Optimize AutoConfigurationSorter

Optimize `AutoConfigurationSorter` by used properties generated by the
annotation processor whenever possible. The removes the need for each
candidate class to be ASM parsed just to access the order annotations.

See gh-7573

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/AutoConfigurationImportSelector.java

@@ -76,19 +76,21 @@ public class AutoConfigurationImportSelector
 	private ResourceLoader resourceLoader;
 
 	@Override
-	public String[] selectImports(AnnotationMetadata metadata) {
-		if (!isEnabled(metadata)) {
+	public String[] selectImports(AnnotationMetadata annotationMetadata) {
+		if (!isEnabled(annotationMetadata)) {
 			return NO_IMPORTS;
 		}
 		try {
-			AnnotationAttributes attributes = getAttributes(metadata);
-			List<String> configurations = getCandidateConfigurations(metadata,
+			AutoConfigurationMetadata autoConfigurationMetadata = AutoConfigurationMetadataLoader
+					.loadMetadata(this.beanClassLoader);
+			AnnotationAttributes attributes = getAttributes(annotationMetadata);
+			List<String> configurations = getCandidateConfigurations(annotationMetadata,
 					attributes);
 			configurations = removeDuplicates(configurations);
-			Set<String> exclusions = getExclusions(metadata, attributes);
+			configurations = sort(configurations, autoConfigurationMetadata);
+			Set<String> exclusions = getExclusions(annotationMetadata, attributes);
 			checkExcludedClasses(configurations, exclusions);
 			configurations.removeAll(exclusions);
-			configurations = sort(configurations);
 			fireAutoConfigurationImportListeners(configurations, exclusions);
 			return configurations.toArray(new String[configurations.size()]);
 		}
@@ -224,9 +226,10 @@ public class AutoConfigurationImportSelector
 		return (Arrays.asList(exclude == null ? new String[0] : exclude));
 	}
 
-	private List<String> sort(List<String> configurations) throws IOException {
-		configurations = new AutoConfigurationSorter(getMetadataReaderFactory())
-				.getInPriorityOrder(configurations);
+	private List<String> sort(List<String> configurations,
+			AutoConfigurationMetadata autoConfigurationMetadata) throws IOException {
+		configurations = new AutoConfigurationSorter(getMetadataReaderFactory(),
+				autoConfigurationMetadata).getInPriorityOrder(configurations);
 		return configurations;
 	}
 

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/AutoConfigurationSorter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -35,8 +35,8 @@ import org.springframework.util.Assert;
 
 /**
  * Sort {@link EnableAutoConfiguration auto-configuration} classes into priority order by
- * reading {@link Ordered}, {@link AutoConfigureBefore} and {@link AutoConfigureAfter}
- * annotations (without loading classes).
+ * reading {@link AutoConfigureOrder}, {@link AutoConfigureBefore} and
+ * {@link AutoConfigureAfter} annotations (without loading classes).
  *
  * @author Phillip Webb
  */
@@ -44,26 +44,31 @@ class AutoConfigurationSorter {
 
 	private final MetadataReaderFactory metadataReaderFactory;
 
-	AutoConfigurationSorter(MetadataReaderFactory metadataReaderFactory) {
+	private final AutoConfigurationMetadata autoConfigurationMetadata;
+
+	AutoConfigurationSorter(MetadataReaderFactory metadataReaderFactory,
+			AutoConfigurationMetadata autoConfigurationMetadata) {
 		Assert.notNull(metadataReaderFactory, "MetadataReaderFactory must not be null");
 		this.metadataReaderFactory = metadataReaderFactory;
+		this.autoConfigurationMetadata = autoConfigurationMetadata;
 	}
 
-	public List<String> getInPriorityOrder(Collection<String> classNames)
-			throws IOException {
+	public List<String> getInPriorityOrder(Collection<String> classNames) {
 		final AutoConfigurationClasses classes = new AutoConfigurationClasses(
-				this.metadataReaderFactory, classNames);
+				this.metadataReaderFactory, this.autoConfigurationMetadata, classNames);
 		List<String> orderedClassNames = new ArrayList<String>(classNames);
 		// Initially sort alphabetically
 		Collections.sort(orderedClassNames);
 		// Then sort by order
 		Collections.sort(orderedClassNames, new Comparator<String>() {
+
 			@Override
 			public int compare(String o1, String o2) {
 				int i1 = classes.get(o1).getOrder();
 				int i2 = classes.get(o2).getOrder();
 				return (i1 < i2) ? -1 : (i1 > i2) ? 1 : 0;
 			}
+
 		});
 		// Then respect @AutoConfigureBefore @AutoConfigureAfter
 		orderedClassNames = sortByAnnotation(classes, orderedClassNames);
@@ -104,11 +109,11 @@ class AutoConfigurationSorter {
 		private final Map<String, AutoConfigurationClass> classes = new HashMap<String, AutoConfigurationClass>();
 
 		AutoConfigurationClasses(MetadataReaderFactory metadataReaderFactory,
-				Collection<String> classNames) throws IOException {
+				AutoConfigurationMetadata autoConfigurationMetadata,
+				Collection<String> classNames) {
 			for (String className : classNames) {
-				MetadataReader metadataReader = metadataReaderFactory
-						.getMetadataReader(className);
-				this.classes.put(className, new AutoConfigurationClass(metadataReader));
+				this.classes.put(className, new AutoConfigurationClass(className,
+						metadataReaderFactory, autoConfigurationMetadata));
 			}
 		}
 
@@ -132,29 +137,65 @@ class AutoConfigurationSorter {
 
 	private static class AutoConfigurationClass {
 
-		private final AnnotationMetadata metadata;
+		private final String className;
 
-		AutoConfigurationClass(MetadataReader metadataReader) {
-			this.metadata = metadataReader.getAnnotationMetadata();
-		}
+		private final MetadataReaderFactory metadataReaderFactory;
 
-		public int getOrder() {
-			Map<String, Object> orderedAnnotation = this.metadata
-					.getAnnotationAttributes(AutoConfigureOrder.class.getName());
-			return (orderedAnnotation == null ? Ordered.LOWEST_PRECEDENCE
-					: (Integer) orderedAnnotation.get("value"));
+		private final AutoConfigurationMetadata autoConfigurationMetadata;
+
+		private AnnotationMetadata annotationMetadata;
+
+		private final Set<String> before;
+
+		private final Set<String> after;
+
+		AutoConfigurationClass(String className,
+				MetadataReaderFactory metadataReaderFactory,
+				AutoConfigurationMetadata autoConfigurationMetadata) {
+			this.className = className;
+			this.metadataReaderFactory = metadataReaderFactory;
+			this.autoConfigurationMetadata = autoConfigurationMetadata;
+			this.before = readBefore();
+			this.after = readAfter();
 		}
 
 		public Set<String> getBefore() {
-			return getAnnotationValue(AutoConfigureBefore.class);
+			return this.before;
 		}
 
 		public Set<String> getAfter() {
+			return this.after;
+		}
+
+		private int getOrder() {
+			if (this.autoConfigurationMetadata.wasProcessed(this.className)) {
+				return this.autoConfigurationMetadata.getInteger(this.className,
+						"AutoConfigureOrder", Ordered.LOWEST_PRECEDENCE);
+			}
+			Map<String, Object> attributes = getAnnotationMetadata()
+					.getAnnotationAttributes(AutoConfigureOrder.class.getName());
+			return (attributes == null ? Ordered.LOWEST_PRECEDENCE
+					: (Integer) attributes.get("value"));
+		}
+
+		private Set<String> readBefore() {
+			if (this.autoConfigurationMetadata.wasProcessed(this.className)) {
+				return this.autoConfigurationMetadata.getSet(this.className,
+						"AutoConfigureBefore", Collections.<String>emptySet());
+			}
+			return getAnnotationValue(AutoConfigureBefore.class);
+		}
+
+		private Set<String> readAfter() {
+			if (this.autoConfigurationMetadata.wasProcessed(this.className)) {
+				return this.autoConfigurationMetadata.getSet(this.className,
+						"AutoConfigureAfter", Collections.<String>emptySet());
+			}
 			return getAnnotationValue(AutoConfigureAfter.class);
 		}
 
 		private Set<String> getAnnotationValue(Class<?> annotation) {
-			Map<String, Object> attributes = this.metadata
+			Map<String, Object> attributes = getAnnotationMetadata()
 					.getAnnotationAttributes(annotation.getName(), true);
 			if (attributes == null) {
 				return Collections.emptySet();
@@ -165,6 +206,21 @@ class AutoConfigurationSorter {
 			return value;
 		}
 
+		private AnnotationMetadata getAnnotationMetadata() {
+			if (this.annotationMetadata == null) {
+				try {
+					MetadataReader metadataReader = this.metadataReaderFactory
+							.getMetadataReader(this.className);
+					this.annotationMetadata = metadataReader.getAnnotationMetadata();
+				}
+				catch (IOException ex) {
+					throw new IllegalStateException(
+							"Unable to read meta-data for class " + this.className, ex);
+				}
+			}
+			return this.annotationMetadata;
+		}
+
 	}
 
 }

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/AutoConfigurationSorterTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -17,7 +17,10 @@
 package org.springframework.boot.autoconfigure;
 
 import java.util.Arrays;
+import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Properties;
+import java.util.Set;
 
 import org.junit.Before;
 import org.junit.Rule;
@@ -26,8 +29,12 @@ import org.junit.rules.ExpectedException;
 
 import org.springframework.core.Ordered;
 import org.springframework.core.type.classreading.CachingMetadataReaderFactory;
+import org.springframework.core.type.classreading.MetadataReaderFactory;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.StringUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
 
 /**
  * Tests for {@link AutoConfigurationSorter}.
@@ -67,9 +74,13 @@ public class AutoConfigurationSorterTests {
 
 	private AutoConfigurationSorter sorter;
 
+	private AutoConfigurationMetadata autoConfigurationMetadata = mock(
+			AutoConfigurationMetadata.class);
+
 	@Before
 	public void setup() {
-		this.sorter = new AutoConfigurationSorter(new CachingMetadataReaderFactory());
+		this.sorter = new AutoConfigurationSorter(new CachingMetadataReaderFactory(),
+				this.autoConfigurationMetadata);
 	}
 
 	@Test
@@ -132,6 +143,56 @@ public class AutoConfigurationSorterTests {
 		this.sorter.getInPriorityOrder(Arrays.asList(A, B, C, D));
 	}
 
+	@Test
+	public void usesAnnotationPropertiesWhenPossible() throws Exception {
+		MetadataReaderFactory readerFactory = mock(MetadataReaderFactory.class);
+		this.autoConfigurationMetadata = getAutoConfigurationMetadata(A2, B, C, W2, X);
+		this.sorter = new AutoConfigurationSorter(readerFactory,
+				this.autoConfigurationMetadata);
+		List<String> actual = this.sorter
+				.getInPriorityOrder(Arrays.asList(A2, B, C, W2, X));
+		assertThat(actual).containsExactly(C, W2, B, A2, X);
+	}
+
+	private AutoConfigurationMetadata getAutoConfigurationMetadata(String... classNames)
+			throws Exception {
+		Properties properties = new Properties();
+		for (String className : classNames) {
+			Class<?> type = ClassUtils.forName(className, null);
+			properties.put(type.getName(), "");
+			AutoConfigureOrder order = type
+					.getDeclaredAnnotation(AutoConfigureOrder.class);
+			if (order != null) {
+				properties.put(className + ".AutoConfigureOrder",
+						String.valueOf(order.value()));
+			}
+			AutoConfigureBefore autoConfigureBefore = type
+					.getDeclaredAnnotation(AutoConfigureBefore.class);
+			if (autoConfigureBefore != null) {
+				properties.put(className + ".AutoConfigureBefore",
+						merge(autoConfigureBefore.value(), autoConfigureBefore.name()));
+			}
+			AutoConfigureAfter autoConfigureAfter = type
+					.getDeclaredAnnotation(AutoConfigureAfter.class);
+			if (autoConfigureAfter != null) {
+				properties.put(className + ".AutoConfigureAfter",
+						merge(autoConfigureAfter.value(), autoConfigureAfter.name()));
+			}
+		}
+		return AutoConfigurationMetadataLoader.loadMetadata(properties);
+	}
+
+	private String merge(Class<?>[] value, String[] name) {
+		Set<String> items = new LinkedHashSet<String>();
+		for (Class<?> type : value) {
+			items.add(type.getName());
+		}
+		for (String type : name) {
+			items.add(type);
+		}
+		return StringUtils.collectionToCommaDelimitedString(items);
+	}
+
 	@AutoConfigureOrder(Ordered.LOWEST_PRECEDENCE)
 	public static class OrderLowest {
 

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/TestAutoConfigurationSorter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.boot.autoconfigure;
 
+import java.util.Properties;
+
 import org.springframework.core.type.classreading.MetadataReaderFactory;
 
 /**
@@ -26,7 +28,8 @@ import org.springframework.core.type.classreading.MetadataReaderFactory;
 public class TestAutoConfigurationSorter extends AutoConfigurationSorter {
 
 	public TestAutoConfigurationSorter(MetadataReaderFactory metadataReaderFactory) {
-		super(metadataReaderFactory);
+		super(metadataReaderFactory,
+				AutoConfigurationMetadataLoader.loadMetadata(new Properties()));
 	}
 
 }