1 files changed, 99 insertions, 0 deletions
diff --git a/mobile/android/base/java/org/mozilla/gecko/restrictions/RestrictionCache.java b/mobile/android/base/java/org/mozilla/gecko/restrictions/RestrictionCache.java
new file mode 100644
index 000000000..523cc113b
--- /dev/null
+++ b/mobile/android/base/java/org/mozilla/gecko/restrictions/RestrictionCache.java
@@ -0,0 +1,99 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil; -*-
+ * 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.restrictions;
+
+import android.annotation.TargetApi;
+import android.content.Context;
+import android.os.Build;
+import android.os.Bundle;
+import android.os.StrictMode;
+import android.os.UserManager;
+
+import org.mozilla.gecko.util.ThreadUtils;
+
+/**
+ * Cache for user and application restrictions.
+ */
+public class RestrictionCache {
+    private static Bundle cachedAppRestrictions;
+    private static Bundle cachedUserRestrictions;
+    private static boolean isCacheInvalid = true;
+
+    private RestrictionCache() {}
+
+    public static synchronized boolean getUserRestriction(Context context, String restriction) {
+        updateCacheIfNeeded(context);
+        return cachedUserRestrictions.getBoolean(restriction);
+    }
+
+    public static synchronized boolean hasApplicationRestriction(Context context, String restriction) {
+        updateCacheIfNeeded(context);
+        return cachedAppRestrictions.containsKey(restriction);
+    }
+
+    public static synchronized boolean getApplicationRestriction(Context context, String restriction, boolean defaultValue) {
+        updateCacheIfNeeded(context);
+        return cachedAppRestrictions.getBoolean(restriction, defaultValue);
+    }
+
+    public static synchronized boolean hasApplicationRestrictions(Context context) {
+        updateCacheIfNeeded(context);
+        return !cachedAppRestrictions.isEmpty();
+    }
+
+    public static synchronized void invalidate() {
+        isCacheInvalid = true;
+    }
+
+    private static void updateCacheIfNeeded(Context context) {
+        // If we are not on the UI thread then we can just go ahead and read the values (Bug 1189347).
+        // Otherwise we read from the cache to avoid blocking the UI thread. If the cache is invalid
+        // then we hazard the consequences and just do the read.
+        if (isCacheInvalid || !ThreadUtils.isOnUiThread()) {
+            readRestrictions(context);
+            isCacheInvalid = false;
+        }
+    }
+
+    @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
+    private static void readRestrictions(Context context) {
+        final UserManager mgr = (UserManager) context.getSystemService(Context.USER_SERVICE);
+
+        // If we do not have anything in the cache yet then this read might happen on the UI thread (Bug 1189347).
+        final StrictMode.ThreadPolicy policy = StrictMode.allowThreadDiskReads();
+
+        try {
+            Bundle appRestrictions = mgr.getApplicationRestrictions(context.getPackageName());
+            migrateRestrictionsIfNeeded(appRestrictions);
+
+            cachedAppRestrictions = appRestrictions;
+            cachedUserRestrictions = mgr.getUserRestrictions(); // Always implies disk read
+        } finally {
+            StrictMode.setThreadPolicy(policy);
+        }
+    }
+
+    /**
+     * This method migrates the old set of DISALLOW_ restrictions to the new restrictable feature ones (Bug 1189336).
+     */
+    /* package-private */ static void migrateRestrictionsIfNeeded(Bundle bundle) {
+        if (!bundle.containsKey(Restrictable.INSTALL_EXTENSION.name) && bundle.containsKey("no_install_extensions")) {
+            bundle.putBoolean(Restrictable.INSTALL_EXTENSION.name, !bundle.getBoolean("no_install_extensions"));
+        }
+
+        if (!bundle.containsKey(Restrictable.PRIVATE_BROWSING.name) && bundle.containsKey("no_private_browsing")) {
+            bundle.putBoolean(Restrictable.PRIVATE_BROWSING.name, !bundle.getBoolean("no_private_browsing"));
+        }
+
+        if (!bundle.containsKey(Restrictable.CLEAR_HISTORY.name) && bundle.containsKey("no_clear_history")) {
+            bundle.putBoolean(Restrictable.CLEAR_HISTORY.name, !bundle.getBoolean("no_clear_history"));
+        }
+
+        if (!bundle.containsKey(Restrictable.ADVANCED_SETTINGS.name) && bundle.containsKey("no_advanced_settings")) {
+            bundle.putBoolean(Restrictable.ADVANCED_SETTINGS.name, !bundle.getBoolean("no_advanced_settings"));
+        }
+    }
+}