org.eclipse.linuxtools.tmf.analysis.xml.core/src/org/eclipse/linuxtools/internal/tmf/analysis/xml/core/stateprovider/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.internal.tmf.analysis.xml.core.stateprovider.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.tmf.analysis.xml.core.module.XmlUtils;
  20 import org.eclipse.linuxtools.tmf.analysis.xml.core.stateprovider.TmfXmlStrings;
  21 import org.eclipse.linuxtools.tmf.analysis.xml.core.stateprovider.XmlStateProvider;
  22 import org.eclipse.linuxtools.tmf.core.event.ITmfEvent;
  23 import org.eclipse.linuxtools.tmf.core.exceptions.AttributeNotFoundException;
  24 import org.eclipse.linuxtools.tmf.core.exceptions.StateValueTypeException;
  25 import org.eclipse.linuxtools.tmf.core.exceptions.TimeRangeException;
  26 import org.w3c.dom.Element;
  27 import org.w3c.dom.Node;
  28
  29 /**
  30  * This Class implement a State Change in the XML state provider
  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 XmlStateProvider fProvider;
  68
  69     /**
  70      * Constructor
  71      *
  72      * @param statechange
  73      *            XML node root of this state change
  74      * @param provider
  75      *            The state provider this state change belongs to
  76      */
  77     public TmfXmlStateChange(Element statechange, XmlStateProvider provider) {
  78         fProvider = provider;
  79
  80         /*
  81          * child nodes is either a list of TmfXmlStateAttributes and
  82          * TmfXmlStateValues, or an if-then-else series of nodes.
  83          */
  84         Node ifNode = statechange.getElementsByTagName(TmfXmlStrings.IF).item(0);
  85         if (ifNode != null) {
  86             /* the state change has a condition */
  87             fChange = new XmlConditionalChange(statechange);
  88         } else {
  89             /* the state change does not have a condition */
  90             fChange = new XmlStateValueChange(statechange);
  91         }
  92     }
  93
  94     /**
  95      * Execute the state change for an event. If necessary, it validates the
  96      * condition and executes the required change.
  97      *
  98      * @param event
  99      *            The event to process
 100      * @throws AttributeNotFoundException
 101      *             Pass through the exception it received
 102      * @throws TimeRangeException
 103      *             Pass through the exception it received
 104      * @throws StateValueTypeException
 105      *             Pass through the exception it received
 106      */
 107     public void handleEvent(@NonNull ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException {
 108         fChange.handleEvent(event);
 109     }
 110
 111     /* Interface for both private classes to handle the event */
 112     private interface IXmlStateChange {
 113         void handleEvent(@NonNull ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException;
 114     }
 115
 116     /**
 117      * Conditional state change with a condition to verify
 118      */
 119     private class XmlConditionalChange implements IXmlStateChange {
 120         private final TmfXmlCondition fCondition;
 121         private final TmfXmlStateChange fThenChange;
 122         private final TmfXmlStateChange fElseChange;
 123
 124         public XmlConditionalChange(Element statechange) {
 125             /*
 126              * The if node exists, it has been verified before calling this
 127              */
 128             Node ifNode = statechange.getElementsByTagName(TmfXmlStrings.IF).item(0);
 129             fCondition = new TmfXmlCondition((Element) ifNode, fProvider);
 130
 131             Node thenNode = statechange.getElementsByTagName(TmfXmlStrings.THEN).item(0);
 132             if (thenNode == null) {
 133                 throw new IllegalArgumentException("Conditional state change: there should be a then clause."); //$NON-NLS-1$
 134             }
 135             fThenChange = new TmfXmlStateChange((Element) thenNode, fProvider);
 136
 137             Node elseNode = statechange.getElementsByTagName(TmfXmlStrings.ELSE).item(0);
 138             if (elseNode != null) {
 139                 fElseChange = new TmfXmlStateChange((Element) elseNode, fProvider);
 140             } else {
 141                 fElseChange = null;
 142             }
 143         }
 144
 145         @Override
 146         public void handleEvent(ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException {
 147             TmfXmlStateChange toExecute = fThenChange;
 148             try {
 149                 if (!fCondition.testForEvent(event)) {
 150                     toExecute = fElseChange;
 151                 }
 152             } catch (AttributeNotFoundException e) {
 153                 /*
 154                  * An attribute in the condition did not exist (yet), return
 155                  * from the state change
 156                  */
 157                 return;
 158             }
 159
 160             if (toExecute == null) {
 161                 return;
 162             }
 163             toExecute.handleEvent(event);
 164         }
 165     }
 166
 167     /**
 168      * State change with no condition
 169      */
 170     private class XmlStateValueChange implements IXmlStateChange {
 171         private final TmfXmlStateValue fValue;
 172
 173         public XmlStateValueChange(Element statechange) {
 174             List<Element> childElements = XmlUtils.getChildElements(statechange);
 175
 176             /*
 177              * Last child element is the state value, the others are attributes
 178              * to reach to value to set
 179              */
 180             Element stateValueElement = childElements.remove(childElements.size() - 1);
 181             List<TmfXmlStateAttribute> attributes = new ArrayList<>();
 182             for (Element element : childElements) {
 183                 if (!element.getNodeName().equals(TmfXmlStrings.STATE_ATTRIBUTE)) {
 184                     throw new IllegalArgumentException("TmfXmlStateChange: a state change must have only TmfXmlStateAttribute elements before the state value"); //$NON-NLS-1$
 185                 }
 186                 TmfXmlStateAttribute attribute = new TmfXmlStateAttribute(element, fProvider);
 187                 attributes.add(attribute);
 188             }
 189             if (attributes.isEmpty()) {
 190                 throw new IllegalArgumentException("TmfXmlStateChange: a state change must have at least one TmfXmlStateAttribute element before the state value"); //$NON-NLS-1$
 191             }
 192             fValue = new TmfXmlStateValue(stateValueElement, fProvider, attributes);
 193         }
 194
 195         @Override
 196         public void handleEvent(ITmfEvent event) throws AttributeNotFoundException, StateValueTypeException, TimeRangeException {
 197             fValue.handleEvent(event);
 198         }
 199     }
 200
 201 }