Package com.googlecode.cqengine.index.offheap

Class OffHeapIndex<A extends Comparable<A>,O,K extends Comparable<K>>

java.lang.Object

com.googlecode.cqengine.index.sqlite.SimplifiedSQLiteIndex<A,O,K>

com.googlecode.cqengine.index.offheap.OffHeapIndex<A,O,K>

All Implemented Interfaces:

ModificationListener<O>, AttributeIndex<A,O>, Index<O>, NonHeapTypeIndex, OffHeapTypeIndex, KeyStatisticsAttributeIndex<A,O>, KeyStatisticsIndex<A,O>, SortedKeyStatisticsAttributeIndex<A,O>, SortedKeyStatisticsIndex<A,O>

public class OffHeapIndex<A extends Comparable<A>,O,K extends Comparable<K>>
extends SimplifiedSQLiteIndex<A,O,K>
implements OffHeapTypeIndex

An index persisted in native memory within the JVM process but outside the Java heap.

This index is similar to the on-heap NavigableIndex and supports the same types of queries.

The current implementation of this index is based on SQLiteIndex.

Author:

niall.gallagher

Method Summary

Modifier and Type	Method	Description
static <A extends Comparable<A>,O> OffHeapIndex<A,O,? extends Comparable<?>>	onAttribute(Attribute<O,A> attribute)	Creates a new OffHeapIndex.
ResultSet<O>	retrieve(Query<O> query, QueryOptions queryOptions)	Returns a ResultSet which when iterated will return objects from the index matching the query supplied.

Methods inherited from class com.googlecode.cqengine.index.sqlite.SimplifiedSQLiteIndex

addAll, clear, destroy, equals, getAttribute, getCountForKey, getCountOfDistinctKeys, getDistinctKeys, getDistinctKeys, getDistinctKeysDescending, getDistinctKeysDescending, getEffectiveIndex, getKeysAndValues, getKeysAndValues, getKeysAndValuesDescending, getKeysAndValuesDescending, getStatisticsForDistinctKeys, getStatisticsForDistinctKeysDescending, hashCode, init, isMutable, isQuantized, removeAll, supportsQuery

Methods inherited from class java.lang.Object

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

Method Detail

retrieve

public ResultSet<O> retrieve(Query<O> query,
                             QueryOptions queryOptions)

Description copied from interface: Index

Returns a ResultSet which when iterated will return objects from the index matching the query supplied.

Usually ResultSets are lazy which means that they don't actually do any work, or encapsulate or materialize matching objects, but rather they encapsulate logic to fetch matching objects from the index on-the-fly as the application iterates through the ResultSet.

Specified by:

retrieve in interface Index<A extends Comparable<A>>

Overrides:

retrieve in class SimplifiedSQLiteIndex<A extends Comparable<A>,O,K extends Comparable<K>>

Parameters:

query - An object which specifies some restriction on an attribute of an object

queryOptions - Optional parameters for the query

Returns:

A set of objects with attributes matching the restriction imposed by the query

See Also:

Index.supportsQuery(Query, QueryOptions)

onAttribute

public static <A extends Comparable<A>,O> OffHeapIndex<A,O,? extends Comparable<?>> onAttribute(Attribute<O,A> attribute)

Creates a new OffHeapIndex.

Type Parameters:

A - The type of the attribute to be indexed.

O - The type of the object containing the attribute.

Parameters:

attribute - The Attribute on which the index will be built.

Returns:

An OffHeapIndex on the given attribute.