com.hp.util.persistence.cassandra.index

Class GenericCustomSecondaryIndex<K extends Serializable,C extends Serializable & Comparable<C>,D>

java.lang.Object

com.hp.util.persistence.cassandra.index.GenericCustomSecondaryIndex<K,C,D>

Type Parameters:

K - type of the value (or composite values) of the indexed column (or columns) in the main column family. This value (or composite value) will become the row key in the secondary index column.

C - type of the column name in the secondary index column family (row key in the main column family or composite value when sorting information is included).

D - type of the denormalized data to set as the value in the indexed columns.

All Implemented Interfaces:

ColumnFamilyHandler, CustomSecondaryIndex<K,C,D>

public class GenericCustomSecondaryIndex<K extends Serializable,C extends Serializable & Comparable<C>,D>
extends Object
implements CustomSecondaryIndex<K,C,D>

Generic implementation of CustomSecondaryIndex

Author:

Fabiel Zuniga

Constructor Summary

Constructors

Constructor and Description
GenericCustomSecondaryIndex(ColumnFamilyDefinition<K,C> columnFamilyDefinition, Denormalizer<C,D> denormalizer) Creates a CustomSecondaryIndex.

Method Summary

Modifier and Type	Method and Description
void	clear(DataStoreContext context) Updates the index after deleting all rows from the main column family.
long	count(K indexKey, DataStoreContext context) Counts the number of columns in the index.
void	delete(C indexEntry, K indexKey, DataStoreContext context) Updates the index after a row has been deleted from the main column family.
void	delete(K indexKey, DataStoreContext context) Deletes a row in the secondary index column family.
Collection<ColumnFamilyDefinition<?,?>>	getColumnFamilyDefinitions() Gets the definition of all column families this handler reads from and writes into.
Provider<ColumnDecoder<C,?>,ColumnName<C,?>>	getDecoderProvider() Returns the decoder provided used to read from the secondary index column family.
void	insert(C indexEntry, D denormalizedData, K indexKey, DataStoreContext context) Updates the index after a row has been inserted into the main column family.
List<Column<C,D>>	read(K indexKey, DataStoreContext context) Reads the index entries.
List<Column<C,D>>	read(List<C> indexEntries, K indexKey, DataStoreContext context) Reads the index entries.

Methods inherited from class java.lang.Object

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

Constructor Detail

GenericCustomSecondaryIndex

public GenericCustomSecondaryIndex(ColumnFamilyDefinition<K,C> columnFamilyDefinition,
                                   Denormalizer<C,D> denormalizer)

Creates a CustomSecondaryIndex.

Parameters:

columnFamilyDefinition - column family this index will keep data into.

denormalizer - strategy to handle denormalized data included as part of the indexed columns. null if no denormalization will be used. Note: If denormalization is used but a Denormalizer is not set then exceptions will be thrown when reading from the index.

Method Detail

getColumnFamilyDefinitions

public Collection<ColumnFamilyDefinition<?,?>> getColumnFamilyDefinitions()

Description copied from interface: ColumnFamilyHandler

Gets the definition of all column families this handler reads from and writes into.

Specified by:

getColumnFamilyDefinitions in interface ColumnFamilyHandler

Returns:

column family definitions.

insert

public void insert(C indexEntry,
                   D denormalizedData,
                   K indexKey,
                   DataStoreContext context)

Description copied from interface: CustomSecondaryIndex

Updates the index after a row has been inserted into the main column family.

Specified by:

insert in interface CustomSecondaryIndex<K extends Serializable,C extends Serializable & Comparable<C>,D>

Parameters:

indexEntry - row key in the main column family (or composite value when sorting information is included). Such row key (or composite value) will become the name of the column in the secondary index.

denormalizedData - denormalized data to include as part of the indexed columns. null if no denormalization is used.

indexKey - value (or composite values) of the indexed column (or columns) in the main column family. This value (or composite value) will become the row key in the secondary index column.

context - data store context.

delete

public void delete(C indexEntry,
                   K indexKey,
                   DataStoreContext context)

Description copied from interface: CustomSecondaryIndex

Updates the index after a row has been deleted from the main column family.

Specified by:

delete in interface CustomSecondaryIndex<K extends Serializable,C extends Serializable & Comparable<C>,D>

Parameters:

indexEntry - key of the row removed from the main column family.

indexKey - value of the indexed column in the main column family.

context - data store context.

delete

public void delete(K indexKey,
                   DataStoreContext context)

Description copied from interface: CustomSecondaryIndex

Deletes a row in the secondary index column family.

This method should be the preferred way to clear a secondary index if it contains a small well-know set of rows. Truncating a column family is an expensive operation.

Specified by:

delete in interface CustomSecondaryIndex<K extends Serializable,C extends Serializable & Comparable<C>,D>

Parameters:

indexKey - value of the indexed column in the main column family.

context - data store context.

clear

public void clear(DataStoreContext context)

Description copied from interface: CustomSecondaryIndex

Updates the index after deleting all rows from the main column family.

Specified by:

clear in interface CustomSecondaryIndex<K extends Serializable,C extends Serializable & Comparable<C>,D>

Parameters:

context - data store context.

count

public long count(K indexKey,
                  DataStoreContext context)

Description copied from interface: CustomSecondaryIndex

Counts the number of columns in the index.

Specified by:

count in interface CustomSecondaryIndex<K extends Serializable,C extends Serializable & Comparable<C>,D>

Parameters:

indexKey - value of the indexed column in the main column family or row key in the secondary index column family.

context - data store context.

Returns:

the number of entries in the index key.

read

public List<Column<C,D>> read(K indexKey,
                              DataStoreContext context)

Description copied from interface: CustomSecondaryIndex

Reads the index entries.

Specified by:

read in interface CustomSecondaryIndex<K extends Serializable,C extends Serializable & Comparable<C>,D>

Parameters:

indexKey - value of the indexed column in the main column family or row key in the secondary index column family.

context - data store context.

Returns:

the list of indexed columns with the denormalized data.

read

public List<Column<C,D>> read(List<C> indexEntries,
                              K indexKey,
                              DataStoreContext context)

Description copied from interface: CustomSecondaryIndex

Reads the index entries.

An index is normally used to get rows (from the main column family) that match a specific indexed value, not to load entries known to match the indexed value - like in this method. This method has been defined to allow secondary indexes to be used by a SecondaryIndexIntegrator.SecondaryIndexReader.

Specified by:

read in interface CustomSecondaryIndex<K extends Serializable,C extends Serializable & Comparable<C>,D>

Parameters:

indexEntries - index entries to read.

indexKey - value of the indexed column in the main column family or row key in the secondary index column family.

context - data store context.

Returns:

the list of indexed columns with the denormalized data. Any index entry from indexEntries that doesn't exist in the index given by indexKey is not included in the result.

getDecoderProvider

public Provider<ColumnDecoder<C,?>,ColumnName<C,?>> getDecoderProvider()

Returns the decoder provided used to read from the secondary index column family.

Returns:

decoder provider.