001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.management;
018    
019    import java.util.Map;
020    
021    import org.apache.camel.CamelContext;
022    import org.apache.camel.Processor;
023    import org.apache.camel.api.management.PerformanceCounter;
024    import org.apache.camel.management.mbean.ManagedPerformanceCounter;
025    import org.apache.camel.model.ProcessorDefinition;
026    import org.apache.camel.spi.InterceptStrategy;
027    import org.apache.camel.util.KeyValueHolder;
028    
029    /**
030     * This strategy class wraps targeted processors with a
031     * {@link InstrumentationProcessor}. Each InstrumentationProcessor has an
032     * embedded {@link ManagedPerformanceCounter} for monitoring performance metrics.
033     * <p/>
034     * This class looks up a map to determine which PerformanceCounter should go into the
035     * InstrumentationProcessor for any particular target processor.
036     *
037     * @version 
038     */
039    public class InstrumentationInterceptStrategy implements InterceptStrategy {
040    
041        private Map<ProcessorDefinition<?>, PerformanceCounter> registeredCounters;
042        private final Map<Processor, KeyValueHolder<ProcessorDefinition<?>, InstrumentationProcessor>> wrappedProcessors;
043    
044        public InstrumentationInterceptStrategy(Map<ProcessorDefinition<?>, PerformanceCounter> registeredCounters,
045                Map<Processor, KeyValueHolder<ProcessorDefinition<?>, InstrumentationProcessor>> wrappedProcessors) {
046            this.registeredCounters = registeredCounters;
047            this.wrappedProcessors = wrappedProcessors;
048        }
049    
050        public Processor wrapProcessorInInterceptors(CamelContext context, ProcessorDefinition<?> definition,
051                                                     Processor target, Processor nextTarget) throws Exception {
052            // do not double wrap it
053            if (target instanceof InstrumentationProcessor) {
054                return target;
055            }
056    
057            // only wrap a performance counter if we have it registered in JMX by the jmx agent
058            PerformanceCounter counter = registeredCounters.get(definition);
059            if (counter != null) {
060                InstrumentationProcessor wrapper = new InstrumentationProcessor(counter);
061                wrapper.setProcessor(target);
062                wrapper.setType(definition.getShortName());
063    
064                // add it to the mapping of wrappers so we can later change it to a decorated counter
065                // that when we register the processor
066                KeyValueHolder<ProcessorDefinition<?>, InstrumentationProcessor> holder =
067                        new KeyValueHolder<ProcessorDefinition<?>, InstrumentationProcessor>(definition, wrapper);
068                wrappedProcessors.put(target, holder);
069                return wrapper;
070            }
071    
072            return target;
073        }
074    
075        @Override
076        public String toString() {
077            return "InstrumentProcessor";
078        }
079    
080    }