Bug 568042 - provide ILogicalStructureTypeDelegate3#releaseValue APIY20201025-1200Y20201024-1200Y20201023-1200I20201026-0840I20201026-0650I20201025-1800I20201025-0040I20201024-1800I20201023-1800I20201023-0250

Provide an API to allow logical structure type delegates to garbage
collect their logical structures once they're no longer displayed.

Change-Id: I25e78c4d5fb84d54d6e47a6b0f12998b6b8b4f37
Signed-off-by: Julian Honnen <julian.honnen@vector.com>

10 files changed, 234 insertions, 4 deletions

diff --git a/org.eclipse.debug.core/core/org/eclipse/debug/core/model/ILogicalStructureTypeDelegate3.java b/org.eclipse.debug.core/core/org/eclipse/debug/core/model/ILogicalStructureTypeDelegate3.java
new file mode 100644
index 000000000..8ba0d52e6
--- /dev/null
+++ b/org.eclipse.debug.core/core/org/eclipse/debug/core/model/ILogicalStructureTypeDelegate3.java
@@ -0,0 +1,35 @@
+/*******************************************************************************
+ *  Copyright (c) 2020 Julian Honnen
+ *
+ *  This program and the accompanying materials
+ *  are made available under the terms of the Eclipse Public License 2.0
+ *  which accompanies this distribution, and is available at
+ *  https://www.eclipse.org/legal/epl-2.0/
+ *
+ *  SPDX-License-Identifier: EPL-2.0
+ *
+ *  Contributors:
+ *     Julian Honnen <julian.honnen@vector.com> - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.debug.core.model;
+
+/**
+ * Optional extension to <code>ILogicalStructureTypeDelegate</code> that allows
+ * a logical structure type delegate to garbage collect its logical structures
+ * once they're no longer displayed.
+ *
+ * @since 3.17
+ * @see ILogicalStructureTypeDelegate
+ */
+public interface ILogicalStructureTypeDelegate3 {
+
+	/**
+	 * Called when the logical structure returned from
+	 * {@link ILogicalStructureTypeDelegate#getLogicalStructure(IValue)} is no
+	 * longer used and can be discarded.
+	 *
+	 * @param logicalStructure the logical structure value to discard
+	 */
+	void releaseValue(IValue logicalStructure);
+
+}
diff --git a/org.eclipse.debug.core/core/org/eclipse/debug/internal/core/LogicalStructureType.java b/org.eclipse.debug.core/core/org/eclipse/debug/internal/core/LogicalStructureType.java
index 7fc9d1739..074fc67d7 100644
--- a/org.eclipse.debug.core/core/org/eclipse/debug/internal/core/LogicalStructureType.java
+++ b/org.eclipse.debug.core/core/org/eclipse/debug/internal/core/LogicalStructureType.java
@@ -23,6 +23,7 @@ import org.eclipse.debug.core.DebugPlugin;
 import org.eclipse.debug.core.ILogicalStructureType;
 import org.eclipse.debug.core.model.ILogicalStructureTypeDelegate;
 import org.eclipse.debug.core.model.ILogicalStructureTypeDelegate2;
+import org.eclipse.debug.core.model.ILogicalStructureTypeDelegate3;
 import org.eclipse.debug.core.model.IValue;
 
 /**
@@ -30,7 +31,7 @@ import org.eclipse.debug.core.model.IValue;
  *
  * @see IConfigurationElementConstants
  */
-public class LogicalStructureType implements ILogicalStructureType {
+public class LogicalStructureType implements ILogicalStructureType, ILogicalStructureTypeDelegate3 {
 
 	private IConfigurationElement fConfigurationElement;
 	private ILogicalStructureTypeDelegate fDelegate;
@@ -108,6 +109,14 @@ public class LogicalStructureType implements ILogicalStructureType {
 		return false;
 	}
 
+	@Override
+	public void releaseValue(IValue logicalStructure) {
+		ILogicalStructureTypeDelegate delegate = getDelegate();
+		if (delegate instanceof ILogicalStructureTypeDelegate3) {
+			((ILogicalStructureTypeDelegate3) delegate).releaseValue(logicalStructure);
+		}
+	}
+
 	/**
 	 * Returns the <code>ILogicalStructuresTypeDelegate</code> delegate
 	 * @return the delegate
diff --git a/org.eclipse.debug.tests/META-INF/MANIFEST.MF b/org.eclipse.debug.tests/META-INF/MANIFEST.MF
index b580480a2..6e3069839 100644
--- a/org.eclipse.debug.tests/META-INF/MANIFEST.MF
+++ b/org.eclipse.debug.tests/META-INF/MANIFEST.MF
@@ -24,6 +24,7 @@ Export-Package: org.eclipse.debug.tests,
  org.eclipse.debug.tests.console,
  org.eclipse.debug.tests.expressions,
  org.eclipse.debug.tests.launching,
+ org.eclipse.debug.tests.logicalstructure,
  org.eclipse.debug.tests.sourcelookup,
  org.eclipse.debug.tests.statushandlers,
  org.eclipse.debug.tests.stepfilters,
diff --git a/org.eclipse.debug.tests/plugin.xml b/org.eclipse.debug.tests/plugin.xml
index ab1d612ec..a350e91c8 100644
--- a/org.eclipse.debug.tests/plugin.xml
+++ b/org.eclipse.debug.tests/plugin.xml
@@ -134,4 +134,12 @@
             id="org.eclipse.debug.tests">
       </debugModelPresentation>
    </extension>
+   <extension
+         point="org.eclipse.debug.core.logicalStructureTypes">
+      <logicalStructureType
+            class="org.eclipse.debug.tests.logicalstructure.TestLogicalStructureTypeDelegate"
+            id="org.eclipse.debug.tests.logicalStructureType1"
+            modelIdentifier="org.eclipse.debug.tests">
+      </logicalStructureType>
+   </extension>
 </plugin>
diff --git a/org.eclipse.debug.tests/src/org/eclipse/debug/tests/AutomatedSuite.java b/org.eclipse.debug.tests/src/org/eclipse/debug/tests/AutomatedSuite.java
index 825625830..b28236add 100644
--- a/org.eclipse.debug.tests/src/org/eclipse/debug/tests/AutomatedSuite.java
+++ b/org.eclipse.debug.tests/src/org/eclipse/debug/tests/AutomatedSuite.java
@@ -39,6 +39,7 @@ import org.eclipse.debug.tests.launching.LaunchHistoryTests;
 import org.eclipse.debug.tests.launching.LaunchManagerTests;
 import org.eclipse.debug.tests.launching.LaunchTests;
 import org.eclipse.debug.tests.launching.RefreshTabTests;
+import org.eclipse.debug.tests.logicalstructure.LogicalStructureCacheTest;
 import org.eclipse.debug.tests.sourcelookup.SourceLookupFacilityTests;
 import org.eclipse.debug.tests.statushandlers.StatusHandlerTests;
 import org.eclipse.debug.tests.stepfilters.StepFiltersTests;
@@ -85,7 +86,7 @@ import org.junit.runners.Suite;
 		FilterTransformTests.class,
 		ChildrenUpdateTests.class,
 		PresentationContextTests.class,
-		
+
 		// Memory view
 		MemoryRenderingTests.class,
 
@@ -122,6 +123,9 @@ import org.junit.runners.Suite;
 
 		// Launch Groups
 		LaunchGroupTests.class,
+
+		// Logical structure
+		LogicalStructureCacheTest.class,
 })
 public class AutomatedSuite {
 }
diff --git a/org.eclipse.debug.tests/src/org/eclipse/debug/tests/logicalstructure/LogicalStructureCacheTest.java b/org.eclipse.debug.tests/src/org/eclipse/debug/tests/logicalstructure/LogicalStructureCacheTest.java
new file mode 100644
index 000000000..ed58260c8
--- /dev/null
+++ b/org.eclipse.debug.tests/src/org/eclipse/debug/tests/logicalstructure/LogicalStructureCacheTest.java
@@ -0,0 +1,41 @@
+/*******************************************************************************
+ *  Copyright (c) 2020 Julian Honnen
+ *
+ *  This program and the accompanying materials
+ *  are made available under the terms of the Eclipse Public License 2.0
+ *  which accompanies this distribution, and is available at
+ *  https://www.eclipse.org/legal/epl-2.0/
+ *
+ *  SPDX-License-Identifier: EPL-2.0
+ *
+ *  Contributors:
+ *     Julian Honnen <julian.honnen@vector.com> - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.debug.tests.logicalstructure;
+
+import static org.junit.Assert.*;
+import org.eclipse.debug.core.DebugPlugin;
+import org.eclipse.debug.core.ILogicalStructureType;
+import org.eclipse.debug.core.model.IValue;
+import org.eclipse.debug.internal.ui.views.variables.LogicalStructureCache;
+import org.eclipse.debug.tests.AbstractDebugTest;
+import org.junit.Test;
+
+public class LogicalStructureCacheTest extends AbstractDebugTest {
+
+	@Test
+	public void testReleaseValuesOnClear() throws Exception {
+		TestValue rawValue = new TestValue("raw");
+		ILogicalStructureType[] logicalStructureTypes = DebugPlugin.getLogicalStructureTypes(rawValue);
+
+		LogicalStructureCache cache = new LogicalStructureCache();
+		IValue logicalStructure = cache.getLogicalStructure(logicalStructureTypes[0], rawValue);
+
+		assertTrue(logicalStructure.isAllocated());
+
+		cache.clear();
+
+		assertFalse(logicalStructure.isAllocated());
+	}
+
+}
diff --git a/org.eclipse.debug.tests/src/org/eclipse/debug/tests/logicalstructure/TestLogicalStructureTypeDelegate.java b/org.eclipse.debug.tests/src/org/eclipse/debug/tests/logicalstructure/TestLogicalStructureTypeDelegate.java
new file mode 100644
index 000000000..13576c139
--- /dev/null
+++ b/org.eclipse.debug.tests/src/org/eclipse/debug/tests/logicalstructure/TestLogicalStructureTypeDelegate.java
@@ -0,0 +1,29 @@
+package org.eclipse.debug.tests.logicalstructure;
+
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.debug.core.model.ILogicalStructureTypeDelegate;
+import org.eclipse.debug.core.model.ILogicalStructureTypeDelegate3;
+import org.eclipse.debug.core.model.IValue;
+
+public class TestLogicalStructureTypeDelegate implements ILogicalStructureTypeDelegate, ILogicalStructureTypeDelegate3 {
+
+	@Override
+	public boolean providesLogicalStructure(IValue value) {
+		if (value instanceof TestValue) {
+			TestValue testValue = (TestValue) value;
+			return "raw".equals(testValue.getValueString());
+		}
+		return false;
+	}
+
+	@Override
+	public IValue getLogicalStructure(IValue value) throws CoreException {
+		return new TestValue("logical structure");
+	}
+
+	@Override
+	public void releaseValue(IValue logicalStructure) {
+		((TestValue) logicalStructure).release();
+	}
+
+}
diff --git a/org.eclipse.debug.tests/src/org/eclipse/debug/tests/logicalstructure/TestValue.java b/org.eclipse.debug.tests/src/org/eclipse/debug/tests/logicalstructure/TestValue.java
new file mode 100644
index 000000000..742f34853
--- /dev/null
+++ b/org.eclipse.debug.tests/src/org/eclipse/debug/tests/logicalstructure/TestValue.java
@@ -0,0 +1,86 @@
+/*******************************************************************************
+ *  Copyright (c) 2020 Julian Honnen
+ *
+ *  This program and the accompanying materials
+ *  are made available under the terms of the Eclipse Public License 2.0
+ *  which accompanies this distribution, and is available at
+ *  https://www.eclipse.org/legal/epl-2.0/
+ *
+ *  SPDX-License-Identifier: EPL-2.0
+ *
+ *  Contributors:
+ *     Julian Honnen <julian.honnen@vector.com> - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.debug.tests.logicalstructure;
+
+import org.eclipse.debug.core.DebugException;
+import org.eclipse.debug.core.ILaunch;
+import org.eclipse.debug.core.model.IDebugTarget;
+import org.eclipse.debug.core.model.IValue;
+import org.eclipse.debug.core.model.IVariable;
+import org.eclipse.debug.tests.TestsPlugin;
+
+class TestValue implements IValue {
+
+	private final String value;
+
+	private boolean allocated = true;
+
+	public TestValue(String value) {
+		this.value = value;
+	}
+
+	@Override
+	public String getModelIdentifier() {
+		return TestsPlugin.PLUGIN_ID;
+	}
+
+	@Override
+	public IDebugTarget getDebugTarget() {
+		return null;
+	}
+
+	@Override
+	public ILaunch getLaunch() {
+		return null;
+	}
+
+	@Override
+	public <T> T getAdapter(Class<T> adapter) {
+		return null;
+	}
+
+	@Override
+	public String getReferenceTypeName() throws DebugException {
+		return null;
+	}
+
+	@Override
+	public String getValueString() {
+		return value;
+	}
+
+	@Override
+	public boolean isAllocated() {
+		return allocated;
+	}
+
+	@Override
+	public IVariable[] getVariables() throws DebugException {
+		return new IVariable[0];
+	}
+
+	@Override
+	public boolean hasVariables() throws DebugException {
+		return false;
+	}
+
+	public void release() {
+		allocated = false;
+	}
+
+	@Override
+	public String toString() {
+		return getValueString();
+	}
+}
diff --git a/org.eclipse.debug.ui/META-INF/MANIFEST.MF b/org.eclipse.debug.ui/META-INF/MANIFEST.MF
index 8b9329f50..039f99a7c 100644
--- a/org.eclipse.debug.ui/META-INF/MANIFEST.MF
+++ b/org.eclipse.debug.ui/META-INF/MANIFEST.MF
@@ -40,7 +40,7 @@ Export-Package: org.eclipse.debug.internal.ui;
  org.eclipse.debug.internal.ui.model.elements;x-friends:="org.eclipse.debug.examples.ui,org.eclipse.jdt.debug.ui,org.eclipse.wst.jsdt.debug.ui",
  org.eclipse.debug.internal.ui.preferences;x-internal:=true,
  org.eclipse.debug.internal.ui.quickaccess;x-internal:=true,
- org.eclipse.debug.internal.ui.sourcelookup;x-friends:="org.eclipse.debug.tests, org.eclipse.jdt.debug.ui",
+ org.eclipse.debug.internal.ui.sourcelookup;x-friends:="org.eclipse.debug.tests,org.eclipse.jdt.debug.ui",
  org.eclipse.debug.internal.ui.sourcelookup.browsers;x-internal:=true,
  org.eclipse.debug.internal.ui.stringsubstitution;x-friends:="org.eclipse.jdt.debug.ui",
  org.eclipse.debug.internal.ui.viewers;x-friends:="org.eclipse.debug.examples.ui",
@@ -68,7 +68,7 @@ Export-Package: org.eclipse.debug.internal.ui;
  org.eclipse.debug.internal.ui.views.memory.renderings;x-internal:=true,
  org.eclipse.debug.internal.ui.views.modules;x-internal:=true,
  org.eclipse.debug.internal.ui.views.registers;x-internal:=true,
- org.eclipse.debug.internal.ui.views.variables;x-friends:="org.eclipse.jdt.debug.ui,org.eclipse.debug.examples.ui",
+ org.eclipse.debug.internal.ui.views.variables;x-friends:="org.eclipse.jdt.debug.ui,org.eclipse.debug.examples.ui,org.eclipse.debug.tests",
  org.eclipse.debug.internal.ui.views.variables.details;x-friends:="org.eclipse.jdt.debug.ui,org.eclipse.wst.jsdt.debug.ui",
  org.eclipse.debug.ui,
  org.eclipse.debug.ui.actions,
diff --git a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/views/variables/LogicalStructureCache.java b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/views/variables/LogicalStructureCache.java
index 2389c3aac..bd4ccc368 100644
--- a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/views/variables/LogicalStructureCache.java
+++ b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/views/variables/LogicalStructureCache.java
@@ -13,6 +13,8 @@
  *******************************************************************************/
 package org.eclipse.debug.internal.ui.views.variables;
 
+import java.util.ArrayList;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
@@ -22,6 +24,7 @@ import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.debug.core.ILogicalStructureType;
+import org.eclipse.debug.core.model.ILogicalStructureTypeDelegate3;
 import org.eclipse.debug.core.model.IValue;
 import org.eclipse.debug.internal.ui.DebugUIPlugin;
 
@@ -59,9 +62,13 @@ public class LogicalStructureCache {
 	 * Clears the cache of all evaluated values.
 	 */
 	public void clear(){
+		Collection<LogicalStructureTypeCache> caches;
 		synchronized (fCacheForType) {
+			caches = new ArrayList<>(fCacheForType.values());
 			fCacheForType.clear();
 		}
+
+		caches.forEach(LogicalStructureTypeCache::dispose);
 	}
 
 	/**
@@ -147,5 +154,15 @@ public class LogicalStructureCache {
 			}
 		}
 
+		public void dispose() {
+			if (!(fType instanceof ILogicalStructureTypeDelegate3)) {
+				return;
+			}
+			ILogicalStructureTypeDelegate3 typeDelegate = (ILogicalStructureTypeDelegate3) fType;
+			synchronized (fKnownValues) {
+				fKnownValues.values().forEach(typeDelegate::releaseValue);
+			}
+		}
+
 	}
 }