DATADOC-199 - Added caching for MongoPersistentProperty.isIdProperty and ….getFieldName.

Continuous field and annotation lookups in those methods have turned out to be some hotspots in performance tests. Added a CachingMongoPersistentProperty that delegates to the actual implementation once and caching it.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/mapping/CachingMongoPersistentProperty.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2011 by the original author(s).
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.core.mapping;
+
+import java.beans.PropertyDescriptor;
+import java.lang.reflect.Field;
+
+import org.springframework.data.mapping.model.SimpleTypeHolder;
+
+/**
+ * {@link MongoPersistentProperty} caching access to {@link #isIdProperty()} and {@link #getFieldName()}.
+ * 
+ * @author Oliver Gierke
+ */
+public class CachingMongoPersistentProperty extends BasicMongoPersistentProperty {
+
+	private Boolean isIdProperty;
+	private String fieldName;
+
+	/**
+	 * Creates a new {@link CachingMongoPersistentProperty}.
+	 * 
+	 * @param field
+	 * @param propertyDescriptor
+	 * @param owner
+	 * @param simpleTypeHolder
+	 */
+	public CachingMongoPersistentProperty(Field field, PropertyDescriptor propertyDescriptor,
+			MongoPersistentEntity<?> owner, SimpleTypeHolder simpleTypeHolder) {
+		super(field, propertyDescriptor, owner, simpleTypeHolder);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.mapping.BasicMongoPersistentProperty#isIdProperty()
+	 */
+	@Override
+	public boolean isIdProperty() {
+
+		if (this.isIdProperty == null) {
+			this.isIdProperty = super.isIdProperty();
+		}
+		
+		return this.isIdProperty;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.mapping.BasicMongoPersistentProperty#getFieldName()
+	 */
+	@Override
+	public String getFieldName() {
+
+		if (this.fieldName == null) {
+			this.fieldName = super.getFieldName();
+		}
+		
+		return super.getFieldName();
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/mapping/MongoMappingContext.java

@@ -43,7 +43,7 @@ public class MongoMappingContext extends AbstractMappingContext<BasicMongoPersis
 	@Override
 	public MongoPersistentProperty createPersistentProperty(Field field, PropertyDescriptor descriptor,
 			BasicMongoPersistentEntity<?> owner, SimpleTypeHolder simpleTypeHolder) {
-		return new BasicMongoPersistentProperty(field, descriptor, owner, simpleTypeHolder);
+		return new CachingMongoPersistentProperty(field, descriptor, owner, simpleTypeHolder);
 	}
 
 	/* (non-Javadoc)