| /* |
| * Copyright 2016-17, OpenCensus Authors |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package io.opencensus.stats; |
| |
| import java.util.Set; |
| import javax.annotation.Nullable; |
| |
| /** |
| * Provides facilities to register {@link View}s for collecting stats and retrieving stats data as a |
| * {@link ViewData}. |
| * |
| * @since 0.8 |
| */ |
| public abstract class ViewManager { |
| /** |
| * Pull model for stats. Registers a {@link View} that will collect data to be accessed via {@link |
| * #getView(View.Name)}. |
| * |
| * @param view the {@code View} to be registered. |
| * @since 0.8 |
| */ |
| public abstract void registerView(View view); |
| |
| /** |
| * Returns the current stats data, {@link ViewData}, associated with the given view name. |
| * |
| * <p>Returns {@code null} if the {@code View} is not registered. |
| * |
| * @param view the name of {@code View} for the current stats. |
| * @return {@code ViewData} for the {@code View}, or {@code null} if the {@code View} is not |
| * registered. |
| * @since 0.8 |
| */ |
| @Nullable |
| public abstract ViewData getView(View.Name view); |
| |
| /** |
| * Returns all registered views that should be exported. |
| * |
| * <p>This method should be used by any stats exporter that automatically exports data for views |
| * registered with the {@link ViewManager}. |
| * |
| * @return all registered views that should be exported. |
| * @since 0.9 |
| */ |
| public abstract Set<View> getAllExportedViews(); |
| } |