Package com.mongodb.operation

Class ParallelCollectionScanOperation<T>

java.lang.Object

com.mongodb.operation.ParallelCollectionScanOperation<T>

Type Parameters:

T - the operations result type.

All Implemented Interfaces:

AsyncReadOperation<List<AsyncBatchCursor<T>>>, ReadOperation<List<BatchCursor<T>>>

public class ParallelCollectionScanOperation<T>
extends Object
implements AsyncReadOperation<List<AsyncBatchCursor<T>>>, ReadOperation<List<BatchCursor<T>>>

Return a list of cursors over the collection that can be used to scan it in parallel.

Note: As of MongoDB 2.6, this operation will work against a mongod, but not a mongos.

Since:

3.0

MongoDB documentation

parallelCollectionScan

Since server release

2.6

Constructor Summary

Constructors

Constructor	Description
ParallelCollectionScanOperation(MongoNamespace namespace, int numCursors, Decoder<T> decoder)	Construct a new instance.

Method Summary

Modifier and Type	Method	Description
ParallelCollectionScanOperation<T>	batchSize(int batchSize)	The batch size to use for each cursor.
List<BatchCursor<T>>	execute(ReadBinding binding)	General execute which can return anything of type T
void	executeAsync(AsyncReadBinding binding, SingleResultCallback<List<AsyncBatchCursor<T>>> callback)	General execute which can return anything of type T
int	getBatchSize()	Gets the batch size to use for each cursor.
int	getNumCursors()	Gets the number of cursors requested.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ParallelCollectionScanOperation

public ParallelCollectionScanOperation(MongoNamespace namespace,
                                       int numCursors,
                                       Decoder<T> decoder)

Construct a new instance.

Parameters:

namespace - the database and collection namespace for the operation.

numCursors - The maximum number of cursors to return. Must be between 1 and 10000, inclusive.

decoder - the decoder for the result documents.

Method Detail

getNumCursors

public int getNumCursors()

Gets the number of cursors requested.

Returns:

number of cursors requested.

getBatchSize

public int getBatchSize()

Gets the batch size to use for each cursor. The default value is 0, which tells the server to use its own default batch size.

Returns:

batch size

MongoDB documentation

BatchSize

batchSize

public ParallelCollectionScanOperation<T> batchSize(int batchSize)

The batch size to use for each cursor.

Parameters:

batchSize - the batch size, which must be greater than or equal to 0

Returns:

this

MongoDB documentation

BatchSize

execute

public List<BatchCursor<T>> execute(ReadBinding binding)

Description copied from interface: ReadOperation

General execute which can return anything of type T

Specified by:

execute in interface ReadOperation<T>

Parameters:

binding - the binding to execute in the context of

Returns:

T, the result of the execution

executeAsync

public void executeAsync(AsyncReadBinding binding,
                         SingleResultCallback<List<AsyncBatchCursor<T>>> callback)

Description copied from interface: AsyncReadOperation

General execute which can return anything of type T

Specified by:

executeAsync in interface AsyncReadOperation<T>

Parameters:

binding - the binding to execute in the context of

callback - the callback to be called when the operation has been executed