org.modeshape.jcr.query.engine.process

Class RestartableSequence

java.lang.Object

org.modeshape.jcr.query.NodeSequence

org.modeshape.jcr.query.engine.process.RestartableSequence

All Implemented Interfaces:

NodeSequence.Restartable

public class RestartableSequence
extends NodeSequence
implements NodeSequence.Restartable

A NodeSequence that captures the buffers as they are used (or all at once) so that the sequence can be restarted.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static interface	RestartableSequence.BatchSequence
protected class	RestartableSequence.QueueBufferSupplier

Nested classes/interfaces inherited from class org.modeshape.jcr.query.NodeSequence

NodeSequence.AlternateSizeBatch, NodeSequence.Batch, NodeSequence.LimitBatch, NodeSequence.MultiWidthBatch, NodeSequence.Restartable, NodeSequence.RowAccessor, NodeSequence.RowFilter, NodeSequence.SingleWidthBatch

Field Summary

Fields

Modifier and Type	Field and Description
protected int	actualNumRowsInMemory
protected AtomicLong	batchSize
protected Queue<NodeSequence.Batch>	inMemoryBatches
protected boolean	loadedAll
protected RestartableSequence.QueueBufferSupplier	offHeapBatchesSupplier
protected NodeSequence	original
protected AtomicLong	remainingRowCount
protected org.mapdb.Serializer<BufferedRows.BufferedRow>	rowSerializer
protected long	totalSize
protected boolean	usedOffHeap
protected int	width
protected String	workspaceName

Fields inherited from class org.modeshape.jcr.query.NodeSequence

LOGGER, NO_PASS_ROW_FILTER, PASS_ROW_FILTER

Constructor Summary

Constructors

Constructor and Description
RestartableSequence(String workspaceName, NodeSequence original, BufferManager bufferMgr, CachedNodeSupplier nodeCache, int numRowsInMemory)

Method Summary

Methods

Modifier and Type	Method and Description
protected NodeSequence.Batch	batchFrom(Iterator<BufferedRows.BufferedRow> rows, long maxBatchSize)
void	close() Signal that this node sequence is no longer needed.
protected BufferedRows.BufferedRow	createRow(NodeSequence.Batch currentRow)
long	getRowCount() Get the number of rows in this sequence.
boolean	isEmpty() Determine whether this results is known to be empty.
protected long	loadBatch(NodeSequence.Batch batch, boolean loadIntoMemory, AtomicReference<NodeSequence.Batch> copyOutput)
protected void	loadRemaining() Load all of the remaining rows from the supplied sequence into the buffer.
NodeSequence.Batch	nextBatch() Get the next batch of NodeKey instances.
void	restart()
protected void	restartBatches()
String	toString()
int	width() Get the number of nodes in each row.

Methods inherited from class org.modeshape.jcr.query.NodeSequence

append, batchFilteredWith, batchOf, batchOf, batchOf, batchOfKeys, batchOfKeys, batchOfKeys, batchOfKeys, batchWithCount, copy, emptyBatch, emptySequence, filter, keyFor, limit, limit, merging, requireBoth, requireEither, skip, withBatch, withBatches, withBatches, withNode, withNodeKeys, withNodeKeys, withNodeKeys, withNodeKeys, withNodes, withNodes

Methods inherited from class java.lang.Object

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

Field Detail

original

protected final NodeSequence original

rowSerializer

protected final org.mapdb.Serializer<BufferedRows.BufferedRow> rowSerializer

inMemoryBatches

protected final Queue<NodeSequence.Batch> inMemoryBatches

offHeapBatchesSupplier

protected final RestartableSequence.QueueBufferSupplier offHeapBatchesSupplier

workspaceName

protected final String workspaceName

remainingRowCount

protected final AtomicLong remainingRowCount

width

protected final int width

batchSize

protected final AtomicLong batchSize

actualNumRowsInMemory

protected int actualNumRowsInMemory

totalSize

protected long totalSize

loadedAll

protected boolean loadedAll

usedOffHeap

protected boolean usedOffHeap

Constructor Detail

RestartableSequence

public RestartableSequence(String workspaceName,
                   NodeSequence original,
                   BufferManager bufferMgr,
                   CachedNodeSupplier nodeCache,
                   int numRowsInMemory)

Method Detail

width

public int width()

Description copied from class: NodeSequence

Get the number of nodes in each row.

Specified by:

width in class NodeSequence

Returns:

the width of each row; always positive

getRowCount

public long getRowCount()

Description copied from class: NodeSequence

Get the number of rows in this sequence. If the actual number of rows is not known, this method returns -1.

Specified by:

getRowCount in class NodeSequence

Returns:

the number of rows, or -1 if the number of rows is not known or cannot be found with significant overhead

isEmpty

public boolean isEmpty()

Description copied from class: NodeSequence

Determine whether this results is known to be empty.

Specified by:

isEmpty in class NodeSequence

Returns:

the true if there are no results, or false if there is at least some or if the number of rows is not known

nextBatch

public NodeSequence.Batch nextBatch()

Description copied from class: NodeSequence

Get the next batch of NodeKey instances.

Specified by:

nextBatch in class NodeSequence

Returns:

the next batch, or null if there are no more batches.

restart

public void restart()

Specified by:

restart in interface NodeSequence.Restartable

restartBatches

protected void restartBatches()

close

public void close()

Description copied from class: NodeSequence

Signal that this node sequence is no longer needed.

Specified by:

close in class NodeSequence

loadRemaining

protected void loadRemaining()

Load all of the remaining rows from the supplied sequence into the buffer.

loadBatch

protected long loadBatch(NodeSequence.Batch batch,
             boolean loadIntoMemory,
             AtomicReference<NodeSequence.Batch> copyOutput)

createRow

protected BufferedRows.BufferedRow createRow(NodeSequence.Batch currentRow)

batchFrom

protected NodeSequence.Batch batchFrom(Iterator<BufferedRows.BufferedRow> rows,
                           long maxBatchSize)

toString

public String toString()

Overrides:

toString in class Object