Bug 1241685 - Add TelemetryPreferences. r=ahunt

MozReview-Commit-ID: 5Tw0GUX0tmW

--HG--
extra : rebase_source : 627a1ae0df2923dcc64f186453e46cc70579a080

mobile/android/base/java/org/mozilla/gecko/telemetry/TelemetryConstants.java

@@ -7,13 +7,10 @@ package org.mozilla.gecko.telemetry;
 import org.mozilla.gecko.AppConstants;
 
 public class TelemetryConstants {
-
-    // Change these two values to enable upload in developer builds.
+    // To test, set this to true & change "toolkit.telemetry.server" in about:config.
     public static final boolean UPLOAD_ENABLED = AppConstants.MOZILLA_OFFICIAL; // Disabled for developer builds.
-    public static final String DEFAULT_SERVER_URL = "https://incoming.telemetry.mozilla.org";
 
     public static final String USER_AGENT =
             "Firefox-Android-Telemetry/" + AppConstants.MOZ_APP_VERSION + " (" + AppConstants.MOZ_APP_UA_NAME + ")";
 
-    public static final String PREF_SERVER_URL = "telemetry-serverUrl";
 }

mobile/android/base/java/org/mozilla/gecko/telemetry/TelemetryPreferences.java

@@ -0,0 +1,73 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.telemetry;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import org.mozilla.gecko.GeckoSharedPrefs;
+import org.mozilla.gecko.PrefsHelper;
+import org.mozilla.gecko.PrefsHelper.PrefHandler;
+
+import java.lang.ref.WeakReference;
+
+/**
+ * Manages getting and setting any preferences related to telemetry.
+ *
+ * This class persists any Gecko preferences beyond shutdown so that these values
+ * can be accessed on the next run before Gecko is started as we expect Telemetry
+ * to run before Gecko is available.
+ */
+public class TelemetryPreferences {
+    private TelemetryPreferences() {}
+
+    private static final String GECKO_PREF_SERVER_URL = "toolkit.telemetry.server";
+    private static final String SHARED_PREF_SERVER_URL = "telemetry-serverUrl";
+
+    // Defaults are a mirror of about:config defaults so we can access them before Gecko is available.
+    private static final String DEFAULT_SERVER_URL = "https://incoming.telemetry.mozilla.org";
+
+    private static final String[] OBSERVED_PREFS = {
+            GECKO_PREF_SERVER_URL,
+    };
+
+    public static String getServerSchemeHostPort(final Context context, final String profileName) {
+        return getSharedPrefs(context, profileName).getString(SHARED_PREF_SERVER_URL, DEFAULT_SERVER_URL);
+    }
+
+    public static void initPreferenceObserver(final Context context, final String profileName) {
+        final PrefHandler prefHandler = new TelemetryPrefHandler(context, profileName);
+        PrefsHelper.addObserver(OBSERVED_PREFS, prefHandler); // gets preference value when gecko starts.
+    }
+
+    private static SharedPreferences getSharedPrefs(final Context context, final String profileName) {
+        return GeckoSharedPrefs.forProfileName(context, profileName);
+    }
+
+    private static class TelemetryPrefHandler extends PrefsHelper.PrefHandlerBase {
+        private final WeakReference<Context> contextWeakReference;
+        private final String profileName;
+
+        private TelemetryPrefHandler(final Context context, final String profileName) {
+            contextWeakReference = new WeakReference<>(context);
+            this.profileName = profileName;
+        }
+
+        @Override
+        public void prefValue(final String pref, final String value) {
+            final Context context = contextWeakReference.get();
+            if (context == null) {
+                return;
+            }
+
+            if (!pref.equals(GECKO_PREF_SERVER_URL)) {
+                throw new IllegalStateException("Unknown preference: " + pref);
+            }
+
+            getSharedPrefs(context, profileName).edit()
+                    .putString(SHARED_PREF_SERVER_URL, value)
+                    .apply();
+        }
+    }
+}

mobile/android/base/moz.build

@@ -593,6 +593,7 @@ gbjar.sources += ['java/org/mozilla/gecko/' + x for x in [
     'telemetry/TelemetryCorePingDelegate.java',
     'telemetry/TelemetryDispatcher.java',
     'telemetry/TelemetryPing.java',
+    'telemetry/TelemetryPreferences.java',
     'telemetry/TelemetryUploadService.java',
     'TelemetryContract.java',
     'text/FloatingActionModeCallback.java',