org.eclipse.tracecompass.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     @Override
 114     public String toString() {
 115         return "TmfXmlStateChange: " + fChange; //$NON-NLS-1$
 116     }
 117
 118     /* Interface for both private classes to handle the event */
 119     private interface IXmlStateChange {
 120         void handleEvent(@NonNull ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException;
 121     }
 122
 123     /**
 124      * Conditional state change with a condition to verify
 125      */
 126     private class XmlConditionalChange implements IXmlStateChange {
 127         private final TmfXmlCondition fCondition;
 128         private final TmfXmlStateChange fThenChange;
 129         private final TmfXmlStateChange fElseChange;
 130
 131         public XmlConditionalChange(ITmfXmlModelFactory modelFactory, Element statechange) {
 132             /*
 133              * The if node exists, it has been verified before calling this
 134              */
 135             Node ifNode = statechange.getElementsByTagName(TmfXmlStrings.IF).item(0);
 136             fCondition = modelFactory.createCondition((Element) ifNode, fContainer);
 137
 138             Node thenNode = statechange.getElementsByTagName(TmfXmlStrings.THEN).item(0);
 139             if (thenNode == null) {
 140                 throw new IllegalArgumentException("Conditional state change: there should be a then clause."); //$NON-NLS-1$
 141             }
 142             fThenChange = modelFactory.createStateChange((Element) thenNode, fContainer);
 143
 144             Node elseNode = statechange.getElementsByTagName(TmfXmlStrings.ELSE).item(0);
 145             if (elseNode != null) {
 146                 fElseChange = modelFactory.createStateChange((Element) elseNode, fContainer);
 147             } else {
 148                 fElseChange = null;
 149             }
 150         }
 151
 152         @Override
 153         public void handleEvent(@NonNull ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException {
 154             TmfXmlStateChange toExecute = fThenChange;
 155             try {
 156                 if (!fCondition.testForEvent(event)) {
 157                     toExecute = fElseChange;
 158                 }
 159             } catch (AttributeNotFoundException e) {
 160                 /*
 161                  * An attribute in the condition did not exist (yet), return
 162                  * from the state change
 163                  */
 164                 return;
 165             }
 166
 167             if (toExecute == null) {
 168                 return;
 169             }
 170             toExecute.handleEvent(event);
 171         }
 172
 173         @Override
 174         public String toString() {
 175             return "Condition: " + fCondition; //$NON-NLS-1$
 176         }
 177     }
 178
 179     /**
 180      * State change with no condition
 181      */
 182     private class XmlStateValueChange implements IXmlStateChange {
 183         private final ITmfXmlStateValue fValue;
 184
 185         public XmlStateValueChange(ITmfXmlModelFactory modelFactory, Element statechange) {
 186             List<Element> childElements = XmlUtils.getChildElements(statechange);
 187
 188             /*
 189              * Last child element is the state value, the others are attributes
 190              * to reach to value to set
 191              */
 192             Element stateValueElement = childElements.remove(childElements.size() - 1);
 193             List<ITmfXmlStateAttribute> attributes = new ArrayList<>();
 194             for (Element element : childElements) {
 195                 if (!element.getNodeName().equals(TmfXmlStrings.STATE_ATTRIBUTE)) {
 196                     throw new IllegalArgumentException("TmfXmlStateChange: a state change must have only TmfXmlStateAttribute elements before the state value"); //$NON-NLS-1$
 197                 }
 198                 ITmfXmlStateAttribute attribute = modelFactory.createStateAttribute(element, fContainer);
 199                 attributes.add(attribute);
 200             }
 201             if (attributes.isEmpty()) {
 202                 throw new IllegalArgumentException("TmfXmlStateChange: a state change must have at least one TmfXmlStateAttribute element before the state value"); //$NON-NLS-1$
 203             }
 204             fValue = modelFactory.createStateValue(stateValueElement, fContainer, attributes);
 205         }
 206
 207         @Override
 208         public void handleEvent(@NonNull ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException {
 209             fValue.handleEvent(event);
 210         }
 211
 212         @Override
 213         public String toString() {
 214             return "Value: " + fValue; //$NON-NLS-1$
 215         }
 216     }
 217
 218 }