[Sync] Move //sync to //components/sync.

sync/android/java/src/org/chromium/sync/ModelTypeHelper.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.sync;
-
-import com.google.ipc.invalidation.external.client.types.ObjectId;
-import com.google.protos.ipc.invalidation.Types;
-
-import org.chromium.base.VisibleForTesting;
-import org.chromium.base.annotations.JNINamespace;
-
-import java.util.Collection;
-import java.util.HashSet;
-import java.util.Set;
-
-/**
- * Helper methods for dealing with ModelTypes.
- *
- * This class deals primarily with converting ModelTypes into notification types (string
- * representations that are used to register for invalidations) and converting notification
- * types into the actual ObjectIds used for invalidations.
- *
- */
-@JNINamespace("syncer")
-public class ModelTypeHelper {
-    /**
-     * Implement this class to override the behavior of
-     * {@link ModelTypeHelper#toNotificationType()} for tests.
-     */
-    public interface TestDelegate {
-        public String toNotificationType(int modelType);
-    }
-
-    private static final String TAG = "ModelTypeHelper";
-
-    private static final Object sLock = new Object();
-
-    private static final int[] NON_INVALIDATION_TYPES_ARRAY = new int[] {
-        ModelType.PROXY_TABS
-    };
-
-    private static TestDelegate sDelegate = null;
-
-    // Convenience sets for checking whether a type can have invalidations. Some ModelTypes
-    // such as PROXY_TABS are not real types and can't be registered. Initializing these
-    // once reduces toNotificationType() calls in the isInvalidationType() method.
-    private static Set<String> sNonInvalidationTypes = null;
-
-    /**
-     * Initializes the non-invalidation sets. Called lazily the first time they're needed.
-     */
-    private static void initNonInvalidationTypes() {
-        synchronized (sLock) {
-            if (sNonInvalidationTypes != null) return;
-
-            sNonInvalidationTypes = new HashSet<String>();
-            for (int i = 0; i < NON_INVALIDATION_TYPES_ARRAY.length; i++) {
-                sNonInvalidationTypes.add(toNotificationType(NON_INVALIDATION_TYPES_ARRAY[i]));
-            }
-        }
-    }
-
-    /**
-     * Checks whether a type is allowed to register for invalidations.
-     */
-    private static boolean isInvalidationType(String notificationType) {
-        initNonInvalidationTypes();
-        return !sNonInvalidationTypes.contains(notificationType);
-    }
-
-    /**
-     * Converts a notification type into an ObjectId.
-     *
-     * If the model type is not an invalidation type, this function uses the string "NULL".
-     */
-    private static ObjectId toObjectId(String notificationType) {
-        String objectIdString = isInvalidationType(notificationType) ? notificationType : "NULL";
-        return ObjectId.newInstance(Types.ObjectSource.CHROME_SYNC, objectIdString.getBytes());
-    }
-
-    @VisibleForTesting
-    public static ObjectId toObjectId(int modelType) {
-        return toObjectId(toNotificationType(modelType));
-    }
-
-    /**
-     * Converts a model type to its notification type representation using JNI.
-     *
-     * This is the value that is stored in the invalidation preferences and used to
-     * register for invalidations.
-     *
-     * @param modelType the model type to convert to a string.
-     * @return the string representation of the model type constant.
-     */
-    public static String toNotificationType(int modelType) {
-        if (sDelegate != null) return sDelegate.toNotificationType(modelType);
-
-        // Because PROXY_TABS isn't an invalidation type, it doesn't have a string from native,
-        // but for backwards compatibility we need to keep its pref value the same as the old
-        // ModelType enum name value.
-        if (modelType == ModelType.PROXY_TABS) {
-            return "PROXY_TABS";
-        }
-        return nativeModelTypeToNotificationType(modelType);
-    }
-
-    /**
-     * Converts a set of {@link String} notification types to a set of {@link ObjectId}.
-     *
-     * This function assumes that all the strings passed in were generated with
-     * ModelTypeHelper.toNotificationType. Any notification types that are nonInvalidationTypes
-     * are filtered out.
-     */
-    public static Set<ObjectId> notificationTypesToObjectIds(Collection<String> notificationTypes) {
-        Set<ObjectId> objectIds = new HashSet<ObjectId>();
-        for (String notificationType : notificationTypes) {
-            if (isInvalidationType(notificationType)) {
-                objectIds.add(toObjectId(notificationType));
-            }
-        }
-        return objectIds;
-    }
-
-    @VisibleForTesting
-    public static void setTestDelegate(TestDelegate delegate) {
-        sDelegate = delegate;
-    }
-
-    private static native String nativeModelTypeToNotificationType(int modelType);
-}