org.apache.calcite.plan

Class RelTraitSet

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList<RelTrait>

org.apache.calcite.plan.RelTraitSet

All Implemented Interfaces:

Iterable<RelTrait>, Collection<RelTrait>, List<RelTrait>

public final class RelTraitSet
extends AbstractList<RelTrait>

RelTraitSet represents an ordered set of RelTraits.

Field Summary

Fields inherited from class java.util.AbstractList

modCount

Method Summary

Methods

Modifier and Type	Method and Description
boolean	allSimple() Returns whether there are any composite traits in this set.
<T extends RelTrait> T	canonize(T trait) Converts a trait to canonical form.
boolean	comprises(RelTrait... relTraits) Returns whether this trait set comprises precisely the list of given traits.
protected String	computeString() Outputs the traits of this set as a String.
boolean	contains(RelTrait trait) Returns whether this trait set contains a given trait.
boolean	containsIfApplicable(RelTrait trait) Returns whether this trait set contains the given trait, or whether the trait is not present because its RelTraitDef is not enabled.
static RelTraitSet	createEmpty() Creates an empty trait set.
com.google.common.collect.ImmutableList<RelTrait>	difference(RelTraitSet traitSet) Returns a list of traits that are in traitSet but not in this RelTraitSet.
boolean	equals(Object obj) Compares two RelTraitSet objects for equality.
RelTrait	get(int index)
RelTrait	getTrait(int index) Retrieves a RelTrait from the set.
<T extends RelTrait> T	getTrait(RelTraitDef<T> traitDef) Retrieves a RelTrait of the given type from the set.
<E extends RelMultipleTrait> List<E>	getTraits(int index) Retrieves a list of traits from the set.
<T extends RelMultipleTrait> List<T>	getTraits(RelTraitDef<T> traitDef) Retrieves a list of traits of the given type from the set.
int	hashCode()
<T extends RelTrait> boolean	isEnabled(RelTraitDef<T> traitDef) Returns whether a given kind of trait is enabled.
boolean	matches(RelTraitSet that) Compares two RelTraitSet objects to see if they match for the purposes of firing a rule.
RelTraitSet	merge(RelTraitSet additionalTraits)
RelTraitSet	plus(RelTrait trait) Returns this trait set with a given trait added or overridden.
RelTraitSet	plusAll(RelTrait[] traits)
RelTraitSet	replace(int index, RelTrait trait) Replaces an existing RelTrait in the set.
<T extends RelMultipleTrait> RelTraitSet	replace(List<T> traits) Replaces the trait(s) of a given type with a list of traits of the same type.
RelTraitSet	replace(RelTrait trait) Returns a trait set consisting of the current set plus a new trait.
<T extends RelMultipleTrait> RelTraitSet	replace(RelTraitDef<T> def, List<T> traits) Replaces the trait(s) of a given type with a list of traits of the same type.
<T extends RelTrait> RelTraitSet	replaceIf(RelTraitDef<T> def, com.google.common.base.Supplier<T> traitSupplier) If a given trait is enabled, replaces it by calling the given function.
<T extends RelMultipleTrait> RelTraitSet	replaceIfs(RelTraitDef<T> def, com.google.common.base.Supplier<List<T>> traitSupplier) If a given multiple trait is enabled, replaces it by calling the given function.
boolean	satisfies(RelTraitSet that) Returns whether this trait set satisfies another trait set.
RelTraitSet	simplify() Returns a trait set similar to this one but with all composite traits flattened.
int	size() Returns the size of the RelTraitSet.
String	toString()

Methods inherited from class java.util.AbstractList

add, add, addAll, clear, indexOf, iterator, lastIndexOf, listIterator, listIterator, remove, removeRange, set, subList

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.List

addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray

Method Detail

createEmpty

public static RelTraitSet createEmpty()

Creates an empty trait set.

It has a new cache, which will be shared by any trait set created from it. Thus each empty trait set is the start of a new ancestral line.

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.

getTraits

public <E extends RelMultipleTrait> List<E> getTraits(int index)

Retrieves a list of traits 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.

get

public RelTrait get(int index)

Specified by:

get in interface List<RelTrait>

Specified by:

get in class AbstractList<RelTrait>

isEnabled

public <T extends RelTrait> boolean isEnabled(RelTraitDef<T> traitDef)

Returns whether a given kind of trait is enabled.

getTrait

public <T extends RelTrait> T getTrait(RelTraitDef<T> traitDef)

Retrieves a RelTrait of the given type from the set.

Parameters:

traitDef - the type of RelTrait to retrieve

Returns:

the RelTrait, or null if not found

getTraits

public <T extends RelMultipleTrait> List<T> getTraits(RelTraitDef<T> traitDef)

Retrieves a list of traits of the given type from the set.

Only valid for traits that support multiple entries. (E.g. collation.)

Parameters:

traitDef - the type of RelTrait to retrieve

Returns:

the RelTrait, or null if not found

replace

public RelTraitSet replace(int index,
                  RelTrait trait)

Replaces an existing RelTrait in the set. Returns a different trait set; does not modify this trait set.

Parameters:

index - 0-based index into ordered RelTraitSet

trait - the new RelTrait

Returns:

the old RelTrait at the index

replace

public RelTraitSet replace(RelTrait trait)

Returns a trait set consisting of the current set plus a new trait.

If the set does not contain a trait of the same RelTraitDef, the trait is ignored, and this trait set is returned.

Parameters:

trait - the new trait

Returns:

New set

See Also:

plus(RelTrait)

replace

public <T extends RelMultipleTrait> RelTraitSet replace(List<T> traits)

Replaces the trait(s) of a given type with a list of traits of the same type.

The list must not be empty, and all traits must be of the same type.

replace

public <T extends RelMultipleTrait> RelTraitSet replace(RelTraitDef<T> def,
                                               List<T> traits)

Replaces the trait(s) of a given type with a list of traits of the same type.

The list must not be empty, and all traits must be of the same type.

replaceIfs

public <T extends RelMultipleTrait> RelTraitSet replaceIfs(RelTraitDef<T> def,
                                                  com.google.common.base.Supplier<List<T>> traitSupplier)

If a given multiple trait is enabled, replaces it by calling the given function.

replaceIf

public <T extends RelTrait> RelTraitSet replaceIf(RelTraitDef<T> def,
                                         com.google.common.base.Supplier<T> traitSupplier)

If a given trait is enabled, replaces it by calling the given function.

size

public int size()

Returns the size of the RelTraitSet.

Specified by:

size in interface Collection<RelTrait>

Specified by:

size in interface List<RelTrait>

Specified by:

size in class AbstractCollection<RelTrait>

Returns:

the size of the RelTraitSet.

canonize

public <T extends RelTrait> T canonize(T 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.

Specified by:

equals in interface Collection<RelTrait>

Specified by:

equals in interface List<RelTrait>

Overrides:

equals in class AbstractList<RelTrait>

Parameters:

obj - another RelTraitSet

Returns:

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

hashCode

public int hashCode()

Specified by:

hashCode in interface Collection<RelTrait>

Specified by:

hashCode in interface List<RelTrait>

Overrides:

hashCode in class AbstractList<RelTrait>

satisfies

public boolean satisfies(RelTraitSet that)

Returns whether this trait set satisfies another trait set.

For that to happen, each trait satisfies the corresponding trait in the other set. In particular, each trait set satisfies itself, because each trait subsumes itself.

Intuitively, if a relational expression is needed that has trait set S (A, B), and trait set S1 (A1, B1) subsumes S, then any relational expression R in S1 meets that need.

For example, if we need a relational expression that has trait set S = {enumerable convention, sorted on [C1 asc]}, and R has {enumerable convention, sorted on [C3], [C1, C2]}. R has two sort keys, but one them [C1, C2] satisfies S [C1], and that is enough.

Parameters:

that - another RelTraitSet

Returns:

whether this trait set satisfies other trait set

See Also:

RelTrait.satisfies(RelTrait)

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

containsIfApplicable

public boolean containsIfApplicable(RelTrait trait)

Returns whether this trait set contains the given trait, or whether the trait is not present because its RelTraitDef is not enabled. Returns false if another trait of the same RelTraitDef is present.

Parameters:

trait - Trait

Returns:

Whether trait is present, or is absent because disabled

comprises

public boolean comprises(RelTrait... relTraits)

Returns whether this trait set comprises precisely the list of given traits.

Parameters:

relTraits - Traits

Returns:

Whether this trait set's traits are the same as the argument

toString

public String toString()

Overrides:

toString in class AbstractCollection<RelTrait>

computeString

protected String computeString()

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

plus

public RelTraitSet plus(RelTrait trait)

Returns this trait set with a given trait added or overridden. Does not modify this trait set.

Parameters:

trait - Trait

Returns:

Trait set with given trait

plusAll

public RelTraitSet plusAll(RelTrait[] traits)

merge

public RelTraitSet merge(RelTraitSet additionalTraits)

difference

public com.google.common.collect.ImmutableList<RelTrait> difference(RelTraitSet traitSet)

Returns a list of traits that are in traitSet but not in this RelTraitSet.

allSimple

public boolean allSimple()

Returns whether there are any composite traits in this set.

simplify

public RelTraitSet simplify()

Returns a trait set similar to this one but with all composite traits flattened.