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

   1 /*******************************************************************************
   2  * Copyright (c) 2014, 2015 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.AttributeNotFoundException;
  22 import org.eclipse.tracecompass.statesystem.core.exceptions.StateSystemDisposedException;
  23 import org.eclipse.tracecompass.statesystem.core.statevalue.ITmfStateValue;
  24 import org.eclipse.tracecompass.tmf.core.event.ITmfEvent;
  25
  26 /**
  27  * Aspect representing a query in a given state system, at the timestamp of the
  28  * event.
  29  *
  30  * This is a good example of how aspects can be "indirect" with regards to their
  31  * events.
  32  *
  33  * @author Alexandre Montplaisir
  34  */
  35 public class TmfStateSystemAspect implements ITmfEventAspect {
  36
  37     private final @Nullable String fName;
  38     private final ITmfStateSystem fSS;
  39     private final int fAttribute;
  40
  41     /**
  42      * Constructor
  43      *
  44      * @param name
  45      *            The name of this aspect. You can use 'null' to use the
  46      *            default name, which is the (base) name of the attribute.
  47      * @param ss
  48      *            The state system in which we want to query
  49      * @param attributeQuark
  50      *            The quark of the attribute in the state system to look for
  51      */
  52     public TmfStateSystemAspect(@Nullable String name, ITmfStateSystem ss, int attributeQuark) {
  53         fName = name;
  54         fSS = ss;
  55         fAttribute = attributeQuark;
  56     }
  57
  58     @Override
  59     public String getName() {
  60         String name = fName;
  61         if (name != null) {
  62             return name;
  63         }
  64
  65         name = fSS.getFullAttributePath(fAttribute);
  66         return name;
  67     }
  68
  69     @Override
  70     public @NonNull String getHelpText() {
  71         return Messages.getMessage(NLS.bind(Messages.AspectHelpText_Statesystem,
  72                 fSS.getSSID(), fSS.getFullAttributePath(fAttribute)));
  73     }
  74
  75     @Override
  76     public @Nullable String resolve(ITmfEvent event) {
  77         try {
  78             ITmfStateValue value = fSS.querySingleState(event.getTimestamp().getValue(), fAttribute).getStateValue();
  79             return checkNotNull(value.toString());
  80         } catch (AttributeNotFoundException | StateSystemDisposedException e) {
  81             return null;
  82         }
  83     }
  84 }