tmf/org.eclipse.tracecompass.tmf.ui/src/org/eclipse/tracecompass/tmf/ui/symbols/SymbolProviderManager.java

   1 /*******************************************************************************
   2  * Copyright (c) 2016 Movidius Inc. and others
   3  *
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  *******************************************************************************/
  10
  11 package org.eclipse.tracecompass.tmf.ui.symbols;
  12
  13 import java.lang.ref.WeakReference;
  14 import java.util.ArrayList;
  15 import java.util.Comparator;
  16 import java.util.List;
  17 import java.util.Map;
  18 import java.util.WeakHashMap;
  19
  20 import org.eclipse.core.runtime.CoreException;
  21 import org.eclipse.core.runtime.IConfigurationElement;
  22 import org.eclipse.core.runtime.Platform;
  23 import org.eclipse.jdt.annotation.NonNull;
  24 import org.eclipse.tracecompass.internal.tmf.ui.Activator;
  25 import org.eclipse.tracecompass.tmf.core.trace.ITmfTrace;
  26
  27 /**
  28  * This class offer services around the
  29  * <code>org.eclipse.tracecompass.tmf.ui.symbolProvider</code> extension point.
  30  *
  31  * @author Robert Kiss
  32  * @since 2.0
  33  *
  34  */
  35 public final class SymbolProviderManager {
  36
  37     /**
  38      * The singleton instance of this manager
  39      */
  40     private static SymbolProviderManager INSTANCE;
  41
  42     private static final String EXTENSION_POINT_ID = "org.eclipse.tracecompass.tmf.ui.symbolProvider"; //$NON-NLS-1$
  43     private static final String ELEM_NAME_PROVIDER = "providerFactory"; //$NON-NLS-1$
  44     private static final String ATTR_CLASS = "class"; //$NON-NLS-1$
  45     private static final String ATTR_PRIORITY = "priority"; //$NON-NLS-1$
  46
  47     private final List<SymbolProviderFactoryWrapper> fProviders;
  48
  49     private final Map<ITmfTrace, WeakReference<ISymbolProvider>> fInstances = new WeakHashMap<>();
  50
  51     /**
  52      * Internal class used to store extension point information
  53      *
  54      */
  55     private static class SymbolProviderFactoryWrapper {
  56
  57         public final ISymbolProviderFactory factory;
  58         public final int priority;
  59
  60         private SymbolProviderFactoryWrapper(ISymbolProviderFactory factory, int priority) {
  61             this.factory = factory;
  62             this.priority = priority;
  63
  64         }
  65
  66     }
  67
  68     /**
  69      *
  70      * @return the singleton instance of this class
  71      */
  72     @SuppressWarnings("null")
  73     public static synchronized @NonNull SymbolProviderManager getInstance() {
  74         if (INSTANCE == null) {
  75             INSTANCE = new SymbolProviderManager();
  76         }
  77         return INSTANCE;
  78     }
  79
  80     /**
  81      * The private constructor of this manager
  82      */
  83     private SymbolProviderManager() {
  84         fProviders = new ArrayList<>();
  85         IConfigurationElement[] configElements = Platform.getExtensionRegistry().getConfigurationElementsFor(EXTENSION_POINT_ID);
  86         for (IConfigurationElement element : configElements) {
  87             if (ELEM_NAME_PROVIDER.equals(element.getName())) {
  88                 try {
  89                     Object extension = element.createExecutableExtension(ATTR_CLASS);
  90                     int priority = 0;
  91                     try {
  92                         priority = Integer.parseInt(element.getAttribute(ATTR_PRIORITY));
  93                     } catch (NumberFormatException e) {
  94                         // safe to ignore
  95                     }
  96                     fProviders.add(new SymbolProviderFactoryWrapper((ISymbolProviderFactory) extension, priority));
  97                 } catch (CoreException | ClassCastException e) {
  98                     Activator.getDefault().logError("Exception while loading extensions", e); //$NON-NLS-1$
  99                 }
 100             }
 101         }
 102         // Those with a higher priority need to be on top
 103         fProviders.sort(Comparator.comparingLong(o -> -o.priority));
 104     }
 105
 106     /**
 107      * Locate an {@link ISymbolProvider} capable to resolve symbols from the
 108      * given trace. If no such provider is defined an instance of
 109      * {@link DefaultSymbolProvider} will be returned
 110      *
 111      * @param trace
 112      *            The trace to create a provider for
 113      * @return a valid {@link ISymbolProvider}, never null
 114      */
 115     public @NonNull ISymbolProvider getSymbolProvider(@NonNull ITmfTrace trace) {
 116         // Check to see if we already have a provider for this trace
 117         synchronized (fInstances) {
 118             WeakReference<ISymbolProvider> reference = fInstances.get(trace);
 119             if (reference != null) {
 120                 ISymbolProvider provider = reference.get();
 121                 if (provider != null) {
 122                     return provider;
 123                 }
 124             }
 125             // we don't have yet an instance, build one
 126             for (SymbolProviderFactoryWrapper wrapper : fProviders) {
 127                 ISymbolProviderFactory factory = wrapper.factory;
 128                 ISymbolProvider provider = factory.createProvider(trace);
 129                 if (provider != null) {
 130                     fInstances.put(trace, new WeakReference<>(provider));
 131                     return provider;
 132                 }
 133             }
 134         }
 135         // No provider found, return the default one
 136         return new DefaultSymbolProvider(trace);
 137     }
 138
 139 }