org.eigenbase.relopt
Class RelTraitSet

java.lang.Object
  org.eigenbase.relopt.RelTraitSet

public class RelTraitSet
extends Object

RelTraitSet represents an ordered set of RelTraits.

Version:

$Id: //open/dev/farrago/src/org/eigenbase/relopt/RelTraitSet.java#12 $

Author:

Stephan Zuercher

Field Summary

private RelTrait[]

traits

Constructor Summary

RelTraitSet(RelTrait... traits)
Constructs a RelTraitSet with the given set of RelTraits.

Method Summary

void	addTrait(RelTrait trait) Adds a new RelTrait to the set.
private RelTrait	canonize(RelTrait trait) Converts a trait to canonical form.
RelTraitSet	clone()
boolean	contains(RelTrait trait) Returns whether this trait set contains a given trait.
boolean	equals(Object obj) Compares two RelTraitSet objects for equality.
private int	findIndex(RelTraitDef traitDef) Finds the index of a trait of a given type in this set.
RelTrait	getTrait(int index) Retrieves a RelTrait from the set.
RelTrait	getTrait(RelTraitDef traitDef) Retrieves a RelTrait of the given type from the set.
boolean	matches(RelTraitSet that) Compares two RelTraitSet objects to see if they match for the purposes of firing a rule.
RelTrait	setTrait(int index, RelTrait trait) Replaces an existing RelTrait in the set.
RelTrait	setTrait(RelTraitDef traitDef, RelTrait trait) Replaces an existing RelTrait in the set.
int	size() Returns the size of the RelTraitSet.
String	toString() Outputs the traits of this set as a String.

Methods inherited from class java.lang.Object

finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

traits

private RelTrait[] traits

Constructor Detail

RelTraitSet

public RelTraitSet(RelTrait... traits)

Constructs a RelTraitSet with the given set of RelTraits.

Parameters:

traits - Traits

Method Detail

getTrait

public RelTrait getTrait(int index)

Retrieves a RelTrait from the set.

Parameters:

index - 0-based index into ordered RelTraitSet

Returns:

the RelTrait

Throws:

ArrayIndexOutOfBoundsException - if index greater than or equal to size() or less than 0.

getTrait

public RelTrait getTrait(RelTraitDef traitDef)

Retrieves a RelTrait of the given type from the set.

Parameters:

traitDef - the type of RelTrit to retrieve

Returns:

the RelTrait, or null if not found

setTrait

public RelTrait setTrait(int index,
                         RelTrait trait)

Replaces an existing RelTrait in the set. This method must not be used to modify the traits of a RelNode that has already been registered with a RelOptPlanner.

Parameters:

index - 0-based index into ordered RelTraitSet

trait - the new RelTrait

Returns:

the old RelTrait at the index

setTrait

public RelTrait setTrait(RelTraitDef traitDef,
                         RelTrait trait)

Replaces an existing RelTrait in the set. This method must not be used to modify the traits of a RelNode that has already been registered with a RelOptPlanner.

Parameters:

traitDef - the type of RelTrait to replace

Returns:

the RelTrait at the index

addTrait

public void addTrait(RelTrait trait)

Adds a new RelTrait to the set. This method must not be used to modify the traits of a RelNode that has already been registered with a RelOptPlanner.

Parameters:

trait - the new RelTrait

size

public int size()

Returns the size of the RelTraitSet.

Returns:

the size of the RelTraitSet.

canonize

private RelTrait canonize(RelTrait trait)

Converts a trait to canonical form.

After canonization, t1.equals(t2) if and only if t1 == t2.

Parameters:

trait - Trait

Returns:

Trait in canonical form

equals

public boolean equals(Object obj)

Compares two RelTraitSet objects for equality.

Overrides:

equals in class Object

Parameters:

obj - another RelTraitSet

Returns:

true if traits are equal and in the same order, false otherwise

matches

public boolean matches(RelTraitSet that)

Compares two RelTraitSet objects to see if they match for the purposes of firing a rule. A null RelTrait within a RelTraitSet indicates a wildcard: any RelTrait in the other RelTraitSet will match. If one RelTraitSet is smaller than the other, comparison stops when the last RelTrait from the smaller set has been examined and the remaining RelTraits in the larger set are assumed to match.

Parameters:

that - another RelTraitSet

Returns:

true if the RelTraitSets match, false otherwise

contains

public boolean contains(RelTrait trait)

Returns whether this trait set contains a given trait.

Parameters:

trait - Sought trait

Returns:

Whether set contains given trait

toString

public String toString()

Outputs the traits of this set as a String. Traits are output in the String in order, separated by periods.

Overrides:

toString in class Object

clone

public RelTraitSet clone()

Overrides:

clone in class Object

findIndex

private int findIndex(RelTraitDef traitDef)

Finds the index of a trait of a given type in this set.

Parameters:

traitDef - Sought trait definition

Returns:

index of trait, or -1 if not found