DATAMONGO-1733 - Added benchmark for projections in FluentMongoOperations.

Original pull request: spring-projects#486.

Author: christophstrobl

spring-data-mongodb-benchmarks/src/main/java/org/springframework/data/mongodb/core/ProjectionsBenchmark.java

@@ -0,0 +1,180 @@
+/*
+ * Copyright 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.
+ * 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;
+
+import org.bson.Document;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.TearDown;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mongodb.core.ExecutableFindOperation.FindOperationWithQuery;
+import org.springframework.data.mongodb.core.ExecutableFindOperation.TerminatingFindOperation;
+import org.springframework.data.mongodb.core.mapping.Field;
+import org.springframework.data.mongodb.core.query.BasicQuery;
+import org.springframework.data.mongodb.microbenchmark.AbstractMicrobenchmark;
+
+import com.mongodb.MongoClient;
+import com.mongodb.ServerAddress;
+import com.mongodb.client.MongoCollection;
+
+/**
+ * @author Christoph Strobl
+ */
+public class ProjectionsBenchmark extends AbstractMicrobenchmark {
+
+	private static final String DB_NAME = "projections-benchmark";
+	private static final String COLLECTION_NAME = "projections";
+
+	private MongoTemplate template;
+	private MongoClient client;
+	private MongoCollection<Document> mongoCollection;
+
+	private Person source;
+
+	private FindOperationWithQuery<Person> asPerson;
+	private FindOperationWithQuery<DtoProjection> asDtoProjection;
+	private FindOperationWithQuery<ClosedProjection> asClosedProjection;
+	private FindOperationWithQuery<OpenProjection> asOpenProjection;
+
+	private TerminatingFindOperation<Person> asPersonWithFieldsRestriction;
+	private Document fields = new Document("firstname", 1);
+
+	@Setup
+	public void setUp() {
+
+		client = new MongoClient(new ServerAddress());
+		template = new MongoTemplate(client, DB_NAME);
+
+		source = new Person();
+		source.firstname = "luke";
+		source.lastname = "skywalker";
+
+		source.address = new Address();
+		source.address.street = "melenium falcon 1";
+		source.address.city = "deathstar";
+
+		template.save(source, COLLECTION_NAME);
+
+		asPerson = template.query(Person.class).inCollection(COLLECTION_NAME);
+		asDtoProjection = template.query(Person.class).inCollection(COLLECTION_NAME).as(DtoProjection.class);
+		asClosedProjection = template.query(Person.class).inCollection(COLLECTION_NAME).as(ClosedProjection.class);
+		asOpenProjection = template.query(Person.class).inCollection(COLLECTION_NAME).as(OpenProjection.class);
+
+		asPersonWithFieldsRestriction = template.query(Person.class).inCollection(COLLECTION_NAME)
+				.matching(new BasicQuery(new Document(), fields));
+
+		mongoCollection = client.getDatabase(DB_NAME).getCollection(COLLECTION_NAME);
+	}
+
+	@TearDown
+	public void tearDown() {
+
+		client.dropDatabase(DB_NAME);
+		client.close();
+	}
+
+	/**
+	 * Set the baseline for comparison by using the plain MongoDB java driver api without any additional fluff.
+	 *
+	 * @return
+	 */
+	@Benchmark // DATAMONGO-1733
+	public Object baseline() {
+		return mongoCollection.find().first();
+	}
+
+	/**
+	 * Read into the domain type including all fields.
+	 *
+	 * @return
+	 */
+	@Benchmark // DATAMONGO-1733
+	public Object readIntoDomainType() {
+		return asPerson.all();
+	}
+
+	/**
+	 * Read into the domain type but restrict query to only return one field.
+	 *
+	 * @return
+	 */
+	@Benchmark // DATAMONGO-1733
+	public Object readIntoDomainTypeRestrictingToOneField() {
+		return asPersonWithFieldsRestriction.all();
+	}
+
+	/**
+	 * Read into dto projection that only needs to map one field back.
+	 *
+	 * @return
+	 */
+	@Benchmark // DATAMONGO-1733
+	public Object readIntoDtoProjectionWithOneField() {
+		return asDtoProjection.all();
+	}
+
+	/**
+	 * Read into closed interface projection.
+	 *
+	 * @return
+	 */
+	@Benchmark // DATAMONGO-1733
+	public Object readIntoClosedProjectionWithOneField() {
+		return asClosedProjection.all();
+	}
+
+	/**
+	 * Read into an open projection backed by the mapped domain object.
+	 *
+	 * @return
+	 */
+	@Benchmark // DATAMONGO-1733
+	public Object readIntoOpenProjection() {
+		return asOpenProjection.all();
+	}
+
+	static class Person {
+
+		@Id String id;
+		String firstname;
+		String lastname;
+		Address address;
+	}
+
+	static class Address {
+
+		String city;
+		String street;
+	}
+
+	static class DtoProjection {
+
+		@Field("firstname") String name;
+	}
+
+	static interface ClosedProjection {
+
+		String getFirstname();
+	}
+
+	static interface OpenProjection {
+
+		@Value("#{target.firstname}")
+		String name();
+	}
+
+}