| /* |
| * 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.trace; |
| |
| import io.opencensus.common.Clock; |
| import io.opencensus.internal.DefaultVisibilityForTesting; |
| import io.opencensus.internal.Provider; |
| import io.opencensus.trace.config.TraceConfig; |
| import io.opencensus.trace.export.ExportComponent; |
| import io.opencensus.trace.propagation.PropagationComponent; |
| import java.util.logging.Level; |
| import java.util.logging.Logger; |
| import javax.annotation.Nullable; |
| |
| /** |
| * Class that manages a global instance of the {@link TraceComponent}. |
| * |
| * @since 0.5 |
| */ |
| public final class Tracing { |
| private static final Logger logger = Logger.getLogger(Tracing.class.getName()); |
| private static final TraceComponent traceComponent = |
| loadTraceComponent(TraceComponent.class.getClassLoader()); |
| |
| /** |
| * Returns the global {@link Tracer}. |
| * |
| * @return the global {@code Tracer}. |
| * @since 0.5 |
| */ |
| public static Tracer getTracer() { |
| return traceComponent.getTracer(); |
| } |
| |
| /** |
| * Returns the global {@link PropagationComponent}. |
| * |
| * @return the global {@code PropagationComponent}. |
| * @since 0.5 |
| */ |
| public static PropagationComponent getPropagationComponent() { |
| return traceComponent.getPropagationComponent(); |
| } |
| |
| /** |
| * Returns the global {@link Clock}. |
| * |
| * @return the global {@code Clock}. |
| * @since 0.5 |
| */ |
| public static Clock getClock() { |
| return traceComponent.getClock(); |
| } |
| |
| /** |
| * Returns the global {@link ExportComponent}. |
| * |
| * @return the global {@code ExportComponent}. |
| * @since 0.5 |
| */ |
| public static ExportComponent getExportComponent() { |
| return traceComponent.getExportComponent(); |
| } |
| |
| /** |
| * Returns the global {@link TraceConfig}. |
| * |
| * @return the global {@code TraceConfig}. |
| * @since 0.5 |
| */ |
| public static TraceConfig getTraceConfig() { |
| return traceComponent.getTraceConfig(); |
| } |
| |
| // Any provider that may be used for TraceComponent can be added here. |
| @DefaultVisibilityForTesting |
| static TraceComponent loadTraceComponent(@Nullable ClassLoader classLoader) { |
| try { |
| // Call Class.forName with literal string name of the class to help shading tools. |
| return Provider.createInstance( |
| Class.forName( |
| "io.opencensus.impl.trace.TraceComponentImpl", /*initialize=*/ true, classLoader), |
| TraceComponent.class); |
| } catch (ClassNotFoundException e) { |
| logger.log( |
| Level.FINE, |
| "Couldn't load full implementation for TraceComponent, now trying to load lite " |
| + "implementation.", |
| e); |
| } |
| try { |
| // Call Class.forName with literal string name of the class to help shading tools. |
| return Provider.createInstance( |
| Class.forName( |
| "io.opencensus.impllite.trace.TraceComponentImplLite", |
| /*initialize=*/ true, |
| classLoader), |
| TraceComponent.class); |
| } catch (ClassNotFoundException e) { |
| logger.log( |
| Level.FINE, |
| "Couldn't load lite implementation for TraceComponent, now using " |
| + "default implementation for TraceComponent.", |
| e); |
| } |
| return TraceComponent.newNoopTraceComponent(); |
| } |
| |
| // No instance of this class. |
| private Tracing() {} |
| } |