com.mongodb.client.internal.AggregateIterableImpl Maven / Gradle / Ivy

/*
 * 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.client.internal;

import com.mongodb.MongoNamespace;
import com.mongodb.ReadConcern;
import com.mongodb.ReadPreference;
import com.mongodb.WriteConcern;
import com.mongodb.client.AggregateIterable;
import com.mongodb.client.ClientSession;
import com.mongodb.client.model.AggregationLevel;
import com.mongodb.client.model.Collation;
import com.mongodb.client.model.FindOptions;
import com.mongodb.internal.operation.SyncOperations;
import com.mongodb.lang.Nullable;
import com.mongodb.operation.BatchCursor;
import com.mongodb.operation.ReadOperation;
import org.bson.BsonDocument;
import org.bson.BsonString;
import org.bson.codecs.configuration.CodecRegistry;
import org.bson.conversions.Bson;

import java.util.List;
import java.util.concurrent.TimeUnit;

import static com.mongodb.assertions.Assertions.notNull;

class AggregateIterableImpl extends MongoIterableImpl implements AggregateIterable {
    private SyncOperations operations;
    private final MongoNamespace namespace;
    private final Class documentClass;
    private final Class resultClass;
    private final CodecRegistry codecRegistry;
    private final List pipeline;
    private final AggregationLevel aggregationLevel;

    private Boolean allowDiskUse;
    private long maxTimeMS;
    private long maxAwaitTimeMS;
    private Boolean useCursor;
    private Boolean bypassDocumentValidation;
    private Collation collation;
    private String comment;
    private Bson hint;

    AggregateIterableImpl(@Nullable final ClientSession clientSession, final String databaseName, final Class documentClass,
                          final Class resultClass, final CodecRegistry codecRegistry, final ReadPreference readPreference,
                          final ReadConcern readConcern, final WriteConcern writeConcern, final OperationExecutor executor,
                          final List pipeline, final AggregationLevel aggregationLevel) {
        this(clientSession, new MongoNamespace(databaseName, "ignored"), documentClass, resultClass, codecRegistry, readPreference,
                readConcern, writeConcern, executor, pipeline, aggregationLevel, true);
    }

    AggregateIterableImpl(@Nullable final ClientSession clientSession, final String databaseName, final Class documentClass,
                          final Class resultClass, final CodecRegistry codecRegistry, final ReadPreference readPreference,
                          final ReadConcern readConcern, final WriteConcern writeConcern, final OperationExecutor executor,
                          final List pipeline, final AggregationLevel aggregationLevel, final boolean retryReads) {
        this(clientSession, new MongoNamespace(databaseName, "ignored"), documentClass, resultClass, codecRegistry, readPreference,
                readConcern, writeConcern, executor, pipeline, aggregationLevel, retryReads);
    }

    AggregateIterableImpl(@Nullable final ClientSession clientSession, final MongoNamespace namespace, final Class documentClass,
                          final Class resultClass, final CodecRegistry codecRegistry, final ReadPreference readPreference,
                          final ReadConcern readConcern, final WriteConcern writeConcern, final OperationExecutor executor,
                          final List pipeline, final AggregationLevel aggregationLevel, final boolean retryReads) {
        super(clientSession, executor, readConcern, readPreference, retryReads);
        this.operations = new SyncOperations(namespace, documentClass, readPreference, codecRegistry, readConcern, writeConcern,
                true, retryReads);
        this.namespace = notNull("namespace", namespace);
        this.documentClass = notNull("documentClass", documentClass);
        this.resultClass = notNull("resultClass", resultClass);
        this.codecRegistry = notNull("codecRegistry", codecRegistry);
        this.pipeline = notNull("pipeline", pipeline);
        this.aggregationLevel = notNull("aggregationLevel", aggregationLevel);
    }

    @Override
    public void toCollection() {
        if (getOutNamespace() == null) {
            throw new IllegalStateException("The last stage of the aggregation pipeline must be $out or $merge");
        }

        getExecutor().execute(operations.aggregateToCollection(pipeline, maxTimeMS, allowDiskUse, bypassDocumentValidation, collation, hint,
                comment, aggregationLevel), getReadConcern(), getClientSession());
    }

    @Override
    public AggregateIterable allowDiskUse(@Nullable final Boolean allowDiskUse) {
        this.allowDiskUse = allowDiskUse;
        return this;
    }

    @Override
    public AggregateIterable batchSize(final int batchSize) {
        super.batchSize(batchSize);
        return this;
    }

    @Override
    public AggregateIterable maxTime(final long maxTime, final TimeUnit timeUnit) {
        notNull("timeUnit", timeUnit);
        this.maxTimeMS = TimeUnit.MILLISECONDS.convert(maxTime, timeUnit);
        return this;
    }

    @Override
    @SuppressWarnings("deprecation")
    public AggregateIterable useCursor(@Nullable final Boolean useCursor) {
        this.useCursor = useCursor;
        return this;
    }

    @Override
    public AggregateIterable maxAwaitTime(final long maxAwaitTime, final TimeUnit timeUnit) {
        notNull("timeUnit", timeUnit);
        this.maxAwaitTimeMS = TimeUnit.MILLISECONDS.convert(maxAwaitTime, timeUnit);
        return this;
    }

    @Override
    public AggregateIterable bypassDocumentValidation(@Nullable final Boolean bypassDocumentValidation) {
        this.bypassDocumentValidation = bypassDocumentValidation;
        return this;
    }

    @Override
    public AggregateIterable collation(@Nullable final Collation collation) {
        this.collation = collation;
        return this;
    }

    @Override
    public AggregateIterable comment(@Nullable final String comment) {
        this.comment = comment;
        return this;
    }

    @Override
    public AggregateIterable hint(@Nullable final Bson hint) {
        this.hint = hint;
        return this;
    }

    @Override
    @SuppressWarnings("deprecation")
    public ReadOperation> asReadOperation() {
        MongoNamespace outNamespace = getOutNamespace();

        if (outNamespace != null) {
            getExecutor().execute(operations.aggregateToCollection(pipeline, maxTimeMS, allowDiskUse, bypassDocumentValidation, collation,
                    hint, comment, aggregationLevel), getReadConcern(), getClientSession());

            FindOptions findOptions = new FindOptions().collation(collation);
            Integer batchSize = getBatchSize();
            if (batchSize != null) {
                findOptions.batchSize(batchSize);
            }
            return operations.find(outNamespace, new BsonDocument(), resultClass, findOptions);
        } else {
            return operations.aggregate(pipeline, resultClass, maxTimeMS, maxAwaitTimeMS, getBatchSize(), collation,
                    hint, comment, allowDiskUse, useCursor, aggregationLevel);
        }
    }

    @Nullable
    private MongoNamespace getOutNamespace() {
        if (pipeline.size() == 0) {
            return null;
        }

        Bson lastStage = notNull("last stage", pipeline.get(pipeline.size() - 1));
        BsonDocument lastStageDocument = lastStage.toBsonDocument(documentClass, codecRegistry);
        if (lastStageDocument.containsKey("$out")) {
            return new MongoNamespace(namespace.getDatabaseName(), lastStageDocument.getString("$out").getValue());
        } else if (lastStageDocument.containsKey("$merge")) {
            BsonDocument mergeDocument = lastStageDocument.getDocument("$merge");
            if (mergeDocument.isDocument("into")) {
                BsonDocument intoDocument = mergeDocument.getDocument("into");
                return new MongoNamespace(intoDocument.getString("db", new BsonString(namespace.getDatabaseName())).getValue(),
                        intoDocument.getString("coll").getValue());
            } else if (mergeDocument.isString("into")) {
                return new MongoNamespace(namespace.getDatabaseName(), mergeDocument.getString("into").getValue());
            }
        }

        return null;
    }
}