Package org.apache.gravitino.messaging

Interface TopicCatalog

@Evolving
public interface TopicCatalog

The TopicCatalog interface defines the public API for managing topic objects in a schema. If the catalog implementation supports topic objects, it should implement this interface.

Method Summary

Modifier and Type	Method	Description
Topic	alterTopic(NameIdentifier ident, TopicChange... changes)	Apply the changes to a topic in the catalog.
Topic	createTopic(NameIdentifier ident, String comment, DataLayout dataLayout, Map<String,String> properties)	Create a topic in the catalog based on the provided details.
boolean	dropTopic(NameIdentifier ident)	Drop a topic from the catalog.
NameIdentifier[]	listTopics(Namespace namespace)	List the topics in a schema namespace from the catalog.
Topic	loadTopic(NameIdentifier ident)	Load topic metadata by NameIdentifier from the catalog.
default boolean	topicExists(NameIdentifier ident)	Check if a topic exists using an NameIdentifier from the catalog.

Method Details

listTopics

NameIdentifier[] listTopics(Namespace namespace)
                     throws NoSuchSchemaException

List the topics in a schema namespace from the catalog.

Parameters:

namespace - A schema namespace.

Returns:

An array of topic identifiers in the namespace.

Throws:

NoSuchSchemaException - If the schema does not exist.

loadTopic

Topic loadTopic(NameIdentifier ident)
         throws NoSuchTopicException

Load topic metadata by NameIdentifier from the catalog.

Parameters:

ident - A topic identifier.

Returns:

The topic metadata.

Throws:

NoSuchTopicException - If the topic does not exist.

topicExists

default boolean topicExists(NameIdentifier ident)

Check if a topic exists using an NameIdentifier from the catalog.

Parameters:

ident - A topic identifier.

Returns:

true If the topic exists, false otherwise.

createTopic

Topic createTopic(NameIdentifier ident,
 String comment,
 DataLayout dataLayout,
 Map<String,String> properties)
           throws NoSuchSchemaException,
TopicAlreadyExistsException

Create a topic in the catalog based on the provided details.

This method returns the topic as defined by the user without applying all defaults. If you need the topic with default values applied, use the loadTopic(NameIdentifier) method after creation.

Parameters:

ident - A topic identifier.

comment - The comment of the topic object. Null is set if no comment is specified.

dataLayout - The message schema of the topic object. Always null because it's not supported yet.

properties - The properties of the topic object. Empty map is set if no properties are specified.

Returns:

The topic as defined by the caller, without all default values.

Throws:

NoSuchSchemaException - If the schema does not exist.

TopicAlreadyExistsException - If the topic already exists.

alterTopic

Topic alterTopic(NameIdentifier ident,
 TopicChange... changes)
          throws NoSuchTopicException,
IllegalArgumentException

Apply the changes to a topic in the catalog.

Parameters:

ident - A topic identifier.

changes - The changes to apply to the topic.

Returns:

The altered topic metadata.

Throws:

NoSuchTopicException - If the topic does not exist.

IllegalArgumentException - If the changes is rejected by the implementation.

dropTopic

boolean dropTopic(NameIdentifier ident)

Drop a topic from the catalog.

Parameters:

ident - A topic identifier.

Returns:

true If the topic is dropped, false if the topic does not exist.