org.modeshape.jcr.query.optimize
Class AddOrderingColumnsToSources

java.lang.Object
  org.modeshape.jcr.query.optimize.AddOrderingColumnsToSources

All Implemented Interfaces:

OptimizerRule

public class AddOrderingColumnsToSources
extends Object
implements OptimizerRule

An OptimizerRule that adds any missing columns required by the ordering specifications to the SORT node's PROJECT, and to the appropriate access nodes.

Field Summary

static AddOrderingColumnsToSources

INSTANCE

Constructor Summary

AddOrderingColumnsToSources()

Method Summary

protected boolean	addIfMissing(QueryContext context, Column column, List<Column> columns, List<String> columnTypes) Check the supplied list of columns for an existing column that matches the supplied Column, and if none is found add the supplied Column to the list and add an appropriate type.
protected void	addSortColumn(QueryContext context, PlanNode node, Column sortColumn) Make sure that the supplied column is included in the projected columns on the supplied plan node or its children.
protected Column	columnFor(SelectorName selector, String property, boolean includeSourceName)
PlanNode	execute(QueryContext context, PlanNode plan, LinkedList<OptimizerRule> ruleStack) Optimize the supplied plan using the supplied context, hints, and yet-to-be-run rules.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final AddOrderingColumnsToSources INSTANCE

Constructor Detail

AddOrderingColumnsToSources

public AddOrderingColumnsToSources()

Method Detail

execute

public PlanNode execute(QueryContext context,
                        PlanNode plan,
                        LinkedList<OptimizerRule> ruleStack)

Description copied from interface: OptimizerRule

Optimize the supplied plan using the supplied context, hints, and yet-to-be-run rules.

Specified by:

execute in interface OptimizerRule

Parameters:

context - the context in which the query is being optimized; never null

plan - the plan to be optimized; never null

ruleStack - the stack of rules that will be run after this rule; never null

Returns:

the optimized plan; never null

addSortColumn

protected void addSortColumn(QueryContext context,
                             PlanNode node,
                             Column sortColumn)

Make sure that the supplied column is included in the projected columns on the supplied plan node or its children.

Parameters:

context - the query context; may not be null

node - the query plan node

sortColumn - the column required by the sort

addIfMissing

protected boolean addIfMissing(QueryContext context,
                               Column column,
                               List<Column> columns,
                               List<String> columnTypes)

Check the supplied list of columns for an existing column that matches the supplied Column, and if none is found add the supplied Column to the list and add an appropriate type.

Parameters:

context - the query context

column - the column that will be added if not already in the list; may not be null

columns - the list of columns; may not be null

columnTypes - the list of column types; may not be null

Returns:

true if the column was added (i.e., the lists were modified), or false if the lists were not modified

columnFor

protected Column columnFor(SelectorName selector,
                           String property,
                           boolean includeSourceName)

toString

public String toString()

Overrides:

toString in class Object