org.eclipse.linuxtools.tmf.analysis.xml.core/src/org/eclipse/linuxtools/tmf/analysis/xml/core/model/TmfXmlStateChange.java

   1 /*******************************************************************************
   2  * Copyright (c) 2014 Ecole Polytechnique de Montreal
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   Florian Wininger - Initial API and implementation
  11  ******************************************************************************/
  12
  13 package org.eclipse.linuxtools.tmf.analysis.xml.core.model;
  14
  15 import java.util.ArrayList;
  16 import java.util.List;
  17
  18 import org.eclipse.jdt.annotation.NonNull;
  19 import org.eclipse.linuxtools.statesystem.core.exceptions.AttributeNotFoundException;
  20 import org.eclipse.linuxtools.statesystem.core.exceptions.StateValueTypeException;
  21 import org.eclipse.linuxtools.statesystem.core.exceptions.TimeRangeException;
  22 import org.eclipse.linuxtools.tmf.analysis.xml.core.module.IXmlStateSystemContainer;
  23 import org.eclipse.linuxtools.tmf.analysis.xml.core.module.XmlUtils;
  24 import org.eclipse.linuxtools.tmf.analysis.xml.core.stateprovider.TmfXmlStrings;
  25 import org.eclipse.linuxtools.tmf.core.event.ITmfEvent;
  26 import org.w3c.dom.Element;
  27 import org.w3c.dom.Node;
  28
  29 /**
  30  * This Class implement a State Change in the XML-defined state system
  31  *
  32  * <pre>
  33  *  example 1: Simple state change
  34  *  <stateChange>
  35  *      <stateAttribute type="location" value="CurrentThread" />
  36  *      <stateAttribute type="constant" value="System_call" />
  37  *      <stateValue type="null" />
  38  *  </stateChange>
  39  *
  40  *  example 2: Conditional state change
  41  *  <stateChange>
  42  *     <if>
  43  *      <condition>
  44  *        <stateAttribute type="location" value="CurrentThread" />
  45  *        <stateAttribute type="constant" value="System_call" />
  46  *        <stateValue type="null" />
  47  *      </condition>
  48  *     </if>
  49  *    <then>
  50  *      <stateAttribute type="location" value="CurrentThread" />
  51  *      <stateAttribute type="constant" value="Status" />
  52  *      <stateValue int="$PROCESS_STATUS_RUN_USERMODE"/>
  53  *    </then>
  54  *    <else>
  55  *      <stateAttribute type="location" value="CurrentThread" />
  56  *      <stateAttribute type="constant" value="Status" />
  57  *      <stateValue int="$PROCESS_STATUS_RUN_SYSCALL"/>
  58  *    </else>
  59  *  </stateChange>
  60  * </pre>
  61  *
  62  * @author Florian Wininger
  63  */
  64 public class TmfXmlStateChange {
  65
  66     private final IXmlStateChange fChange;
  67     private final IXmlStateSystemContainer fContainer;
  68
  69     /**
  70      * Constructor
  71      *
  72      * @param modelFactory
  73      *            The factory used to create XML model elements
  74      * @param statechange
  75      *            XML node root of this state change
  76      * @param container
  77      *            The state system container this state change belongs to
  78      */
  79     public TmfXmlStateChange(ITmfXmlModelFactory modelFactory, Element statechange, IXmlStateSystemContainer container) {
  80         fContainer = container;
  81
  82         /*
  83          * child nodes is either a list of TmfXmlStateAttributes and
  84          * TmfXmlStateValues, or an if-then-else series of nodes.
  85          */
  86         Node ifNode = statechange.getElementsByTagName(TmfXmlStrings.IF).item(0);
  87         if (ifNode != null) {
  88             /* the state change has a condition */
  89             fChange = new XmlConditionalChange(modelFactory, statechange);
  90         } else {
  91             /* the state change does not have a condition */
  92             fChange = new XmlStateValueChange(modelFactory, statechange);
  93         }
  94     }
  95
  96     /**
  97      * Execute the state change for an event. If necessary, it validates the
  98      * condition and executes the required change.
  99      *
 100      * @param event
 101      *            The event to process
 102      * @throws AttributeNotFoundException
 103      *             Pass through the exception it received
 104      * @throws TimeRangeException
 105      *             Pass through the exception it received
 106      * @throws StateValueTypeException
 107      *             Pass through the exception it received
 108      */
 109     public void handleEvent(@NonNull ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException {
 110         fChange.handleEvent(event);
 111     }
 112
 113     /* Interface for both private classes to handle the event */
 114     private interface IXmlStateChange {
 115         void handleEvent(@NonNull ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException;
 116     }
 117
 118     /**
 119      * Conditional state change with a condition to verify
 120      */
 121     private class XmlConditionalChange implements IXmlStateChange {
 122         private final TmfXmlCondition fCondition;
 123         private final TmfXmlStateChange fThenChange;
 124         private final TmfXmlStateChange fElseChange;
 125
 126         public XmlConditionalChange(ITmfXmlModelFactory modelFactory, Element statechange) {
 127             /*
 128              * The if node exists, it has been verified before calling this
 129              */
 130             Node ifNode = statechange.getElementsByTagName(TmfXmlStrings.IF).item(0);
 131             fCondition = modelFactory.createCondition((Element) ifNode, fContainer);
 132
 133             Node thenNode = statechange.getElementsByTagName(TmfXmlStrings.THEN).item(0);
 134             if (thenNode == null) {
 135                 throw new IllegalArgumentException("Conditional state change: there should be a then clause."); //$NON-NLS-1$
 136             }
 137             fThenChange = modelFactory.createStateChange((Element) thenNode, fContainer);
 138
 139             Node elseNode = statechange.getElementsByTagName(TmfXmlStrings.ELSE).item(0);
 140             if (elseNode != null) {
 141                 fElseChange = modelFactory.createStateChange((Element) elseNode, fContainer);
 142             } else {
 143                 fElseChange = null;
 144             }
 145         }
 146
 147         @Override
 148         public void handleEvent(@NonNull ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException {
 149             TmfXmlStateChange toExecute = fThenChange;
 150             try {
 151                 if (!fCondition.testForEvent(event)) {
 152                     toExecute = fElseChange;
 153                 }
 154             } catch (AttributeNotFoundException e) {
 155                 /*
 156                  * An attribute in the condition did not exist (yet), return
 157                  * from the state change
 158                  */
 159                 return;
 160             }
 161
 162             if (toExecute == null) {
 163                 return;
 164             }
 165             toExecute.handleEvent(event);
 166         }
 167     }
 168
 169     /**
 170      * State change with no condition
 171      */
 172     private class XmlStateValueChange implements IXmlStateChange {
 173         private final ITmfXmlStateValue fValue;
 174
 175         public XmlStateValueChange(ITmfXmlModelFactory modelFactory, Element statechange) {
 176             List<Element> childElements = XmlUtils.getChildElements(statechange);
 177
 178             /*
 179              * Last child element is the state value, the others are attributes
 180              * to reach to value to set
 181              */
 182             Element stateValueElement = childElements.remove(childElements.size() - 1);
 183             List<ITmfXmlStateAttribute> attributes = new ArrayList<>();
 184             for (Element element : childElements) {
 185                 if (!element.getNodeName().equals(TmfXmlStrings.STATE_ATTRIBUTE)) {
 186                     throw new IllegalArgumentException("TmfXmlStateChange: a state change must have only TmfXmlStateAttribute elements before the state value"); //$NON-NLS-1$
 187                 }
 188                 ITmfXmlStateAttribute attribute = modelFactory.createStateAttribute(element, fContainer);
 189                 attributes.add(attribute);
 190             }
 191             if (attributes.isEmpty()) {
 192                 throw new IllegalArgumentException("TmfXmlStateChange: a state change must have at least one TmfXmlStateAttribute element before the state value"); //$NON-NLS-1$
 193             }
 194             fValue = modelFactory.createStateValue(stateValueElement, fContainer, attributes);
 195         }
 196
 197         @Override
 198         public void handleEvent(@NonNull ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException {
 199             fValue.handleEvent(event);
 200         }
 201     }
 202
 203 }