org.objectweb.medor.eval.lib
Class ProjectEvaluatedTC

java.lang.Object
  org.objectweb.medor.eval.lib.BasicBinaryEvalutedTC
      org.objectweb.medor.eval.lib.ProjectEvaluatedTC

All Implemented Interfaces:

BinaryEvaluatedTC, PrefetchBufferHolder, TupleCollection

public class ProjectEvaluatedTC

extends BasicBinaryEvalutedTC

implements BinaryEvaluatedTC, PrefetchBufferHolder

A project Operation QueryNode is performed by this TupleCollection. This operation is not costs and doeas not uses buffers.

Field Summary

Fields inherited from class org.objectweb.medor.eval.lib.BasicBinaryEvalutedTC

closed, debug, log

Constructor Summary

ProjectEvaluatedTC(QueryNode query, NodeEvaluator subNodeEvaluator, ParameterOperand[] parameters, PrefetchBuffer pb)

Method Summary

int	card()
void	close() It closes the TupleCollection, relaeases used resources (example : ResultSet).
void	first() Moves the cursor to the first Tuple, row number 1.
int	getLeftTCCursor() Get the current row of the left TupleCollection
TupleStructure	getMetaData() Retrieves the number,types and stors properties of the data sources of this TupleCollection Object.
int	getRightTCCursor() Get the current row of the right TupleCollection
int	getRow() Retrieves the current row Number.
Tuple	getTuple() Returns the Tuple value of the current row of this TupleCollection object.
Tuple	getTuple(int numTuple) Returns the Tuple value of the designeted row of this TupleCollection object.
void	invalidatePrefetchBuffer() Invalidates the PrefetchBuffer referenced by the object.
boolean	isEmpty() Tell whether the current TupleCollection Object is empty or no.
boolean	isLast() Indicates whether the cursor is on the last row of this TupleCollection object.
boolean	next() Moves the cursor down one row from its current position to the next tuple of this TupleCollection object.
boolean	row(int numTuple) Moves the cursor to the given row number in this TupleCollection object.

Methods inherited from class java.lang.Object

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

Constructor Detail

ProjectEvaluatedTC

public ProjectEvaluatedTC(QueryNode query,
                          NodeEvaluator subNodeEvaluator,
                          ParameterOperand[] parameters,
                          PrefetchBuffer pb)
                   throws MedorException

Method Detail

invalidatePrefetchBuffer

public void invalidatePrefetchBuffer()
                              throws MedorException

Description copied from interface: PrefetchBufferHolder

Invalidates the PrefetchBuffer referenced by the object.

This is typically done when the user closes a TupleCollection.

Specified by:

invalidatePrefetchBuffer in interface PrefetchBufferHolder

Throws:

MedorException

close

public void close()
           throws MedorException

Description copied from interface: TupleCollection

It closes the TupleCollection, relaeases used resources (example : ResultSet). The next uses of the TupleCollection will throw an exception.

Specified by:

close in interface TupleCollection

Overrides:

close in class BasicBinaryEvalutedTC

Throws:

MedorException

getMetaData

public TupleStructure getMetaData()
                           throws MedorException

Description copied from interface: TupleCollection

Retrieves the number,types and stors properties of the data sources of this TupleCollection Object.

Specified by:

getMetaData in interface TupleCollection

Returns:

a TupleCollectionMetaData Object defining teh TupleCollection.

Throws:

MedorException - if a data source access error occurs

isLast

public boolean isLast()
               throws MedorException

Description copied from interface: TupleCollection

Indicates whether the cursor is on the last row of this TupleCollection object.

Specified by:

isLast in interface TupleCollection

Returns:

true if the current Tuple is the last one or if the TupleCollection is Empty.

Throws:

MedorException - if data source access error

card

public int card()
         throws MedorException

Throws:

MedorException

next

public boolean next()
             throws MedorException

Description copied from interface: TupleCollection

Moves the cursor down one row from its current position to the next tuple of this TupleCollection object.

Specified by:

next in interface TupleCollection

Returns:

true if move is impossible and false if move is not performed.

Throws:

MedorException - if data source access error

first

public void first()
           throws MedorException

Description copied from interface: TupleCollection

Moves the cursor to the first Tuple, row number 1.

Specified by:

first in interface TupleCollection

Throws:

MedorException - if data source access error

getRow

public int getRow()
           throws MedorException

Description copied from interface: TupleCollection

Retrieves the current row Number.

Specified by:

getRow in interface TupleCollection

Returns:

-1 if the iterator is out of bounds of the TupleCollection or if it is empty.

Throws:

MedorException - if data source access error.

getTuple

public Tuple getTuple()
               throws MedorException

Description copied from interface: TupleCollection

Returns the Tuple value of the current row of this TupleCollection object.

Specified by:

getTuple in interface TupleCollection

Returns:

the value of the current Tuple.

Throws:

MedorException - if data source access error.

getTuple

public Tuple getTuple(int numTuple)
               throws MedorException

Description copied from interface: TupleCollection

Returns the Tuple value of the designeted row of this TupleCollection object.

Specified by:

getTuple in interface TupleCollection

Parameters:

numTuple - :int

Returns:

the a Tuple Number row.

Throws:

MedorException - if data source access error.

isEmpty

public boolean isEmpty()
                throws MedorException

Description copied from interface: TupleCollection

Tell whether the current TupleCollection Object is empty or no.

Specified by:

isEmpty in interface TupleCollection

Returns:

true if the TupleCollection is empty.

Throws:

MedorException - if data source access error.

row

public boolean row(int numTuple)
            throws MedorException

Description copied from interface: TupleCollection

Moves the cursor to the given row number in this TupleCollection object. The first row is row 1, the second is row 2, and so on.

Specified by:

row in interface TupleCollection

Returns:

true if move is possible

Throws:

MedorException - if row number is invelid or data source access error

getLeftTCCursor

public int getLeftTCCursor()
                    throws MedorException

Description copied from interface: BinaryEvaluatedTC

Get the current row of the left TupleCollection

Specified by:

getLeftTCCursor in interface BinaryEvaluatedTC

Returns:

an int

Throws:

MedorException - if error in left TupleCollection

getRightTCCursor

public int getRightTCCursor()
                     throws MedorException

Description copied from interface: BinaryEvaluatedTC

Get the current row of the right TupleCollection

Specified by:

getRightTCCursor in interface BinaryEvaluatedTC

Returns:

an int

Throws:

MedorException - if error in right TupleCollection