All Downloads are FREE. Search and download functionalities are using the official Maven repository.

com.mongodb.operation.AsyncQueryBatchCursor Maven / Gradle / Ivy

There is a newer version: 2024.11.18751.20241128T090041Z-241100
Show newest version
/*
 * 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.operation;

import com.mongodb.MongoCommandException;
import com.mongodb.MongoException;
import com.mongodb.MongoNamespace;
import com.mongodb.ReadPreference;
import com.mongodb.ServerCursor;
import com.mongodb.async.AsyncAggregateResponseBatchCursor;
import com.mongodb.async.SingleResultCallback;
import com.mongodb.binding.AsyncConnectionSource;
import com.mongodb.connection.AsyncConnection;
import com.mongodb.connection.QueryResult;
import com.mongodb.internal.validator.NoOpFieldNameValidator;
import org.bson.BsonArray;
import org.bson.BsonDocument;
import org.bson.BsonInt32;
import org.bson.BsonInt64;
import org.bson.BsonString;
import org.bson.BsonTimestamp;
import org.bson.FieldNameValidator;
import org.bson.codecs.BsonDocumentCodec;
import org.bson.codecs.Decoder;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
import static com.mongodb.assertions.Assertions.isTrue;
import static com.mongodb.assertions.Assertions.isTrueArgument;
import static com.mongodb.assertions.Assertions.notNull;
import static com.mongodb.internal.async.ErrorHandlingResultCallback.errorHandlingCallback;
import static com.mongodb.operation.CursorHelper.getNumberToReturn;
import static com.mongodb.operation.OperationHelper.LOGGER;
import static com.mongodb.operation.OperationHelper.getMoreCursorDocumentToQueryResult;
import static com.mongodb.internal.operation.ServerVersionHelper.serverIsAtLeastVersionThreeDotTwo;
import static com.mongodb.operation.QueryHelper.translateCommandException;
import static java.lang.String.format;
import static java.util.Collections.singletonList;

// @deprecated Usage of this API is not supported in AEM as a Cloud Service.
@Deprecated(since = "2021-05-27")
class AsyncQueryBatchCursor implements AsyncAggregateResponseBatchCursor {

    private static final FieldNameValidator NO_OP_FIELD_NAME_VALIDATOR = new NoOpFieldNameValidator();

    private static final String CURSOR = "cursor";

    private static final String POST_BATCH_RESUME_TOKEN = "postBatchResumeToken";

    private static final String OPERATION_TIME = "operationTime";

    private final MongoNamespace namespace;

    private final int limit;

    private final Decoder decoder;

    private final long maxTimeMS;

    private final AsyncConnectionSource connectionSource;

    private final AtomicReference cursor;

    private volatile QueryResult firstBatch;

    private volatile int batchSize;

    private final AtomicInteger count = new AtomicInteger();

    private volatile BsonDocument postBatchResumeToken;

    private volatile BsonTimestamp operationTime;

    private volatile boolean firstBatchEmpty;

    /* protected by `this` */
    private boolean isOperationInProgress = false;

    private boolean isClosed = false;

    private boolean isClosePending = false;

    /* protected by `this` */
    AsyncQueryBatchCursor(final QueryResult firstBatch, final int limit, final int batchSize, final long maxTimeMS, final Decoder decoder, final AsyncConnectionSource connectionSource, final AsyncConnection connection) {
        this(firstBatch, limit, batchSize, maxTimeMS, decoder, connectionSource, connection, null);
    }

    AsyncQueryBatchCursor(final QueryResult firstBatch, final int limit, final int batchSize, final long maxTimeMS, final Decoder decoder, final AsyncConnectionSource connectionSource, final AsyncConnection connection, final BsonDocument result) {
        isTrueArgument("maxTimeMS >= 0", maxTimeMS >= 0);
        this.maxTimeMS = maxTimeMS;
        this.namespace = firstBatch.getNamespace();
        this.firstBatch = firstBatch;
        this.limit = limit;
        this.batchSize = batchSize;
        this.decoder = decoder;
        this.cursor = new AtomicReference(firstBatch.getCursor());
        this.connectionSource = notNull("connectionSource", connectionSource);
        this.count.addAndGet(firstBatch.getResults().size());
        if (result != null) {
            this.operationTime = result.getTimestamp(OPERATION_TIME, null);
            this.postBatchResumeToken = getPostBatchResumeTokenFromResponse(result);
        }
        firstBatchEmpty = firstBatch.getResults().isEmpty();
        if (firstBatch.getCursor() != null) {
            connectionSource.retain();
            if (limitReached()) {
                killCursor(connection);
            }
        }
    }

    @Override
    public void close() {
        boolean killCursor = false;
        synchronized (this) {
            if (isOperationInProgress) {
                isClosePending = true;
            } else {
                killCursor = !isClosed;
                isClosed = true;
                isClosePending = false;
            }
        }
        if (killCursor) {
            killCursorOnClose();
        }
    }

    @Override
    public void next(final SingleResultCallback> callback) {
        next(callback, false);
    }

    @Override
    public void tryNext(final SingleResultCallback> callback) {
        next(callback, true);
    }

    @Override
    public void setBatchSize(final int batchSize) {
        synchronized (this) {
            isTrue("open", !isClosed);
        }
        this.batchSize = batchSize;
    }

    @Override
    public int getBatchSize() {
        synchronized (this) {
            isTrue("open", !isClosed);
        }
        return batchSize;
    }

    @Override
    public boolean isClosed() {
        synchronized (this) {
            return isClosed;
        }
    }

    @Override
    public BsonDocument getPostBatchResumeToken() {
        return postBatchResumeToken;
    }

    @Override
    public BsonTimestamp getOperationTime() {
        return operationTime;
    }

    @Override
    public boolean isFirstBatchEmpty() {
        return firstBatchEmpty;
    }

    private void next(final SingleResultCallback> callback, final boolean tryNext) {
        if (isClosed()) {
            callback.onResult(null, new MongoException(format("%s called after the cursor was closed.", tryNext ? "tryNext()" : "next()")));
        } else if (firstBatch != null && (tryNext || !firstBatch.getResults().isEmpty())) {
            // May be empty for a tailable cursor
            List results = firstBatch.getResults();
            if (tryNext && results.isEmpty()) {
                results = null;
            }
            firstBatch = null;
            callback.onResult(results, null);
        } else {
            ServerCursor localCursor = getServerCursor();
            if (localCursor == null) {
                synchronized (this) {
                    isClosed = true;
                }
                callback.onResult(null, null);
            } else {
                synchronized (this) {
                    if (isClosed) {
                        callback.onResult(null, new MongoException(format("%s called after the cursor was closed.", tryNext ? "tryNext()" : "next()")));
                        return;
                    }
                    isOperationInProgress = true;
                }
                getMore(localCursor, callback, tryNext);
            }
        }
    }

    private boolean limitReached() {
        return Math.abs(limit) != 0 && count.get() >= Math.abs(limit);
    }

    private void getMore(final ServerCursor cursor, final SingleResultCallback> callback, final boolean tryNext) {
        connectionSource.getConnection(new SingleResultCallback() {

            @Override
            public void onResult(final AsyncConnection connection, final Throwable t) {
                if (t != null) {
                    endOperationInProgress();
                    callback.onResult(null, t);
                } else {
                    getMore(connection, cursor, callback, tryNext);
                }
            }
        });
    }

    private void getMore(final AsyncConnection connection, final ServerCursor cursor, final SingleResultCallback> callback, final boolean tryNext) {
        if (serverIsAtLeastVersionThreeDotTwo(connection.getDescription())) {
            connection.commandAsync(namespace.getDatabaseName(), asGetMoreCommandDocument(cursor.getId()), NO_OP_FIELD_NAME_VALIDATOR, ReadPreference.primary(), CommandResultDocumentCodec.create(decoder, "nextBatch"), connectionSource.getSessionContext(), new CommandResultSingleResultCallback(connection, cursor, callback, tryNext));
        } else {
            connection.getMoreAsync(namespace, cursor.getId(), getNumberToReturn(limit, batchSize, count.get()), decoder, new QueryResultSingleResultCallback(connection, callback, tryNext));
        }
    }

    private BsonDocument asGetMoreCommandDocument(final long cursorId) {
        BsonDocument document = new BsonDocument("getMore", new BsonInt64(cursorId)).append("collection", new BsonString(namespace.getCollectionName()));
        int batchSizeForGetMoreCommand = Math.abs(getNumberToReturn(limit, this.batchSize, count.get()));
        if (batchSizeForGetMoreCommand != 0) {
            document.append("batchSize", new BsonInt32(batchSizeForGetMoreCommand));
        }
        if (maxTimeMS != 0) {
            document.append("maxTimeMS", new BsonInt64(maxTimeMS));
        }
        return document;
    }

    private void killCursorOnClose() {
        final ServerCursor localCursor = getServerCursor();
        if (localCursor != null) {
            connectionSource.getConnection(new SingleResultCallback() {

                @Override
                public void onResult(final AsyncConnection connection, final Throwable t) {
                    if (t != null) {
                        connectionSource.release();
                    } else {
                        killCursorAsynchronouslyAndReleaseConnectionAndSource(connection, localCursor);
                    }
                }
            });
        }
    }

    private void killCursor(final AsyncConnection connection) {
        ServerCursor localCursor = cursor.getAndSet(null);
        if (localCursor != null) {
            killCursorAsynchronouslyAndReleaseConnectionAndSource(connection.retain(), localCursor);
        } else {
            connectionSource.release();
        }
    }

    private void killCursorAsynchronouslyAndReleaseConnectionAndSource(final AsyncConnection connection, final ServerCursor localCursor) {
        if (serverIsAtLeastVersionThreeDotTwo(connection.getDescription())) {
            connection.commandAsync(namespace.getDatabaseName(), asKillCursorsCommandDocument(localCursor), NO_OP_FIELD_NAME_VALIDATOR, ReadPreference.primary(), new BsonDocumentCodec(), connectionSource.getSessionContext(), new SingleResultCallback() {

                @Override
                public void onResult(final BsonDocument result, final Throwable t) {
                    connection.release();
                    connectionSource.release();
                }
            });
        } else {
            connection.killCursorAsync(namespace, singletonList(localCursor.getId()), new SingleResultCallback() {

                @Override
                public void onResult(final Void result, final Throwable t) {
                    connection.release();
                    connectionSource.release();
                }
            });
        }
    }

    private BsonDocument asKillCursorsCommandDocument(final ServerCursor localCursor) {
        return new BsonDocument("killCursors", new BsonString(namespace.getCollectionName())).append("cursors", new BsonArray(singletonList(new BsonInt64(localCursor.getId()))));
    }

    private void endOperationInProgress() {
        boolean closePending = false;
        synchronized (this) {
            isOperationInProgress = false;
            closePending = this.isClosePending;
        }
        if (closePending) {
            close();
        }
    }

    private void handleGetMoreQueryResult(final AsyncConnection connection, final SingleResultCallback> callback, final QueryResult result, final boolean tryNext) {
        cursor.set(result.getCursor());
        if (!tryNext && result.getResults().isEmpty() && result.getCursor() != null) {
            getMore(connection, result.getCursor(), callback, false);
        } else {
            count.addAndGet(result.getResults().size());
            if (limitReached()) {
                killCursor(connection);
                connection.release();
            } else {
                connection.release();
                if (result.getCursor() == null) {
                    connectionSource.release();
                }
            }
            endOperationInProgress();
            if (result.getResults().isEmpty()) {
                callback.onResult(null, null);
            } else {
                callback.onResult(result.getResults(), null);
            }
        }
    }

    // @deprecated Usage of this API is not supported in AEM as a Cloud Service.
    @Deprecated(since = "2021-05-27")
    private class CommandResultSingleResultCallback implements SingleResultCallback {

        private final AsyncConnection connection;

        private final ServerCursor cursor;

        private final SingleResultCallback> callback;

        private final boolean tryNext;

        CommandResultSingleResultCallback(final AsyncConnection connection, final ServerCursor cursor, final SingleResultCallback> callback, final boolean tryNext) {
            this.connection = connection;
            this.cursor = cursor;
            this.callback = errorHandlingCallback(callback, LOGGER);
            this.tryNext = tryNext;
        }

        @Override
        public void onResult(final BsonDocument result, final Throwable t) {
            if (t != null) {
                Throwable translatedException = t instanceof MongoCommandException ? translateCommandException((MongoCommandException) t, cursor) : t;
                connection.release();
                endOperationInProgress();
                callback.onResult(null, translatedException);
            } else {
                QueryResult queryResult = getMoreCursorDocumentToQueryResult(result.getDocument(CURSOR), connection.getDescription().getServerAddress());
                postBatchResumeToken = getPostBatchResumeTokenFromResponse(result);
                handleGetMoreQueryResult(connection, callback, queryResult, tryNext);
            }
        }
    }

    // @deprecated Usage of this API is not supported in AEM as a Cloud Service.
    @Deprecated(since = "2021-05-27")
    private class QueryResultSingleResultCallback implements SingleResultCallback> {

        private final AsyncConnection connection;

        private final SingleResultCallback> callback;

        private final boolean tryNext;

        QueryResultSingleResultCallback(final AsyncConnection connection, final SingleResultCallback> callback, final boolean tryNext) {
            this.connection = connection;
            this.callback = errorHandlingCallback(callback, LOGGER);
            this.tryNext = tryNext;
        }

        @Override
        public void onResult(final QueryResult result, final Throwable t) {
            if (t != null) {
                connection.release();
                endOperationInProgress();
                callback.onResult(null, t);
            } else {
                handleGetMoreQueryResult(connection, callback, result, tryNext);
            }
        }
    }

    ServerCursor getServerCursor() {
        return cursor.get();
    }

    private BsonDocument getPostBatchResumeTokenFromResponse(final BsonDocument result) {
        BsonDocument cursor = result.getDocument(CURSOR, null);
        if (cursor != null) {
            return cursor.getDocument(POST_BATCH_RESUME_TOKEN, null);
        }
        return null;
    }
}




© 2015 - 2024 Weber Informatics LLC | Privacy Policy