From ec78e1b8a1590dd7559cf763cc7bddc0bc93f9ed Mon Sep 17 00:00:00 2001
From: Oliver Drotbohm <oliver.drotbohm@broadcom.com>
Date: Mon, 25 Mar 2024 12:34:12 +0100
Subject: [PATCH] Cache query method metadata to avoid repeated calculations.

We now calculate information about query methods in RepositoryInformationSupport lazily and keep it around to avoid repeated calculations that involve traversals over declared method and Stream allocations.

Fixes GH-3066.
---
 .../core/RepositoryInformationSupport.java    | 88 ++++++++++++-------
 1 file changed, 57 insertions(+), 31 deletions(-)

diff --git a/src/main/java/org/springframework/data/repository/core/RepositoryInformationSupport.java b/src/main/java/org/springframework/data/repository/core/RepositoryInformationSupport.java
index eb46371c1..ddc85065f 100644
--- a/src/main/java/org/springframework/data/repository/core/RepositoryInformationSupport.java
+++ b/src/main/java/org/springframework/data/repository/core/RepositoryInformationSupport.java
@@ -19,8 +19,7 @@ import static org.springframework.data.repository.util.ClassUtils.*;
 
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
-import java.util.Collections;
-import java.util.HashSet;
+import java.util.Arrays;
 import java.util.Set;
 import java.util.function.Supplier;
 
@@ -43,6 +42,7 @@ public abstract class RepositoryInformationSupport implements RepositoryInformat
 
 	private final Supplier<RepositoryMetadata> metadata;
 	private final Supplier<Class<?>> repositoryBaseClass;
+	private final Supplier<DefaultQueryMethods> queryMethods;
 
 	public RepositoryInformationSupport(Supplier<RepositoryMetadata> metadata, Supplier<Class<?>> repositoryBaseClass) {
 
@@ -51,25 +51,12 @@ public abstract class RepositoryInformationSupport implements RepositoryInformat
 
 		this.metadata = Lazy.of(metadata);
 		this.repositoryBaseClass = Lazy.of(repositoryBaseClass);
+		this.queryMethods = Lazy.of(this::calculateQueryMethods);
 	}
 
 	@Override
 	public Streamable<Method> getQueryMethods() {
-
-		Set<Method> result = new HashSet<>();
-
-		for (Method method : getRepositoryInterface().getMethods()) {
-			method = ClassUtils.getMostSpecificMethod(method, getRepositoryInterface());
-			if (isQueryMethodCandidate(method)) {
-				result.add(method);
-			}
-		}
-
-		return Streamable.of(Collections.unmodifiableSet(result));
-	}
-
-	private RepositoryMetadata getMetadata() {
-		return metadata.get();
+		return queryMethods.get().methods;
 	}
 
 	@Override
@@ -139,21 +126,12 @@ public abstract class RepositoryInformationSupport implements RepositoryInformat
 
 	@Override
 	public boolean hasCustomMethod() {
+		return queryMethods.get().hasCustomMethod;
+	}
 
-		Class<?> repositoryInterface = getRepositoryInterface();
-
-		// No detection required if no typing interface was configured
-		if (isGenericRepositoryInterface(repositoryInterface)) {
-			return false;
-		}
-
-		for (Method method : repositoryInterface.getMethods()) {
-			if (isCustomMethod(method) && !isBaseClassMethod(method)) {
-				return true;
-			}
-		}
-
-		return false;
+	@Override
+	public boolean hasQueryMethods() {
+		return queryMethods.get().hasQueryMethod;
 	}
 
 	/**
@@ -178,4 +156,52 @@ public abstract class RepositoryInformationSupport implements RepositoryInformat
 				&& !Modifier.isStatic(method.getModifiers()) //
 				&& (isQueryAnnotationPresentOn(method) || !isCustomMethod(method) && !isBaseClassMethod(method));
 	}
+
+	private RepositoryMetadata getMetadata() {
+		return metadata.get();
+	}
+
+	private final DefaultQueryMethods calculateQueryMethods() {
+
+		Class<?> repositoryInterface = getRepositoryInterface();
+
+		return new DefaultQueryMethods(Streamable.of(Arrays.stream(repositoryInterface.getMethods())
+				.map(it -> ClassUtils.getMostSpecificMethod(it, repositoryInterface))
+				.filter(this::isQueryMethodCandidate)
+				.toList()), calculateHasCustomMethod(repositoryInterface));
+	}
+
+	private final boolean calculateHasCustomMethod(Class<?> repositoryInterface) {
+
+		// No detection required if no typing interface was configured
+		if (isGenericRepositoryInterface(repositoryInterface)) {
+			return false;
+		}
+
+		for (Method method : repositoryInterface.getMethods()) {
+			if (isCustomMethod(method) && !isBaseClassMethod(method)) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * Information about query methods to allow canonical computation and reuse of that information.
+	 *
+	 * @author Oliver Drotbohm
+	 */
+	private static class DefaultQueryMethods {
+
+		private final Streamable<Method> methods;
+		private final boolean hasCustomMethod, hasQueryMethod;
+
+		DefaultQueryMethods(Streamable<Method> methods, boolean hasCustomMethod) {
+
+			this.methods = methods;
+			this.hasCustomMethod = hasCustomMethod;
+			this.hasQueryMethod = !methods.isEmpty();
+		}
+	}
 }