it.unimi.di.mg4j.query.nodes
Class Remap

java.lang.Object
  it.unimi.di.mg4j.query.nodes.Remap

All Implemented Interfaces:

Query, Serializable

public class Remap
extends Object
implements Query

A node representing an index remapping.

A remapping takes results of the underlying Query for an internal index (which must be one of the indices for which the query provides results) and exhibits them as results of an external index. The map provided at construction time under the form of two parallel arrays should remap internal indices to external indices.

Author:

Sebastiano Vigna

See Also:

RemappingDocumentIterator, Serialized Form

Field Summary

Object2ObjectLinkedOpenHashMap<String,String>	indexInverseRemapping The remapping from external to internal indices.
Object2ObjectLinkedOpenHashMap<String,String>	indexRemapping The remapping from internal to external indices.
Query	query The only underlying node.

Constructor Summary

Remap(Query query, CharSequence[] internalIndex, CharSequence[] externalIndex)
Creates a new index remapping query node given explicit lists external and internal indices.

Remap(Query query, Object2ObjectMap<String,String> indexRemapping)
Creates a new index remapping query node given an index remapping.

Method Summary

<T> T	accept(QueryBuilderVisitor<T> visitor) Accepts a visitor.
boolean	equals(Object o)
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

query

public final Query query

The only underlying node.

indexRemapping

public final Object2ObjectLinkedOpenHashMap<String,String> indexRemapping

The remapping from internal to external indices.

indexInverseRemapping

public final Object2ObjectLinkedOpenHashMap<String,String> indexInverseRemapping

The remapping from external to internal indices.

Constructor Detail

Remap

public Remap(Query query,
             CharSequence[] internalIndex,
             CharSequence[] externalIndex)

Creates a new index remapping query node given explicit lists external and internal indices.

Parameters:

query - the underlying query.

internalIndex - the array of internal index names.

externalIndex - the array of external index names, parallel to internalIndex.

Remap

public Remap(Query query,
             Object2ObjectMap<String,String> indexRemapping)

Creates a new index remapping query node given an index remapping.

Parameters:

query - the underlying query.

indexRemapping - a map from internal to external indices, which will be copied internally.

Method Detail

toString

public String toString()

Overrides:

toString in class Object

accept

public <T> T accept(QueryBuilderVisitor<T> visitor)
         throws QueryBuilderVisitorException

Description copied from interface: Query

Accepts a visitor.

Specified by:

accept in interface Query

Parameters:

visitor - the visitor.

Returns:

the result of the visit, or null if the visit should stop.

Throws:

QueryBuilderVisitorException

See Also:

Query

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object