/*
* 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.ReadBinding;
import com.mongodb.client.model.Collation;
import com.mongodb.connection.AsyncConnection;
import com.mongodb.connection.Connection;
import com.mongodb.operation.CommandOperationHelper.CommandTransformer;
import com.mongodb.operation.OperationHelper.AsyncCallableWithConnection;
import com.mongodb.operation.OperationHelper.CallableWithConnection;
import org.bson.BsonDocument;
import org.bson.BsonString;
import org.bson.BsonValue;
import org.bson.codecs.BsonDocumentCodec;
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.putIfNotNull;
import static com.mongodb.operation.DocumentHelper.putIfNotZero;
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;
/**
* An operation that executes a count.
*
* @since 3.0
*/
public class CountOperation implements AsyncReadOperation<Long>, ReadOperation<Long> {
private final MongoNamespace namespace;
private BsonDocument filter;
private BsonValue hint;
private long skip;
private long limit;
private long maxTimeMS;
private ReadConcern readConcern = ReadConcern.DEFAULT;
private Collation collation;
/**
* Construct a new instance.
*
* @param namespace the database and collection namespace for the operation.
*/
public CountOperation(final MongoNamespace namespace) {
this.namespace = notNull("namespace", namespace);
}
/**
* 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, which may be null.
* @return this
* @mongodb.driver.manual reference/method/db.collection.find/ Filter
*/
public CountOperation filter(final BsonDocument filter) {
this.filter = filter;
return this;
}
/**
* Gets the hint to apply.
*
* @return the hint, which should describe an existing
*/
public BsonValue getHint() {
return hint;
}
/**
* Sets the hint to apply.
*
* @param hint a value describing the index which should be used for this operation.
* @return this
*/
public CountOperation hint(final BsonValue hint) {
this.hint = hint;
return this;
}
/**
* Gets the limit to apply. The default is 0, which means there is no limit.
*
* @return the limit
* @mongodb.driver.manual reference/method/cursor.limit/#cursor.limit Limit
*/
public long getLimit() {
return limit;
}
/**
* Sets the limit to apply.
*
* @param limit the limit
* @return this
* @mongodb.driver.manual reference/method/cursor.limit/#cursor.limit Limit
*/
public CountOperation limit(final long limit) {
this.limit = limit;
return this;
}
/**
* Gets the number of documents to skip. The default is 0.
*
* @return the number of documents to skip, which may be null
* @mongodb.driver.manual reference/method/cursor.skip/#cursor.skip Skip
*/
public long getSkip() {
return skip;
}
/**
* Sets the number of documents to skip.
*
* @param skip the number of documents to skip
* @return this
* @mongodb.driver.manual reference/method/cursor.skip/#cursor.skip Skip
*/
public CountOperation skip(final long skip) {
this.skip = skip;
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
*/
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
*/
public CountOperation 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 CountOperation readConcern(final ReadConcern readConcern) {
this.readConcern = notNull("readConcern", readConcern);
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
*/
public CountOperation collation(final Collation collation) {
this.collation = collation;
return this;
}
@Override
public Long execute(final ReadBinding binding) {
return withConnection(binding, new CallableWithConnection<Long>() {
@Override
public Long call(final Connection connection) {
validateReadConcernAndCollation(connection, readConcern, collation);
return executeWrappedCommandProtocol(binding, namespace.getDatabaseName(), getCommand(), new BsonDocumentCodec(),
connection, transformer());
}
});
}
@Override
public void executeAsync(final AsyncReadBinding binding, final SingleResultCallback<Long> callback) {
withConnection(binding, new AsyncCallableWithConnection() {
@Override
public void call(final AsyncConnection connection, final Throwable t) {
SingleResultCallback<Long> errHandlingCallback = errorHandlingCallback(callback, LOGGER);
if (t != null) {
errHandlingCallback.onResult(null, t);
} else {
final SingleResultCallback<Long> 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(),
new BsonDocumentCodec(), connection, transformer(), 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, Long> transformer() {
return new CommandTransformer<BsonDocument, Long>() {
@Override
public Long apply(final BsonDocument result, final ServerAddress serverAddress) {
return (result.getNumber("n")).longValue();
}
};
}
private BsonDocument getCommand() {
BsonDocument document = new BsonDocument("count", new BsonString(namespace.getCollectionName()));
putIfNotNull(document, "query", filter);
putIfNotZero(document, "limit", limit);
putIfNotZero(document, "skip", skip);
putIfNotNull(document, "hint", hint);
putIfNotZero(document, "maxTimeMS", maxTimeMS);
if (!readConcern.isServerDefault()) {
document.put("readConcern", readConcern.asDocument());
}
if (collation != null) {
document.put("collation", collation.asDocument());
}
return document;
}
}