tmf/org.eclipse.tracecompass.tmf.core/src/org/eclipse/tracecompass/tmf/core/event/aspect/TmfStateSystemAspect.java

   1 /*******************************************************************************
   2  * Copyright (c) 2014, 2016 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are made
   5  * 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  *   Alexandre Montplaisir - Initial API and implementation
  11  *******************************************************************************/
  12
  13 package org.eclipse.tracecompass.tmf.core.event.aspect;
  14
  15 import static org.eclipse.tracecompass.common.core.NonNullUtils.checkNotNull;
  16
  17 import org.eclipse.jdt.annotation.NonNull;
  18 import org.eclipse.jdt.annotation.Nullable;
  19 import org.eclipse.osgi.util.NLS;
  20 import org.eclipse.tracecompass.statesystem.core.ITmfStateSystem;
  21 import org.eclipse.tracecompass.statesystem.core.exceptions.StateSystemDisposedException;
  22 import org.eclipse.tracecompass.statesystem.core.statevalue.ITmfStateValue;
  23 import org.eclipse.tracecompass.tmf.core.event.ITmfEvent;
  24
  25 /**
  26  * Aspect representing a query in a given state system, at the timestamp of the
  27  * event.
  28  *
  29  * This is a good example of how aspects can be "indirect" with regards to their
  30  * events.
  31  *
  32  * @author Alexandre Montplaisir
  33  */
  34 public class TmfStateSystemAspect implements ITmfEventAspect<String> {
  35
  36     private final @Nullable String fName;
  37     private final ITmfStateSystem fSS;
  38     private final int fAttribute;
  39
  40     /**
  41      * Constructor
  42      *
  43      * @param name
  44      *            The name of this aspect. You can use 'null' to use the
  45      *            default name, which is the (base) name of the attribute.
  46      * @param ss
  47      *            The state system in which we want to query
  48      * @param attributeQuark
  49      *            The quark of the attribute in the state system to look for
  50      */
  51     public TmfStateSystemAspect(@Nullable String name, ITmfStateSystem ss, int attributeQuark) {
  52         fName = name;
  53         fSS = ss;
  54         fAttribute = attributeQuark;
  55     }
  56
  57     @Override
  58     public String getName() {
  59         String name = fName;
  60         if (name != null) {
  61             return name;
  62         }
  63
  64         name = fSS.getFullAttributePath(fAttribute);
  65         return name;
  66     }
  67
  68     @Override
  69     public @NonNull String getHelpText() {
  70         return Messages.getMessage(NLS.bind(Messages.AspectHelpText_Statesystem,
  71                 fSS.getSSID(), fSS.getFullAttributePath(fAttribute)));
  72     }
  73
  74     @Override
  75     public @Nullable String resolve(ITmfEvent event) {
  76         try {
  77             ITmfStateValue value = fSS.querySingleState(event.getTimestamp().getValue(), fAttribute).getStateValue();
  78             return checkNotNull(value.toString());
  79         } catch (StateSystemDisposedException e) {
  80             return null;
  81         }
  82     }
  83 }