Bug 509898 - CPPSemantics.isReachableFromAst is slow and is causing UI

freezes

Optimized IndexFileSet.containsDeclaration method for performance and to
reduce its memory footprint.

Change-Id: I0e867b96c6d6ab102561bc999127980d1be26a7b

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/index/IIndexFragmentFileSet.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008, 2012 Wind River Systems, Inc. and others.
+ * Copyright (c) 2008, 2017 Wind River Systems, Inc. and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -7,6 +7,7 @@
  *
  * Contributors:
  *     Markus Schorn - initial API and implementation
+ *     Sergey Prigogin (Google)
  *******************************************************************************/ 
 package org.eclipse.cdt.internal.core.index;
 
@@ -15,7 +16,6 @@ import org.eclipse.core.runtime.CoreException;
 public interface IIndexFragmentFileSet {
 	/**
 	 * Returns whether the file-set contains the file of the local binding.
-	 * @throws CoreException 
 	 */
 	boolean containsFileOfLocalBinding(IIndexFragmentBinding binding) throws CoreException;
 
@@ -33,4 +33,9 @@ public interface IIndexFragmentFileSet {
 	 * Returns whether the file set contains the given file.
 	 */
 	boolean contains(IIndexFragmentFile file) throws CoreException;
+
+	/**
+	 * Returns {@code true} if this file set is empty.
+	 */
+	boolean isEmpty();
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/index/IndexFileSet.java

@@ -21,6 +21,11 @@ import org.eclipse.cdt.core.index.IIndexBinding;
 import org.eclipse.cdt.core.index.IIndexFile;
 import org.eclipse.cdt.core.index.IIndexFileLocation;
 import org.eclipse.cdt.core.index.IIndexFileSet;
+import org.eclipse.cdt.internal.core.pdom.PDOM;
+import org.eclipse.cdt.internal.core.pdom.PDOMFileSet;
+import org.eclipse.cdt.internal.core.pdom.db.Database;
+import org.eclipse.cdt.internal.core.pdom.dom.IRecordIterator;
+import org.eclipse.cdt.internal.core.pdom.dom.PDOMName;
 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.CoreException;
 
@@ -45,26 +50,30 @@ public class IndexFileSet implements IIndexFileSet {
 
 	@Override
 	public void remove(IIndexFile indexFile) {
-		final IIndexFragmentFile fragFile = (IIndexFragmentFile) indexFile;
+		final IIndexFragmentFile fragmentFile = (IIndexFragmentFile) indexFile;
-		final IIndexFragment frag= fragFile.getIndexFragment();
+		final IIndexFragment fragment = fragmentFile.getIndexFragment();
-		IIndexFragmentFileSet subSet= fSubSets.get(frag);		
+		IIndexFragmentFileSet subSet = fSubSets.get(fragment);		
 		if (subSet != null) {
-			subSet.remove(fragFile);
+			subSet.remove(fragmentFile);
 		}
 	}
 
 	@Override
 	public boolean containsDeclaration(IIndexBinding binding) {
 		for (Map.Entry<IIndexFragment, IIndexFragmentFileSet> entry : fSubSets.entrySet()) {
+			IIndexFragment fragment = entry.getKey();
+			IIndexFragmentFileSet fragmentFileSet = entry.getValue();
 			try {
-				IIndexFragmentName[] names =
+				if (!fragmentFileSet.isEmpty() && fragmentFileSet instanceof PDOMFileSet && fragment instanceof PDOM) {
-						entry.getKey().findNames(binding, IIndexFragment.FIND_DECLARATIONS_DEFINITIONS);
+					PDOM pdom = (PDOM) fragment;
-				for (IIndexFragmentName name : names) {
+					PDOMFileSet pdomFileSet = (PDOMFileSet) fragmentFileSet;
-					try {
+					Database db = pdom.getDB();
-						if (entry.getValue().contains((IIndexFragmentFile) name.getFile())) 
+					IRecordIterator nameIterator = pdom.getDeclarationsDefintitionsRecordIterator(binding);
+					long nameRecord;
+					while ((nameRecord = nameIterator.next()) != 0) {
+						long fileRecord = PDOMName.getFileRecord(db, nameRecord);
+						if (pdomFileSet.containsFile(fileRecord))
 							return true;
-					} catch (CoreException e) {
-						CCorePlugin.log(e);
 					}
 				}
 			} catch (CoreException e) {

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/PDOM.java

@@ -77,9 +77,11 @@ import org.eclipse.cdt.internal.core.pdom.db.Database;
 import org.eclipse.cdt.internal.core.pdom.db.IBTreeComparator;
 import org.eclipse.cdt.internal.core.pdom.db.IBTreeVisitor;
 import org.eclipse.cdt.internal.core.pdom.dom.BindingCollector;
+import org.eclipse.cdt.internal.core.pdom.dom.CompoundRecordIterator;
 import org.eclipse.cdt.internal.core.pdom.dom.FindBinding;
 import org.eclipse.cdt.internal.core.pdom.dom.IPDOMIterator;
 import org.eclipse.cdt.internal.core.pdom.dom.IPDOMLinkageFactory;
+import org.eclipse.cdt.internal.core.pdom.dom.IRecordIterator;
 import org.eclipse.cdt.internal.core.pdom.dom.MacroContainerCollector;
 import org.eclipse.cdt.internal.core.pdom.dom.MacroContainerPatternCollector;
 import org.eclipse.cdt.internal.core.pdom.dom.PDOMBinding;
@@ -1270,6 +1272,16 @@ public class PDOM extends PlatformObject implements IPDOM {
 		}
 	}
 
+	public IRecordIterator getDeclarationsDefintitionsRecordIterator(IIndexBinding binding) throws CoreException {
+		IIndexFragmentBinding myBinding= adaptBinding(binding);
+		if (myBinding instanceof PDOMBinding) {
+			PDOMBinding pdomBinding = (PDOMBinding) myBinding;
+			return new CompoundRecordIterator(pdomBinding.getDeclarationRecordIterator(),
+					pdomBinding.getDefinitionRecordIterator());
+		}
+		return IRecordIterator.EMPTY;
+	}
+
 	protected boolean isCommitted(PDOMName name) throws CoreException {
 		return true;
 	}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/PDOMFileSet.java

@@ -19,7 +19,7 @@ import org.eclipse.cdt.internal.core.pdom.dom.PDOMBinding;
 import org.eclipse.cdt.internal.core.pdom.dom.PDOMFile;
 import org.eclipse.core.runtime.CoreException;
 
-public class PDOMFileSet implements IIndexFragmentFileSet {
+public final class PDOMFileSet implements IIndexFragmentFileSet {
 	private final HashSet<Long> fFileIDs= new HashSet<>();
 	
 	@Override
@@ -50,4 +50,16 @@ public class PDOMFileSet implements IIndexFragmentFileSet {
 		}
 		return false;
 	}
+
+	/**
+	 * Returns whether the file set contains the file corresponding to the given record.
+	 */
+	public boolean containsFile(long fileRecord) {
+		return fFileIDs.contains(fileRecord);
+	}
+
+	@Override
+	public boolean isEmpty() {
+		return fFileIDs.isEmpty();
+	}
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/CompoundRecordIterator.java

@@ -0,0 +1,43 @@
+/*******************************************************************************
+ * Copyright (c) 2017 Google, Inc and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ * 	   Sergey Prigogin (Google) - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.cdt.internal.core.pdom.dom;
+
+import org.eclipse.core.runtime.CoreException;
+
+/**
+ * A record iterator that is a concatenation of multiple record iterators.
+ */
+public final class CompoundRecordIterator implements IRecordIterator {
+	private final IRecordIterator[] iterators;
+	private int currentOffset;
+
+	/**
+	 * Initializes the compound iterator.
+	 * 
+	 * @param iterators the iterators to concatenate
+	 */
+	public CompoundRecordIterator(IRecordIterator... iterators) {
+		if (iterators == null)
+			throw new NullPointerException();
+		this.iterators = iterators;
+	}
+
+	@Override
+	public long next() throws CoreException {
+		for (; currentOffset < iterators.length; currentOffset++) {
+			IRecordIterator iterator = iterators[currentOffset];
+			long record = iterator.next();
+			if (record != 0)
+				return record;
+		}
+		return 0;
+	}
+}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/IRecordIterator.java

@@ -0,0 +1,27 @@
+/*******************************************************************************
+ * Copyright (c) 2017 Google, Inc and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ * 	   Sergey Prigogin (Google) - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.cdt.internal.core.pdom.dom;
+
+import org.eclipse.core.runtime.CoreException;
+
+/**
+ * An interface for iterating through lists that are stored in the PDOM without instantiating objects.
+ */
+@FunctionalInterface
+public interface IRecordIterator {
+	public static final IRecordIterator EMPTY = () -> 0;
+
+	/**
+	 * Returns the record of next element in the iteration, or zero if there are no elements left in
+	 * the iteration.
+	 */
+	public long next() throws CoreException;
+}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/PDOMBinding.java

@@ -175,6 +175,16 @@ public abstract class PDOMBinding extends PDOMNamedNode implements IPDOMBinding
 		return namerec != 0 ? new PDOMName(getLinkage(), namerec) : null;
 	}
 
+	public IRecordIterator getDeclarationRecordIterator() throws CoreException {
+		Database db = getDB();
+		return PDOMName.getNameInBindingRecordIterator(db, db.getRecPtr(record + FIRST_DECL));
+	}
+
+	public IRecordIterator getDefinitionRecordIterator() throws CoreException {
+		Database db = getDB();
+		return PDOMName.getNameInBindingRecordIterator(db, db.getRecPtr(record + FIRST_DEF));
+	}
+
 	/**
 	 * Returns an iterator over the names in other linkages that reference this binding.  Does
 	 * not return null.

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/PDOMName.java

@@ -195,6 +195,10 @@ public final class PDOMName implements IIndexFragmentName, IASTFileLocation {
 		linkage.getDB().putRecPtr(record + FILE_REC_OFFSET, file != null ? file.getRecord() : 0);
 	}
 
+	public static long getFileRecord(Database db, long record) throws CoreException {
+		return db.getRecPtr(record + FILE_REC_OFFSET);
+	}
+
 	@Override
 	public IIndexName getEnclosingDefinition() throws CoreException {
 		long namerec = getEnclosingDefinitionRecord();
@@ -419,7 +423,7 @@ public final class PDOMName implements IIndexFragmentName, IASTFileLocation {
 
 	@Override
 	public IIndexName[] getEnclosedNames() throws CoreException {
-		ArrayList<PDOMName> result= new ArrayList<PDOMName>();
+		ArrayList<PDOMName> result= new ArrayList<>();
 		PDOMName name= getNextInFile();
 		while (name != null) {
 			if (name.getEnclosingDefinitionRecord() == record) {
@@ -429,4 +433,35 @@ public final class PDOMName implements IIndexFragmentName, IASTFileLocation {
 		}
 		return result.toArray(new PDOMName[result.size()]);
 	}
+
+	/**
+	 * Returns an iterator over names in binding. This is a lighter weight alternative to
+	 * the {@link #getNextInBinding()} method. 
+	 */
+	public static IRecordIterator getNameInBindingRecordIterator(Database db, long nameRecord) {
+		if (nameRecord == 0)
+			return IRecordIterator.EMPTY;
+		return new NameInBindingRecordIterator(db, nameRecord);
+	}
+
+	/**
+	 * Iterator over PDOMName records in a binding.
+	 */
+	private static class NameInBindingRecordIterator implements IRecordIterator {
+		final Database db;
+		long nameRecord;
+
+		public NameInBindingRecordIterator(Database db, long nameRecord) {
+			this.db = db;
+			this.nameRecord = nameRecord;
+		}
+
+		@Override
+		public long next() throws CoreException {
+			long record = nameRecord;
+			if (record != 0)
+				nameRecord = db.getRecPtr(record + BINDING_NEXT_OFFSET);
+			return record;
+		}
+	}
 }