Class UnionedMappingRelation.MyCursor

java.lang.Object

se.liu.ida.hefquin.mappings.algebra.exec.UnionedMappingRelation.MyCursor

All Implemented Interfaces:

MappingRelationCursor

Enclosing class:

UnionedMappingRelation

protected class UnionedMappingRelation.MyCursor
extends Object
implements MappingRelationCursor

Field Summary

Fields

Modifier and Type	Field	Description
protected MappingRelationCursor	currentInput
protected List<String>	currentInputSchema	This is the schema of currentInput, which we need to remember to be able to check whether currentSchemaMapping needs to be updated when we move to the next non-empty currentInput.
protected int[]	currentSchemaMapping	The i-th position in this array corresponds to the i-th attribute in the schema of myRelation and the integer at that position in the array is the position of the same attribute in currentInputSchema.
protected final Iterator<MappingRelation>	inputIt
protected final MappingRelation	myRelation

Constructor Summary

Constructors

Constructor	Description
MyCursor(MappingRelation myRelation)

Method Summary

Modifier and Type	Method	Description
void	advance()
MappingRelation	getMappingRelation()	Returns the mapping relation over which this cursor iterates.
org.apache.jena.graph.Node	getValueOfCurrentTuple(int idxOfAttribute)
boolean	hasNext()
protected void	updateSchemaMapping(List<String> inputSchema)

Methods inherited from class java.lang.Object

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

Field Details

myRelation

protected final MappingRelation myRelation

inputIt

protected final Iterator<MappingRelation> inputIt

currentInput

protected MappingRelationCursor currentInput

currentInputSchema

protected List<String> currentInputSchema

This is the schema of currentInput, which we need to remember to be able to check whether currentSchemaMapping needs to be updated when we move to the next non-empty currentInput.

currentSchemaMapping

protected int[] currentSchemaMapping

The i-th position in this array corresponds to the i-th attribute in the schema of myRelation and the integer at that position in the array is the position of the same attribute in currentInputSchema. As an optimization, the array is null if the two schemas coincide.

Constructor Details

MyCursor

public MyCursor(MappingRelation myRelation)

Method Details

getMappingRelation

public MappingRelation getMappingRelation()

Description copied from interface: MappingRelationCursor

Returns the mapping relation over which this cursor iterates.

Specified by:

getMappingRelation in interface MappingRelationCursor

hasNext

public boolean hasNext()

Specified by:

hasNext in interface MappingRelationCursor

updateSchemaMapping

protected void updateSchemaMapping(List<String> inputSchema)

advance

public void advance()

Specified by:

advance in interface MappingRelationCursor

getValueOfCurrentTuple

public org.apache.jena.graph.Node getValueOfCurrentTuple(int idxOfAttribute)

Specified by:

getValueOfCurrentTuple in interface MappingRelationCursor