org.eigenbase.relopt
Class CallingConventionTraitDef

java.lang.Object
  org.eigenbase.relopt.RelTraitDef
      org.eigenbase.relopt.CallingConventionTraitDef

public class CallingConventionTraitDef
extends RelTraitDef

CallingConventionTraitDef is a RelTraitDef that defines the calling-convention trait. A new set of conversion information is created for each planner that registers at least one ConverterRule instance.

Conversion data is held in a WeakHashMap so that the JVM's garbage collector may reclaim the conversion data after the planner itself has been garbage collected. The conversion information consists of a graph of conversions (from one calling convention to another) and a map of graph arcs to ConverterRules.

Version:

$Id: //open/dev/farrago/src/org/eigenbase/relopt/CallingConventionTraitDef.java#13 $

Author:

Stephan Zuercher

Nested Class Summary

private static class

CallingConventionTraitDef.ConversionData

Field Summary

static CallingConventionTraitDef	instance
private WeakHashMap<RelOptPlanner,CallingConventionTraitDef.ConversionData>	plannerConversionMap Weak-key map of RelOptPlanner to ConversionData.

Constructor Summary

private

CallingConventionTraitDef()

Method Summary

boolean	canConvert(RelOptPlanner planner, RelTrait fromTrait, RelTrait toTrait) Tests whether the given RelTrait can be converted to another RelTrait.
private RelNode	changeConvention(RelNode rel, Graph.Arc arc, MultiMap<Graph.Arc,ConverterRule> mapArcToConverterRule) Tries to convert a relational expression to the target convention of an arc.
RelNode	convert(RelOptPlanner planner, RelNode rel, RelTrait toTrait, boolean allowInfiniteCostConverters) Converts the given RelNode to the given RelTrait.
void	deregisterConverterRule(RelOptPlanner planner, ConverterRule converterRule) Provides notification that a particular ConverterRule has been deregistered from a RelOptPlanner.
private CallingConventionTraitDef.ConversionData	getConversionData(RelOptPlanner planner)
String	getSimpleName()
Class	getTraitClass()
void	registerConverterRule(RelOptPlanner planner, ConverterRule converterRule) Provides notification of the registration of a particular ConverterRule with a RelOptPlanner.

Methods inherited from class org.eigenbase.relopt.RelTraitDef

canonize

Methods inherited from class java.lang.Object

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

Field Detail

instance

public static final CallingConventionTraitDef instance

plannerConversionMap

private final WeakHashMap<RelOptPlanner,CallingConventionTraitDef.ConversionData> plannerConversionMap

Weak-key map of RelOptPlanner to ConversionData. The idea is that when the planner goes away, so does the map entry.

Constructor Detail

CallingConventionTraitDef

private CallingConventionTraitDef()

Method Detail

getTraitClass

public Class getTraitClass()

Specified by:

getTraitClass in class RelTraitDef

Returns:

the specific RelTrait type associated with this RelTraitDef.

getSimpleName

public String getSimpleName()

Specified by:

getSimpleName in class RelTraitDef

Returns:

a simple name for this RelTraitDef (for use in RelNode.explain(RelOptPlanWriter)).

registerConverterRule

public void registerConverterRule(RelOptPlanner planner,
                                  ConverterRule converterRule)

Description copied from class: RelTraitDef

Provides notification of the registration of a particular ConverterRule with a RelOptPlanner. The default implementation does nothing.

Overrides:

registerConverterRule in class RelTraitDef

Parameters:

planner - the planner registering the rule

converterRule - the registered converter rule

deregisterConverterRule

public void deregisterConverterRule(RelOptPlanner planner,
                                    ConverterRule converterRule)

Description copied from class: RelTraitDef

Provides notification that a particular ConverterRule has been deregistered from a RelOptPlanner. The default implementation does nothing.

Overrides:

deregisterConverterRule in class RelTraitDef

Parameters:

planner - the planner registering the rule

converterRule - the registered converter rule

convert

public RelNode convert(RelOptPlanner planner,
                       RelNode rel,
                       RelTrait toTrait,
                       boolean allowInfiniteCostConverters)

Description copied from class: RelTraitDef

Converts the given RelNode to the given RelTrait.

Specified by:

convert in class RelTraitDef

Parameters:

planner - the planner requesting the conversion

rel - RelNode to convert

toTrait - RelTrait to convert to

allowInfiniteCostConverters - flag indicating whether infinite cost converters are allowe

Returns:

a converted RelNode or null if conversion is not possible

changeConvention

private RelNode changeConvention(RelNode rel,
                                 Graph.Arc arc,
                                 MultiMap<Graph.Arc,ConverterRule> mapArcToConverterRule)

Tries to convert a relational expression to the target convention of an arc.

canConvert

public boolean canConvert(RelOptPlanner planner,
                          RelTrait fromTrait,
                          RelTrait toTrait)

Description copied from class: RelTraitDef

Tests whether the given RelTrait can be converted to another RelTrait.

Specified by:

canConvert in class RelTraitDef

Parameters:

planner - the planner requesting the conversion test

fromTrait - the RelTrait to convert from

toTrait - the RelTrait to conver to

Returns:

true if fromTrait can be converted to toTrait

getConversionData

private CallingConventionTraitDef.ConversionData getConversionData(RelOptPlanner planner)