org.knime.core.data.container
Class ContainerTable

java.lang.Object
  org.knime.core.data.container.ContainerTable

All Implemented Interfaces:

Iterable<DataRow>, DataTable, BufferedDataTable.KnowsRowCountTable

public final class ContainerTable
extends Object
implements DataTable, BufferedDataTable.KnowsRowCountTable

Class implementing the DataTable interface and using a buffer from a DataContainer as data source. This class doesn't do functional things. It only provides the DataTable methods.

We split it from the Buffer implementation as a buffer is dynamic in size. This table should only be used when the buffer has been fixed.

Author:

Bernd Wiswedel, University of Konstanz

Constructor Summary

ContainerTable(Buffer buffer)
Create new Table based on a Buffer.

ContainerTable(CopyOnAccessTask readTask, DataTableSpec spec)
Constructor when table is read from file.

Method Summary

void	clear() Do not call this method! It's used internally to delete temp files.
void	ensureOpen() Do not use this method (only invoked by the framework).
(package private) Buffer	getBuffer() Get reference to buffer.
int	getBufferID() Delegates to buffer to get its ID.
DataTableSpec	getDataTableSpec() Returns the DataTableSpec object of this table which gives information about the structure of this data table.
BufferedDataTable[]	getReferenceTables() Returns an empty array.
int	getRowCount() Row count of the table.
CloseableRowIterator	iterator() Returns a row iterator which returns each row one-by-one from the table.
void	putIntoTableRepository(HashMap<Integer,ContainerTable> rep) Put this table into the global table repository.
boolean	removeFromTableRepository(HashMap<Integer,ContainerTable> rep) Remove this table from global table repository.
protected void	restoreIntoMemory() Instruct the underlying buffer to cache the rows into main memory to accelerate future iterations.
void	saveToFile(File f, NodeSettingsWO settings, ExecutionMonitor exec) Do not call this method! Internal use! Save the table to a file.

Methods inherited from class java.lang.Object

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

Constructor Detail

ContainerTable

ContainerTable(Buffer buffer)

Create new Table based on a Buffer. This constructor is called from DataContainer.getTable().

Parameters:

buffer - To read data from.

See Also:

DataContainer.getTable()

ContainerTable

ContainerTable(CopyOnAccessTask readTask,
               DataTableSpec spec)

Constructor when table is read from file.

Parameters:

readTask - Carries out the copy process when iterator is requested (just once).

spec - The spec of this table.

Method Detail

getDataTableSpec

public DataTableSpec getDataTableSpec()

Returns the DataTableSpec object of this table which gives information about the structure of this data table.

Specified by:

getDataTableSpec in interface DataTable

Returns:

the DataTableSpec of this table

iterator

public CloseableRowIterator iterator()

Returns a row iterator which returns each row one-by-one from the table.

Specified by:

iterator in interface Iterable<DataRow>

Specified by:

iterator in interface DataTable

Specified by:

iterator in interface BufferedDataTable.KnowsRowCountTable

Returns:

row iterator

See Also:

DataRow

getRowCount

public int getRowCount()

Row count of the table.

Specified by:

getRowCount in interface BufferedDataTable.KnowsRowCountTable

Returns:

The row count.

getBuffer

Buffer getBuffer()

Get reference to buffer.

Returns:

The buffer backing this object.

getBufferID

public int getBufferID()

Delegates to buffer to get its ID.

Returns:

the buffer ID

See Also:

Buffer.getBufferID()

restoreIntoMemory

protected void restoreIntoMemory()

Instruct the underlying buffer to cache the rows into main memory to accelerate future iterations. This method does nothing if the buffer is reading from memory already.

See Also:

Buffer.restoreIntoMemory()

saveToFile

public void saveToFile(File f,
                       NodeSettingsWO settings,
                       ExecutionMonitor exec)
                throws IOException,
                       CanceledExecutionException

Do not call this method! Internal use! Save the table to a file.

Specified by:

saveToFile in interface BufferedDataTable.KnowsRowCountTable

Parameters:

f - To write to.

settings - To add meta information to.

exec - For progress/cancel.

Throws:

IOException - If writing fails.

CanceledExecutionException - If canceled.

putIntoTableRepository

public void putIntoTableRepository(HashMap<Integer,ContainerTable> rep)

Put this table into the global table repository. Called when execution finished.

Specified by:

putIntoTableRepository in interface BufferedDataTable.KnowsRowCountTable

Parameters:

rep - The workflow table repository.

removeFromTableRepository

public boolean removeFromTableRepository(HashMap<Integer,ContainerTable> rep)

Remove this table from global table repository. Called when node is reset.

Specified by:

removeFromTableRepository in interface BufferedDataTable.KnowsRowCountTable

Parameters:

rep - The workflow table repository.

Returns:

If this table was indeed removed from the table repository (true for ordinary container tables but false for wrappers such as concatenate or spec replacer)

clear

public void clear()

Do not call this method! It's used internally to delete temp files. Any subsequent iteration on the table will fail!

Specified by:

clear in interface BufferedDataTable.KnowsRowCountTable

See Also:

BufferedDataTable.KnowsRowCountTable.clear()

ensureOpen

public void ensureOpen()

Do not use this method (only invoked by the framework). Implementation of BufferedDataTable.ensureOpen().

Specified by:

ensureOpen in interface BufferedDataTable.KnowsRowCountTable

getReferenceTables

public BufferedDataTable[] getReferenceTables()

Returns an empty array. This method is used internally. Reference to the underlying tables, if any. A reference table exists if this object is just a wrapper, such as a RearrangeColumnsTable or if this table concatenates a set of other tables.

Specified by:

getReferenceTables in interface BufferedDataTable.KnowsRowCountTable

Returns:

The reference table or null.