/*
* 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.connection;
import org.bson.io.BsonOutput;
/**
* Base class for OP_QUERY messages.
*
* @mongodb.driver.manual ../meta-driver/latest/legacy/mongodb-wire-protocol/#op-query OP_QUERY
*/
abstract class BaseQueryMessage extends RequestMessage {
private final int skip;
private final int numberToReturn;
private boolean tailableCursor;
private boolean slaveOk;
private boolean oplogReplay;
private boolean noCursorTimeout;
private boolean awaitData;
private boolean partial;
BaseQueryMessage(final String collectionName, final int skip, final int numberToReturn, final MessageSettings settings) {
super(collectionName, OpCode.OP_QUERY, settings);
this.skip = skip;
this.numberToReturn = numberToReturn;
}
/**
* Gets whether the cursor is configured to be a tailable cursor.
*
* <p>Tailable means the cursor is not closed when the last data is retrieved. Rather, the cursor marks the final object's position. You
* can resume using the cursor later, from where it was located, if more data were received. Like any "latent cursor",
* the cursor may become invalid at some point - for example if the final object it references were deleted.</p>
*
* @return true if the cursor is configured to be a tailable cursor
* @mongodb.driver.manual ../meta-driver/latest/legacy/mongodb-wire-protocol/#op-query OP_QUERY
*/
public boolean isTailableCursor() {
return tailableCursor;
}
/**
* Sets whether the cursor should be a tailable cursor.
*
* <p>Tailable means the cursor is not closed when the last data is retrieved. Rather, the cursor marks the final object's position. You
* can resume using the cursor later, from where it was located, if more data were received. Like any "latent cursor",
* the cursor may become invalid at some point - for example if the final object it references were deleted.</p>
*
* @param tailableCursor whether the cursor should be a tailable cursor.
* @return this
* @mongodb.driver.manual ../meta-driver/latest/legacy/mongodb-wire-protocol/#op-query OP_QUERY
*/
public BaseQueryMessage tailableCursor(final boolean tailableCursor) {
this.tailableCursor = tailableCursor;
return this;
}
/**
* Returns true if set to allowed to query non-primary replica set members.
*
* @return true if set to allowed to query non-primary replica set members.
* @mongodb.driver.manual ../meta-driver/latest/legacy/mongodb-wire-protocol/#op-query OP_QUERY
*/
public boolean isSlaveOk() {
return slaveOk;
}
/**
* Sets if allowed to query non-primary replica set members.
*
* @param slaveOk true if allowed to query non-primary replica set members.
* @return this
* @mongodb.driver.manual ../meta-driver/latest/legacy/mongodb-wire-protocol/#op-query OP_QUERY
*/
public BaseQueryMessage slaveOk(final boolean slaveOk) {
this.slaveOk = slaveOk;
return this;
}
/**
* Internal replication use only. Driver users should ordinarily not use this.
*
* @return oplogReplay
* @mongodb.driver.manual ../meta-driver/latest/legacy/mongodb-wire-protocol/#op-query OP_QUERY
*/
public boolean isOplogReplay() {
return oplogReplay;
}
/**
* Internal replication use only. Driver users should ordinarily not use this.
*
* @param oplogReplay the oplogReplay value
* @return this
* @mongodb.driver.manual ../meta-driver/latest/legacy/mongodb-wire-protocol/#op-query OP_QUERY
*/
public BaseQueryMessage oplogReplay(final boolean oplogReplay) {
this.oplogReplay = oplogReplay;
return this;
}
/**
* Returns true if cursor timeout has been turned off.
*
* <p>The server normally times out idle cursors after an inactivity period (10 minutes) to prevent excess memory use.</p>
*
* @return if cursor timeout has been turned off
* @mongodb.driver.manual ../meta-driver/latest/legacy/mongodb-wire-protocol/#op-query OP_QUERY
*/
public boolean isNoCursorTimeout() {
return noCursorTimeout;
}
/**
* Sets if the cursor timeout should be turned off.
*
* @param noCursorTimeout true if the cursor timeout should be turned off.
* @return this
* @mongodb.driver.manual ../meta-driver/latest/legacy/mongodb-wire-protocol/#op-query OP_QUERY
*/
public BaseQueryMessage noCursorTimeout(final boolean noCursorTimeout) {
this.noCursorTimeout = noCursorTimeout;
return this;
}
/**
* Returns true if the cursor should await for data.
*
* <p>Use with {@link #tailableCursor}. If we are at the end of the data, block for a while rather than returning no data. After a
* timeout period, we do return as normal.</p>
*
* @return if the cursor should await for data
* @mongodb.driver.manual ../meta-driver/latest/legacy/mongodb-wire-protocol/#op-query OP_QUERY
*/
public boolean isAwaitData() {
return awaitData;
}
/**
* Sets if the cursor should await for data.
*
* <p>Use with {@link #tailableCursor}. If we are at the end of the data, block for a while rather than returning no data. After a
* timeout period, we do return as normal.</p>
*
* @param awaitData if we should await for data
* @return this
* @mongodb.driver.manual ../meta-driver/latest/legacy/mongodb-wire-protocol/#op-query OP_QUERY
*/
public BaseQueryMessage awaitData(final boolean awaitData) {
this.awaitData = awaitData;
return this;
}
/**
* Returns true if can get partial results from a mongos if some shards are down.
*
* @return if can get partial results from a mongos if some shards are down
* @mongodb.driver.manual ../meta-driver/latest/legacy/mongodb-wire-protocol/#op-query OP_QUERY
*/
public boolean isPartial() {
return partial;
}
/**
* Sets if partial results from a mongos if some shards are down are allowed
*
* @param partial allow partial results from a mongos if some shards are down
* @return this
* @mongodb.driver.manual ../meta-driver/latest/legacy/mongodb-wire-protocol/#op-query OP_QUERY
*/
public BaseQueryMessage partial(final boolean partial) {
this.partial = partial;
return this;
}
private int getCursorFlag() {
int cursorFlag = 0;
if (isTailableCursor()) {
cursorFlag |= 1 << 1;
}
if (isSlaveOk()){
cursorFlag |= 1 << 2;
}
if (isOplogReplay()){
cursorFlag |= 1 << 3;
}
if (isNoCursorTimeout()){
cursorFlag |= 1 << 4;
}
if (isAwaitData()){
cursorFlag |= 1 << 5;
}
if (isPartial()) {
cursorFlag |= 1 << 7;
}
return cursorFlag;
}
/**
* Write the query prologue to the given BSON output.
*
* @param bsonOutput the BSON output
*/
protected void writeQueryPrologue(final BsonOutput bsonOutput) {
bsonOutput.writeInt32(getCursorFlag());
bsonOutput.writeCString(getCollectionName());
bsonOutput.writeInt32(skip);
bsonOutput.writeInt32(numberToReturn);
}
}