com.vertica.sdk.SourceIterator Class Reference

Inheritance diagram for com.vertica.sdk.SourceIterator:

Collaboration diagram for com.vertica.sdk.SourceIterator:

Public Member Functions
final void	cancelUDX (ServerInterface srvInterface)
abstract UnsizedUDSource	createNextSource (ServerInterface srvInterface) throws UdfException
void	destroy (ServerInterface srvInterface, NodeSpecifyingPlanContext planCtxt) throws UdfException
abstract int	getNumberOfSources () throws UdfException
Integer	getSizeOfSource (int sourceNum) throws UdfException
boolean	isCanceled ()
void	setup (ServerInterface srvInterface, NodeSpecifyingPlanContext planCtxt) throws UdfException

Protected Member Functions
void	cancel (ServerInterface srvInterface)

Detailed Description

Constructs a set of Sources to be used by an IterativeSourceFactory.

createNextSource() will be called repeatedly until it returns NULL. Each resulting Source will be read to completion, and the contained data passed to the Filter and Parser.

Member Function Documentation

cancel()

void com.vertica.sdk.UDXObject.cancel ( ServerInterface  srvInterface )

protectedinherited

Cancel callback to be overridden by the UDX implementation. Called when the query running the UDX has been canceled.

• This method will be invoked at most once per UDX object. Once a UDX object has been canceled, it will never be un-canceled.
• This method may be called from a separate thread, concurrently with other methods of this UDX object (but never the constructor). Implementations must be thread-safe with all methods of this UDX.
• This method will be invoked for either an explicit user cancel, or in the event of an error during query execution.

Parameters

srvInterface

a ServerInterface object used to communicate with Vertica

Referenced by com.vertica.sdk.UDXObject.cancelUDX().

cancelUDX()

final void com.vertica.sdk.UDXObject.cancelUDX ( ServerInterface  srvInterface )

inherited

Cancel callback invoked when the query running the UDX has been canceled.

See cancel().

Parameters

srvInterface

a ServerInterface object used to communicate with Vertica

createNextSource()

abstract UnsizedUDSource com.vertica.sdk.SourceIterator.createNextSource ( ServerInterface  srvInterface ) throws UdfException

abstract

Create the next UDSource to process.

Should return NULL if no further sources are available for processing.

Note that the previous Source may still be open and in use on a different thread when this function is called.

Parameters

srvInterface

a ServerInterface object used to communicate with Vertica

Returns

a new Source instance corresponding to a new input stream

Exceptions

UdfException

UDF problem

destroy()

void com.vertica.sdk.SourceIterator.destroy	(	ServerInterface	srvInterface,
		NodeSpecifyingPlanContext	planCtxt
	)		throws UdfException

Tear down this SourceIterator

Should perform clean-up

Parameters

srvInterface	a ServerInterface object used to communicate with Vertica
planCtxt	a plan context

Exceptions

UdfException

UDF problem

getNumberOfSources()

abstract int com.vertica.sdk.SourceIterator.getNumberOfSources ( ) throws UdfException

abstract

Returns

the total number of Sources that this factory will produce

Exceptions

UdfException

UDF problem

Referenced by com.vertica.sdk.SourceFactory.getDesiredThreads().

getSizeOfSource()

Integer com.vertica.sdk.SourceIterator.getSizeOfSource

(

int

sourceNum

)

throws UdfException

Parameters

sourceNum

which source to query

Returns

the raw-data size of the sourceNum'th source that will be produced by createNextSource(). Should return vint_null if the size is unknown.

This value is used as a hint, and is used by the "load_streams" table to display load progress. If incorrect or not set, "load_streams" may contain incorrect or unhelpful information.

Exceptions

UdfException

UDF problem

isCanceled()

boolean com.vertica.sdk.UDXObject.isCanceled ( )

inherited

Returns

true if execution was canceled.

Referenced by com.vertica.sdk.UDXObject.cancelUDX().

setup()

void com.vertica.sdk.SourceIterator.setup	(	ServerInterface	srvInterface,
		NodeSpecifyingPlanContext	planCtxt
	)		throws UdfException

Set up this SourceIterator

Should perform setup that should not take place in the constructor due to the exception-handling semantics of constructors

Parameters

srvInterface	a ServerInterface object used to communicate with Vertica
planCtxt	a plan context

Exceptions

UdfException

UDF problem