| 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 | import com.google.common.collect.ImmutableList; |
| 28 | |
| 29 | /** |
| 30 | * This class offer services around the |
| 31 | * <code>org.eclipse.tracecompass.tmf.ui.symbolProvider</code> extension point. |
| 32 | * |
| 33 | * @author Robert Kiss |
| 34 | * @since 2.0 |
| 35 | * |
| 36 | */ |
| 37 | public final class SymbolProviderManager { |
| 38 | |
| 39 | /** |
| 40 | * The singleton instance of this manager |
| 41 | */ |
| 42 | private static SymbolProviderManager INSTANCE; |
| 43 | |
| 44 | private static final String EXTENSION_POINT_ID = "org.eclipse.tracecompass.tmf.ui.symbolProvider"; //$NON-NLS-1$ |
| 45 | private static final String ELEM_NAME_PROVIDER = "providerFactory"; //$NON-NLS-1$ |
| 46 | private static final String ATTR_CLASS = "class"; //$NON-NLS-1$ |
| 47 | private static final String ATTR_PRIORITY = "priority"; //$NON-NLS-1$ |
| 48 | |
| 49 | private final List<SymbolProviderFactoryWrapper> fProviders; |
| 50 | |
| 51 | private final Map<ITmfTrace, WeakReference<ISymbolProvider>> fInstances = new WeakHashMap<>(); |
| 52 | |
| 53 | /** |
| 54 | * Internal class used to store extension point information |
| 55 | * |
| 56 | */ |
| 57 | private static class SymbolProviderFactoryWrapper { |
| 58 | |
| 59 | public final ISymbolProviderFactory factory; |
| 60 | public final int priority; |
| 61 | |
| 62 | private SymbolProviderFactoryWrapper(ISymbolProviderFactory factory, int priority) { |
| 63 | this.factory = factory; |
| 64 | this.priority = priority; |
| 65 | |
| 66 | } |
| 67 | |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * Get the instance of the {@link SymbolProviderManager} |
| 72 | * @return the singleton instance of this class |
| 73 | */ |
| 74 | @SuppressWarnings("null") |
| 75 | public static synchronized @NonNull SymbolProviderManager getInstance() { |
| 76 | if (INSTANCE == null) { |
| 77 | List<@NonNull SymbolProviderFactoryWrapper> providers = new ArrayList<>(); |
| 78 | IConfigurationElement[] configElements = Platform.getExtensionRegistry().getConfigurationElementsFor(EXTENSION_POINT_ID); |
| 79 | for (IConfigurationElement element : configElements) { |
| 80 | if (ELEM_NAME_PROVIDER.equals(element.getName())) { |
| 81 | try { |
| 82 | Object extension = element.createExecutableExtension(ATTR_CLASS); |
| 83 | int priority = 0; |
| 84 | try { |
| 85 | priority = Integer.parseInt(element.getAttribute(ATTR_PRIORITY)); |
| 86 | } catch (NumberFormatException e) { |
| 87 | // safe to ignore |
| 88 | } |
| 89 | providers.add(new SymbolProviderFactoryWrapper((ISymbolProviderFactory) extension, priority)); |
| 90 | } catch (CoreException | ClassCastException e) { |
| 91 | Activator.getDefault().logError("Exception while loading extensions", e); //$NON-NLS-1$ |
| 92 | } |
| 93 | } |
| 94 | } |
| 95 | /* |
| 96 | * Those with a higher priority need to be on top |
| 97 | * |
| 98 | * Note: we cannot simply sort by negative priority because |
| 99 | * (-Long.MIN_VAL) == Long.MIN_VAL |
| 100 | */ |
| 101 | providers.sort(Comparator.<SymbolProviderFactoryWrapper> comparingLong(o -> o.priority).reversed()); |
| 102 | INSTANCE = new SymbolProviderManager(providers); |
| 103 | } |
| 104 | return INSTANCE; |
| 105 | } |
| 106 | |
| 107 | /** |
| 108 | * The private constructor of this manager |
| 109 | */ |
| 110 | private SymbolProviderManager(@NonNull List<@NonNull SymbolProviderFactoryWrapper> providers) { |
| 111 | fProviders = ImmutableList.copyOf(providers); |
| 112 | } |
| 113 | |
| 114 | /** |
| 115 | * Locate an {@link ISymbolProvider} capable to resolve symbols from the |
| 116 | * given trace. If no such provider is defined an instance of |
| 117 | * {@link DefaultSymbolProvider} will be returned |
| 118 | * |
| 119 | * @param trace |
| 120 | * The trace to create a provider for |
| 121 | * @return a valid {@link ISymbolProvider}, never null |
| 122 | */ |
| 123 | public @NonNull ISymbolProvider getSymbolProvider(@NonNull ITmfTrace trace) { |
| 124 | // Check to see if we already have a provider for this trace |
| 125 | synchronized (fInstances) { |
| 126 | WeakReference<ISymbolProvider> reference = fInstances.get(trace); |
| 127 | if (reference != null) { |
| 128 | ISymbolProvider provider = reference.get(); |
| 129 | if (provider != null) { |
| 130 | return provider; |
| 131 | } |
| 132 | } |
| 133 | // we don't have yet an instance, build one |
| 134 | for (SymbolProviderFactoryWrapper wrapper : fProviders) { |
| 135 | ISymbolProviderFactory factory = wrapper.factory; |
| 136 | ISymbolProvider provider = factory.createProvider(trace); |
| 137 | if (provider != null) { |
| 138 | fInstances.put(trace, new WeakReference<>(provider)); |
| 139 | return provider; |
| 140 | } |
| 141 | } |
| 142 | } |
| 143 | // No provider found, return the default one |
| 144 | return new DefaultSymbolProvider(trace); |
| 145 | } |
| 146 | |
| 147 | } |