Add caching to o.s.b.test.system.OutputCapture

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/system/OutputCapture.java

@@ -23,6 +23,8 @@
 import java.util.ArrayList;
 import java.util.Deque;
 import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.Consumer;
 import java.util.function.Predicate;
 
@@ -39,6 +41,7 @@
  * @author Phillip Webb
  * @author Andy Wilkinson
  * @author Sam Brannen
+ * @author Pavel Anisimov
  * @see OutputCaptureExtension
  * @see OutputCaptureRule
  */
@@ -48,14 +51,16 @@ class OutputCapture implements CapturedOutput {
 
 	private AnsiOutputState ansiOutputState;
 
+	private final Map<Predicate<Type>, String> filter2CachedCapturedStrings = new ConcurrentHashMap<>();
+
 	/**
 	 * Push a new system capture session onto the stack.
 	 */
 	final void push() {
 		if (this.systemCaptures.isEmpty()) {
 			this.ansiOutputState = AnsiOutputState.saveAndDisable();
 		}
-		this.systemCaptures.addLast(new SystemCapture());
+		this.systemCaptures.addLast(new SystemCapture(this));
 	}
 
 	/**
@@ -97,7 +102,7 @@ public String toString() {
 	 */
 	@Override
 	public String getAll() {
-		return get((type) -> true);
+		return get(Type.filterAll);
 	}
 
 	/**
@@ -106,7 +111,7 @@ public String getAll() {
 	 */
 	@Override
 	public String getOut() {
-		return get(Type.OUT::equals);
+		return get(Type.filterOut);
 	}
 
 	/**
@@ -115,7 +120,7 @@ public String getOut() {
 	 */
 	@Override
 	public String getErr() {
-		return get(Type.ERR::equals);
+		return get(Type.filterErr);
 	}
 
 	/**
@@ -128,15 +133,21 @@ void reset() {
 	private String get(Predicate<Type> filter) {
 		Assert.state(!this.systemCaptures.isEmpty(),
 				"No system captures found. Please check your output capture registration.");
+		String cachedCapturedStrings = this.filter2CachedCapturedStrings.get(filter);
+		if (cachedCapturedStrings != null) {
+			return cachedCapturedStrings;
+		}
 		StringBuilder builder = new StringBuilder();
 		for (SystemCapture systemCapture : this.systemCaptures) {
 			systemCapture.append(builder, filter);
 		}
-		return builder.toString();
+		String capturedStrings = builder.toString();
+		this.filter2CachedCapturedStrings.put(filter, capturedStrings);
+		return capturedStrings;
 	}
 
 	/**
-	 * A capture session that captures {@link System#out System.out} and {@link System#out
+	 * A capture session that captures {@link System#out System.out} and {@link System#err
 	 * System.err}.
 	 */
 	private static class SystemCapture {
@@ -149,26 +160,34 @@ private static class SystemCapture {
 
 		private final List<CapturedString> capturedStrings = new ArrayList<>();
 
-		SystemCapture() {
+		private final OutputCapture owner;
+
+		SystemCapture(OutputCapture owner) {
 			this.out = new PrintStreamCapture(System.out, this::captureOut);
 			this.err = new PrintStreamCapture(System.err, this::captureErr);
+			this.owner = owner;
 			System.setOut(this.out);
 			System.setErr(this.err);
 		}
 
 		void release() {
+			this.owner.filter2CachedCapturedStrings.clear();
 			System.setOut(this.out.getParent());
 			System.setErr(this.err.getParent());
 		}
 
 		private void captureOut(String string) {
 			synchronized (this.monitor) {
+				this.owner.filter2CachedCapturedStrings.remove(Type.filterOut);
+				this.owner.filter2CachedCapturedStrings.remove(Type.filterAll);
 				this.capturedStrings.add(new CapturedString(Type.OUT, string));
 			}
 		}
 
 		private void captureErr(String string) {
 			synchronized (this.monitor) {
+				this.owner.filter2CachedCapturedStrings.remove(Type.filterErr);
+				this.owner.filter2CachedCapturedStrings.remove(Type.filterAll);
 				this.capturedStrings.add(new CapturedString(Type.ERR, string));
 			}
 		}
@@ -185,6 +204,7 @@ void append(StringBuilder builder, Predicate<Type> filter) {
 
 		void reset() {
 			synchronized (this.monitor) {
+				this.owner.filter2CachedCapturedStrings.clear();
 				this.capturedStrings.clear();
 			}
 		}
@@ -278,7 +298,13 @@ public String toString() {
 	 */
 	private enum Type {
 
-		OUT, ERR
+		OUT, ERR;
+
+		private static final Predicate<Type> filterOut = OUT::equals;
+
+		private static final Predicate<Type> filterErr = ERR::equals;
+
+		private static final Predicate<Type> filterAll = (type) -> true;
 
 	}
 

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/system/package-info.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.