GAIA ID migration for Android

chrome/android/java/src/org/chromium/chrome/browser/signin/AccountTrackerService.java

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.signin;
+
+import android.content.Context;
+import android.os.AsyncTask;
+import android.util.Log;
+
+import org.chromium.base.ObserverList;
+import org.chromium.base.ThreadUtils;
+import org.chromium.sync.signin.AccountManagerHelper;
+
+import java.util.concurrent.Semaphore;
+
+/**
+* Android wrapper of AccountTrackerService which provides access from the java layer.
+* It offers the capability of fetching and seeding system accounts into AccountTrackerService in C++
+* layer, and notifies observers when it is complete.
+*/
+public class AccountTrackerService {
+    private static final String TAG = "AccountTrackerService";
+    private static AccountTrackerService sAccountTrackerService;
+    private static SystemAccountsSeedingStatus sSystemAccountsSeedingStatus =
+            SystemAccountsSeedingStatus.SEEDING_NOT_STARTED;
+
+    private final Context mContext;
+    private final long mNativeAccountTrackerService;
+    private final Semaphore mSemaphore = new Semaphore(1, true);
+
+    private enum SystemAccountsSeedingStatus {
+        SEEDING_NOT_STARTED,
+        SEEDING_IN_PROGRESS,
+        SEEDING_DONE
+    }
+
+    /**
+    * Classes that want to listen for system accounts fetching and seeding should implement
+    * this interface and register with {@link #addSystemAccountsSeededListener}.
+    */
+    public interface OnSystemAccountsSeededListener {
+        void onSystemAccountsSeedingComplete();
+        void onSystemAccountsForceRefreshed();
+    }
+
+    private static final ObserverList<OnSystemAccountsSeededListener>
+            sSystemAccountsSeedingObservers = new ObserverList<OnSystemAccountsSeededListener>();
+
+    public static AccountTrackerService get(Context context) {
+        ThreadUtils.assertOnUiThread();
+        if (sAccountTrackerService == null) {
+            sAccountTrackerService = new AccountTrackerService(context);
+        }
+        return sAccountTrackerService;
+    }
+
+    private AccountTrackerService(Context context) {
+        mContext = context;
+        mNativeAccountTrackerService = nativeInit();
+    }
+
+    /**
+    * Check whether systems accounts have been seeded into AccountTrackerService in C++ layer.
+    */
+    public boolean isSystemAccountsSeeded() {
+        ThreadUtils.assertOnUiThread();
+        if (sSystemAccountsSeedingStatus == SystemAccountsSeedingStatus.SEEDING_DONE) {
+            return true;
+        }
+
+        if (sSystemAccountsSeedingStatus == SystemAccountsSeedingStatus.SEEDING_NOT_STARTED) {
+            seedSystemAccounts();
+        }
+
+        return false;
+    }
+
+    /**
+    * Register an |observer| to observe system accounts seeding status.
+    */
+    public static void addSystemAccountsSeededListener(OnSystemAccountsSeededListener observer) {
+        ThreadUtils.assertOnUiThread();
+        sSystemAccountsSeedingObservers.addObserver(observer);
+        if (sSystemAccountsSeedingStatus == SystemAccountsSeedingStatus.SEEDING_DONE) {
+            observer.onSystemAccountsSeedingComplete();
+        }
+    }
+
+    private void seedSystemAccounts() {
+        AccountManagerHelper accountManagerHelper = AccountManagerHelper.get(mContext);
+        java.util.List<String> accountNamesList = accountManagerHelper.getGoogleAccountNames();
+        final String[] accountNames = accountNamesList.toArray(new String[accountNamesList.size()]);
+        new AsyncTask<Void, Void, String[]>() {
+            @Override
+            public String[] doInBackground(Void... params) {
+                try {
+                    mSemaphore.acquire();

[Roger Tawa OOO till Jul 10th, 2015/08/19 14:37:26]

seedSystemAccounts() can only be called from UI thread.  You should add a check
for that.

Because of this, you can check at line 91 is the state is SEEDING_NOT_STARTED. 
If so, set state to SEEDING_IN_PROGRESS and proceed with this function,
otherwise just return.  I don't think you need a semaphore for synchronization. 
Where is SEEDING_IN_PROGRESS set right now, I don't see it in this file.

[gogerald1, 2015/08/20 15:48:49]

Done. Add one more flag to get rid of semaphore.

+                } catch (InterruptedException e) {
+                    Log.w(TAG, "Got InterruptedException while waiting for semaphore");
+                    return new String[0];
+                }
+                if (sSystemAccountsSeedingStatus
+                        == SystemAccountsSeedingStatus.SEEDING_NOT_STARTED) {
+                    Log.d(TAG, "Getting id/email mapping");
+                    sSystemAccountsSeedingStatus = SystemAccountsSeedingStatus.SEEDING_IN_PROGRESS;
+                    String[] accountIds = new String[accountNames.length];
+                    AccountIdProvider provider = AccountIdProvider.getInstance();
+                    for (int i = 0; i < accountIds.length; ++i) {
+                        accountIds[i] = provider.getAccountId(mContext, accountNames[i]);
+                    }
+                    return accountIds;
+                }
+                return new String[0];
+            }
+            @Override
+            public void onPostExecute(String[] accountIds) {
+                if (sSystemAccountsSeedingStatus
+                        == SystemAccountsSeedingStatus.SEEDING_IN_PROGRESS) {
+                    nativeSeedAccountsInfo(mNativeAccountTrackerService, accountIds, accountNames);
+                    sSystemAccountsSeedingStatus = SystemAccountsSeedingStatus.SEEDING_DONE;
+                    notifyObserversOnSeedingComplete();
+                }
+                mSemaphore.release();
+            }
+
+        }.execute();
+    }
+
+    private void notifyObserversOnSeedingComplete() {
+        for (OnSystemAccountsSeededListener observer : sSystemAccountsSeedingObservers) {
+            observer.onSystemAccountsSeedingComplete();
+        }
+    }
+
+    /**
+    * Force AccountTrackerService refresh/update systems accounts.
+    */
+    public void forceRefresh() {
+        ThreadUtils.assertOnUiThread();
+        sSystemAccountsSeedingStatus = SystemAccountsSeedingStatus.SEEDING_NOT_STARTED;
+        notifyObserversOnForceRefreshed();
+        seedSystemAccounts();
+    }
+
+    private void notifyObserversOnForceRefreshed() {
+        for (OnSystemAccountsSeededListener observer : sSystemAccountsSeedingObservers) {
+            observer.onSystemAccountsForceRefreshed();
+        }
+    }
+
+    // Native methods.
+    private native long nativeInit();
+    private native void nativeSeedAccountsInfo(
+            long nativeAccountTrackerServiceAndroid, String[] gaiaIds, String[] accountNames);
+}