/*
 * 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.
 */
package org.apache.sling.performance;

import java.util.LinkedList;
import java.util.List;

/**
 * Abstract base class for individual performance benchmarks.
 */
public abstract class AbstractTest {
	
	protected static int getScale(int def) {
        int scale = Integer.getInteger("scale", 0);
        if (scale == 0) {
            scale = def;
        }
        return scale;
    }

    private volatile boolean running;

    private List<Thread> threads;
    
    /**
     * Adds a background thread that repeatedly executes the given job
     * until all the iterations of this test have been executed.
     *
     * @param job background job
     */
    protected void addBackgroundJob(final Runnable job) {
        Thread thread = new Thread() {
            @Override
            public void run() {
                while (running) {
                    job.run();
                }
            }
        };
        thread.start();
        threads.add(thread);
    }
	
	/**
     * Run after all iterations of this test have been executed. Subclasses can
     * override this method to clean up static test content.
     *
     * @throws Exception if an error occurs
     */
    protected void afterSuite() throws Exception {
    }
    
    protected void afterTest() throws Exception {
    }

    
    /**
     * Run before any iterations of this test get executed. Subclasses can
     * override this method to set up static test content.
     *
     * @throws Exception if an error occurs
     */
    protected void beforeSuite() throws Exception {
    }

    protected void beforeTest() throws Exception {
    }

    /**
     * Executes a single iteration of this test.
     *
     * @return number of milliseconds spent in this iteration
     * @throws Exception if an error occurs
     */
    public long execute() throws Exception {
        beforeTest();
        try {
            long start = System.currentTimeMillis();
            runTest();
            return System.currentTimeMillis() - start;
        } finally {
            afterTest();
        }
    }

    protected abstract void runTest() throws Exception;
    
    /**
     * Prepares this performance benchmark.
     *
     * @param repository the repository to use
     * @param credentials credentials of a user with write access
     * @throws Exception if the benchmark can not be prepared
     */
    public void setUp()
            throws Exception {
        this.threads = new LinkedList<Thread>();
        this.running = true;
        beforeSuite();
    }
    
    /**
     * Cleans up after this performance benchmark.
     *
     * @throws Exception if the benchmark can not be cleaned up
     */
    public void tearDown() throws Exception {
        this.running = false;
        for (Thread thread : threads) {
            thread.join();
        }
        afterSuite();
        this.threads = null;
    }

    public String toString() {
        String name = getClass().getName();
        return name.substring(name.lastIndexOf('.') + 1);
    }
 }