cascading.tap.partition
Class BasePartitionTap<Config,Input,Output>

java.lang.Object
  cascading.tap.Tap<Config,Input,Output>
      cascading.tap.partition.BasePartitionTap<Config,Input,Output>

All Implemented Interfaces:

FlowElement, Serializable

public abstract class BasePartitionTap<Config,Input,Output>
extends Tap<Config,Input,Output>

See Also:

Serialized Form

Nested Class Summary

static class	BasePartitionTap.Counters
class	BasePartitionTap.PartitionCollector
static class	BasePartitionTap.PartitionScheme<Config,Input,Output>

Field Summary

protected boolean	keepParentOnDelete Field keepParentOnDelete
protected static int	OPEN_WRITES_THRESHOLD_DEFAULT Field OPEN_FILES_THRESHOLD_DEFAULT
protected int	openWritesThreshold Field openTapsThreshold
protected Tap	parent Field parent
protected Partition	partition Field partition

Constructor Summary

protected	BasePartitionTap(Tap parent, Partition partition, int openWritesThreshold)
protected	BasePartitionTap(Tap parent, Partition partition, SinkMode sinkMode)
protected	BasePartitionTap(Tap parent, Partition partition, SinkMode sinkMode, boolean keepParentOnDelete, int openWritesThreshold)

Method Summary

boolean	commitResource(Config conf) Method commitResource allows the underlying resource to be notified when all write processing is successful so that any additional cleanup or processing may be completed.
boolean	createResource(Config conf) Method createResource creates the underlying resource.
protected abstract TupleEntrySchemeCollector	createTupleEntrySchemeCollector(FlowProcess<Config> flowProcess, Tap parent, String path, long sequence)
protected abstract TupleEntrySchemeIterator	createTupleEntrySchemeIterator(FlowProcess<Config> flowProcess, Tap parent, String path, Input input)
boolean	deleteResource(Config conf) Method deleteResource deletes the resource represented by this instance.
boolean	equals(Object object)
String[]	getChildPartitionIdentifiers(FlowProcess<Config> flowProcess, boolean fullyQualified) Method getChildPartitionIdentifiers returns an array of all identifiers for all available partitions.
protected abstract String	getCurrentIdentifier(FlowProcess<Config> flowProcess)
String	getIdentifier() Method getIdentifier returns a String representing the resource this Tap instance represents.
long	getModifiedTime(Config conf) Method getModifiedTime returns the date this resource was last modified.
int	getOpenWritesThreshold() Method getOpenWritesThreshold returns the openTapsThreshold of this PartitionTap object.
Tap	getParent() Method getParent returns the parent Tap of this PartitionTap object.
Partition	getPartition() Method getPartition returns the Partition instance used by this PartitionTap
int	hashCode()
TupleEntryIterator	openForRead(FlowProcess<Config> flowProcess, Input input) Method openForRead opens the resource represented by this Tap instance for reading.
TupleEntryCollector	openForWrite(FlowProcess<Config> flowProcess, Output output) Method openForWrite opens the resource represented by this Tap instance for writing.
boolean	resourceExists(Config conf) Method resourceExists returns true if the path represented by this instance exists.
boolean	rollbackResource(Config conf) Method rollbackResource allows the underlying resource to be notified when any write processing has failed or was stopped so that any cleanup may be started.
String	toString()

Methods inherited from class cascading.tap.Tap

createResource, deleteResource, flowConfInit, getConfigDef, getFullIdentifier, getFullIdentifier, getModifiedTime, getScheme, getSinkFields, getSinkMode, getSourceFields, getStepConfigDef, getTrace, hasConfigDef, hasStepConfigDef, id, isEquivalentTo, isKeep, isReplace, isSink, isSource, isTemporary, isUpdate, openForRead, openForWrite, outgoingScopeFor, presentSinkFields, presentSourceFields, resolveIncomingOperationArgumentFields, resolveIncomingOperationPassThroughFields, resourceExists, retrieveSinkFields, retrieveSourceFields, setScheme, sinkConfInit, sourceConfInit, taps

Methods inherited from class java.lang.Object

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

Field Detail

OPEN_WRITES_THRESHOLD_DEFAULT

protected static final int OPEN_WRITES_THRESHOLD_DEFAULT

Field OPEN_FILES_THRESHOLD_DEFAULT

See Also:

Constant Field Values

parent

protected Tap parent

Field parent

partition

protected Partition partition

Field partition

keepParentOnDelete

protected boolean keepParentOnDelete

Field keepParentOnDelete

openWritesThreshold

protected int openWritesThreshold

Field openTapsThreshold

Constructor Detail

BasePartitionTap

protected BasePartitionTap(Tap parent,
                           Partition partition,
                           int openWritesThreshold)

BasePartitionTap

protected BasePartitionTap(Tap parent,
                           Partition partition,
                           SinkMode sinkMode)

BasePartitionTap

protected BasePartitionTap(Tap parent,
                           Partition partition,
                           SinkMode sinkMode,
                           boolean keepParentOnDelete,
                           int openWritesThreshold)

Method Detail

createTupleEntrySchemeCollector

protected abstract TupleEntrySchemeCollector createTupleEntrySchemeCollector(FlowProcess<Config> flowProcess,
                                                                             Tap parent,
                                                                             String path,
                                                                             long sequence)
                                                                      throws IOException

Throws:

IOException

createTupleEntrySchemeIterator

protected abstract TupleEntrySchemeIterator createTupleEntrySchemeIterator(FlowProcess<Config> flowProcess,
                                                                           Tap parent,
                                                                           String path,
                                                                           Input input)
                                                                    throws IOException

Throws:

IOException

getParent

public Tap getParent()

Method getParent returns the parent Tap of this PartitionTap object.

Returns:

the parent (type Tap) of this PartitionTap object.

getPartition

public Partition getPartition()

Method getPartition returns the Partition instance used by this PartitionTap

Returns:

the partition instance

getChildPartitionIdentifiers

public String[] getChildPartitionIdentifiers(FlowProcess<Config> flowProcess,
                                             boolean fullyQualified)
                                      throws IOException

Method getChildPartitionIdentifiers returns an array of all identifiers for all available partitions.

This method is used internally to set all incoming paths, override to limit applicable partitions.

Note the returns array may be large.

Parameters:

flowProcess - of type FlowProcess

fullyQualified - of type boolean

Returns:

a String[] of partition identifiers

Throws:

IOException

getIdentifier

public String getIdentifier()

Description copied from class: Tap

Method getIdentifier returns a String representing the resource this Tap instance represents.

Often, if the tap accesses a filesystem, the identifier is nothing more than the path to the file or directory. In other cases it may be a an URL or URI representing a connection string or remote resource.

Any two Tap instances having the same value for the identifier are considered equal.

Specified by:

getIdentifier in class Tap<Config,Input,Output>

Returns:

String

getCurrentIdentifier

protected abstract String getCurrentIdentifier(FlowProcess<Config> flowProcess)

getOpenWritesThreshold

public int getOpenWritesThreshold()

Method getOpenWritesThreshold returns the openTapsThreshold of this PartitionTap object.

Returns:

the openTapsThreshold (type int) of this PartitionTap object.

openForWrite

public TupleEntryCollector openForWrite(FlowProcess<Config> flowProcess,
                                        Output output)
                                 throws IOException

Description copied from class: Tap

Method openForWrite opens the resource represented by this Tap instance for writing.

This method is used internally and does not honor the SinkMode setting. If SinkMode is SinkMode.REPLACE, this call may fail. See Tap.openForWrite(cascading.flow.FlowProcess).

output value may be null, if so, sub-classes must inquire with the underlying Scheme via Scheme.sinkConfInit(cascading.flow.FlowProcess, Tap, Object) to get the proper output type and instantiate it before calling super.openForWrite().

Specified by:

openForWrite in class Tap<Config,Input,Output>

Parameters:

flowProcess - of type FlowProcess

output - of type Output

Returns:

TupleEntryCollector

Throws:

IOException - when the resource cannot be opened

openForRead

public TupleEntryIterator openForRead(FlowProcess<Config> flowProcess,
                                      Input input)
                               throws IOException

Description copied from class: Tap

Method openForRead opens the resource represented by this Tap instance for reading.

input value may be null, if so, sub-classes must inquire with the underlying Scheme via Scheme.sourceConfInit(cascading.flow.FlowProcess, Tap, Object) to get the proper input type and instantiate it before calling super.openForRead().

Note the returned iterator will return the same instance of TupleEntry on every call, thus a copy must be made of either the TupleEntry or the underlying Tuple instance if they are to be stored in a Collection.

Specified by:

openForRead in class Tap<Config,Input,Output>

Parameters:

flowProcess - of type FlowProcess

input - of type Input

Returns:

TupleEntryIterator

Throws:

IOException - when the resource cannot be opened

createResource

public boolean createResource(Config conf)
                       throws IOException

Description copied from class: Tap

Method createResource creates the underlying resource.

Specified by:

createResource in class Tap<Config,Input,Output>

Parameters:

conf - of type Config

Returns:

boolean

Throws:

IOException - when there is an error making directories

deleteResource

public boolean deleteResource(Config conf)
                       throws IOException

Description copied from class: Tap

Method deleteResource deletes the resource represented by this instance.

Specified by:

deleteResource in class Tap<Config,Input,Output>

Parameters:

conf - of type Config

Returns:

boolean

Throws:

IOException - when the resource cannot be deleted

commitResource

public boolean commitResource(Config conf)
                       throws IOException

Description copied from class: Tap

Method commitResource allows the underlying resource to be notified when all write processing is successful so that any additional cleanup or processing may be completed.

See Tap.rollbackResource(Object) to handle cleanup in the face of failures.

This method is invoked once "client side" and not in the cluster, if any.

If other sink Tap instance in a given Flow fail on commitResource after called on this instance, rollbackResource will not be called.

This is an experimental API and subject to refinement!!

Overrides:

commitResource in class Tap<Config,Input,Output>

Parameters:

conf - of type Config

Returns:

returns true if successful

Throws:

IOException

rollbackResource

public boolean rollbackResource(Config conf)
                         throws IOException

Description copied from class: Tap

Method rollbackResource allows the underlying resource to be notified when any write processing has failed or was stopped so that any cleanup may be started.

See Tap.commitResource(Object) to handle cleanup when the write has successfully completed.

This method is invoked once "client side" and not in the cluster, if any.

This is an experimental API and subject to refinement!!

Overrides:

rollbackResource in class Tap<Config,Input,Output>

Parameters:

conf - of type Config

Returns:

returns true if successful

Throws:

IOException

resourceExists

public boolean resourceExists(Config conf)
                       throws IOException

Description copied from class: Tap

Method resourceExists returns true if the path represented by this instance exists.

Specified by:

resourceExists in class Tap<Config,Input,Output>

Parameters:

conf - of type Config

Returns:

true if the underlying resource already exists

Throws:

IOException - when the status cannot be determined

getModifiedTime

public long getModifiedTime(Config conf)
                     throws IOException

Description copied from class: Tap

Method getModifiedTime returns the date this resource was last modified.

Specified by:

getModifiedTime in class Tap<Config,Input,Output>

Parameters:

conf - of type Config

Returns:

The date this resource was last modified.

Throws:

IOException

equals

public boolean equals(Object object)

Overrides:

equals in class Tap<Config,Input,Output>

hashCode

public int hashCode()

Overrides:

hashCode in class Tap<Config,Input,Output>

toString

public String toString()

Overrides:

toString in class Tap<Config,Input,Output>