Fixes history update race condition

 Bug: 3270709
 Since ContentResolver does not have transaction support, I moved
 history updates to a controller that can serialize updates to the
 history table. This prevents the race condition.

Change-Id: Ic33bedb9d6faef2393379306f8f88778d16caf24

1 files changed, 118 insertions, 0 deletions

diff --git a/src/com/android/browser/DataController.java b/src/com/android/browser/DataController.java
new file mode 100644
index 00000000..be38d704
--- /dev/null
+++ b/src/com/android/browser/DataController.java
@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2010 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 com.android.browser;
+
+import android.content.ContentResolver;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.Looper;
+import android.os.Message;
+import android.provider.BrowserContract.History;
+
+public class DataController {
+    // Message IDs
+    private static final int HISTORY_UPDATE_VISITED = 100;
+    private static final int HISTORY_UPDATE_TITLE = 101;
+    private static DataController sInstance;
+
+    private Context mContext;
+    private Handler mHandler;
+
+    /* package */ static DataController getInstance(Context c) {
+        if (sInstance == null) {
+            sInstance = new DataController(c);
+        }
+        return sInstance;
+    }
+
+    private DataController(Context c) {
+        mContext = c.getApplicationContext();
+        HandlerThread thread = new HandlerThread("DataController");
+        thread.setDaemon(true);
+        thread.start();
+        mHandler = new DataControllerHandler(thread.getLooper());
+    }
+
+    public void updateVisitedHistory(String url) {
+        mHandler.obtainMessage(HISTORY_UPDATE_VISITED, url).sendToTarget();
+    }
+
+    public void updateHistoryTitle(String url, String title) {
+        mHandler.obtainMessage(HISTORY_UPDATE_TITLE, new String[] { url, title })
+                .sendToTarget();
+    }
+
+    class DataControllerHandler extends Handler {
+        public DataControllerHandler(Looper looper) {
+            super(looper);
+        }
+
+        @Override
+        public void handleMessage(Message msg) {
+            switch (msg.what) {
+            case HISTORY_UPDATE_VISITED:
+                doUpdateVisitedHistory((String) msg.obj);
+                break;
+            case HISTORY_UPDATE_TITLE:
+                String[] args = (String[]) msg.obj;
+                doUpdateHistoryTitle(args[0], args[1]);
+                break;
+            }
+        }
+    }
+
+    private void doUpdateVisitedHistory(String url) {
+        ContentResolver cr = mContext.getContentResolver();
+        Cursor c = null;
+        try {
+            c = cr.query(History.CONTENT_URI, new String[] { History._ID, History.VISITS },
+                    History.URL + "=?", new String[] { url }, null);
+            if (c.moveToFirst()) {
+                ContentValues values = new ContentValues();
+                values.put(History.VISITS, c.getInt(1) + 1);
+                values.put(History.DATE_LAST_VISITED, System.currentTimeMillis());
+                cr.update(ContentUris.withAppendedId(History.CONTENT_URI, c.getLong(0)),
+                        values, null, null);
+            } else {
+                android.provider.Browser.truncateHistory(cr);
+                ContentValues values = new ContentValues();
+                values.put(History.URL, url);
+                values.put(History.VISITS, 1);
+                values.put(History.DATE_LAST_VISITED, System.currentTimeMillis());
+                values.put(History.TITLE, url);
+                values.put(History.DATE_CREATED, 0);
+                values.put(History.USER_ENTERED, 0);
+                cr.insert(History.CONTENT_URI, values);
+            }
+        } finally {
+            if (c != null) c.close();
+        }
+    }
+
+    private void doUpdateHistoryTitle(String url, String title) {
+        ContentResolver cr = mContext.getContentResolver();
+        ContentValues values = new ContentValues();
+        values.put(History.TITLE, title);
+        cr.update(History.CONTENT_URI, values, History.URL + "=?",
+                new String[] { url });
+    }
+}