The Tor Browser: mobile/android/base/GlobalHistory.java@fc2d59ddac77

     1 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-

     2  * This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     6 package org.mozilla.gecko;

     8 import org.mozilla.gecko.db.BrowserDB;

     9 import org.mozilla.gecko.util.ThreadUtils;

    11 import android.database.Cursor;

    12 import android.net.Uri;

    13 import android.os.Handler;

    14 import android.util.Log;

    16 import java.lang.ref.SoftReference;

    17 import java.util.HashSet;

    18 import java.util.LinkedList;

    19 import java.util.Queue;

    20 import java.util.Set;

    22 class GlobalHistory {

    23     private static final String LOGTAG = "GeckoGlobalHistory";

    25     private static GlobalHistory sInstance = new GlobalHistory();

    27     static GlobalHistory getInstance() {

    28         return sInstance;

    29     }

    31     // this is the delay between receiving a URI check request and processing it.

    32     // this allows batching together multiple requests and processing them together,

    33     // which is more efficient.

    34     private static final long BATCHING_DELAY_MS = 100;

    36     private final Handler mHandler;                     // a background thread on which we can process requests

    37     private final Queue<String> mPendingUris;           // URIs that need to be checked

    38     private SoftReference<Set<String>> mVisitedCache;   // cache of the visited URI list

    39     private final Runnable mNotifierRunnable;           // off-thread runnable used to check URIs

    40     private boolean mProcessing; // = false             // whether or not the runnable is queued/working

    42     private GlobalHistory() {

    43         mHandler = ThreadUtils.getBackgroundHandler();

    44         mPendingUris = new LinkedList<String>();

    45         mVisitedCache = new SoftReference<Set<String>>(null);

    46         mNotifierRunnable = new Runnable() {

    47             @Override

    48             public void run() {

    49                 Set<String> visitedSet = mVisitedCache.get();

    50                 if (visitedSet == null) {

    51                     // the cache was wiped away, repopulate it

    52                     Log.w(LOGTAG, "Rebuilding visited link set...");

    53                     visitedSet = new HashSet<String>();

    54                     Cursor c = null;

    55                     try {

    56                         c = BrowserDB.getAllVisitedHistory(GeckoAppShell.getContext().getContentResolver());

    57                         if (c == null) {

    58                             return;

    59                         }

    61                         if (c.moveToFirst()) {

    62                             do {

    63                                 visitedSet.add(c.getString(0));

    64                             } while (c.moveToNext());

    65                         }

    66                         mVisitedCache = new SoftReference<Set<String>>(visitedSet);

    67                     } finally {

    68                         if (c != null)

    69                             c.close();

    70                     }

    71                 }

    73                 // this runs on the same handler thread as the checkUriVisited code,

    74                 // so no synchronization needed

    75                 while (true) {

    76                     String uri = mPendingUris.poll();

    77                     if (uri == null) {

    78                         break;

    79                     }

    80                     if (visitedSet.contains(uri)) {

    81                         GeckoAppShell.notifyUriVisited(uri);

    82                     }

    83                 }

    84                 mProcessing = false;

    85             }

    86         };

    87     }

    89     public void addToGeckoOnly(String uri) {

    90         Set<String> visitedSet = mVisitedCache.get();

    91         if (visitedSet != null) {

    92             visitedSet.add(uri);

    93         }

    94         GeckoAppShell.notifyUriVisited(uri);

    95     }

    97     public void add(String uri) {

    98         BrowserDB.updateVisitedHistory(GeckoAppShell.getContext().getContentResolver(), uri);

    99         addToGeckoOnly(uri);

   100     }

   102     public void update(String uri, String title) {

   103         BrowserDB.updateHistoryTitle(GeckoAppShell.getContext().getContentResolver(), uri, title);

   104     }

   106     public void checkUriVisited(final String uri) {

   107         mHandler.post(new Runnable() {

   108             @Override

   109             public void run() {

   110                 // this runs on the same handler thread as the processing loop,

   111                 // so no synchronization needed

   112                 mPendingUris.add(uri);

   113                 if (mProcessing) {

   114                     // there's already a runnable queued up or working away, so

   115                     // no need to post another

   116                     return;

   117                 }

   118                 mProcessing = true;

   119                 mHandler.postDelayed(mNotifierRunnable, BATCHING_DELAY_MS);

   120             }

   121         });

   122     }

   123 }

The Tor Browser / file revision