org.apache.samza.metadatastore

Interface MetadataStore

@InterfaceStability.Evolving
public interface MetadataStore

Store abstraction responsible for managing the metadata of a Samza job.

Method Summary

Modifier and Type	Method and Description
java.util.Map<byte[],byte[]>	all() Returns all the entries in this metadata store.
void	close() Closes the metadata store, if applicable, relinquishing all the underlying resources and connections.
void	delete(byte[] key) Deletes the mapping for the specified key from this metadata store (if such mapping exists).
void	flush() Flushes the metadata store, if applicable.
byte[]	get(byte[] key) Gets the value associated with the specified key.
void	init() Initializes the metadata store, if applicable, setting up the underlying resources and connections to the store endpoints.
void	put(byte[] key, byte[] value) Updates the mapping of the specified key-value pair.

Method Detail

init

void init()

Initializes the metadata store, if applicable, setting up the underlying resources and connections to the store endpoints.

get

byte[] get(byte[] key)

Gets the value associated with the specified key.

Parameters:

key - the key with which the associated value is to be fetched.

Returns:

if found, the value associated with the specified key; otherwise, null.

put

void put(byte[] key,
         byte[] value)

Updates the mapping of the specified key-value pair.

Parameters:

key - the key with which the specified value is to be associated.

value - the value with which the specified key is to be associated.

delete

void delete(byte[] key)

Deletes the mapping for the specified key from this metadata store (if such mapping exists).

Parameters:

key - the key for which the mapping is to be deleted.

all

java.util.Map<byte[],byte[]> all()

Returns all the entries in this metadata store.

Returns:

all entries in this metadata store.

flush

void flush()

Flushes the metadata store, if applicable.

close

void close()

Closes the metadata store, if applicable, relinquishing all the underlying resources and connections.