org.aksw.jena_sparql_api.io.endpoint

Class DestinationFromSwitch

java.lang.Object

org.aksw.jena_sparql_api.io.endpoint.DestinationFromSwitch

All Implemented Interfaces:

Destination

public class DestinationFromSwitch
extends Object
implements Destination

Switching destination If a file for a DestinationFromFileCreation finishes, it can replace itself with a DestinationFromFile Right now I am not sure whether this is useful: If a stream is requested, it has to do all the preparation work anyway If we think of a source + filter as a virtual source, then it is actually ok: Let's not forget that a destination is a supplier for input streams Repeatedly executing such a workflow may re-use prior generated files instead of repeating the process again from the source file However, the purpose of this framework is not to do full caching, but only abstract java and system filters, but allow controlling what should happen with the files in case they get generated. The next level of abstraction could be thought of as treating files as stores: E.g. writing a stream to HDFS and passing a reference to it to a system command

Author:

raven

Field Summary

Fields

Modifier and Type	Field and Description
protected Destination	destination

Constructor Summary

Constructors

Constructor and Description
DestinationFromSwitch()

Method Summary

Modifier and Type	Method and Description
String	getCreationStatus() Get a description of the creation status.
Destination	getDestination()
io.reactivex.rxjava3.core.Single<DestinationFromFile>	materialize(Supplier<Path> preferredPathCallback) Materialize the destination to a given file.
io.reactivex.rxjava3.core.Single<InputStreamSupplier>	prepareStream() This method requests a supplier for inputstreams.
FilterConfig	transferTo(FilterEngine engine)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.aksw.jena_sparql_api.io.endpoint.Destination

cancelCreation

Field Detail

destination

protected Destination destination

Constructor Detail

DestinationFromSwitch

public DestinationFromSwitch()

Method Detail

getDestination

public Destination getDestination()

prepareStream

public io.reactivex.rxjava3.core.Single<InputStreamSupplier> prepareStream()

Description copied from interface: Destination

This method requests a supplier for inputstreams. For basic destinations, such as FileDestination, this process does not involve any overhead. However, if the destination represents a workflow, prepareStream may trigger a complex execution. The execution may generate a file from which streams can be obtained, or nothing gets executed at this point, and execution only occur when opening an input stream.

Specified by:

prepareStream in interface Destination

Returns:

transferTo

public FilterConfig transferTo(FilterEngine engine)

Specified by:

transferTo in interface Destination

materialize

public io.reactivex.rxjava3.core.Single<DestinationFromFile> materialize(Supplier<Path> preferredPathCallback)
                                                                  throws IOException

Description copied from interface: Destination

Materialize the destination to a given file. If the destination is already a file it waits until it has been completed. For non-file destinations, the callback is invoked to obtain a preferred file name

Specified by:

materialize in interface Destination

Returns:

Throws:

IOException

getCreationStatus

public String getCreationStatus()

Description copied from interface: Destination

Get a description of the creation status.

Specified by:

getCreationStatus in interface Destination

Returns: