org.apache.crunch.impl.dist.collect

Class BaseGroupedTable<K,V>

java.lang.Object

org.apache.crunch.impl.dist.collect.PCollectionImpl<Pair<K,Iterable<V>>>

org.apache.crunch.impl.dist.collect.BaseGroupedTable<K,V>

All Implemented Interfaces:

PCollection<Pair<K,Iterable<V>>>, PGroupedTable<K,V>

Direct Known Subclasses:

PGroupedTableImpl

public class BaseGroupedTable<K,V>
extends PCollectionImpl<Pair<K,Iterable<V>>>
implements PGroupedTable<K,V>

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.crunch.impl.dist.collect.PCollectionImpl

PCollectionImpl.Visitor

Method Summary

Modifier and Type	Method and Description
PTable<K,V>	combineValues(Aggregator<V> agg) Combine the values in each group using the given Aggregator.
PTable<K,V>	combineValues(Aggregator<V> combineAgg, Aggregator<V> reduceAgg) Combine and reduces the values in each group using the given Aggregator instances.
PTable<K,V>	combineValues(CombineFn<K,V> combineFn) Combines the values of this grouping using the given CombineFn.
PTable<K,V>	combineValues(CombineFn<K,V> combineFn, CombineFn<K,V> reduceFn) Combines and reduces the values of this grouping using the given CombineFn instances.
PGroupedTableType<K,V>	getGroupedTableType() Return the PGroupedTableType containing serialization information for this PGroupedTable.
long	getLastModifiedAt() The time of the most recent modification to one of the input sources to the collection.
List<PCollectionImpl<?>>	getParents()
PType<Pair<K,Iterable<V>>>	getPType() Returns the PType of this PCollection.
Set<Target>	getTargetDependencies()
<U> PTable<K,U>	mapValues(MapFn<Iterable<V>,U> mapFn, PType<U> ptype) Maps the Iterable<V> elements of each record to a new type.
<U> PTable<K,U>	mapValues(String name, MapFn<Iterable<V>,U> mapFn, PType<U> ptype) Maps the Iterable<V> elements of each record to a new type.
PTable<K,V>	ungroup() Convert this grouping back into a multimap.

Methods inherited from class org.apache.crunch.impl.dist.collect.PCollectionImpl

accept, aggregate, asCollection, asReadable, by, by, cache, cache, count, filter, filter, first, getDepth, getMaterializedAt, getName, getOnlyParent, getParallelDoOptions, getPipeline, getSize, getTypeFamily, isBreakpoint, length, materialize, materializeAt, max, min, parallelDo, parallelDo, parallelDo, parallelDo, parallelDo, parallelDo, sequentialDo, setBreakpoint, toString, union, union, write, write

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.crunch.PCollection

aggregate, asCollection, asReadable, by, by, cache, cache, count, filter, filter, first, getName, getPipeline, getSize, getTypeFamily, length, materialize, max, min, parallelDo, parallelDo, parallelDo, parallelDo, parallelDo, parallelDo, sequentialDo, union, union, write, write

Method Detail

getPType

public PType<Pair<K,Iterable<V>>> getPType()

Description copied from interface: PCollection

Returns the PType of this PCollection.

Specified by:

getPType in interface PCollection<Pair<K,Iterable<V>>>

combineValues

public PTable<K,V> combineValues(CombineFn<K,V> combineFn,
                                 CombineFn<K,V> reduceFn)

Description copied from interface: PGroupedTable

Combines and reduces the values of this grouping using the given CombineFn instances.

Specified by:

combineValues in interface PGroupedTable<K,V>

Parameters:

combineFn - The combiner function during the combine phase

reduceFn - The combiner function during the reduce phase

Returns:

A PTable where each key has a single value

combineValues

public PTable<K,V> combineValues(CombineFn<K,V> combineFn)

Description copied from interface: PGroupedTable

Combines the values of this grouping using the given CombineFn.

Specified by:

combineValues in interface PGroupedTable<K,V>

Parameters:

combineFn - The combiner function

Returns:

A PTable where each key has a single value

combineValues

public PTable<K,V> combineValues(Aggregator<V> agg)

Description copied from interface: PGroupedTable

Combine the values in each group using the given Aggregator.

Specified by:

combineValues in interface PGroupedTable<K,V>

Parameters:

agg - The function to use

Returns:

A PTable where each group key maps to an aggregated value. Group keys may be repeated if an aggregator returns more than one value.

combineValues

public PTable<K,V> combineValues(Aggregator<V> combineAgg,
                                 Aggregator<V> reduceAgg)

Description copied from interface: PGroupedTable

Combine and reduces the values in each group using the given Aggregator instances.

Specified by:

combineValues in interface PGroupedTable<K,V>

Parameters:

combineAgg - The aggregator to use during the combine phase

reduceAgg - The aggregator to use during the reduce phase

Returns:

A PTable where each group key maps to an aggregated value. Group keys may be repeated if an aggregator returns more than one value.

ungroup

public PTable<K,V> ungroup()

Description copied from interface: PGroupedTable

Convert this grouping back into a multimap.

Specified by:

ungroup in interface PGroupedTable<K,V>

Returns:

an ungrouped version of the data in this PGroupedTable.

mapValues

public <U> PTable<K,U> mapValues(MapFn<Iterable<V>,U> mapFn,
                                 PType<U> ptype)

Description copied from interface: PGroupedTable

Maps the Iterable<V> elements of each record to a new type. Just like any parallelDo operation on a PGroupedTable, this may only be called once.

Specified by:

mapValues in interface PGroupedTable<K,V>

Parameters:

mapFn - The mapping function

ptype - The serialization information for the returned data

Returns:

A new PTable instance

mapValues

public <U> PTable<K,U> mapValues(String name,
                                 MapFn<Iterable<V>,U> mapFn,
                                 PType<U> ptype)

Description copied from interface: PGroupedTable

Maps the Iterable<V> elements of each record to a new type. Just like any parallelDo operation on a PGroupedTable, this may only be called once.

Specified by:

mapValues in interface PGroupedTable<K,V>

Parameters:

name - A name for this operation

mapFn - The mapping function

ptype - The serialization information for the returned data

Returns:

A new PTable instance

getGroupedTableType

public PGroupedTableType<K,V> getGroupedTableType()

Description copied from interface: PGroupedTable

Return the PGroupedTableType containing serialization information for this PGroupedTable.

Specified by:

getGroupedTableType in interface PGroupedTable<K,V>

getTargetDependencies

public Set<Target> getTargetDependencies()

Overrides:

getTargetDependencies in class PCollectionImpl<Pair<K,Iterable<V>>>

getParents

public List<PCollectionImpl<?>> getParents()

Specified by:

getParents in class PCollectionImpl<Pair<K,Iterable<V>>>

getLastModifiedAt

public long getLastModifiedAt()

Description copied from class: PCollectionImpl

The time of the most recent modification to one of the input sources to the collection. If the time can not be determined then -1 should be returned.

Specified by:

getLastModifiedAt in class PCollectionImpl<Pair<K,Iterable<V>>>

Returns:

time of the most recent modification to one of the input sources to the collection.