org.apache.samza.metadatastore

Interface MetadataStore

All Known Implementing Classes:

InMemoryMetadataStore

@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<java.lang.String,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(java.lang.String 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(java.lang.String 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(java.lang.String key, byte[] value) Updates the mapping of the specified key-value pair.
default void	putAll(java.util.Map<java.lang.String,byte[]> entries) Updates the mapping with the specified map.

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(java.lang.String 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(java.lang.String 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.

putAll

default void putAll(java.util.Map<java.lang.String,byte[]> entries)

Updates the mapping with the specified map. This is not guaranteed to be atomic.

Parameters:

entries - mapping of key to values to write to the metadata store

delete

void delete(java.lang.String 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<java.lang.String,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.