch (FileNotFoundException e) { |
| 296 | // the files in the cache directory can be removed by the |
| 297 | // system. If it is gone, clean up the database |
| 298 | mDataBase.removeCache(url); |
| 299 | return null; |
| 300 | } |
| 301 | } |
| 302 | } else { |
| 303 | return null; |
| 304 | } |
| 305 | |
| 306 | // null headers request coming from CACHE_MODE_CACHE_ONLY |
| 307 | // which implies that it needs cache even it is expired. |
| 308 | // negative expires means time in the far future. |
| 309 | if (headers != null && result.expires >= 0 |
| 310 | && result.expires <= System.currentTimeMillis()) { |
| 311 | if (result.lastModified == null && result.etag == null) { |
| 312 | return null; |
| 313 | } |
| 314 | // return HEADER_KEY_IFNONEMATCH or HEADER_KEY_IFMODIFIEDSINCE |
| 315 | // for requesting validation |
| 316 | if (result.etag != null) { |
| 317 | headers.put(HEADER_KEY_IFNONEMATCH, result.etag); |
| 318 | } |
| 319 | if (result.lastModified != null) { |
| 320 | headers.put(HEADER_KEY_IFMODIFIEDSINCE, result.lastModified); |
| 321 | } |
| 322 | } |
| 323 | |
Dave Bort | 42bc2ff | 2009-04-13 15:07:51 -0700 | [diff] [blame] | 324 | if (WebView.LOGV_ENABLED) { |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 325 | Log.v(LOGTAG, "getCacheFile for url " + url); |
| 326 | } |
| 327 | |
| 328 | return result; |
| 329 | } |
| 330 | |
| 331 | /** |
| 332 | * Given a url and its full headers, returns CacheResult if a local cache |
| 333 | * can be stored. Otherwise returns null. The mimetype is passed in so that |
| 334 | * the function can use the mimetype that will be passed to WebCore which |
| 335 | * could be different from the mimetype defined in the headers. |
| 336 | * forceCache is for out-of-package callers to force creation of a |
| 337 | * CacheResult, and is used to supply surrogate responses for URL |
| 338 | * interception. |
| 339 | * @return CacheResult for a given url |
| 340 | * @hide - hide createCacheFile since it has a parameter of type headers, which is |
| 341 | * in a hidden package. |
| 342 | */ |
| 343 | // can be called from any thread |
| 344 | public static CacheResult createCacheFile(String url, int statusCode, |
| 345 | Headers headers, String mimeType, boolean forceCache) { |
| 346 | if (!forceCache && mDisabled) { |
| 347 | return null; |
| 348 | } |
| 349 | |
The Android Open Source Project | 1059253 | 2009-03-18 17:39:46 -0700 | [diff] [blame] | 350 | // according to the rfc 2616, the 303 response MUST NOT be cached. |
| 351 | if (statusCode == 303) { |
| 352 | return null; |
| 353 | } |
| 354 | |
| 355 | // like the other browsers, do not cache redirects containing a cookie |
| 356 | // header. |
| 357 | if (checkCacheRedirect(statusCode) && !headers.getSetCookie().isEmpty()) { |
| 358 | return null; |
| 359 | } |
| 360 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 361 | CacheResult ret = parseHeaders(statusCode, headers, mimeType); |
| 362 | if (ret != null) { |
| 363 | setupFiles(url, ret); |
| 364 | try { |
| 365 | ret.outStream = new FileOutputStream(ret.outFile); |
| 366 | } catch (FileNotFoundException e) { |
| 367 | // This can happen with the system did a purge and our |
| 368 | // subdirectory has gone, so lets try to create it again |
| 369 | if (createCacheDirectory()) { |
| 370 | try { |
| 371 | ret.outStream = new FileOutputStream(ret.outFile); |
| 372 | } catch (FileNotFoundException e2) { |
| 373 | // We failed to create the file again, so there |
| 374 | // is something else wrong. Return null. |
| 375 | return null; |
| 376 | } |
| 377 | } else { |
| 378 | // Failed to create cache directory |
| 379 | return null; |
| 380 | } |
| 381 | } |
| 382 | ret.mimeType = mimeType; |
| 383 | } |
| 384 | |
| 385 | return ret; |
| 386 | } |
| 387 | |
| 388 | /** |
| 389 | * Save the info of a cache file for a given url to the CacheMap so that it |
| 390 | * can be reused later |
| 391 | */ |
| 392 | // only called from WebCore thread |
| 393 | public static void saveCacheFile(String url, CacheResult cacheRet) { |
| 394 | try { |
| 395 | cacheRet.outStream.close(); |
| 396 | } catch (IOException e) { |
| 397 | return; |
| 398 | } |
| 399 | |
| 400 | if (!cacheRet.outFile.exists()) { |
| 401 | // the file in the cache directory can be removed by the system |
| 402 | return; |
| 403 | } |
| 404 | |
| 405 | cacheRet.contentLength = cacheRet.outFile.length(); |
The Android Open Source Project | 1059253 | 2009-03-18 17:39:46 -0700 | [diff] [blame] | 406 | if (checkCacheRedirect(cacheRet.httpStatusCode)) { |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 407 | // location is in database, no need to keep the file |
| 408 | cacheRet.contentLength = 0; |
| 409 | cacheRet.localPath = new String(); |
| 410 | cacheRet.outFile.delete(); |
| 411 | } else if (cacheRet.contentLength == 0) { |
| 412 | cacheRet.outFile.delete(); |
| 413 | return; |
| 414 | } |
| 415 | |
| 416 | mDataBase.addCache(url, cacheRet); |
| 417 | |
Dave Bort | 42bc2ff | 2009-04-13 15:07:51 -0700 | [diff] [blame] | 418 | if (WebView.LOGV_ENABLED) { |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 419 | Log.v(LOGTAG, "saveCacheFile for url " + url); |
| 420 | } |
| 421 | } |
| 422 | |
| 423 | /** |
| 424 | * remove all cache files |
| 425 | * |
| 426 | * @return true if it succeeds |
| 427 | */ |
| 428 | // only called from WebCore thread |
| 429 | static boolean removeAllCacheFiles() { |
| 430 | // Note, this is called before init() when the database is |
| 431 | // created or upgraded. |
| 432 | if (mBaseDir == null) { |
| 433 | // Init() has not been called yet, so just flag that |
| 434 | // we need to clear the cache when init() is called. |
| 435 | mClearCacheOnInit = true; |
| 436 | return true; |
| 437 | } |
| 438 | // delete cache in a separate thread to not block UI. |
| 439 | final Runnable clearCache = new Runnable() { |
| 440 | public void run() { |
| 441 | // delete all cache files |
| 442 | try { |
| 443 | String[] files = mBaseDir.list(); |
| 444 | // if mBaseDir doesn't exist, files can be null. |
| 445 | if (files != null) { |
| 446 | for (int i = 0; i < files.length; i++) { |
| 447 | new File(mBaseDir, files[i]).delete(); |
| 448 | } |
| 449 | } |
| 450 | } catch (SecurityException e) { |
| 451 | // Ignore SecurityExceptions. |
| 452 | } |
| 453 | // delete database |
| 454 | mDataBase.clearCache(); |
| 455 | } |
| 456 | }; |
| 457 | new Thread(clearCache).start(); |
| 458 | return true; |
| 459 | } |
| 460 | |
| 461 | /** |
| 462 | * Return true if the cache is empty. |
| 463 | */ |
| 464 | // only called from WebCore thread |
| 465 | static boolean cacheEmpty() { |
| 466 | return mDataBase.hasCache(); |
| 467 | } |
| 468 | |
| 469 | // only called from WebCore thread |
| 470 | static void trimCacheIfNeeded() { |
| 471 | if (mDataBase.getCacheTotalSize() > CACHE_THRESHOLD) { |
| 472 | ArrayList<String> pathList = mDataBase.trimCache(CACHE_TRIM_AMOUNT); |
| 473 | int size = pathList.size(); |
| 474 | for (int i = 0; i < size; i++) { |
| 475 | new File(mBaseDir, pathList.get(i)).delete(); |
| 476 | } |
| 477 | } |
| 478 | } |
| 479 | |
The Android Open Source Project | 1059253 | 2009-03-18 17:39:46 -0700 | [diff] [blame] | 480 | private static boolean checkCacheRedirect(int statusCode) { |
| 481 | if (statusCode == 301 || statusCode == 302 || statusCode == 307) { |
| 482 | // as 303 can't be cached, we do not return true |
| 483 | return true; |
| 484 | } else { |
| 485 | return false; |
| 486 | } |
| 487 | } |
| 488 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 489 | @SuppressWarnings("deprecation") |
| 490 | private static void setupFiles(String url, CacheResult cacheRet) { |
| 491 | if (true) { |
| 492 | // Note: SHA1 is much stronger hash. But the cost of setupFiles() is |
| 493 | // 3.2% cpu time for a fresh load of nytimes.com. While a simple |
| 494 | // String.hashCode() is only 0.6%. If adding the collision resolving |
| 495 | // to String.hashCode(), it makes the cpu time to be 1.6% for a |
| 496 | // fresh load, but 5.3% for the worst case where all the files |
| 497 | // already exist in the file system, but database is gone. So it |
| 498 | // needs to resolve collision for every file at least once. |
| 499 | int hashCode = url.hashCode(); |
| 500 | StringBuffer ret = new StringBuffer(8); |
| 501 | appendAsHex(hashCode, ret); |
| 502 | String path = ret.toString(); |
| 503 | File file = new File(mBaseDir, path); |
| 504 | if (true) { |
| 505 | boolean checkOldPath = true; |
| 506 | // Check hash collision. If the hash file doesn't exist, just |
| 507 | // continue. There is a chance that the old cache file is not |
| 508 | // same as the hash file. As mDataBase.getCache() is more |
| 509 | // expansive than "leak" a file until clear cache, don't bother. |
| 510 | // If the hash file exists, make sure that it is same as the |
| 511 | // cache file. If it is not, resolve the collision. |
| 512 | while (file.exists()) { |
| 513 | if (checkOldPath) { |
| 514 | // as this is called from http thread through |
| 515 | // createCacheFile, we need endCacheTransaction before |
| 516 | // database access. |
| 517 | WebViewCore.endCacheTransaction(); |
| 518 | CacheResult oldResult = mDataBase.getCache(url); |
| 519 | WebViewCore.startCacheTransaction(); |
| 520 | if (oldResult != null && oldResult.contentLength > 0) { |
| 521 | if (path.equals(oldResult.localPath)) { |
| 522 | path = oldResult.localPath; |
| 523 | } else { |
| 524 | path = oldResult.localPath; |
| 525 | file = new File(mBaseDir, path); |
| 526 | } |
| 527 | break; |
| 528 | } |
| 529 | checkOldPath = false; |
| 530 | } |
| 531 | ret = new StringBuffer(8); |
| 532 | appendAsHex(++hashCode, ret); |
| 533 | path = ret.toString(); |
| 534 | file = new File(mBaseDir, path); |
| 535 | } |
| 536 | } |
| 537 | cacheRet.localPath = path; |
| 538 | cacheRet.outFile = file; |
| 539 | } else { |
| 540 | // get hash in byte[] |
| 541 | Digest digest = new SHA1Digest(); |
| 542 | int digestLen = digest.getDigestSize(); |
| 543 | byte[] hash = new byte[digestLen]; |
| 544 | int urlLen = url.length(); |
| 545 | byte[] data = new byte[urlLen]; |
| 546 | url.getBytes(0, urlLen, data, 0); |
| 547 | digest.update(data, 0, urlLen); |
| 548 | digest.doFinal(hash, 0); |
| 549 | // convert byte[] to hex String |
| 550 | StringBuffer result = new StringBuffer(2 * digestLen); |
| 551 | for (int i = 0; i < digestLen; i = i + 4) { |
| 552 | int h = (0x00ff & hash[i]) << 24 | (0x00ff & hash[i + 1]) << 16 |
| 553 | | (0x00ff & hash[i + 2]) << 8 | (0x00ff & hash[i + 3]); |
| 554 | appendAsHex(h, result); |
| 555 | } |
| 556 | cacheRet.localPath = result.toString(); |
| 557 | cacheRet.outFile = new File(mBaseDir, cacheRet.localPath); |
| 558 | } |
| 559 | } |
| 560 | |
| 561 | private static void appendAsHex(int i, StringBuffer ret) { |
| 562 | String hex = Integer.toHexString(i); |
| 563 | switch (hex.length()) { |
| 564 | case 1: |
| 565 | ret.append("0000000"); |
| 566 | break; |
| 567 | case 2: |
| 568 | ret.append("000000"); |
| 569 | break; |
| 570 | case 3: |
| 571 | ret.append("00000"); |
| 572 | break; |
| 573 | case 4: |
| 574 | ret.append("0000"); |
| 575 | break; |
| 576 | case 5: |
| 577 | ret.append("000"); |
| 578 | break; |
| 579 | case 6: |
| 580 | ret.append("00"); |
| 581 | break; |
| 582 | case 7: |
| 583 | ret.append("0"); |
| 584 | break; |
| 585 | } |
| 586 | ret.append(hex); |
| 587 | } |
| 588 | |
| 589 | private static CacheResult parseHeaders(int statusCode, Headers headers, |
| 590 | String mimeType) { |
| 591 | // TODO: if authenticated or secure, return null |
| 592 | CacheResult ret = new CacheResult(); |
| 593 | ret.httpStatusCode = statusCode; |
| 594 | |
| 595 | String location = headers.getLocation(); |
| 596 | if (location != null) ret.location = location; |
| 597 | |
| 598 | ret.expires = -1; |
| 599 | String expires = headers.getExpires(); |
| 600 | if (expires != null) { |
| 601 | try { |
| 602 | ret.expires = HttpDateTime.parse(expires); |
| 603 | } catch (IllegalArgumentException ex) { |
| 604 | // Take care of the special "-1" and "0" cases |
| 605 | if ("-1".equals(expires) || "0".equals(expires)) { |
| 606 | // make it expired, but can be used for history navigation |
| 607 | ret.expires = 0; |
| 608 | } else { |
| 609 | Log.e(LOGTAG, "illegal expires: " + expires); |
| 610 | } |
| 611 | } |
| 612 | } |
| 613 | |
| 614 | String lastModified = headers.getLastModified(); |
| 615 | if (lastModified != null) ret.lastModified = lastModified; |
| 616 | |
| 617 | String etag = headers.getEtag(); |
| 618 | if (etag != null) ret.etag = etag; |
| 619 | |
| 620 | String cacheControl = headers.getCacheControl(); |
| 621 | if (cacheControl != null) { |
| 622 | String[] controls = cacheControl.toLowerCase().split("[ ,;]"); |
| 623 | for (int i = 0; i < controls.length; i++) { |
| 624 | if (NO_STORE.equals(controls[i])) { |
| 625 | return null; |
| 626 | } |
| 627 | // According to the spec, 'no-cache' means that the content |
| 628 | // must be re-validated on every load. It does not mean that |
| 629 | // the content can not be cached. set to expire 0 means it |
| 630 | // can only be used in CACHE_MODE_CACHE_ONLY case |
The Android Open Source Project | ba87e3e | 2009-03-13 13:04:22 -0700 | [diff] [blame] | 631 | if (NO_CACHE.equals(controls[i]) || PRIVATE.equals(controls[i])) { |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 632 | ret.expires = 0; |
| 633 | } else if (controls[i].startsWith(MAX_AGE)) { |
| 634 | int separator = controls[i].indexOf('='); |
| 635 | if (separator < 0) { |
| 636 | separator = controls[i].indexOf(':'); |
| 637 | } |
| 638 | if (separator > 0) { |
| 639 | String s = controls[i].substring(separator + 1); |
| 640 | try { |
| 641 | long sec = Long.parseLong(s); |
| 642 | if (sec >= 0) { |
| 643 | ret.expires = System.currentTimeMillis() + 1000 |
| 644 | * sec; |
| 645 | } |
| 646 | } catch (NumberFormatException ex) { |
| 647 | if ("1d".equals(s)) { |
| 648 | // Take care of the special "1d" case |
| 649 | ret.expires = System.currentTimeMillis() + 86400000; // 24*60*60*1000 |
| 650 | } else { |
| 651 | Log.e(LOGTAG, "exception in parseHeaders for " |
| 652 | + "max-age:" |
| 653 | + controls[i].substring(separator + 1)); |
| 654 | ret.expires = 0; |
| 655 | } |
| 656 | } |
| 657 | } |
| 658 | } |
| 659 | } |
| 660 | } |
| 661 | |
| 662 | // According to RFC 2616 section 14.32: |
| 663 | // HTTP/1.1 caches SHOULD treat "Pragma: no-cache" as if the |
| 664 | // client had sent "Cache-Control: no-cache" |
| 665 | if (NO_CACHE.equals(headers.getPragma())) { |
| 666 | ret.expires = 0; |
| 667 | } |
| 668 | |
| 669 | // According to RFC 2616 section 13.2.4, if an expiration has not been |
| 670 | // explicitly defined a heuristic to set an expiration may be used. |
| 671 | if (ret.expires == -1) { |
| 672 | if (ret.httpStatusCode == 301) { |
| 673 | // If it is a permanent redirect, and it did not have an |
| 674 | // explicit cache directive, then it never expires |
| 675 | ret.expires = Long.MAX_VALUE; |
| 676 | } else if (ret.httpStatusCode == 302 || ret.httpStatusCode == 307) { |
| 677 | // If it is temporary redirect, expires |
| 678 | ret.expires = 0; |
| 679 | } else if (ret.lastModified == null) { |
| 680 | // When we have no last-modified, then expire the content with |
| 681 | // in 24hrs as, according to the RFC, longer time requires a |
| 682 | // warning 113 to be added to the response. |
| 683 | |
| 684 | // Only add the default expiration for non-html markup. Some |
| 685 | // sites like news.google.com have no cache directives. |
| 686 | if (!mimeType.startsWith("text/html")) { |
| 687 | ret.expires = System.currentTimeMillis() + 86400000; // 24*60*60*1000 |
| 688 | } else { |
| 689 | // Setting a expires as zero will cache the result for |
| 690 | // forward/back nav. |
| 691 | ret.expires = 0; |
| 692 | } |
| 693 | } else { |
| 694 | // If we have a last-modified value, we could use it to set the |
| 695 | // expiration. Suggestion from RFC is 10% of time since |
| 696 | // last-modified. As we are on mobile, loads are expensive, |
| 697 | // increasing this to 20%. |
| 698 | |
| 699 | // 24 * 60 * 60 * 1000 |
| 700 | long lastmod = System.currentTimeMillis() + 86400000; |
| 701 | try { |
| 702 | lastmod = HttpDateTime.parse(ret.lastModified); |
| 703 | } catch (IllegalArgumentException ex) { |
| 704 | Log.e(LOGTAG, "illegal lastModified: " + ret.lastModified); |
| 705 | } |
| 706 | long difference = System.currentTimeMillis() - lastmod; |
| 707 | if (difference > 0) { |
| 708 | ret.expires = System.currentTimeMillis() + difference / 5; |
| 709 | } else { |
| 710 | // last modified is in the future, expire the content |
| 711 | // on the last modified |
| 712 | ret.expires = lastmod; |
| 713 | } |
| 714 | } |
| 715 | } |
| 716 | |
| 717 | return ret; |
| 718 | } |
| 719 | } |