org.taverna.server.master.utils.CallTimeLogger.java Source code

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Here is the source code for org.taverna.server.master.utils.CallTimeLogger.java

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/*
 */
package org.taverna.server.master.utils;
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

import static java.lang.String.format;
import static java.lang.System.nanoTime;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import static org.apache.commons.logging.LogFactory.getLog;
import static org.taverna.server.master.TavernaServer.JMX_ROOT;

import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import org.apache.commons.logging.Log;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.jmx.export.annotation.ManagedAttribute;
import org.springframework.jmx.export.annotation.ManagedResource;
import org.taverna.server.master.common.version.Version;

/**
 * This class is responsible for timing all invocations of publicly-exposed
 * methods of the webapp. It's connected to the webapp through an AspectJ-style
 * pointcut that targets a custom annotation.
 * 
 * @author Donal Fellows
 */
@Aspect
@ManagedResource(objectName = JMX_ROOT
        + "PerformanceMonitor", description = "The performance monitor for Taverna Server " + Version.JAVA
                + ". Writes to application log using the category 'Taverna.Server.Performance'.")
public class CallTimeLogger {
    private long threshold = 4000000;
    private Log log = getLog("Taverna.Server.Performance");

    @ManagedAttribute(description = "Threshold beneath which monitored call times are not logged. In nanoseconds.")
    public long getThreshold() {
        return threshold;
    }

    @ManagedAttribute(description = "Threshold beneath which monitored call times are not logged. In nanoseconds.")
    public void setThreshold(long threshold) {
        this.threshold = threshold;
    }

    /**
     * The timer for this aspect. The wrapped invocation will be timed, and a
     * log message written if the configured threshold is exceeded.
     * 
     * @param call
     *            The call being wrapped.
     * @return The result of the call.
     * @throws Throwable
     *             If anything goes wrong with the wrapped call.
     * @see System#nanoTime()
     */
    @Around("@annotation(org.taverna.server.master.utils.CallTimeLogger.PerfLogged)")
    public Object time(ProceedingJoinPoint call) throws Throwable {
        long fore = nanoTime();
        try {
            return call.proceed();
        } finally {
            long aft = nanoTime();
            long elapsed = aft - fore;
            if (elapsed > threshold)
                log.info(format("call to %s took %.3fms", call.toShortString(), elapsed / 1000000.0));
        }
    }

    /**
     * Mark methods that should be counted by the invocation counter.
     * 
     * @author Donal Fellows
     */
    @Retention(RUNTIME)
    @Documented
    @Target(METHOD)
    public static @interface PerfLogged {
    }
}