tmf/org.eclipse.tracecompass.tmf.analysis.xml.core/src/org/eclipse/tracecompass/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.tracecompass.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.jdt.annotation.Nullable;
  20 import org.eclipse.tracecompass.statesystem.core.exceptions.AttributeNotFoundException;
  21 import org.eclipse.tracecompass.statesystem.core.exceptions.StateValueTypeException;
  22 import org.eclipse.tracecompass.statesystem.core.exceptions.TimeRangeException;
  23 import org.eclipse.tracecompass.tmf.analysis.xml.core.module.IXmlStateSystemContainer;
  24 import org.eclipse.tracecompass.tmf.analysis.xml.core.module.XmlUtils;
  25 import org.eclipse.tracecompass.tmf.analysis.xml.core.stateprovider.TmfXmlStrings;
  26 import org.eclipse.tracecompass.tmf.core.event.ITmfEvent;
  27 import org.w3c.dom.Element;
  28 import org.w3c.dom.Node;
  29
  30 /**
  31  * This Class implement a State Change in the XML-defined state system
  32  *
  33  * <pre>
  34  *  example 1: Simple state change
  35  *  <stateChange>
  36  *      <stateAttribute type="location" value="CurrentThread" />
  37  *      <stateAttribute type="constant" value="System_call" />
  38  *      <stateValue type="null" />
  39  *  </stateChange>
  40  *
  41  *  example 2: Conditional state change
  42  *  <stateChange>
  43  *     <if>
  44  *      <condition>
  45  *        <stateAttribute type="location" value="CurrentThread" />
  46  *        <stateAttribute type="constant" value="System_call" />
  47  *        <stateValue type="null" />
  48  *      </condition>
  49  *     </if>
  50  *    <then>
  51  *      <stateAttribute type="location" value="CurrentThread" />
  52  *      <stateAttribute type="constant" value="Status" />
  53  *      <stateValue int="$PROCESS_STATUS_RUN_USERMODE"/>
  54  *    </then>
  55  *    <else>
  56  *      <stateAttribute type="location" value="CurrentThread" />
  57  *      <stateAttribute type="constant" value="Status" />
  58  *      <stateValue int="$PROCESS_STATUS_RUN_SYSCALL"/>
  59  *    </else>
  60  *  </stateChange>
  61  * </pre>
  62  *
  63  * @author Florian Wininger
  64  */
  65 public class TmfXmlStateChange {
  66
  67     private final IXmlStateChange fChange;
  68     private final IXmlStateSystemContainer fContainer;
  69
  70     /**
  71      * Constructor
  72      *
  73      * @param modelFactory
  74      *            The factory used to create XML model elements
  75      * @param statechange
  76      *            XML node root of this state change
  77      * @param container
  78      *            The state system container this state change belongs to
  79      */
  80     public TmfXmlStateChange(ITmfXmlModelFactory modelFactory, Element statechange, IXmlStateSystemContainer container) {
  81         fContainer = container;
  82
  83         /*
  84          * child nodes is either a list of TmfXmlStateAttributes and
  85          * TmfXmlStateValues, or an if-then-else series of nodes.
  86          */
  87         Node ifNode = statechange.getElementsByTagName(TmfXmlStrings.IF).item(0);
  88         if (ifNode != null) {
  89             /* the state change has a condition */
  90             fChange = new XmlConditionalChange(modelFactory, statechange);
  91         } else {
  92             /* the state change does not have a condition */
  93             fChange = new XmlStateValueChange(modelFactory, statechange);
  94         }
  95     }
  96
  97     /**
  98      * Execute the state change for an event. If necessary, it validates the
  99      * condition and executes the required change.
 100      *
 101      * @param event
 102      *            The event to process
 103      * @throws AttributeNotFoundException
 104      *             Pass through the exception it received
 105      * @throws TimeRangeException
 106      *             Pass through the exception it received
 107      * @throws StateValueTypeException
 108      *             Pass through the exception it received
 109      */
 110     public void handleEvent(ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException {
 111         fChange.handleEvent(event);
 112     }
 113
 114     @Override
 115     public String toString() {
 116         return "TmfXmlStateChange: " + fChange; //$NON-NLS-1$
 117     }
 118
 119     /* Interface for both private classes to handle the event */
 120     private interface IXmlStateChange {
 121         void handleEvent(ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException;
 122     }
 123
 124     /**
 125      * Conditional state change with a condition to verify
 126      */
 127     private class XmlConditionalChange implements IXmlStateChange {
 128         private final TmfXmlCondition fCondition;
 129         private final TmfXmlStateChange fThenChange;
 130         private final @Nullable TmfXmlStateChange fElseChange;
 131
 132         public XmlConditionalChange(ITmfXmlModelFactory modelFactory, Element statechange) {
 133             /*
 134              * The if node exists, it has been verified before calling this
 135              */
 136             Node ifNode = statechange.getElementsByTagName(TmfXmlStrings.IF).item(0);
 137             if (ifNode == null) {
 138                 throw new IllegalArgumentException();
 139             }
 140             fCondition = modelFactory.createCondition((Element) ifNode, fContainer);
 141
 142             Node thenNode = statechange.getElementsByTagName(TmfXmlStrings.THEN).item(0);
 143             if (thenNode == null) {
 144                 throw new IllegalArgumentException("Conditional state change: there should be a then clause."); //$NON-NLS-1$
 145             }
 146             fThenChange = modelFactory.createStateChange((Element) thenNode, fContainer);
 147
 148             Node elseNode = statechange.getElementsByTagName(TmfXmlStrings.ELSE).item(0);
 149             if (elseNode != null) {
 150                 fElseChange = modelFactory.createStateChange((Element) elseNode, fContainer);
 151             } else {
 152                 fElseChange = null;
 153             }
 154         }
 155
 156         @Override
 157         public void handleEvent(@NonNull ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException {
 158             TmfXmlStateChange toExecute = fThenChange;
 159             try {
 160                 if (!fCondition.testForEvent(event)) {
 161                     toExecute = fElseChange;
 162                 }
 163             } catch (AttributeNotFoundException e) {
 164                 /*
 165                  * An attribute in the condition did not exist (yet), return
 166                  * from the state change
 167                  */
 168                 return;
 169             }
 170
 171             if (toExecute == null) {
 172                 return;
 173             }
 174             toExecute.handleEvent(event);
 175         }
 176
 177         @Override
 178         public String toString() {
 179             return "Condition: " + fCondition; //$NON-NLS-1$
 180         }
 181     }
 182
 183     /**
 184      * State change with no condition
 185      */
 186     private class XmlStateValueChange implements IXmlStateChange {
 187         private final ITmfXmlStateValue fValue;
 188
 189         public XmlStateValueChange(ITmfXmlModelFactory modelFactory, Element statechange) {
 190             List<@Nullable Element> childElements = XmlUtils.getChildElements(statechange);
 191
 192             /*
 193              * Last child element is the state value, the others are attributes
 194              * to reach to value to set
 195              */
 196             Element stateValueElement = childElements.remove(childElements.size() - 1);
 197             if (stateValueElement == null) {
 198                 throw new IllegalStateException();
 199             }
 200             List<ITmfXmlStateAttribute> attributes = new ArrayList<>();
 201             for (Element element : childElements) {
 202                 if (element == null || !element.getNodeName().equals(TmfXmlStrings.STATE_ATTRIBUTE)) {
 203                     throw new IllegalArgumentException("TmfXmlStateChange: a state change must have only TmfXmlStateAttribute elements before the state value"); //$NON-NLS-1$
 204                 }
 205                 ITmfXmlStateAttribute attribute = modelFactory.createStateAttribute(element, fContainer);
 206                 attributes.add(attribute);
 207             }
 208             if (attributes.isEmpty()) {
 209                 throw new IllegalArgumentException("TmfXmlStateChange: a state change must have at least one TmfXmlStateAttribute element before the state value"); //$NON-NLS-1$
 210             }
 211             fValue = modelFactory.createStateValue(stateValueElement, fContainer, attributes);
 212         }
 213
 214         @Override
 215         public void handleEvent(@NonNull ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException {
 216             fValue.handleEvent(event);
 217         }
 218
 219         @Override
 220         public String toString() {
 221             return "Value: " + fValue; //$NON-NLS-1$
 222         }
 223     }
 224
 225 }