io.cdap.wrangler.registry

Class CompositeDirectiveRegistry

java.lang.Object

io.cdap.wrangler.registry.CompositeDirectiveRegistry

All Implemented Interfaces:

DirectiveRegistry, Closeable, AutoCloseable

public final class CompositeDirectiveRegistry
extends Object
implements DirectiveRegistry

This class implements a Composition of multiple registries.

It implements the DirectiveRegistry interface. Search for a directives uses the order of the directives specified at the construction time.

If the directive is not found in any of the registry, then a null is returned.

Constructor Summary

Constructors

Constructor and Description
CompositeDirectiveRegistry(DirectiveRegistry... registries)

Method Summary

Modifier and Type	Method and Description
void	close() Closes any resources acquired during initialization or otherwise.
DirectiveInfo	get(String namespace, String directive) This method looks for the directive in all the registered registries.
ArtifactSummary	getLatestWranglerArtifact() Retrieve latest Wrangler transform artifact information
Iterable<DirectiveInfo>	list(String namespace) List the directives in the specified namespace
void	reload(String namespace) This method reloads the directives from the artifacts into the registry.

Methods inherited from class java.lang.Object

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

Constructor Detail

CompositeDirectiveRegistry

public CompositeDirectiveRegistry(DirectiveRegistry... registries)

Method Detail

get

@Nullable
public DirectiveInfo get(String namespace,
                                   String directive)
                            throws DirectiveLoadException

This method looks for the directive in all the registered registries.

The order of search is as specified by the collection order. Upon finding the first valid instance of directive, the DirectiveInfo is returned.

Specified by:

get in interface DirectiveRegistry

Parameters:

directive - of the directive to be retrived from the registry.

namespace - the namespace of the directive

Returns:

an instance of DirectiveInfo if found, else null.

Throws:

DirectiveLoadException

reload

public void reload(String namespace)
            throws DirectiveLoadException

Description copied from interface: DirectiveRegistry

This method reloads the directives from the artifacts into the registry. Any implementation of this method should provide support for deletes, updates and additions.

Specified by:

reload in interface DirectiveRegistry

Parameters:

namespace - the namespace to reload directives in

Throws:

DirectiveLoadException - thrown when there are any issues with loading directives into the registry.

getLatestWranglerArtifact

@Nullable
public ArtifactSummary getLatestWranglerArtifact()

Description copied from interface: DirectiveRegistry

Retrieve latest Wrangler transform artifact information

Specified by:

getLatestWranglerArtifact in interface DirectiveRegistry

list

public Iterable<DirectiveInfo> list(String namespace)

Description copied from interface: DirectiveRegistry

List the directives in the specified namespace

Specified by:

list in interface DirectiveRegistry

Parameters:

namespace - the namespace to list from

Returns:

Returns an iterator to iterate through all the DirectiveInfo objects maintained within the registry.

close

public void close()
           throws IOException

Closes any resources acquired during initialization or otherwise.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException