scope.java

bpel执行引擎用来执行bpel业务流程

/*
 * 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.ode.bpel.runtime;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import javax.xml.namespace.QName;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.ode.bpel.evt.ScopeFaultEvent;
import org.apache.ode.bpel.evt.ScopeStartEvent;
import org.apache.ode.bpel.evt.VariableModificationEvent;
import org.apache.ode.bpel.o.OBase;
import org.apache.ode.bpel.o.OCatch;
import org.apache.ode.bpel.o.OElementVarType;
import org.apache.ode.bpel.o.OEventHandler;
import org.apache.ode.bpel.o.OFailureHandling;
import org.apache.ode.bpel.o.OFaultHandler;
import org.apache.ode.bpel.o.OLink;
import org.apache.ode.bpel.o.OMessageVarType;
import org.apache.ode.bpel.o.OScope;
import org.apache.ode.bpel.o.OVarType;
import org.apache.ode.bpel.runtime.channels.CompensationChannel;
import org.apache.ode.bpel.runtime.channels.EventHandlerControlChannel;
import org.apache.ode.bpel.runtime.channels.FaultData;
import org.apache.ode.bpel.runtime.channels.ParentScopeChannel;
import org.apache.ode.bpel.runtime.channels.ParentScopeChannelListener;
import org.apache.ode.bpel.runtime.channels.TerminationChannel;
import org.apache.ode.bpel.runtime.channels.TerminationChannelListener;
import org.apache.ode.jacob.ChannelListener;
import org.apache.ode.jacob.SynchChannel;
import org.w3c.dom.Element;

/**
 * An active scope.
 */
class SCOPE extends ACTIVITY {
    private static final long serialVersionUID = 6111903798996023525L;
    
    private static final Log __log = LogFactory.getLog(SCOPE.class);

    private OScope _oscope;
    private ActivityInfo _child;
    private Set<EventHandlerInfo> _eventHandlers = new HashSet<EventHandlerInfo>();

    /** Constructor. */
    public SCOPE(ActivityInfo self, ScopeFrame frame, LinkFrame linkFrame) {
        super(self, frame, linkFrame);
        _oscope = (OScope) self.o;
        assert _oscope.activity != null;
    }

    public void run() {
        
        // Start the child activity.
        _child = new ActivityInfo(genMonotonic(),
            _oscope.activity,
            newChannel(TerminationChannel.class), newChannel(ParentScopeChannel.class));
        instance(createChild(_child, _scopeFrame, _linkFrame));

        if (_oscope.eventHandler != null) {
            for (Iterator<OEventHandler.OAlarm> i = _oscope.eventHandler.onAlarms.iterator(); i.hasNext(); ) {
                OEventHandler.OAlarm alarm = i.next();
                EventHandlerInfo ehi = new EventHandlerInfo(alarm,
                        newChannel(EventHandlerControlChannel.class),
                        newChannel(ParentScopeChannel.class),
                        newChannel(TerminationChannel.class));
                _eventHandlers.add(ehi);
                instance(new EH_ALARM(ehi.psc,ehi.tc, ehi.cc, alarm, _scopeFrame));
            }
            
            for (Iterator<OEventHandler.OEvent> i = _oscope.eventHandler.onMessages.iterator(); i.hasNext(); ) {
                OEventHandler.OEvent event = i.next();
                EventHandlerInfo ehi = new EventHandlerInfo(event,
                        newChannel(EventHandlerControlChannel.class),
                        newChannel(ParentScopeChannel.class),
                        newChannel(TerminationChannel.class));
                _eventHandlers.add(ehi);
                instance(new EH_EVENT(ehi.psc,ehi.tc, ehi.cc, event, _scopeFrame));
            }
        }

        getBpelRuntimeContext().initializePartnerLinks(_scopeFrame.scopeInstanceId, 
            _oscope.partnerLinks.values());

        sendEvent(new ScopeStartEvent());
        instance(new ACTIVE());
    }

    private List<CompensationHandler> findCompensationData(OScope scope) {
        List<CompensationHandler> out = new ArrayList<CompensationHandler>();
        for (Iterator<CompensationHandler> i = _scopeFrame.availableCompensations.iterator(); i.hasNext(); ) {
            CompensationHandler  ch = i.next();
            if (null == scope || ch.compensated.oscope.equals(scope))
                out.add(ch);
        }
        // TODO: sort out in terms of completion order
        return out;
    }

    class ACTIVE extends ACTIVITY {
        private static final long serialVersionUID = -5876892592071965346L;
        /** Links collected. */
        private boolean _terminated;
        private FaultData _fault;
        private long _startTime;
        private final HashSet<CompensationHandler> _compensations = new HashSet<CompensationHandler>();
        private boolean _childTermRequested;

        ACTIVE() {
            super(SCOPE.this._self, SCOPE.this._scopeFrame, SCOPE.this._linkFrame);
            _startTime = System.currentTimeMillis();
        }

        public void run() {
            if (_child != null || !_eventHandlers.isEmpty()) {
                HashSet<ChannelListener> mlSet = new HashSet<ChannelListener>();

                // Listen to messages from our parent.
                mlSet.add(new TerminationChannelListener(_self.self) {
                    private static final long serialVersionUID = 1913414844895865116L;

                    public void terminate() {
                        _terminated = true;

                        // Forward the termination request to the nested activity.
                        if (_child != null && !_childTermRequested) {
                            replication(_child.self).terminate();
                            _childTermRequested = true;
                        }

                        // Forward the termination request to our event handlers.
                        terminateEventHandlers();

                        instance(ACTIVE.this);
                    }
                });

                // Handle messages from the child if it is still alive
                if (_child != null) {
                    mlSet.add(new ParentScopeChannelListener(_child.parent) {
                        private static final long serialVersionUID = -6934246487304813033L;

                        public void compensate(OScope scope, SynchChannel ret) {
                            //  If this scope does not have available compensations, defer to
                            // parent scope, otherwise do compensation.
                            if (_scopeFrame.availableCompensations == null)
                                _self.parent.compensate(scope, ret);
                            else {
                                // TODO: Check if we are doing duplicate compensation
                                List<CompensationHandler> compensations = findCompensationData(scope);
                                _scopeFrame.availableCompensations.removeAll(compensations);
                                instance(new ORDEREDCOMPENSATOR(compensations, ret));
                            }
                            instance(ACTIVE.this);
                        }

                        public void completed(FaultData flt, Set<CompensationHandler> compenstations) {
                              // Set the fault to the activity's choice, if and only if no previous fault
                              // has been detected (first fault wins).
                              if (flt != null && _fault == null)
                                  _fault = flt;
                              _child = null;
                              _compensations.addAll(compenstations);

                              if (flt == null)
                                  stopEventHandlers();
                              else
                                  terminateEventHandlers();

                              instance(ACTIVE.this);
                        }

                        public void cancelled() {
                            // Implicit scope holds links of the enclosed activity,
                            // they only get cancelled when we propagate upwards.
                            if (_oscope.implicitScope)
                                _self.parent.cancelled();
                            else
                                completed(null, CompensationHandler.emptySet());
                        }

                        public void failure(String reason, Element data) {
                            completed(createFault(OFailureHandling.FAILURE_FAULT_NAME, _self.o, null),
                                      CompensationHandler.emptySet());
                        }

                    });
                }

                // Similarly, handle messages from the event handler, if one exists
                // and if it has not completed.
                for (Iterator<EventHandlerInfo> i = _eventHandlers.iterator();i.hasNext();) {
                    final EventHandlerInfo ehi = i.next();

                    mlSet.add(new ParentScopeChannelListener(ehi.psc) {
                        private static final long serialVersionUID = -4694721357537858221L;

                        public void compensate(OScope scope, SynchChannel ret) {
                            // ACTIVE scopes do not compensate, send request up to parent.
                            _self.parent.compensate(scope, ret);
                            instance(ACTIVE.this);
                        }

                        public void completed(FaultData flt, Set<CompensationHandler> compenstations) {
                            // Set the fault to the activity's choice, if and only if no previous fault
                            // has been detected (first fault wins).
                            if (flt != null && _fault == null)
                                _fault = flt;
                            _eventHandlers.remove(ehi);
                            _compensations.addAll(compenstations);

                            if (flt != null) {
                                // Terminate child if we get a fault from the event handler.
                                if (_child != null && !_childTermRequested) {
                                    replication(_child.self).terminate();
                                    _childTermRequested = true;
                                }