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/* * Copyright 2008-present 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; import com.mongodb.client.model.Collation; import com.mongodb.lang.Nullable; import java.util.Map; import java.util.concurrent.TimeUnit; import static java.util.concurrent.TimeUnit.MILLISECONDS; /** * This class groups the argument for a map/reduce operation and can build the underlying command object * * @mongodb.driver.manual applications/map-reduce Map-Reduce */ public class MapReduceCommand { private final String mapReduce; private final String map; private final String reduce; private String finalize; private ReadPreference readPreference; private final OutputType outputType; private final String outputCollection; private String outputDB; private final DBObject query; private DBObject sort; private int limit; private long maxTimeMS; private Map<String, Object> scope; private Boolean jsMode; private Boolean verbose; private Boolean bypassDocumentValidation; private Collation collation; /** * Represents the command for a map reduce operation Runs the command in REPLACE output type to a named collection * * @param inputCollection collection to use as the source documents to perform the map reduce operation. * @param map a JavaScript function that associates or "maps" a value with a key and emits the key and value pair. * @param reduce a JavaScript function that "reduces" to a single object all the values associated with a particular key. * @param outputCollection optional - leave null if want to get the result inline * @param type the type of output * @param query specifies the selection criteria using query operators for determining the documents input to the map * function. * @mongodb.driver.manual reference/command/mapReduce/ Map Reduce Command */ public MapReduceCommand(final DBCollection inputCollection, final String map, final String reduce, @Nullable final String outputCollection, final OutputType type, final DBObject query) { this.mapReduce = inputCollection.getName(); this.map = map; this.reduce = reduce; this.outputCollection = outputCollection; this.outputType = type; this.query = query; this.outputDB = null; this.verbose = true; } /** * Sets the verbosity of the MapReduce job, defaults to 'true' * * @param verbose The verbosity level. */ public void setVerbose(final Boolean verbose) { this.verbose = verbose; } /** * Gets the verbosity of the MapReduce job. * * @return the verbosity level. */ public Boolean isVerbose() { return verbose; } /** * Get the name of the collection the MapReduce will read from * * @return name of the collection the MapReduce will read from */ public String getInput() { return mapReduce; } /** * Get the map function, as a JS String * * @return the map function (as a JS String) */ public String getMap() { return map; } /** * Gets the reduce function, as a JS String * * @return the reduce function (as a JS String) */ public String getReduce() { return reduce; } /** * Gets the output target (name of collection to save to) This value is nullable only if OutputType is set to INLINE * * @return The outputCollection */ @Nullable public String getOutputTarget() { return outputCollection; } /** * Gets the OutputType for this instance. * * @return The outputType. */ public OutputType getOutputType() { return outputType; } /** * Gets the Finalize JS Function * * @return The finalize function (as a JS String). */ @Nullable public String getFinalize() { return finalize; } /** * Sets the Finalize JS Function * * @param finalize The finalize function (as a JS String) */ public void setFinalize(@Nullable final String finalize) { this.finalize = finalize; } /** * Gets the query to run for this MapReduce job * * @return The query object */ @Nullable public DBObject getQuery() { return query; } /** * Gets the (optional) sort specification object * * @return the Sort DBObject */ @Nullable public DBObject getSort() { return sort; } /** * Sets the (optional) sort specification object * * @param sort The sort specification object */ public void setSort(@Nullable final DBObject sort) { this.sort = sort; } /** * Gets the (optional) limit on input * * @return The limit specification object */ public int getLimit() { return limit; } /** * Sets the (optional) limit on input * * @param limit The limit specification object */ public void setLimit(final int limit) { this.limit = limit; } /** * Gets the max execution time for this command, in the given time unit. * * @param timeUnit the time unit to return the value in. * @return the maximum execution time * @mongodb.server.release 2.6 * @since 2.12.0 */ public long getMaxTime(final TimeUnit timeUnit) { return timeUnit.convert(maxTimeMS, MILLISECONDS); } /** * Sets the max execution time for this command, in the given time unit. * * @param maxTime the maximum execution time. A non-zero value requires a server version >= 2.6 * @param timeUnit the time unit that maxTime is specified in * @mongodb.server.release 2.6 * @since 2.12.0 */ public void setMaxTime(final long maxTime, final TimeUnit timeUnit) { this.maxTimeMS = MILLISECONDS.convert(maxTime, timeUnit); } /** * Gets the (optional) JavaScript scope * * @return The JavaScript scope */ @Nullable public Map<String, Object> getScope() { return scope; } /** * Sets the (optional) JavaScript scope * * @param scope The JavaScript scope */ public void setScope(@Nullable final Map<String, Object> scope) { this.scope = scope; } /** * Gets the (optional) JavaScript mode * * @return The JavaScript mode * @since 2.13 */ @Nullable public Boolean getJsMode() { return jsMode; } /** * Sets the (optional) JavaScript Mode * * @param jsMode Specifies whether to convert intermediate data into BSON format between the execution of the map and reduce functions * @since 2.13 */ public void setJsMode(final @Nullable Boolean jsMode) { this.jsMode = jsMode; } /** * Gets the (optional) database name where the output collection should reside * * @return the name of the database the result is stored in, or null. */ @Nullable public String getOutputDB() { return this.outputDB; } /** * Sets the (optional) database name where the output collection should reside * * @param outputDB the name of the database to send the Map Reduce output to */ public void setOutputDB(@Nullable final String outputDB) { this.outputDB = outputDB; } /** * Gets whether to bypass document validation, or null if unspecified. The default is null. * * @return whether to bypass document validation, or null if unspecified. * @since 2.14 * @mongodb.server.release 3.2 */ @Nullable public Boolean getBypassDocumentValidation() { return bypassDocumentValidation; } /** * Sets whether to bypass document validation. * * @param bypassDocumentValidation whether to bypass document validation, or null if unspecified * @since 2.14 * @mongodb.server.release 3.2 */ public void setBypassDocumentValidation(@Nullable final Boolean bypassDocumentValidation) { this.bypassDocumentValidation = bypassDocumentValidation; } /** * Turns this command into a DBObject representation of this map reduce command. * * @return a DBObject that contains the MongoDB document representation of this command. */ public DBObject toDBObject() { BasicDBObject cmd = new BasicDBObject(); cmd.put("mapreduce", mapReduce); cmd.put("map", map); cmd.put("reduce", reduce); if (verbose != null) { cmd.put("verbose", verbose); } BasicDBObject out = new BasicDBObject(); switch (outputType) { case INLINE: out.put("inline", 1); break; case REPLACE: out.put("replace", outputCollection); break; case MERGE: out.put("merge", outputCollection); break; case REDUCE: out.put("reduce", outputCollection); break; default: throw new IllegalArgumentException("Unexpected output type"); } if (outputDB != null) { out.put("db", outputDB); } cmd.put("out", out); if (query != null) { cmd.put("query", query); } if (finalize != null) { cmd.put("finalize", finalize); } if (sort != null) { cmd.put("sort", sort); } if (limit > 0) { cmd.put("limit", limit); } if (scope != null) { cmd.put("scope", scope); } if (jsMode != null) { cmd.put("jsMode", jsMode); } if (maxTimeMS != 0) { cmd.put("maxTimeMS", maxTimeMS); } return cmd; } /** * Sets the read preference for this command. See the * documentation for {@link ReadPreference} for more information. * * @param preference Read Preference to use */ public void setReadPreference(@Nullable final ReadPreference preference) { this.readPreference = preference; } /** * Gets the read preference * * @return the readPreference */ @Nullable public ReadPreference getReadPreference() { return readPreference; } /** * Returns the collation * * @return the collation * @since 3.4 * @mongodb.server.release 3.4 */ @Nullable public Collation getCollation() { return collation; } /** * Sets the collation options * * @param collation the collation options * @since 3.4 * @mongodb.server.release 3.4 */ @Nullable public void setCollation(final Collation collation) { this.collation = collation; } @Override public String toString() { return toDBObject().toString(); } String getOutputTargetNonNull() { if (outputCollection == null) { throw new MongoInternalException("outputCollection can not be null in this context"); } return outputCollection; } /** * Represents the different options available for outputting the results of a map-reduce operation. * * @mongodb.driver.manual reference/command/mapReduce/#mapreduce-out-cmd Output options */ public enum OutputType { /** * Save the job output to a collection, replacing its previous content */ REPLACE, /** * Merge the job output with the existing contents of outputTarget collection */ MERGE, /** * Reduce the job output with the existing contents of outputTarget collection */ REDUCE, /** * Return results inline, no result is written to the DB server */ INLINE } }