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 */
017package org.apache.camel.spi;
018
019import java.util.EventObject;
020
021import org.apache.camel.Exchange;
022import org.apache.camel.NamedNode;
023import org.apache.camel.Processor;
024import org.apache.camel.spi.CamelEvent.ExchangeEvent;
025
026/**
027 * {@link org.apache.camel.spi.Breakpoint} are used by the {@link org.apache.camel.spi.Debugger} API.
028 * <p/>
029 * This allows you to register {@link org.apache.camel.spi.Breakpoint}s to the {@link org.apache.camel.spi.Debugger}
030 * and have those breakpoints activated when their {@link org.apache.camel.spi.Condition}s match.
031 * <p/>
032 * If any exceptions is thrown from the callback methods then the {@link org.apache.camel.spi.Debugger}
033 * will catch and log those at <tt>WARN</tt> level and continue. This ensures Camel can continue to route
034 * the message without having breakpoints causing issues.
035 * @see org.apache.camel.spi.Debugger
036 * @see org.apache.camel.spi.Condition
037 */
038public interface Breakpoint {
039
040    /**
041     * State of the breakpoint as either active or suspended.
042     */
043    enum State {
044        Active, Suspended
045    }
046
047    /**
048     * Gets the state of this break
049     *
050     * @return the state
051     */
052    State getState();
053
054    /**
055     * Suspend this breakpoint
056     */
057    void suspend();
058
059    /**
060     * Activates this breakpoint
061     */
062    void activate();
063
064    /**
065     * Callback invoked when the breakpoint was hit and the {@link Exchange} is about to be processed (before).
066     *  @param exchange   the {@link Exchange}
067     * @param processor  the {@link Processor} about to be processed
068     * @param definition the {@link NamedNode} definition of the processor
069     */
070    void beforeProcess(Exchange exchange, Processor processor, NamedNode definition);
071
072    /**
073     * Callback invoked when the breakpoint was hit and the {@link Exchange} has been processed (after).
074     *  @param exchange   the {@link Exchange}
075     * @param processor  the {@link Processor} which was processed
076     * @param definition the {@link NamedNode} definition of the processor
077     * @param timeTaken  time in millis it took to process the {@link Exchange} - time spend in breakpoint callbacks may affect this time
078     */
079    void afterProcess(Exchange exchange, Processor processor, NamedNode definition, long timeTaken);
080
081    /**
082     * Callback invoked when the breakpoint was hit and any of the {@link Exchange} {@link EventObject event}s occurred.
083     *
084     * @param exchange   the {@link Exchange}
085     * @param event      the event (instance of {@link ExchangeEvent}
086     * @param definition the {@link NamedNode} definition of the last processor executed,
087     *                   may be <tt>null</tt> if not possible to resolve from tracing
088     * @see ExchangeEvent
089     */
090    void onEvent(Exchange exchange, ExchangeEvent event, NamedNode definition);
091
092}