/*
* Copyright (c) 2008-2014 MongoDB, Inc.
*
* 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 com.mongodb.operation;
import com.mongodb.ExplainVerbosity;
import com.mongodb.MongoNamespace;
import com.mongodb.ReadConcern;
import com.mongodb.ServerAddress;
import com.mongodb.async.AsyncBatchCursor;
import com.mongodb.async.SingleResultCallback;
import com.mongodb.binding.AsyncConnectionSource;
import com.mongodb.binding.AsyncReadBinding;
import com.mongodb.binding.ConnectionSource;
import com.mongodb.binding.ReadBinding;
import com.mongodb.client.model.Collation;
import com.mongodb.connection.AsyncConnection;
import com.mongodb.connection.Connection;
import com.mongodb.connection.ConnectionDescription;
import com.mongodb.connection.QueryResult;
import com.mongodb.operation.CommandOperationHelper.CommandTransformer;
import org.bson.BsonArray;
import org.bson.BsonBoolean;
import org.bson.BsonDocument;
import org.bson.BsonInt32;
import org.bson.BsonInt64;
import org.bson.BsonString;
import org.bson.codecs.Decoder;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.TimeUnit;
import static com.mongodb.assertions.Assertions.notNull;
import static com.mongodb.internal.async.ErrorHandlingResultCallback.errorHandlingCallback;
import static com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol;
import static com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocolAsync;
import static com.mongodb.operation.OperationHelper.AsyncCallableWithConnectionAndSource;
import static com.mongodb.operation.OperationHelper.CallableWithConnectionAndSource;
import static com.mongodb.operation.OperationHelper.LOGGER;
import static com.mongodb.operation.OperationHelper.cursorDocumentToQueryResult;
import static com.mongodb.operation.OperationHelper.releasingCallback;
import static com.mongodb.operation.OperationHelper.serverIsAtLeastVersionThreeDotSix;
import static com.mongodb.operation.OperationHelper.serverIsAtLeastVersionTwoDotSix;
import static com.mongodb.operation.OperationHelper.validateReadConcernAndCollation;
import static com.mongodb.operation.OperationHelper.withConnection;
/**
* An operation that executes an aggregation query.
*
* @param <T> the operations result type.
* @mongodb.driver.manual aggregation/ Aggregation
* @mongodb.server.release 2.2
* @since 3.0
*/
public class AggregateOperation<T> implements AsyncReadOperation<AsyncBatchCursor<T>>, ReadOperation<BatchCursor<T>> {
private static final String RESULT = "result";
private static final String CURSOR = "cursor";
private static final String FIRST_BATCH = "firstBatch";
private static final List<String> FIELD_NAMES_WITH_RESULT = Arrays.asList(RESULT, FIRST_BATCH);
private final MongoNamespace namespace;
private final List<BsonDocument> pipeline;
private final Decoder<T> decoder;
private Boolean allowDiskUse;
private Integer batchSize;
private long maxTimeMS;
private Boolean useCursor;
private ReadConcern readConcern = ReadConcern.DEFAULT;
private Collation collation;
/**
* Construct a new instance.
*
* @param namespace the database and collection namespace for the operation.
* @param pipeline the aggregation pipeline.
* @param decoder the decoder for the result documents.
*/
public AggregateOperation(final MongoNamespace namespace, final List<BsonDocument> pipeline, final Decoder<T> decoder) {
this.namespace = notNull("namespace", namespace);
this.pipeline = notNull("pipeline", pipeline);
this.decoder = notNull("decoder", decoder);
}
/**
* Gets the aggregation pipeline.
*
* @return the pipeline
* @mongodb.driver.manual core/aggregation-introduction/#aggregation-pipelines Aggregation Pipeline
*/
public List<BsonDocument> getPipeline() {
return pipeline;
}
/**
* Whether writing to temporary files is enabled. A null value indicates that it's unspecified.
*
* @return true if writing to temporary files is enabled
* @mongodb.driver.manual reference/command/aggregate/ Aggregation
* @mongodb.server.release 2.6
*/
public Boolean getAllowDiskUse() {
return allowDiskUse;
}
/**
* Enables writing to temporary files. A null value indicates that it's unspecified.
*
* @param allowDiskUse true if writing to temporary files is enabled
* @return this
* @mongodb.driver.manual reference/command/aggregate/ Aggregation
* @mongodb.server.release 2.6
*/
public AggregateOperation<T> allowDiskUse(final Boolean allowDiskUse) {
this.allowDiskUse = allowDiskUse;
return this;
}
/**
* Gets the number of documents to return per batch. Default to 0, which indicates that the server chooses an appropriate batch size.
*
* @return the batch size, which may be null
* @mongodb.driver.manual reference/method/cursor.batchSize/#cursor.batchSize Batch Size
*/
public Integer getBatchSize() {
return batchSize;
}
/**
* Sets the number of documents to return per batch.
*
* @param batchSize the batch size
* @return this
* @mongodb.driver.manual reference/method/cursor.batchSize/#cursor.batchSize Batch Size
*/
public AggregateOperation<T> batchSize(final Integer batchSize) {
this.batchSize = batchSize;
return this;
}
/**
* Gets the maximum execution time on the server for this operation. The default is 0, which places no limit on the execution time.
*
* @param timeUnit the time unit to return the result in
* @return the maximum execution time in the given time unit
* @mongodb.driver.manual reference/method/cursor.maxTimeMS/#cursor.maxTimeMS Max Time
*/
public long getMaxTime(final TimeUnit timeUnit) {
notNull("timeUnit", timeUnit);
return timeUnit.convert(maxTimeMS, TimeUnit.MILLISECONDS);
}
/**
* Sets the maximum execution time on the server for this operation.
*
* @param maxTime the max time
* @param timeUnit the time unit, which may not be null
* @return this
* @mongodb.driver.manual reference/method/cursor.maxTimeMS/#cursor.maxTimeMS Max Time
*/
public AggregateOperation<T> maxTime(final long maxTime, final TimeUnit timeUnit) {
notNull("timeUnit", timeUnit);
this.maxTimeMS = TimeUnit.MILLISECONDS.convert(maxTime, timeUnit);
return this;
}
/**
* Gets whether the server should use a cursor to return results. The default value is null, in which case a cursor will be used if the
* server supports it.
*
* @return whether the server should use a cursor to return results
* @mongodb.driver.manual reference/command/aggregate/ Aggregation
* @mongodb.server.release 2.6
* @deprecated There is no replacement for this. Applications can assume that the driver will use a cursor for server versions
* that support it (>= 2.6). The driver will ignore this as of MongoDB 3.6, which does not support inline results for the aggregate
* command.
*/
@Deprecated
public Boolean getUseCursor() {
return useCursor;
}
/**
* Sets whether the server should use a cursor to return results.
*
* @param useCursor whether the server should use a cursor to return results
* @return this
* @mongodb.driver.manual reference/command/aggregate/ Aggregation
* @mongodb.server.release 2.6
* @deprecated There is no replacement for this. Applications can assume that the driver will use a cursor for server versions
* that support it (>= 2.6). The driver will ignore this as of MongoDB 3.6, which does not support inline results for the aggregate
* command.
*/
@Deprecated
public AggregateOperation<T> useCursor(final Boolean useCursor) {
this.useCursor = useCursor;
return this;
}
/**
* Gets the read concern
*
* @return the read concern
* @since 3.2
* @mongodb.driver.manual reference/readConcern/ Read Concern
*/
public ReadConcern getReadConcern() {
return readConcern;
}
/**
* Sets the read concern
* @param readConcern the read concern
* @return this
* @since 3.2
* @mongodb.driver.manual reference/readConcern/ Read Concern
*/
public AggregateOperation<T> readConcern(final ReadConcern readConcern) {
this.readConcern = notNull("readConcern", readConcern);
return this;
}
/**
* Returns the collation options
*
* @return the collation options
* @since 3.4
* @mongodb.driver.manual reference/command/aggregate/ Aggregation
* @mongodb.server.release 3.4
*/
public Collation getCollation() {
return collation;
}
/**
* Sets the collation options
*
* <p>A null value represents the server default.</p>
* @param collation the collation options to use
* @return this
* @since 3.4
* @mongodb.driver.manual reference/command/aggregate/ Aggregation
* @mongodb.server.release 3.4
*/
public AggregateOperation<T> collation(final Collation collation) {
this.collation = collation;
return this;
}
@Override
public BatchCursor<T> execute(final ReadBinding binding) {
return withConnection(binding, new CallableWithConnectionAndSource<BatchCursor<T>>() {
@Override
public BatchCursor<T> call(final ConnectionSource source, final Connection connection) {
validateReadConcernAndCollation(connection, readConcern, collation);
return executeWrappedCommandProtocol(binding, namespace.getDatabaseName(), getCommand(connection.getDescription()),
CommandResultDocumentCodec.create(decoder, FIELD_NAMES_WITH_RESULT),
connection, transformer(source, connection));
}
});
}
@Override
public void executeAsync(final AsyncReadBinding binding, final SingleResultCallback<AsyncBatchCursor<T>> callback) {
withConnection(binding, new AsyncCallableWithConnectionAndSource() {
@Override
public void call(final AsyncConnectionSource source, final AsyncConnection connection, final Throwable t) {
SingleResultCallback<AsyncBatchCursor<T>> errHandlingCallback = errorHandlingCallback(callback, LOGGER);
if (t != null) {
errHandlingCallback.onResult(null, t);
} else {
final SingleResultCallback<AsyncBatchCursor<T>> wrappedCallback =
releasingCallback(errHandlingCallback, source, connection);
validateReadConcernAndCollation(source, connection, readConcern, collation,
new AsyncCallableWithConnectionAndSource() {
@Override
public void call(final AsyncConnectionSource source, final AsyncConnection connection, final Throwable t) {
if (t != null) {
wrappedCallback.onResult(null, t);
} else {
executeWrappedCommandProtocolAsync(binding, namespace.getDatabaseName(),
getCommand(connection.getDescription()),
CommandResultDocumentCodec.create(decoder, FIELD_NAMES_WITH_RESULT),
connection, asyncTransformer(source, connection), wrappedCallback);
}
}
});
}
}
});
}
/**
* Gets an operation whose execution explains this operation.
*
* @param explainVerbosity the explain verbosity
* @return a read operation that when executed will explain this operation
*/
public ReadOperation<BsonDocument> asExplainableOperation(final ExplainVerbosity explainVerbosity) {
return new AggregateExplainOperation(namespace, pipeline)
.allowDiskUse(allowDiskUse)
.maxTime(maxTimeMS, TimeUnit.MILLISECONDS);
}
/**
* Gets an operation whose execution explains this operation.
*
* @param explainVerbosity the explain verbosity
* @return a read operation that when executed will explain this operation
*/
public AsyncReadOperation<BsonDocument> asExplainableOperationAsync(final ExplainVerbosity explainVerbosity) {
return new AggregateExplainOperation(namespace, pipeline)
.allowDiskUse(allowDiskUse)
.maxTime(maxTimeMS, TimeUnit.MILLISECONDS);
}
private boolean isInline(final ConnectionDescription description) {
return !serverIsAtLeastVersionThreeDotSix(description)
&& ((useCursor != null && !useCursor) || !serverIsAtLeastVersionTwoDotSix(description));
}
private BsonDocument getCommand(final ConnectionDescription description) {
BsonDocument commandDocument = new BsonDocument("aggregate", new BsonString(namespace.getCollectionName()));
commandDocument.put("pipeline", new BsonArray(pipeline));
if (maxTimeMS > 0) {
commandDocument.put("maxTimeMS", new BsonInt64(maxTimeMS));
}
if (!isInline(description)) {
BsonDocument cursor = new BsonDocument();
if (batchSize != null) {
cursor.put("batchSize", new BsonInt32(batchSize));
}
commandDocument.put(CURSOR, cursor);
}
if (allowDiskUse != null) {
commandDocument.put("allowDiskUse", BsonBoolean.valueOf(allowDiskUse));
}
if (!readConcern.isServerDefault()) {
commandDocument.put("readConcern", readConcern.asDocument());
}
if (collation != null) {
commandDocument.put("collation", collation.asDocument());
}
return commandDocument;
}
private QueryResult<T> createQueryResult(final BsonDocument result, final ConnectionDescription description) {
if (!isInline(description) || result.containsKey(CURSOR)) {
return cursorDocumentToQueryResult(result.getDocument(CURSOR), description.getServerAddress());
} else {
return new QueryResult<T>(namespace, BsonDocumentWrapperHelper.<T>toList(result, RESULT), 0L,
description.getServerAddress());
}
}
private CommandTransformer<BsonDocument, BatchCursor<T>> transformer(final ConnectionSource source, final Connection connection) {
return new CommandTransformer<BsonDocument, BatchCursor<T>>() {
@Override
public BatchCursor<T> apply(final BsonDocument result, final ServerAddress serverAddress) {
QueryResult<T> queryResult = createQueryResult(result, connection.getDescription());
return new QueryBatchCursor<T>(queryResult, 0, batchSize != null ? batchSize : 0, decoder, source);
}
};
}
private CommandTransformer<BsonDocument, AsyncBatchCursor<T>> asyncTransformer(final AsyncConnectionSource source,
final AsyncConnection connection) {
return new CommandTransformer<BsonDocument, AsyncBatchCursor<T>>() {
@Override
public AsyncBatchCursor<T> apply(final BsonDocument result, final ServerAddress serverAddress) {
QueryResult<T> queryResult = createQueryResult(result, connection.getDescription());
return new AsyncQueryBatchCursor<T>(queryResult, 0, batchSize != null ? batchSize : 0, 0, decoder, source, connection);
}
};
}
}