/*
* 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.SingleResultCallback;
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 com.mongodb.operation.OperationHelper.AsyncCallableWithConnection;
import org.bson.BsonBoolean;
import org.bson.BsonDocument;
import org.bson.BsonInt32;
import org.bson.BsonJavaScript;
import org.bson.BsonNull;
import org.bson.BsonString;
import org.bson.BsonValue;
import org.bson.codecs.BsonDocumentCodec;
import org.bson.codecs.Decoder;
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.DocumentHelper.putIfNotZero;
import static com.mongodb.operation.DocumentHelper.putIfTrue;
import static com.mongodb.operation.OperationHelper.CallableWithConnectionAndSource;
import static com.mongodb.operation.OperationHelper.LOGGER;
import static com.mongodb.operation.OperationHelper.validateReadConcernAndCollation;
import static com.mongodb.operation.OperationHelper.releasingCallback;
import static com.mongodb.operation.OperationHelper.withConnection;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
/**
* <p>Operation that runs a Map Reduce against a MongoDB instance. This operation only supports "inline" results, i.e. the results will be
* returned as a result of running this operation.</p>
*
* <p>To run a map reduce operation into a given collection, use {@code MapReduceToCollectionOperation}.</p>
*
* @param <T> the operations result type.
* @mongodb.driver.manual reference/command/mapReduce/ mapReduce
* @mongodb.driver.manual core/map-reduce Map-Reduce
* @since 3.0
*/
public class MapReduceWithInlineResultsOperation<T> implements AsyncReadOperation<MapReduceAsyncBatchCursor<T>>,
ReadOperation<MapReduceBatchCursor<T>> {
private final MongoNamespace namespace;
private final BsonJavaScript mapFunction;
private final BsonJavaScript reduceFunction;
private final Decoder<T> decoder;
private BsonJavaScript finalizeFunction;
private BsonDocument scope;
private BsonDocument filter;
private BsonDocument sort;
private int limit;
private boolean jsMode;
private boolean verbose;
private long maxTimeMS;
private ReadConcern readConcern = ReadConcern.DEFAULT;
private Collation collation;
/**
* Construct a MapReduceOperation with all the criteria it needs to execute.
*
* @param namespace the database and collection namespace for the operation.
* @param mapFunction a JavaScript function that associates or "maps" a value with a key and emits the key and value pair.
* @param reduceFunction a JavaScript function that "reduces" to a single object all the values associated with a particular key.
* @param decoder the decoder for the result documents.
* @mongodb.driver.manual reference/command/mapReduce/ mapReduce
*/
public MapReduceWithInlineResultsOperation(final MongoNamespace namespace, final BsonJavaScript mapFunction,
final BsonJavaScript reduceFunction, final Decoder<T> decoder) {
this.namespace = notNull("namespace", namespace);
this.mapFunction = notNull("mapFunction", mapFunction);
this.reduceFunction = notNull("reduceFunction", reduceFunction);
this.decoder = notNull("decoder", decoder);
}
/**
* Gets the namespace.
*
* @return the namespace
* @since 3.4
*/
public MongoNamespace getNamespace() {
return namespace;
}
/**
* Gets the decoder used to decode the result documents.
*
* @return the decoder
* @since 3.4
*/
public Decoder<T> getDecoder() {
return decoder;
}
/**
* Gets the JavaScript function that associates or "maps" a value with a key and emits the key and value pair.
*
* @return the JavaScript function that associates or "maps" a value with a key and emits the key and value pair.
*/
public BsonJavaScript getMapFunction() {
return mapFunction;
}
/**
* Gets the JavaScript function that "reduces" to a single object all the values associated with a particular key.
*
* @return the JavaScript function that "reduces" to a single object all the values associated with a particular key.
*/
public BsonJavaScript getReduceFunction() {
return reduceFunction;
}
/**
* Gets the JavaScript function that follows the reduce method and modifies the output. Default is null
*
* @return the JavaScript function that follows the reduce method and modifies the output.
* @mongodb.driver.manual reference/command/mapReduce/#mapreduce-finalize-cmd Requirements for the finalize Function
*/
public BsonJavaScript getFinalizeFunction() {
return finalizeFunction;
}
/**
* Sets the JavaScript function that follows the reduce method and modifies the output.
*
* @param finalizeFunction the JavaScript function that follows the reduce method and modifies the output.
* @return this
* @mongodb.driver.manual reference/command/mapReduce/#mapreduce-finalize-cmd Requirements for the finalize Function
*/
public MapReduceWithInlineResultsOperation<T> finalizeFunction(final BsonJavaScript finalizeFunction) {
this.finalizeFunction = finalizeFunction;
return this;
}
/**
* Gets the global variables that are accessible in the map, reduce and finalize functions.
*
* @return the global variables that are accessible in the map, reduce and finalize functions.
* @mongodb.driver.manual reference/command/mapReduce Scope
*/
public BsonDocument getScope() {
return scope;
}
/**
* Sets the global variables that are accessible in the map, reduce and finalize functions.
*
* @param scope the global variables that are accessible in the map, reduce and finalize functions.
* @return this
* @mongodb.driver.manual reference/command/mapReduce mapReduce
*/
public MapReduceWithInlineResultsOperation<T> scope(final BsonDocument scope) {
this.scope = scope;
return this;
}
/**
* Gets the query filter.
*
* @return the query filter
* @mongodb.driver.manual reference/method/db.collection.find/ Filter
*/
public BsonDocument getFilter() {
return filter;
}
/**
* Sets the filter to apply to the query.
*
* @param filter the filter to apply to the query.
* @return this
* @mongodb.driver.manual reference/method/db.collection.find/ Filter
*/
public MapReduceWithInlineResultsOperation<T> filter(final BsonDocument filter) {
this.filter = filter;
return this;
}
/**
* Gets the sort criteria to apply to the query. The default is null, which means that the documents will be returned in an undefined
* order.
*
* @return a document describing the sort criteria
* @mongodb.driver.manual reference/method/cursor.sort/ Sort
*/
public BsonDocument getSort() {
return sort;
}
/**
* Sets the sort criteria to apply to the query.
*
* @param sort the sort criteria, which may be null.
* @return this
* @mongodb.driver.manual reference/method/cursor.sort/ Sort
*/
public MapReduceWithInlineResultsOperation<T> sort(final BsonDocument sort) {
this.sort = sort;
return this;
}
/**
* Gets the limit to apply. The default is null.
*
* @return the limit
* @mongodb.driver.manual reference/method/cursor.limit/#cursor.limit Limit
*/
public int getLimit() {
return limit;
}
/**
* Sets the limit to apply.
*
* @param limit the limit, which may be null
* @return this
* @mongodb.driver.manual reference/method/cursor.limit/#cursor.limit Limit
*/
public MapReduceWithInlineResultsOperation<T> limit(final int limit) {
this.limit = limit;
return this;
}
/**
* Gets the flag that specifies whether to convert intermediate data into BSON format between the execution of the map and reduce
* functions. Defaults to false.
*
* @return jsMode
* @mongodb.driver.manual reference/command/mapReduce mapReduce
*/
public boolean isJsMode() {
return jsMode;
}
/**
* Sets the flag that specifies whether to convert intermediate data into BSON format between the execution of the map and reduce
* functions. Defaults to false.
*
* @param jsMode the flag that specifies whether to convert intermediate data into BSON format between the execution of the map and
* reduce functions
* @return jsMode
* @mongodb.driver.manual reference/command/mapReduce mapReduce
*/
public MapReduceWithInlineResultsOperation<T> jsMode(final boolean jsMode) {
this.jsMode = jsMode;
return this;
}
/**
* Gets whether to include the timing information in the result information. Defaults to true.
*
* @return whether to include the timing information in the result information
*/
public boolean isVerbose() {
return verbose;
}
/**
* Sets whether to include the timing information in the result information.
*
* @param verbose whether to include the timing information in the result information.
* @return this
*/
public MapReduceWithInlineResultsOperation<T> verbose(final boolean verbose) {
this.verbose = verbose;
return this;
}
/**
* Returns the collation options
*
* @return the collation options
* @since 3.4
* @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.server.release 3.4
*/
public MapReduceWithInlineResultsOperation<T> collation(final Collation collation) {
this.collation = collation;
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 MapReduceWithInlineResultsOperation<T> maxTime(final long maxTime, final TimeUnit timeUnit) {
notNull("timeUnit", timeUnit);
this.maxTimeMS = TimeUnit.MILLISECONDS.convert(maxTime, timeUnit);
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 MapReduceWithInlineResultsOperation<T> readConcern(final ReadConcern readConcern) {
this.readConcern = notNull("readConcern", readConcern);
return this;
}
/**
* Executing this will return a cursor with your results and the statistics in.
*
* @param binding the binding
* @return a MapReduceCursor that can be iterated over to find all the results of the Map Reduce operation.
*/
@Override
@SuppressWarnings("unchecked")
public MapReduceBatchCursor<T> execute(final ReadBinding binding) {
return withConnection(binding, new CallableWithConnectionAndSource<MapReduceBatchCursor<T>>() {
@Override
public MapReduceBatchCursor<T> call(final ConnectionSource source, final Connection connection) {
validateReadConcernAndCollation(connection, readConcern, collation);
return executeWrappedCommandProtocol(binding, namespace.getDatabaseName(), getCommand(),
CommandResultDocumentCodec.create(decoder, "results"),
connection, transformer(source, connection));
}
});
}
@Override
public void executeAsync(final AsyncReadBinding binding, final SingleResultCallback<MapReduceAsyncBatchCursor<T>> callback) {
withConnection(binding, new AsyncCallableWithConnection() {
@Override
public void call(final AsyncConnection connection, final Throwable t) {
SingleResultCallback<MapReduceAsyncBatchCursor<T>> errHandlingCallback = errorHandlingCallback(callback, LOGGER);
if (t != null) {
errHandlingCallback.onResult(null, t);
} else {
final SingleResultCallback<MapReduceAsyncBatchCursor<T>> wrappedCallback = releasingCallback(
errHandlingCallback, connection);
validateReadConcernAndCollation(connection, readConcern, collation, new AsyncCallableWithConnection() {
@Override
public void call(final AsyncConnection connection, final Throwable t) {
if (t != null) {
wrappedCallback.onResult(null, t);
} else {
executeWrappedCommandProtocolAsync(binding, namespace.getDatabaseName(), getCommand(),
CommandResultDocumentCodec.create(decoder, "results"), connection, asyncTransformer(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 createExplainableOperation(explainVerbosity);
}
/**
* 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 createExplainableOperation(explainVerbosity);
}
private CommandReadOperation<BsonDocument> createExplainableOperation(final ExplainVerbosity explainVerbosity) {
return new CommandReadOperation<BsonDocument>(namespace.getDatabaseName(),
ExplainHelper.asExplainCommand(getCommand(), explainVerbosity),
new BsonDocumentCodec());
}
private CommandTransformer<BsonDocument, MapReduceBatchCursor<T>> transformer(final ConnectionSource source,
final Connection connection) {
return new CommandTransformer<BsonDocument, MapReduceBatchCursor<T>>() {
@Override
public MapReduceBatchCursor<T> apply(final BsonDocument result, final ServerAddress serverAddress) {
return new MapReduceInlineResultsCursor<T>(createQueryResult(result, connection.getDescription()), decoder, source,
MapReduceHelper.createStatistics(result));
}
};
}
private CommandTransformer<BsonDocument, MapReduceAsyncBatchCursor<T>> asyncTransformer(final AsyncConnection connection) {
return new CommandTransformer<BsonDocument, MapReduceAsyncBatchCursor<T>>() {
@Override
public MapReduceAsyncBatchCursor<T> apply(final BsonDocument result, final ServerAddress serverAddress) {
return new MapReduceInlineResultsAsyncCursor<T>(createQueryResult(result, connection.getDescription()),
MapReduceHelper.createStatistics(result));
}
};
}
private BsonDocument getCommand() {
BsonDocument commandDocument = new BsonDocument("mapreduce", new BsonString(namespace.getCollectionName()))
.append("map", getMapFunction())
.append("reduce", getReduceFunction())
.append("out", new BsonDocument("inline", new BsonInt32(1)))
.append("query", asValueOrNull(getFilter()))
.append("sort", asValueOrNull(getSort()))
.append("finalize", asValueOrNull(getFinalizeFunction()))
.append("scope", asValueOrNull(getScope()))
.append("verbose", BsonBoolean.valueOf(isVerbose()));
putIfNotZero(commandDocument, "limit", getLimit());
putIfNotZero(commandDocument, "maxTimeMS", getMaxTime(MILLISECONDS));
putIfTrue(commandDocument, "jsMode", isJsMode());
if (!readConcern.isServerDefault()) {
commandDocument.put("readConcern", readConcern.asDocument());
}
if (collation != null) {
commandDocument.put("collation", collation.asDocument());
}
return commandDocument;
}
@SuppressWarnings("unchecked")
private QueryResult<T> createQueryResult(final BsonDocument result, final ConnectionDescription description) {
return new QueryResult<T>(namespace, BsonDocumentWrapperHelper.<T>toList(result, "results"), 0,
description.getServerAddress());
}
private static BsonValue asValueOrNull(final BsonValue value) {
return value == null ? BsonNull.VALUE : value;
}
}