| /* |
| * Copyright (C) 2006 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.webkit; |
| |
| import android.content.Context; |
| import android.net.http.AndroidHttpClient; |
| import android.net.http.Headers; |
| import android.os.FileUtils; |
| import android.util.Log; |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.FileNotFoundException; |
| import java.io.FileOutputStream; |
| import java.io.FilenameFilter; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.util.List; |
| import java.util.Map; |
| |
| |
| import org.bouncycastle.crypto.Digest; |
| import org.bouncycastle.crypto.digests.SHA1Digest; |
| |
| /** |
| * The class CacheManager provides the persistent cache of content that is |
| * received over the network. The component handles parsing of HTTP headers and |
| * utilizes the relevant cache headers to determine if the content should be |
| * stored and if so, how long it is valid for. Network requests are provided to |
| * this component and if they can not be resolved by the cache, the HTTP headers |
| * are attached, as appropriate, to the request for revalidation of content. The |
| * class also manages the cache size. |
| */ |
| public final class CacheManager { |
| |
| private static final String LOGTAG = "cache"; |
| |
| static final String HEADER_KEY_IFMODIFIEDSINCE = "if-modified-since"; |
| static final String HEADER_KEY_IFNONEMATCH = "if-none-match"; |
| |
| private static final String NO_STORE = "no-store"; |
| private static final String NO_CACHE = "no-cache"; |
| private static final String MAX_AGE = "max-age"; |
| private static final String MANIFEST_MIME = "text/cache-manifest"; |
| |
| private static long CACHE_THRESHOLD = 6 * 1024 * 1024; |
| private static long CACHE_TRIM_AMOUNT = 2 * 1024 * 1024; |
| |
| // Limit the maximum cache file size to half of the normal capacity |
| static long CACHE_MAX_SIZE = (CACHE_THRESHOLD - CACHE_TRIM_AMOUNT) / 2; |
| |
| private static boolean mDisabled; |
| |
| // Reference count the enable/disable transaction |
| private static int mRefCount; |
| |
| // trimCacheIfNeeded() is called when a page is fully loaded. But JavaScript |
| // can load the content, e.g. in a slideshow, continuously, so we need to |
| // trim the cache on a timer base too. endCacheTransaction() is called on a |
| // timer base. We share the same timer with less frequent update. |
| private static int mTrimCacheCount = 0; |
| private static final int TRIM_CACHE_INTERVAL = 5; |
| |
| private static WebViewDatabase mDataBase; |
| private static File mBaseDir; |
| |
| // Flag to clear the cache when the CacheManager is initialized |
| private static boolean mClearCacheOnInit = false; |
| |
| /** |
| * This class represents a resource retrieved from the HTTP cache. |
| * Instances of this class can be obtained by invoking the |
| * CacheManager.getCacheFile() method. |
| */ |
| public static class CacheResult { |
| // these fields are saved to the database |
| int httpStatusCode; |
| long contentLength; |
| long expires; |
| String expiresString; |
| String localPath; |
| String lastModified; |
| String etag; |
| String mimeType; |
| String location; |
| String encoding; |
| String contentdisposition; |
| String crossDomain; |
| |
| // these fields are NOT saved to the database |
| InputStream inStream; |
| OutputStream outStream; |
| File outFile; |
| |
| public int getHttpStatusCode() { |
| return httpStatusCode; |
| } |
| |
| public long getContentLength() { |
| return contentLength; |
| } |
| |
| public String getLocalPath() { |
| return localPath; |
| } |
| |
| public long getExpires() { |
| return expires; |
| } |
| |
| public String getExpiresString() { |
| return expiresString; |
| } |
| |
| public String getLastModified() { |
| return lastModified; |
| } |
| |
| public String getETag() { |
| return etag; |
| } |
| |
| public String getMimeType() { |
| return mimeType; |
| } |
| |
| public String getLocation() { |
| return location; |
| } |
| |
| public String getEncoding() { |
| return encoding; |
| } |
| |
| public String getContentDisposition() { |
| return contentdisposition; |
| } |
| |
| // For out-of-package access to the underlying streams. |
| public InputStream getInputStream() { |
| return inStream; |
| } |
| |
| public OutputStream getOutputStream() { |
| return outStream; |
| } |
| |
| // These fields can be set manually. |
| public void setInputStream(InputStream stream) { |
| this.inStream = stream; |
| } |
| |
| public void setEncoding(String encoding) { |
| this.encoding = encoding; |
| } |
| } |
| |
| /** |
| * initialize the CacheManager. WebView should handle this for each process. |
| * |
| * @param context The application context. |
| */ |
| static void init(Context context) { |
| mDataBase = WebViewDatabase.getInstance(context.getApplicationContext()); |
| mBaseDir = new File(context.getCacheDir(), "webviewCache"); |
| if (createCacheDirectory() && mClearCacheOnInit) { |
| removeAllCacheFiles(); |
| mClearCacheOnInit = false; |
| } |
| } |
| |
| /** |
| * Create the cache directory if it does not already exist. |
| * |
| * @return true if the cache directory didn't exist and was created. |
| */ |
| static private boolean createCacheDirectory() { |
| if (!mBaseDir.exists()) { |
| if(!mBaseDir.mkdirs()) { |
| Log.w(LOGTAG, "Unable to create webviewCache directory"); |
| return false; |
| } |
| FileUtils.setPermissions( |
| mBaseDir.toString(), |
| FileUtils.S_IRWXU|FileUtils.S_IRWXG|FileUtils.S_IXOTH, |
| -1, -1); |
| // If we did create the directory, we need to flush |
| // the cache database. The directory could be recreated |
| // because the system flushed all the data/cache directories |
| // to free up disk space. |
| // delete rows in the cache database |
| WebViewWorker.getHandler().sendEmptyMessage( |
| WebViewWorker.MSG_CLEAR_CACHE); |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * get the base directory of the cache. With localPath of the CacheResult, |
| * it identifies the cache file. |
| * |
| * @return File The base directory of the cache. |
| */ |
| public static File getCacheFileBaseDir() { |
| return mBaseDir; |
| } |
| |
| /** |
| * set the flag to control whether cache is enabled or disabled |
| * |
| * @param disabled true to disable the cache |
| */ |
| static void setCacheDisabled(boolean disabled) { |
| if (disabled == mDisabled) { |
| return; |
| } |
| mDisabled = disabled; |
| if (mDisabled) { |
| removeAllCacheFiles(); |
| } |
| } |
| |
| /** |
| * get the state of the current cache, enabled or disabled |
| * |
| * @return return if it is disabled |
| */ |
| public static boolean cacheDisabled() { |
| return mDisabled; |
| } |
| |
| // only called from WebViewWorkerThread |
| // make sure to call enableTransaction/disableTransaction in pair |
| static boolean enableTransaction() { |
| if (++mRefCount == 1) { |
| mDataBase.startCacheTransaction(); |
| return true; |
| } |
| return false; |
| } |
| |
| // only called from WebViewWorkerThread |
| // make sure to call enableTransaction/disableTransaction in pair |
| static boolean disableTransaction() { |
| if (--mRefCount == 0) { |
| mDataBase.endCacheTransaction(); |
| return true; |
| } |
| return false; |
| } |
| |
| // only called from WebViewWorkerThread |
| // make sure to call startTransaction/endTransaction in pair |
| static boolean startTransaction() { |
| return mDataBase.startCacheTransaction(); |
| } |
| |
| // only called from WebViewWorkerThread |
| // make sure to call startTransaction/endTransaction in pair |
| static boolean endTransaction() { |
| boolean ret = mDataBase.endCacheTransaction(); |
| if (++mTrimCacheCount >= TRIM_CACHE_INTERVAL) { |
| mTrimCacheCount = 0; |
| trimCacheIfNeeded(); |
| } |
| return ret; |
| } |
| |
| // only called from WebCore Thread |
| // make sure to call startCacheTransaction/endCacheTransaction in pair |
| /** |
| * @deprecated Always returns false. |
| */ |
| @Deprecated |
| public static boolean startCacheTransaction() { |
| return false; |
| } |
| |
| // only called from WebCore Thread |
| // make sure to call startCacheTransaction/endCacheTransaction in pair |
| /** |
| * @deprecated Always returns false. |
| */ |
| @Deprecated |
| public static boolean endCacheTransaction() { |
| return false; |
| } |
| |
| /** |
| * Given a url, returns the CacheResult if exists. Otherwise returns null. |
| * If headers are provided and a cache needs validation, |
| * HEADER_KEY_IFNONEMATCH or HEADER_KEY_IFMODIFIEDSINCE will be set in the |
| * cached headers. |
| * |
| * @return the CacheResult for a given url |
| */ |
| public static CacheResult getCacheFile(String url, |
| Map<String, String> headers) { |
| return getCacheFile(url, 0, headers); |
| } |
| |
| static CacheResult getCacheFile(String url, long postIdentifier, |
| Map<String, String> headers) { |
| if (mDisabled) { |
| return null; |
| } |
| |
| String databaseKey = getDatabaseKey(url, postIdentifier); |
| |
| CacheResult result = mDataBase.getCache(databaseKey); |
| if (result != null) { |
| if (result.contentLength == 0) { |
| if (!checkCacheRedirect(result.httpStatusCode)) { |
| // this should not happen. If it does, remove it. |
| mDataBase.removeCache(databaseKey); |
| return null; |
| } |
| } else { |
| File src = new File(mBaseDir, result.localPath); |
| try { |
| // open here so that even the file is deleted, the content |
| // is still readable by the caller until close() is called |
| result.inStream = new FileInputStream(src); |
| } catch (FileNotFoundException e) { |
| // the files in the cache directory can be removed by the |
| // system. If it is gone, clean up the database |
| mDataBase.removeCache(databaseKey); |
| return null; |
| } |
| } |
| } else { |
| return null; |
| } |
| |
| // null headers request coming from CACHE_MODE_CACHE_ONLY |
| // which implies that it needs cache even it is expired. |
| // negative expires means time in the far future. |
| if (headers != null && result.expires >= 0 |
| && result.expires <= System.currentTimeMillis()) { |
| if (result.lastModified == null && result.etag == null) { |
| return null; |
| } |
| // return HEADER_KEY_IFNONEMATCH or HEADER_KEY_IFMODIFIEDSINCE |
| // for requesting validation |
| if (result.etag != null) { |
| headers.put(HEADER_KEY_IFNONEMATCH, result.etag); |
| } |
| if (result.lastModified != null) { |
| headers.put(HEADER_KEY_IFMODIFIEDSINCE, result.lastModified); |
| } |
| } |
| |
| if (DebugFlags.CACHE_MANAGER) { |
| Log.v(LOGTAG, "getCacheFile for url " + url); |
| } |
| |
| return result; |
| } |
| |
| /** |
| * Given a url and its full headers, returns CacheResult if a local cache |
| * can be stored. Otherwise returns null. The mimetype is passed in so that |
| * the function can use the mimetype that will be passed to WebCore which |
| * could be different from the mimetype defined in the headers. |
| * forceCache is for out-of-package callers to force creation of a |
| * CacheResult, and is used to supply surrogate responses for URL |
| * interception. |
| * @return CacheResult for a given url |
| * @hide - hide createCacheFile since it has a parameter of type headers, which is |
| * in a hidden package. |
| */ |
| public static CacheResult createCacheFile(String url, int statusCode, |
| Headers headers, String mimeType, boolean forceCache) { |
| return createCacheFile(url, statusCode, headers, mimeType, 0, |
| forceCache); |
| } |
| |
| static CacheResult createCacheFile(String url, int statusCode, |
| Headers headers, String mimeType, long postIdentifier, |
| boolean forceCache) { |
| if (!forceCache && mDisabled) { |
| return null; |
| } |
| |
| String databaseKey = getDatabaseKey(url, postIdentifier); |
| |
| // according to the rfc 2616, the 303 response MUST NOT be cached. |
| if (statusCode == 303) { |
| // remove the saved cache if there is any |
| mDataBase.removeCache(databaseKey); |
| return null; |
| } |
| |
| // like the other browsers, do not cache redirects containing a cookie |
| // header. |
| if (checkCacheRedirect(statusCode) && !headers.getSetCookie().isEmpty()) { |
| // remove the saved cache if there is any |
| mDataBase.removeCache(databaseKey); |
| return null; |
| } |
| |
| CacheResult ret = parseHeaders(statusCode, headers, mimeType); |
| if (ret == null) { |
| // this should only happen if the headers has "no-store" in the |
| // cache-control. remove the saved cache if there is any |
| mDataBase.removeCache(databaseKey); |
| } else { |
| setupFiles(databaseKey, ret); |
| try { |
| ret.outStream = new FileOutputStream(ret.outFile); |
| } catch (FileNotFoundException e) { |
| // This can happen with the system did a purge and our |
| // subdirectory has gone, so lets try to create it again |
| if (createCacheDirectory()) { |
| try { |
| ret.outStream = new FileOutputStream(ret.outFile); |
| } catch (FileNotFoundException e2) { |
| // We failed to create the file again, so there |
| // is something else wrong. Return null. |
| return null; |
| } |
| } else { |
| // Failed to create cache directory |
| return null; |
| } |
| } |
| ret.mimeType = mimeType; |
| } |
| |
| return ret; |
| } |
| |
| /** |
| * Save the info of a cache file for a given url to the CacheMap so that it |
| * can be reused later |
| */ |
| public static void saveCacheFile(String url, CacheResult cacheRet) { |
| saveCacheFile(url, 0, cacheRet); |
| } |
| |
| static void saveCacheFile(String url, long postIdentifier, |
| CacheResult cacheRet) { |
| try { |
| cacheRet.outStream.close(); |
| } catch (IOException e) { |
| return; |
| } |
| |
| if (!cacheRet.outFile.exists()) { |
| // the file in the cache directory can be removed by the system |
| return; |
| } |
| |
| boolean redirect = checkCacheRedirect(cacheRet.httpStatusCode); |
| if (redirect) { |
| // location is in database, no need to keep the file |
| cacheRet.contentLength = 0; |
| cacheRet.localPath = ""; |
| } |
| if ((redirect || cacheRet.contentLength == 0) |
| && !cacheRet.outFile.delete()) { |
| Log.e(LOGTAG, cacheRet.outFile.getPath() + " delete failed."); |
| } |
| if (cacheRet.contentLength == 0) { |
| return; |
| } |
| |
| mDataBase.addCache(getDatabaseKey(url, postIdentifier), cacheRet); |
| |
| if (DebugFlags.CACHE_MANAGER) { |
| Log.v(LOGTAG, "saveCacheFile for url " + url); |
| } |
| } |
| |
| static boolean cleanupCacheFile(CacheResult cacheRet) { |
| try { |
| cacheRet.outStream.close(); |
| } catch (IOException e) { |
| return false; |
| } |
| return cacheRet.outFile.delete(); |
| } |
| |
| /** |
| * remove all cache files |
| * |
| * @return true if it succeeds |
| */ |
| static boolean removeAllCacheFiles() { |
| // Note, this is called before init() when the database is |
| // created or upgraded. |
| if (mBaseDir == null) { |
| // Init() has not been called yet, so just flag that |
| // we need to clear the cache when init() is called. |
| mClearCacheOnInit = true; |
| return true; |
| } |
| // delete rows in the cache database |
| WebViewWorker.getHandler().sendEmptyMessage( |
| WebViewWorker.MSG_CLEAR_CACHE); |
| // delete cache files in a separate thread to not block UI. |
| final Runnable clearCache = new Runnable() { |
| public void run() { |
| // delete all cache files |
| try { |
| String[] files = mBaseDir.list(); |
| // if mBaseDir doesn't exist, files can be null. |
| if (files != null) { |
| for (int i = 0; i < files.length; i++) { |
| File f = new File(mBaseDir, files[i]); |
| if (!f.delete()) { |
| Log.e(LOGTAG, f.getPath() + " delete failed."); |
| } |
| } |
| } |
| } catch (SecurityException e) { |
| // Ignore SecurityExceptions. |
| } |
| } |
| }; |
| new Thread(clearCache).start(); |
| return true; |
| } |
| |
| /** |
| * Return true if the cache is empty. |
| */ |
| static boolean cacheEmpty() { |
| return mDataBase.hasCache(); |
| } |
| |
| static void trimCacheIfNeeded() { |
| if (mDataBase.getCacheTotalSize() > CACHE_THRESHOLD) { |
| List<String> pathList = mDataBase.trimCache(CACHE_TRIM_AMOUNT); |
| int size = pathList.size(); |
| for (int i = 0; i < size; i++) { |
| File f = new File(mBaseDir, pathList.get(i)); |
| if (!f.delete()) { |
| Log.e(LOGTAG, f.getPath() + " delete failed."); |
| } |
| } |
| // remove the unreferenced files in the cache directory |
| final List<String> fileList = mDataBase.getAllCacheFileNames(); |
| if (fileList == null) return; |
| String[] toDelete = mBaseDir.list(new FilenameFilter() { |
| public boolean accept(File dir, String filename) { |
| if (fileList.contains(filename)) { |
| return false; |
| } else { |
| return true; |
| } |
| } |
| }); |
| if (toDelete == null) return; |
| size = toDelete.length; |
| for (int i = 0; i < size; i++) { |
| File f = new File(mBaseDir, toDelete[i]); |
| if (!f.delete()) { |
| Log.e(LOGTAG, f.getPath() + " delete failed."); |
| } |
| } |
| } |
| } |
| |
| static void clearCache() { |
| // delete database |
| mDataBase.clearCache(); |
| } |
| |
| private static boolean checkCacheRedirect(int statusCode) { |
| if (statusCode == 301 || statusCode == 302 || statusCode == 307) { |
| // as 303 can't be cached, we do not return true |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| private static String getDatabaseKey(String url, long postIdentifier) { |
| if (postIdentifier == 0) return url; |
| return postIdentifier + url; |
| } |
| |
| @SuppressWarnings("deprecation") |
| private static void setupFiles(String url, CacheResult cacheRet) { |
| if (true) { |
| // Note: SHA1 is much stronger hash. But the cost of setupFiles() is |
| // 3.2% cpu time for a fresh load of nytimes.com. While a simple |
| // String.hashCode() is only 0.6%. If adding the collision resolving |
| // to String.hashCode(), it makes the cpu time to be 1.6% for a |
| // fresh load, but 5.3% for the worst case where all the files |
| // already exist in the file system, but database is gone. So it |
| // needs to resolve collision for every file at least once. |
| int hashCode = url.hashCode(); |
| StringBuffer ret = new StringBuffer(8); |
| appendAsHex(hashCode, ret); |
| String path = ret.toString(); |
| File file = new File(mBaseDir, path); |
| if (true) { |
| boolean checkOldPath = true; |
| // Check hash collision. If the hash file doesn't exist, just |
| // continue. There is a chance that the old cache file is not |
| // same as the hash file. As mDataBase.getCache() is more |
| // expansive than "leak" a file until clear cache, don't bother. |
| // If the hash file exists, make sure that it is same as the |
| // cache file. If it is not, resolve the collision. |
| while (file.exists()) { |
| if (checkOldPath) { |
| CacheResult oldResult = mDataBase.getCache(url); |
| if (oldResult != null && oldResult.contentLength > 0) { |
| if (path.equals(oldResult.localPath)) { |
| path = oldResult.localPath; |
| } else { |
| path = oldResult.localPath; |
| file = new File(mBaseDir, path); |
| } |
| break; |
| } |
| checkOldPath = false; |
| } |
| ret = new StringBuffer(8); |
| appendAsHex(++hashCode, ret); |
| path = ret.toString(); |
| file = new File(mBaseDir, path); |
| } |
| } |
| cacheRet.localPath = path; |
| cacheRet.outFile = file; |
| } else { |
| // get hash in byte[] |
| Digest digest = new SHA1Digest(); |
| int digestLen = digest.getDigestSize(); |
| byte[] hash = new byte[digestLen]; |
| int urlLen = url.length(); |
| byte[] data = new byte[urlLen]; |
| url.getBytes(0, urlLen, data, 0); |
| digest.update(data, 0, urlLen); |
| digest.doFinal(hash, 0); |
| // convert byte[] to hex String |
| StringBuffer result = new StringBuffer(2 * digestLen); |
| for (int i = 0; i < digestLen; i = i + 4) { |
| int h = (0x00ff & hash[i]) << 24 | (0x00ff & hash[i + 1]) << 16 |
| | (0x00ff & hash[i + 2]) << 8 | (0x00ff & hash[i + 3]); |
| appendAsHex(h, result); |
| } |
| cacheRet.localPath = result.toString(); |
| cacheRet.outFile = new File(mBaseDir, cacheRet.localPath); |
| } |
| } |
| |
| private static void appendAsHex(int i, StringBuffer ret) { |
| String hex = Integer.toHexString(i); |
| switch (hex.length()) { |
| case 1: |
| ret.append("0000000"); |
| break; |
| case 2: |
| ret.append("000000"); |
| break; |
| case 3: |
| ret.append("00000"); |
| break; |
| case 4: |
| ret.append("0000"); |
| break; |
| case 5: |
| ret.append("000"); |
| break; |
| case 6: |
| ret.append("00"); |
| break; |
| case 7: |
| ret.append("0"); |
| break; |
| } |
| ret.append(hex); |
| } |
| |
| private static CacheResult parseHeaders(int statusCode, Headers headers, |
| String mimeType) { |
| // if the contentLength is already larger than CACHE_MAX_SIZE, skip it |
| if (headers.getContentLength() > CACHE_MAX_SIZE) return null; |
| |
| // The HTML 5 spec, section 6.9.4, step 7.3 of the application cache |
| // process states that HTTP caching rules are ignored for the |
| // purposes of the application cache download process. |
| // At this point we can't tell that if a file is part of this process, |
| // except for the manifest, which has its own mimeType. |
| // TODO: work out a way to distinguish all responses that are part of |
| // the application download process and skip them. |
| if (MANIFEST_MIME.equals(mimeType)) return null; |
| |
| // TODO: if authenticated or secure, return null |
| CacheResult ret = new CacheResult(); |
| ret.httpStatusCode = statusCode; |
| |
| String location = headers.getLocation(); |
| if (location != null) ret.location = location; |
| |
| ret.expires = -1; |
| ret.expiresString = headers.getExpires(); |
| if (ret.expiresString != null) { |
| try { |
| ret.expires = AndroidHttpClient.parseDate(ret.expiresString); |
| } catch (IllegalArgumentException ex) { |
| // Take care of the special "-1" and "0" cases |
| if ("-1".equals(ret.expiresString) |
| || "0".equals(ret.expiresString)) { |
| // make it expired, but can be used for history navigation |
| ret.expires = 0; |
| } else { |
| Log.e(LOGTAG, "illegal expires: " + ret.expiresString); |
| } |
| } |
| } |
| |
| String contentDisposition = headers.getContentDisposition(); |
| if (contentDisposition != null) { |
| ret.contentdisposition = contentDisposition; |
| } |
| |
| String crossDomain = headers.getXPermittedCrossDomainPolicies(); |
| if (crossDomain != null) { |
| ret.crossDomain = crossDomain; |
| } |
| |
| // lastModified and etag may be set back to http header. So they can't |
| // be empty string. |
| String lastModified = headers.getLastModified(); |
| if (lastModified != null && lastModified.length() > 0) { |
| ret.lastModified = lastModified; |
| } |
| |
| String etag = headers.getEtag(); |
| if (etag != null && etag.length() > 0) ret.etag = etag; |
| |
| String cacheControl = headers.getCacheControl(); |
| if (cacheControl != null) { |
| String[] controls = cacheControl.toLowerCase().split("[ ,;]"); |
| for (int i = 0; i < controls.length; i++) { |
| if (NO_STORE.equals(controls[i])) { |
| return null; |
| } |
| // According to the spec, 'no-cache' means that the content |
| // must be re-validated on every load. It does not mean that |
| // the content can not be cached. set to expire 0 means it |
| // can only be used in CACHE_MODE_CACHE_ONLY case |
| if (NO_CACHE.equals(controls[i])) { |
| ret.expires = 0; |
| } else if (controls[i].startsWith(MAX_AGE)) { |
| int separator = controls[i].indexOf('='); |
| if (separator < 0) { |
| separator = controls[i].indexOf(':'); |
| } |
| if (separator > 0) { |
| String s = controls[i].substring(separator + 1); |
| try { |
| long sec = Long.parseLong(s); |
| if (sec >= 0) { |
| ret.expires = System.currentTimeMillis() + 1000 |
| * sec; |
| } |
| } catch (NumberFormatException ex) { |
| if ("1d".equals(s)) { |
| // Take care of the special "1d" case |
| ret.expires = System.currentTimeMillis() + 86400000; // 24*60*60*1000 |
| } else { |
| Log.e(LOGTAG, "exception in parseHeaders for " |
| + "max-age:" |
| + controls[i].substring(separator + 1)); |
| ret.expires = 0; |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| // According to RFC 2616 section 14.32: |
| // HTTP/1.1 caches SHOULD treat "Pragma: no-cache" as if the |
| // client had sent "Cache-Control: no-cache" |
| if (NO_CACHE.equals(headers.getPragma())) { |
| ret.expires = 0; |
| } |
| |
| // According to RFC 2616 section 13.2.4, if an expiration has not been |
| // explicitly defined a heuristic to set an expiration may be used. |
| if (ret.expires == -1) { |
| if (ret.httpStatusCode == 301) { |
| // If it is a permanent redirect, and it did not have an |
| // explicit cache directive, then it never expires |
| ret.expires = Long.MAX_VALUE; |
| } else if (ret.httpStatusCode == 302 || ret.httpStatusCode == 307) { |
| // If it is temporary redirect, expires |
| ret.expires = 0; |
| } else if (ret.lastModified == null) { |
| // When we have no last-modified, then expire the content with |
| // in 24hrs as, according to the RFC, longer time requires a |
| // warning 113 to be added to the response. |
| |
| // Only add the default expiration for non-html markup. Some |
| // sites like news.google.com have no cache directives. |
| if (!mimeType.startsWith("text/html")) { |
| ret.expires = System.currentTimeMillis() + 86400000; // 24*60*60*1000 |
| } else { |
| // Setting a expires as zero will cache the result for |
| // forward/back nav. |
| ret.expires = 0; |
| } |
| } else { |
| // If we have a last-modified value, we could use it to set the |
| // expiration. Suggestion from RFC is 10% of time since |
| // last-modified. As we are on mobile, loads are expensive, |
| // increasing this to 20%. |
| |
| // 24 * 60 * 60 * 1000 |
| long lastmod = System.currentTimeMillis() + 86400000; |
| try { |
| lastmod = AndroidHttpClient.parseDate(ret.lastModified); |
| } catch (IllegalArgumentException ex) { |
| Log.e(LOGTAG, "illegal lastModified: " + ret.lastModified); |
| } |
| long difference = System.currentTimeMillis() - lastmod; |
| if (difference > 0) { |
| ret.expires = System.currentTimeMillis() + difference / 5; |
| } else { |
| // last modified is in the future, expire the content |
| // on the last modified |
| ret.expires = lastmod; |
| } |
| } |
| } |
| |
| return ret; |
| } |
| } |
