Bug 734893: Faster DB accessing with priority for GeckoAsyncTask. [r=mfinkle, r=blassey]

mobile/android/base/GeckoAsyncTask.java

@@ -41,15 +41,42 @@ package org.mozilla.gecko;
 // We construct these off of the main thread, and we want that to run
 // on the main UI thread, so this is a convenience class to do that
 public abstract class GeckoAsyncTask<Params, Progress, Result> {
+    public static final int PRIORITY_NORMAL = 0;
+    public static final int PRIORITY_HIGH = 1;
+
+    private int mPriority;
+
+    public GeckoAsyncTask() {
+        mPriority = PRIORITY_NORMAL;
+    }
+
+    private class BackgroundTaskRunnable implements Runnable {
+        private Params[] mParams;
+
+        public BackgroundTaskRunnable(Params... params) {
+            mParams = params;
+        }
+
+        public void run() {
+            final Result result = doInBackground(mParams);
+            GeckoApp.mAppContext.runOnUiThread(new Runnable() {
+                public void run() {
+                    onPostExecute(result);
+                }
+            });
+        }
+    }
+
     public void execute(final Params... params) {
-        GeckoAppShell.getHandler().post(new Runnable() {
-            public void run() {
-                final Result result = doInBackground(params);
-                GeckoApp.mAppContext.runOnUiThread(new Runnable() {
-                    public void run() {
-                        onPostExecute(result);
-                    }});
-            }});
+        if (mPriority == PRIORITY_HIGH)
+            GeckoAppShell.getHandler().postAtFrontOfQueue(new BackgroundTaskRunnable(params));
+        else
+            GeckoAppShell.getHandler().post(new BackgroundTaskRunnable(params));
+    }
+
+    public GeckoAsyncTask<Params, Progress, Result> setPriority(int priority) {
+        mPriority = priority;
+        return this;
     }
 
     protected abstract Result doInBackground(Params... params);

mobile/android/base/TabsAccessor.java

@@ -20,6 +20,10 @@ import android.util.Log;
 public final class TabsAccessor {
     private static final String LOGTAG = "GeckoTabsAccessor";
 
+    private static final String[] CLIENTS_AVAILABILITY_PROJECTION = new String[] {
+                                                                        BrowserContract.Clients.GUID
+                                                                    };
+
     private static final String[] TABS_PROJECTION_COLUMNS = new String[] {
                                                                 BrowserContract.Tabs.TITLE,
                                                                 BrowserContract.Tabs.URL,
@@ -35,6 +39,7 @@ public final class TabsAccessor {
         NAME
     };
 
+    private static final String CLIENTS_SELECTION = BrowserContract.Clients.GUID + " IS NOT NULL";
     private static final String TABS_SELECTION = BrowserContract.Tabs.CLIENT_GUID + " IS NOT NULL";
 
     public static class RemoteTab {
@@ -60,9 +65,14 @@ public final class TabsAccessor {
         (new GeckoAsyncTask<Void, Void, Boolean> () {
             @Override
             protected Boolean doInBackground(Void... unused) {
-                Cursor cursor = context.getContentResolver().query(BrowserContract.Clients.CONTENT_URI,
-                                                                   null,
-                                                                   null,
+                Uri uri = BrowserContract.Tabs.CONTENT_URI;
+                uri = uri.buildUpon()
+                         .appendQueryParameter(BrowserContract.PARAM_LIMIT, "1")
+                         .build();
+
+                Cursor cursor = context.getContentResolver().query(uri,
+                                                                   CLIENTS_AVAILABILITY_PROJECTION,
+                                                                   CLIENTS_SELECTION,
                                                                    null,
                                                                    null);
                 
@@ -80,7 +90,7 @@ public final class TabsAccessor {
             protected void onPostExecute(Boolean availability) {
                 listener.areAvailable(availability);
             }
-        }).execute();
+        }).setPriority(GeckoAsyncTask.PRIORITY_HIGH).execute();
     }
 
     // This method returns all tabs from all remote clients,