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.List;
020
021import org.apache.camel.RouteNode;
022import org.apache.camel.model.ProcessorDefinition;
023
024/**
025 * Tracing information used by {@link org.apache.camel.processor.interceptor.TraceInterceptor}
026 * so we can trace the exact route path a given {@link org.apache.camel.Exchange} has been processed.
027 *
028 * @version 
029 */
030public interface TracedRouteNodes {
031
032    /**
033     * Adds the entry that was intercepted
034     *
035     * @param entry the entry
036     */
037    void addTraced(RouteNode entry);
038
039    /**
040     * Gets the last node, is <tt>null</tt> if no last exists.
041     *
042     * @return the last node
043     */
044    RouteNode getLastNode();
045
046    /**
047     * Gets the 2nd last node, is <tt>null</tt> if no last exists.
048     *
049     * @return the 2nd last
050     */
051    RouteNode getSecondLastNode();
052
053    /**
054     * Gets the current list of nodes, representing the route path the
055     * current {@link org.apache.camel.Exchange} has currently taken.
056     *
057     * @return the node path
058     */
059    List<RouteNode> getNodes();
060
061    /**
062     * Prepares a new block for tracing.
063     * <p/>
064     * This is needed when you have child block such as a multicast or aggregator
065     */
066    void pushBlock();
067
068    /**
069     * Pops the last block from tracing.
070     */
071    void popBlock();
072
073    /**
074     * Clears all traced information
075     */
076    void clear();
077
078    /**
079     * A private counter that increments, is used to as book keeping how far this
080     * exchange have been intercepted by the general intercept().
081     * <p/>
082     * We need this special book keeping to keep correct order when dealing
083     * with concurrent exchanges being routed in the same route path.
084     *
085     * @param node the intercept node
086     * @return the current count
087     */
088    int getAndIncrementCounter(ProcessorDefinition<?> node);
089
090}