Bug 802749 - Make background sync over metered connections optional. r=Grisha Kruglov

MozReview-Commit-ID: 4UhQqyxT90N

--HG--
extra : rebase_source : 937a8f6b9515678811b5d03e1a7514ef32b98af1

mobile/android/base/locales/en-US/sync_strings.dtd

@@ -68,6 +68,10 @@
 <!ENTITY fxaccount_status_passwords2 'Logins'>
 <!ENTITY fxaccount_status_tabs 'Open tabs'>
 <!ENTITY fxaccount_status_additional_settings 'Additional Settings'>
+<!ENTITY fxaccount_pref_sync_use_metered 'Sync over metered connections'>
+<!-- Localization note: Only affects background syncing, user initiated 
+     syncs will still be done regardless of the connection -->
+<!ENTITY fxaccount_pref_sync_use_metered_summary 'Allow usage of cellular data and metered wi-fi to sync in the background'>
 <!ENTITY fxaccount_status_legal 'Legal' >
 <!-- Localization note: when tapped, the following two strings link to
      external web pages.  Compare fxaccount_policy_{linktos,linkprivacy}:

mobile/android/services/src/main/java/org/mozilla/gecko/fxa/activities/FxAccountStatusFragment.java

@@ -13,13 +13,9 @@ import android.content.IntentFilter;
 import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.os.Handler;
-import android.preference.CheckBoxPreference;
-import android.preference.EditTextPreference;
-import android.preference.Preference;
+import android.preference.*;
 import android.preference.Preference.OnPreferenceChangeListener;
 import android.preference.Preference.OnPreferenceClickListener;
-import android.preference.PreferenceCategory;
-import android.preference.PreferenceScreen;
 import android.support.v4.content.LocalBroadcastManager;
 import android.text.TextUtils;
 import android.text.format.DateUtils;
@@ -37,6 +33,7 @@ import org.mozilla.gecko.fxa.SyncStatusListener;
 import org.mozilla.gecko.fxa.authenticator.AndroidFxAccount;
 import org.mozilla.gecko.fxa.login.Married;
 import org.mozilla.gecko.fxa.login.State;
+import org.mozilla.gecko.fxa.sync.FxAccountSyncAdapter;
 import org.mozilla.gecko.fxa.sync.FxAccountSyncStatusHelper;
 import org.mozilla.gecko.sync.ExtendedJSONObject;
 import org.mozilla.gecko.sync.SharedPreferencesClientsDataDelegate;
@@ -105,6 +102,7 @@ public class FxAccountStatusFragment
   protected CheckBoxPreference passwordsPreference;
 
   protected EditTextPreference deviceNamePreference;
+  protected SwitchPreference syncOverMeteredPreference;
   protected Preference syncServerPreference;
   protected Preference syncNowPreference;
 
@@ -184,6 +182,9 @@ public class FxAccountStatusFragment
     tabsPreference.setOnPreferenceClickListener(this);
     passwordsPreference.setOnPreferenceClickListener(this);
 
+    syncOverMeteredPreference = (SwitchPreference) ensureFindPreference(FxAccountSyncAdapter.PREFS_SYNC_METERED);
+    syncOverMeteredPreference.setOnPreferenceChangeListener(this);
+
     deviceNamePreference = (EditTextPreference) ensureFindPreference("device_name");
     deviceNamePreference.setOnPreferenceChangeListener(this);
 
@@ -948,6 +949,14 @@ public class FxAccountStatusFragment
       return true;
     }
 
+    if (preference == syncOverMeteredPreference) {
+      try {
+        fxAccount.getSyncPrefs().edit().putBoolean(FxAccountSyncAdapter.PREFS_SYNC_METERED, (Boolean) newValue).apply();
+      } catch (Exception e) {
+        Logger.error(LOG_TAG, "Failed to save the new for syncMeteredPreference");
+      }
+    }
+
     // For everything else, accept the change.
     return true;
   }

mobile/android/services/src/main/java/org/mozilla/gecko/fxa/authenticator/AndroidFxAccount.java

@@ -147,6 +147,7 @@ public class AndroidFxAccount {
 
   protected final Context context;
   private final AccountManager accountManager;
+  private final long neverSynced = -1;
 
   // This is really, really meant to be final. Only changed when account name changes.
   // See Bug 1368147.
@@ -647,7 +648,7 @@ public class AndroidFxAccount {
    *
    * @param stagesToSync stage names to sync; can be null to sync <b>all</b> known stages.
    * @param stagesToSkip stage names to skip; can be null to skip <b>no</b> known stages.
-   * @param ignoreSettings whether we should check preferences for syncing over metered connections.
+   * @param ignoreSettings whether we should check if syncing is allowed via in-app or system settings.
    */
   public void requestImmediateSync(String[] stagesToSync, String[] stagesToSkip, boolean ignoreSettings) {
     FirefoxAccounts.requestImmediateSync(getAndroidAccount(), stagesToSync, stagesToSkip, ignoreSettings);
@@ -799,7 +800,6 @@ public class AndroidFxAccount {
   }
 
   public long getLastSyncedTimestamp() {
-    final long neverSynced = -1L;
     try {
       return getSyncPrefs().getLong(PREF_KEY_LAST_SYNCED_TIMESTAMP, neverSynced);
     } catch (Exception e) {
@@ -808,6 +808,15 @@ public class AndroidFxAccount {
     }
   }
 
+  public boolean neverSynced() {
+    try {
+      return getSyncPrefs().getLong(PREF_KEY_LAST_SYNCED_TIMESTAMP, neverSynced) == -1;
+    } catch (Exception e) {
+      Logger.warn(LOG_TAG, "Got exception getting last synced time; ignoring.", e);
+      return false;
+    }
+  }
+
   // Debug only!  This is dangerous!
   public void unsafeTransitionToDefaultEndpoints() {
     unsafeTransitionToStageEndpoints(

mobile/android/services/src/main/java/org/mozilla/gecko/fxa/sync/FxAccountSyncAdapter.java

@@ -12,6 +12,7 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.SyncResult;
+import android.net.ConnectivityManager;
 import android.os.Bundle;
 import android.os.SystemClock;
 import android.support.v4.content.LocalBroadcastManager;
@@ -73,6 +74,8 @@ public class FxAccountSyncAdapter extends AbstractThreadedSyncAdapter {
 
   // Tracks the last seen storage hostname for backoff purposes.
   private static final String PREF_BACKOFF_STORAGE_HOST = "backoffStorageHost";
+  // Preference key for allowing sync over metered connections.
+  public static final String PREFS_SYNC_METERED = "sync.allow_metered";
 
   // Used to do cheap in-memory rate limiting. Don't sync again if we
   // successfully synced within this duration.
@@ -502,6 +505,27 @@ public class FxAccountSyncAdapter extends AbstractThreadedSyncAdapter {
     final Context context = getContext();
     final AndroidFxAccount fxAccount = new AndroidFxAccount(context, account);
 
+    // This flag is used to conclude whether we should ignore syncing
+    // based on user preference for syncing over metered connections.
+    boolean shouldRejectSyncViaSettings = false;
+    // Check whether we should ignore settings or not.
+    if (!extras.getBoolean(ContentResolver.SYNC_EXTRAS_IGNORE_SETTINGS, false)) {
+      // If it's not user-initiated, we should check if we are allowed to sync on metered connections.
+      boolean isMeteredAllowed = true;
+      try {
+        isMeteredAllowed = fxAccount.getSyncPrefs().getBoolean(PREFS_SYNC_METERED, true);
+      } catch (Exception e) {
+        Logger.error(LOG_TAG, "Failed to read sync preferences. Allowing metered connections by default.");
+      }
+      // Check if the device is on a metered connection or not.
+      final ConnectivityManager manager = (ConnectivityManager) getContext().getSystemService(Context.CONNECTIVITY_SERVICE);
+      final boolean isMetered = manager.isActiveNetworkMetered();
+      // If the connection is metered and syncing over metered connections is
+      // not permitted, we should bail.
+      shouldRejectSyncViaSettings = !isMeteredAllowed && isMetered;
+    }
+
+
     // NB: we use elapsedRealtime which is time since boot, to ensure our clock is monotonic and isn't
     // paused while CPU is in the power-saving mode.
     final long syncDeadline = SystemClock.elapsedRealtime() + SYNC_DEADLINE_DELTA_MILLIS;
@@ -545,9 +569,26 @@ public class FxAccountSyncAdapter extends AbstractThreadedSyncAdapter {
     Collection<String> knownStageNames = SyncConfiguration.validEngineNames();
     Collection<String> stageNamesToSync = Utils.getStagesToSyncFromBundle(knownStageNames, extras);
 
+    // If syncing should be rejected due to metered connection preferences
+    // and we are doing the first sync ever, we should at least sync the
+    // 'clients' collection to ensure we upload our local client record.
+    // see {@link <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=802749">Bug 802749</a>}
+    // for more information.
+    if (shouldRejectSyncViaSettings && fxAccount.neverSynced()) {
+      stageNamesToSync.clear();
+      stageNamesToSync.add("clients");
+    }
+
     final SyncDelegate syncDelegate = new SyncDelegate(latch, syncResult, fxAccount, stageNamesToSync);
     Result offeredResult = null;
 
+    if (shouldRejectSyncViaSettings && !fxAccount.neverSynced()) {
+      // The user is on a metered connection and has disabled syncing over metered connections,
+      // we should reject the sync.
+      syncDelegate.rejectSync();
+      return;
+    }
+
     try {
       // This will be the same chunk of SharedPreferences that we pass through to GlobalSession/SyncConfiguration.
       final SharedPreferences sharedPrefs = fxAccount.getSyncPrefs();

mobile/android/services/src/main/res/xml/fxaccount_status_prefscreen.xml

@@ -84,6 +84,11 @@
         android:key="device_name"
         android:persistent="false"
         android:title="@string/fxaccount_status_device_name" />
+    <SwitchPreference 
+	android:key="sync.allow_metered"
+	android:defaultValue="true"
+	android:title="@string/fxaccount_pref_sync_use_metered"
+	android:summary="@string/fxaccount_pref_sync_use_metered_summary"/>
 
     <org.mozilla.gecko.fxa.activities.CustomColorPreference
         android:editable="false"

mobile/android/services/strings.xml.in

@@ -47,6 +47,8 @@
 <string name="fxaccount_status_history">&fxaccount_status_history;</string>
 <string name="fxaccount_status_passwords">&fxaccount_status_passwords2;</string>
 <string name="fxaccount_status_tabs">&fxaccount_status_tabs;</string>
+<string name="fxaccount_pref_sync_use_metered">&fxaccount_pref_sync_use_metered;</string>
+<string name="fxaccount_pref_sync_use_metered_summary">&fxaccount_pref_sync_use_metered_summary;</string>
 <string name="fxaccount_status_additional_settings">&fxaccount_status_additional_settings;</string>
 <string name="fxaccount_status_legal">&fxaccount_status_legal;</string>
 <string name="fxaccount_status_linktos">&fxaccount_status_linktos2;</string>