perf: reuse empty arrays

eclipse · Aug 24, 2024 · c81f927 · c81f927
1 parent 69b08ed
commit c81f927
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Showing 21 changed files with 108 additions and 44 deletions.
diff --git a/org.eclipse.lsp4e.debug/src/org/eclipse/lsp4e/debug/debugmodel/DSPStackFrame.java b/org.eclipse.lsp4e.debug/src/org/eclipse/lsp4e/debug/debugmodel/DSPStackFrame.java
@@ -26,6 +26,9 @@
 import org.eclipse.lsp4j.debug.StackFrame;
 
 public class DSPStackFrame extends DSPDebugElement implements IStackFrame {
+
+	private static final IRegisterGroup[] NO_REGISTER_GROUPS = new IRegisterGroup[0];
+
 	private final DSPThread thread;
 	private StackFrame stackFrame;
 	private final int depth;
@@ -157,7 +160,7 @@ public DSPThread getThread() {
 
 	@Override
 	public IRegisterGroup[] getRegisterGroups() throws DebugException {
-		return new IRegisterGroup[0];
+		return NO_REGISTER_GROUPS;
 	}
 
 	@Override

diff --git a/org.eclipse.lsp4e.debug/src/org/eclipse/lsp4e/debug/debugmodel/DSPThread.java b/org.eclipse.lsp4e.debug/src/org/eclipse/lsp4e/debug/debugmodel/DSPThread.java
@@ -35,6 +35,10 @@
 import org.eclipse.lsp4j.debug.Thread;
 
 public class DSPThread extends DSPDebugElement implements IThread {
+
+	private static final IStackFrame[] NO_STACK_FRAMES = new IStackFrame[0];
+	private static final IBreakpoint[] NO_BREAKPOINTS = new IBreakpoint[0];
+
 	private final Integer id;
 	/**
 	 * The name may not be known, if it is requested we will ask for it from the
@@ -232,7 +236,7 @@ public boolean hasStackFrames() throws DebugException {
 	@Override
 	public IStackFrame[] getStackFrames() throws DebugException {
 		if (!isSuspended()) {
-			return new IStackFrame[0];
+			return NO_STACK_FRAMES;
 		}
 		if (!refreshFrames.getAndSet(false)) {
 			synchronized (frames) {
@@ -263,12 +267,12 @@ public IStackFrame[] getStackFrames() throws DebugException {
 			return future.get();
 		} catch (RuntimeException | ExecutionException e) {
 			if (isTerminated()) {
-				return new DSPStackFrame[0];
+				return NO_STACK_FRAMES;
 			}
 			throw newTargetRequestFailedException(e.getMessage(), e);
 		} catch (InterruptedException e) {
 			java.lang.Thread.currentThread().interrupt();
-			return new DSPStackFrame[0];
+			return NO_STACK_FRAMES;
 		}
 	}
 
@@ -291,7 +295,7 @@ public String getName() {
 	@Override
 	public IBreakpoint[] getBreakpoints() {
 		// TODO update breakpoints from stopped messages from server
-		return new IBreakpoint[0];
+		return NO_BREAKPOINTS;
 	}
 
 	public Integer getId() {

diff --git a/org.eclipse.lsp4e.debug/src/org/eclipse/lsp4e/debug/debugmodel/DSPValue.java b/org.eclipse.lsp4e.debug/src/org/eclipse/lsp4e/debug/debugmodel/DSPValue.java
@@ -19,6 +19,8 @@
 
 public final class DSPValue extends DSPDebugElement implements IValue {
 
+	private static final IVariable[] NO_VARIABLES = new IVariable[0];
+
 	private final @Nullable DSPVariable modelVariable;
 	private final Integer variablesReference;
 	private final String value;
@@ -41,7 +43,7 @@ public DSPValue(DSPDebugTarget debugger, Integer variablesReference, String valu
 	@Override
 	public IVariable @Nullable [] getVariables() throws DebugException {
 		if (!hasVariables()) {
-			return new IVariable[0];
+			return NO_VARIABLES;
 		}
 		if (cachedVariables == null) {
 			final var arguments = new VariablesArguments();

diff --git a/org.eclipse.lsp4e.debug/src/org/eclipse/lsp4e/debug/presentation/DAPWatchExpression.java b/org.eclipse.lsp4e.debug/src/org/eclipse/lsp4e/debug/presentation/DAPWatchExpression.java
@@ -8,6 +8,7 @@
  *******************************************************************************/
 package org.eclipse.lsp4e.debug.presentation;
 
+import static org.eclipse.lsp4e.internal.ArrayUtil.NO_STRINGS;
 import static org.eclipse.lsp4e.internal.NullSafetyHelper.castNonNull;
 
 import org.eclipse.core.runtime.Adapters;
@@ -21,6 +22,7 @@
 import org.eclipse.lsp4e.debug.debugmodel.DSPDebugTarget;
 import org.eclipse.lsp4e.debug.debugmodel.DSPStackFrame;
 import org.eclipse.lsp4e.debug.debugmodel.DSPValue;
+import org.eclipse.lsp4e.internal.ArrayUtil;
 import org.eclipse.lsp4j.debug.EvaluateArguments;
 import org.eclipse.lsp4j.debug.EvaluateResponse;
 
@@ -63,7 +65,7 @@ public String getExpressionText() {
 
 			@Override
 			public String[] getErrorMessages() {
-				return new String[0];
+				return NO_STRINGS;
 			}
 		};
 	}

diff --git a/...pse.lsp4e.debug/src/org/eclipse/lsp4e/debug/sourcelookup/AbsolutePathSourceContainer.java b/...pse.lsp4e.debug/src/org/eclipse/lsp4e/debug/sourcelookup/AbsolutePathSourceContainer.java
@@ -8,6 +8,8 @@
  *******************************************************************************/
 package org.eclipse.lsp4e.debug.sourcelookup;
 
+import static org.eclipse.lsp4e.internal.ArrayUtil.NO_OBJECTS;
+
 import java.nio.file.Paths;
 
 import org.eclipse.core.runtime.CoreException;
@@ -23,7 +25,7 @@ public Object[] findSourceElements(String name) throws CoreException {
 		if (name != null && Paths.get(name).isAbsolute()) {
 			return new Object[] { name };
 		}
-		return new Object[0];
+		return NO_OBJECTS;
 	}
 
 	@Override

diff --git a/org.eclipse.lsp4e.jdt/src/org/eclipse/lsp4e/jdt/LspJavaQuickAssistProcessor.java b/org.eclipse.lsp4e.jdt/src/org/eclipse/lsp4e/jdt/LspJavaQuickAssistProcessor.java
@@ -30,6 +30,7 @@
 public class LspJavaQuickAssistProcessor extends LSPCodeActionQuickAssistProcessor implements IQuickAssistProcessor {
 
 	private static final int RELEVANCE = 100;
+	private static final IJavaCompletionProposal[] NO_JAVA_COMPLETION_PROPOSALS = new IJavaCompletionProposal[0];
 
 	private IQuickAssistInvocationContext getContext(IInvocationContext context) {
 		return new IQuickAssistInvocationContext() {
@@ -63,7 +64,7 @@ public boolean hasAssists(@NonNullByDefault({}) IInvocationContext context) thro
 
 		ICompletionProposal[] proposals = computeQuickAssistProposals(getContext(context));
 		if (proposals == null)
-			return new IJavaCompletionProposal[0];
+			return NO_JAVA_COMPLETION_PROPOSALS;
 
 		final var javaProposals = new IJavaCompletionProposal[proposals.length];
 		for (int i = 0; i < proposals.length; i++) {

diff --git a/org.eclipse.lsp4e/src/org/eclipse/lsp4e/LaunchConfigurationStreamProvider.java b/org.eclipse.lsp4e/src/org/eclipse/lsp4e/LaunchConfigurationStreamProvider.java
@@ -12,6 +12,7 @@
  *******************************************************************************/
 package org.eclipse.lsp4e;
 
+import static org.eclipse.lsp4e.internal.ArrayUtil.NO_BYTES;
 import static org.eclipse.lsp4e.internal.NullSafetyHelper.castNonNull;
 
 import java.io.IOException;
@@ -60,11 +61,10 @@ public class LaunchConfigurationStreamProvider implements StreamConnectionProvid
 	protected static class StreamProxyInputStream extends InputStream implements IStreamListener {
 
 		private static final int EOF = -1;
-		private static final byte[] NO_DATA = new byte[0];
 
 		private final ConcurrentLinkedQueue<byte[]> queue = new ConcurrentLinkedQueue<>();
 		private final IProcess process;
-		private byte[] currentBuffer = NO_DATA;
+		private byte[] currentBuffer = NO_BYTES;
 		private int currentBufferPos = 0;
 
 		public StreamProxyInputStream(IProcess process) {

diff --git a/org.eclipse.lsp4e/src/org/eclipse/lsp4e/callhierarchy/CallHierarchyContentProvider.java b/org.eclipse.lsp4e/src/org/eclipse/lsp4e/callhierarchy/CallHierarchyContentProvider.java
@@ -26,6 +26,7 @@
 import org.eclipse.lsp4e.LanguageServerWrapper;
 import org.eclipse.lsp4e.LanguageServers;
 import org.eclipse.lsp4e.LanguageServers.LanguageServerDocumentExecutor;
+import org.eclipse.lsp4e.internal.ArrayUtil;
 import org.eclipse.lsp4e.internal.Pair;
 import org.eclipse.lsp4e.ui.Messages;
 import org.eclipse.lsp4e.ui.views.HierarchyViewInput;
@@ -59,7 +60,7 @@ public Object[] getChildren(final Object parentElement) {
 		if (parentElement instanceof CallHierarchyViewTreeNode treeNode) {
 			return findCallers(treeNode);
 		} else {
-			return new Object[0];
+			return ArrayUtil.NO_OBJECTS;
 		}
 	}
 

diff --git a/org.eclipse.lsp4e/src/org/eclipse/lsp4e/internal/ArrayUtil.java b/org.eclipse.lsp4e/src/org/eclipse/lsp4e/internal/ArrayUtil.java
@@ -0,0 +1,30 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Sebastian Thomschke and others.
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * Sebastian Thomschke - initial implementation
+ *******************************************************************************/
+package org.eclipse.lsp4e.internal;
+
+public class ArrayUtil {
+
+	/** reusable empty byte array */
+	public static final byte[] NO_BYTES = new byte[0];
+
+	/** reusable empty char array */
+	public static final char[] NO_CHARS = new char[0];
+
+	/** reusable empty {@link Object} array */
+	public static final Object[] NO_OBJECTS = new Object[0];
+
+	/** reusable empty {@link String} array */
+	public static final String[] NO_STRINGS = new String[0];
+
+	private ArrayUtil() {
+	}
+}
diff --git a/org.eclipse.lsp4e/src/org/eclipse/lsp4e/operations/codeactions/CommandMarkerResolution.java b/org.eclipse.lsp4e/src/org/eclipse/lsp4e/operations/codeactions/CommandMarkerResolution.java
@@ -31,6 +31,8 @@
 
 public class CommandMarkerResolution extends WorkbenchMarkerResolution implements IMarkerResolution {
 
+	private static final IMarker[] NO_MARKERS = new IMarker[0];
+
 	private final Command command;
 
 	public CommandMarkerResolution(Command command) {
@@ -80,7 +82,7 @@ public String getDescription() {
 
 	@Override
 	public IMarker[] findOtherMarkers(IMarker[] markers) {
-		return new IMarker[0];
+		return NO_MARKERS;
 	}
 
 }
diff --git a/...pse.lsp4e/src/org/eclipse/lsp4e/operations/codeactions/LSPCodeActionMarkerResolution.java b/...pse.lsp4e/src/org/eclipse/lsp4e/operations/codeactions/LSPCodeActionMarkerResolution.java
@@ -68,6 +68,8 @@
 
 public class LSPCodeActionMarkerResolution implements IMarkerResolutionGenerator2 {
 
+	private static final IMarkerResolution[] NO_MARKER_RESOLUTIONS = new IMarkerResolution[0];
+
 	private static final String LSP_REMEDIATION = "lspCodeActions"; //$NON-NLS-1$
 
 	private static final IMarkerResolution2 COMPUTING = new IMarkerResolution2() {
@@ -106,15 +108,15 @@ public IMarkerResolution[] getResolutions(IMarker marker) {
 		} catch (InterruptedException e) {
 			LanguageServerPlugin.logError(e);
 			Thread.currentThread().interrupt();
-			return new IMarkerResolution[0];
+			return NO_MARKER_RESOLUTIONS;
 		} catch (Exception e) {
 			LanguageServerPlugin.logError(e);
-			return new IMarkerResolution[0];
+			return NO_MARKER_RESOLUTIONS;
 		}
 		if (att == COMPUTING) {
 			return new IMarkerResolution[] { COMPUTING };
 		} else if (att == null) {
-			return new IMarkerResolution[0];
+			return NO_MARKER_RESOLUTIONS;
 		}
 		return ((List<Either<Command, CodeAction>>) att).stream().filter(LSPCodeActionMarkerResolution::canPerform)
 				.map(command -> command.map(CommandMarkerResolution::new, CodeActionMarkerResolution::new))

diff --git a/org.eclipse.lsp4e/src/org/eclipse/lsp4e/operations/completion/LSContentAssistProcessor.java b/org.eclipse.lsp4e/src/org/eclipse/lsp4e/operations/completion/LSContentAssistProcessor.java
@@ -13,6 +13,7 @@
  *******************************************************************************/
 package org.eclipse.lsp4e.operations.completion;
 
+import static org.eclipse.lsp4e.internal.ArrayUtil.NO_CHARS;
 import static org.eclipse.lsp4e.internal.NullSafetyHelper.castNonNull;
 
 import java.net.URI;
@@ -68,17 +69,19 @@
 
 public class LSContentAssistProcessor implements IContentAssistProcessor {
 
+	private static final ICompletionProposal[] NO_COMPLETION_PROPOSALS = new ICompletionProposal[0];
 	private static final long TRIGGERS_TIMEOUT = 50;
 	private static final long CONTEXT_INFORMATION_TIMEOUT = 1000;
+
 	private @Nullable IDocument currentDocument;
 	private @Nullable String errorMessage;
 	private final boolean errorAsCompletionItem;
 	private @Nullable CompletableFuture<List<Void>> completionLanguageServersFuture;
 	private final Object completionTriggerCharsSemaphore = new Object();
-	private char[] completionTriggerChars = new char[0];
+	private char[] completionTriggerChars = NO_CHARS;
 	private @Nullable CompletableFuture<List<Void>> contextInformationLanguageServersFuture;
 	private final Object contextTriggerCharsSemaphore = new Object();
-	private char[] contextTriggerChars = new char[0];
+	private char[] contextTriggerChars = NO_CHARS;
 	private final boolean incompleteAsCompletionItem;
 
 	/**
@@ -107,12 +110,12 @@ public LSContentAssistProcessor(boolean errorAsCompletionItem, boolean incomplet
 	public ICompletionProposal @Nullable [] computeCompletionProposals(ITextViewer viewer, int offset) {
 		IDocument document = viewer.getDocument();
 		if (document == null) {
-			return new LSCompletionProposal[0];
+			return NO_COMPLETION_PROPOSALS;
 		}
 
 		URI uri = LSPEclipseUtils.toUri(document);
 		if (uri == null) {
-			return new LSCompletionProposal[0];
+			return NO_COMPLETION_PROPOSALS;
 		}
 
 		initiateLanguageServers(document);
@@ -201,7 +204,7 @@ private ICompletionProposal[] createErrorProposal(int offset, Exception ex) {
 			return new ICompletionProposal[] {
 					new CompletionProposal("", offset, 0, 0, null, Messages.completionError, null, ex.getMessage()) }; //$NON-NLS-1$
 		} else {
-			return new ICompletionProposal[0];
+			return NO_COMPLETION_PROPOSALS;
 		}
 	}
 
@@ -214,7 +217,7 @@ private ICompletionProposal[] createIncompleProposal(int offset, boolean incompl
 			return new ICompletionProposal[] { new CompletionProposal("", offset, 0, 0, null, //$NON-NLS-1$
 					Messages.completionIncomplete, null, Messages.continueIncomplete) };
 		}
-		return new ICompletionProposal[0];
+		return NO_COMPLETION_PROPOSALS;
 	}
 
 	private void initiateLanguageServers(IDocument document) {
@@ -234,8 +237,8 @@ private void initiateLanguageServers(IDocument document) {
 					// nothing
 				}
 			}
-			this.completionTriggerChars = new char[0];
-			this.contextTriggerChars = new char[0];
+			this.completionTriggerChars = NO_CHARS;
+			this.contextTriggerChars = NO_CHARS;
 
 			this.completionLanguageServersFuture = LanguageServers.forDocument(document)
 					.withFilter(capabilities -> capabilities.getCompletionProvider() != null) //
@@ -368,7 +371,7 @@ private void getFuture(@Nullable CompletableFuture<List<Void>> future) {
 	private static char[] mergeTriggers(char @Nullable [] initialArray,
 			@Nullable Collection<String> additionalTriggers) {
 		if (initialArray == null) {
-			initialArray = new char[0];
+			initialArray = NO_CHARS;
 		}
 		if (additionalTriggers == null) {
 			additionalTriggers = Collections.emptySet();

diff --git a/...eclipse.lsp4e/src/org/eclipse/lsp4e/operations/folding/LSPFoldingReconcilingStrategy.java b/...eclipse.lsp4e/src/org/eclipse/lsp4e/operations/folding/LSPFoldingReconcilingStrategy.java
@@ -59,6 +59,8 @@
 public class LSPFoldingReconcilingStrategy
 		implements IReconcilingStrategy, IReconcilingStrategyExtension, IProjectionListener, ITextViewerLifecycle {
 
+	private static final Annotation[] NO_ANNOTATIONS = new Annotation[0];
+
 	private @Nullable IDocument document;
 	private @Nullable ProjectionAnnotationModel projectionAnnotationModel;
 	private @Nullable ProjectionViewer viewer;
@@ -181,7 +183,7 @@ private void applyFolding(@Nullable List<FoldingRange> ranges) {
 			// send the calculated updates to the annotations to the
 			// annotation model
 			theProjectionAnnotationModel.modifyAnnotations(deletions.toArray(Annotation[]::new), additions,
-					new Annotation[0]);
+					NO_ANNOTATIONS);
 		}
 	}
 

diff --git a/org.eclipse.lsp4e/src/org/eclipse/lsp4e/operations/references/LSSearchResult.java b/org.eclipse.lsp4e/src/org/eclipse/lsp4e/operations/references/LSSearchResult.java
@@ -39,7 +39,7 @@ public LSSearchResult(LSSearchQuery query) {
 		super(query);
 	}
 
-	private static final Match[] EMPTY_ARR= new Match[0];
+	private static final Match[] NO_MATCHES = new Match[0];
 	private final Set<Object> nonFileElements = ConcurrentHashMap.newKeySet();
 
 	@Override
@@ -68,7 +68,7 @@ public Match[] computeContainedMatches(AbstractTextSearchResult result, IEditorP
 		} else if (ei instanceof IURIEditorInput uriInput) {
 			return getMatches(uriInput.getURI());
 		}
-		return EMPTY_ARR;
+		return NO_MATCHES;
 	}
 
 	@Override

diff --git a/org.eclipse.lsp4e/src/org/eclipse/lsp4e/operations/references/LSSearchResultPage.java b/org.eclipse.lsp4e/src/org/eclipse/lsp4e/operations/references/LSSearchResultPage.java
@@ -19,6 +19,7 @@
 import org.eclipse.jface.viewers.Viewer;
 import org.eclipse.jface.viewers.ViewerComparator;
 import org.eclipse.lsp4e.LSPEclipseUtils;
+import org.eclipse.lsp4e.internal.ArrayUtil;
 import org.eclipse.lsp4e.operations.references.FileAndURIMatchLabelProvider.FileAndURIMatchBaseLabelProvider;
 import org.eclipse.search.internal.ui.text.DecoratingFileSearchLabelProvider;
 import org.eclipse.search.internal.ui.text.FileMatch;
@@ -81,7 +82,7 @@ protected void elementsChanged(Object[] objects) {
 
 	@Override
 	protected void clear() {
-		getViewer().setInput(new Object[0]);
+		getViewer().setInput(ArrayUtil.NO_OBJECTS);
 	}
 
 	@Override