Package com.apple.foundationdb.record.query.plan.temp

Class ValueIndexExpansionVisitor

java.lang.Object

com.apple.foundationdb.record.query.plan.temp.ValueIndexLikeExpansionVisitor

com.apple.foundationdb.record.query.plan.temp.ValueIndexExpansionVisitor

All Implemented Interfaces:

ExpansionVisitor<ValueIndexLikeExpansionVisitor.VisitorState>, KeyExpressionVisitor<ValueIndexLikeExpansionVisitor.VisitorState,GraphExpansion>

public class ValueIndexExpansionVisitor
extends ValueIndexLikeExpansionVisitor

Class to expand value index access into a candidate graph. The visitation methods are left unchanged from the super class ValueIndexLikeExpansionVisitor, this class merely provides a specific expand(com.apple.foundationdb.record.query.plan.temp.Quantifier.ForEach, com.apple.foundationdb.record.metadata.expressions.KeyExpression, boolean) method.

Nested Class Summary

Nested classes/interfaces inherited from class com.apple.foundationdb.record.query.plan.temp.ValueIndexLikeExpansionVisitor

ValueIndexLikeExpansionVisitor.VisitorState

Nested classes/interfaces inherited from interface com.apple.foundationdb.record.query.plan.temp.KeyExpressionVisitor

KeyExpressionVisitor.Result, KeyExpressionVisitor.State

Constructor Summary

Constructors

Constructor	Description
ValueIndexExpansionVisitor(Index index)

Method Summary

Modifier and Type	Method	Description
MatchCandidate	expand(Quantifier.ForEach baseQuantifier, KeyExpression primaryKey, boolean isReverse)	Method that expands a data structure into a data flow graph
static KeyExpression	fullKey(Index index, KeyExpression primaryKey)	Compute the full key of an index (given that the index is a value index).

Methods inherited from class com.apple.foundationdb.record.query.plan.temp.ValueIndexLikeExpansionVisitor

getCurrentState, pop, pop, push, visitExpression, visitExpression, visitExpression, visitExpression, visitExpression, visitExpression, visitExpression

Methods inherited from class java.lang.Object

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

Constructor Detail

ValueIndexExpansionVisitor

public ValueIndexExpansionVisitor(@Nonnull
                                  Index index)

Method Detail

expand

@Nonnull
public MatchCandidate expand(@Nonnull
                             Quantifier.ForEach baseQuantifier,
                             @Nullable
                             KeyExpression primaryKey,
                             boolean isReverse)

Description copied from interface: ExpansionVisitor

Method that expands a data structure into a data flow graph

Parameters:

baseQuantifier - a quantifier representing the base data access

primaryKey - the primary key of the data object the caller wants to access

isReverse - an indicator whether the result set is expected to be returned in reverse order

Returns:

a new MatchCandidate that can be used for matching.

fullKey

@Nonnull
public static KeyExpression fullKey(@Nonnull
                                    Index index,
                                    @Nullable
                                    KeyExpression primaryKey)

Compute the full key of an index (given that the index is a value index).

Parameters:

index - index to be expanded

primaryKey - primary key of the records the index ranges over. The primary key is used to determine parts in the index definition that already contain parts of the primary key. All primary key components that are not already part of the index key are appended to the index key.

Returns:

a KeyExpression describing the full index key as stored