org.apache.samza.table.remote

Interface TableReadFunction<K,V>

Type Parameters:

K - the type of the key in this table

V - the type of the value in this table

All Superinterfaces:

ClosableFunction, java.io.Serializable, TableFunction, TablePart

@InterfaceStability.Unstable
public interface TableReadFunction<K,V>
extends TableFunction

A function object to be used with a remote readable table implementation. It encapsulates the functionality of reading table record(s) for a provided set of key(s).

Instances of TableReadFunction are meant to be serializable. ie. any non-serializable state (eg: network sockets) should be marked as transient and recreated inside readObject().

Implementations are expected to be thread-safe.

Method Summary

Modifier and Type	Method and Description
default V	get(K key) Fetch single table record for a specified key.
default java.util.Map<K,V>	getAll(java.util.Collection<K> keys) Fetch the table records for specified keys.
default java.util.concurrent.CompletableFuture<java.util.Map<K,V>>	getAllAsync(java.util.Collection<K> keys) Asynchronously fetch the table records for specified keys.
default java.util.concurrent.CompletableFuture<java.util.Map<K,V>>	getAllAsync(java.util.Collection<K> keys, java.lang.Object... args) Asynchronously fetch the table records for specified keys and additional arguments.
java.util.concurrent.CompletableFuture<V>	getAsync(K key) Asynchronously fetch single table record for a specified key.
default java.util.concurrent.CompletableFuture<V>	getAsync(K key, java.lang.Object... args) Asynchronously fetch single table record for a specified key with additional arguments.
default <T> java.util.concurrent.CompletableFuture<T>	readAsync(int opId, java.lang.Object... args) Asynchronously read data from table for specified opId and additional arguments.

Methods inherited from interface org.apache.samza.table.remote.TableFunction

init, isRetriable

Methods inherited from interface org.apache.samza.table.remote.TablePart

toConfig

Methods inherited from interface org.apache.samza.operators.functions.ClosableFunction

close

Method Detail

get

default V get(K key)

Fetch single table record for a specified key. This method must be thread-safe. The default implementation calls getAsync and blocks on the completion afterwards.

Parameters:

key - key for the table record

Returns:

table record for the specified key

getAsync

java.util.concurrent.CompletableFuture<V> getAsync(K key)

Asynchronously fetch single table record for a specified key. This method must be thread-safe.

Parameters:

key - key for the table record

Returns:

CompletableFuture for the get request

getAsync

default java.util.concurrent.CompletableFuture<V> getAsync(K key,
                                                           java.lang.Object... args)

Asynchronously fetch single table record for a specified key with additional arguments. This method must be thread-safe.

Parameters:

key - key for the table record

args - additional arguments

Returns:

CompletableFuture for the get request

getAll

default java.util.Map<K,V> getAll(java.util.Collection<K> keys)

Fetch the table records for specified keys. This method must be thread-safe. The default implementation calls getAllAsync and blocks on the completion afterwards.

Parameters:

keys - keys for the table records

Returns:

all records for the specified keys.

getAllAsync

default java.util.concurrent.CompletableFuture<java.util.Map<K,V>> getAllAsync(java.util.Collection<K> keys)

Asynchronously fetch the table records for specified keys. This method must be thread-safe. The default implementation calls getAsync for each key and return a combined future.

Parameters:

keys - keys for the table records

Returns:

CompletableFuture for the get request

getAllAsync

default java.util.concurrent.CompletableFuture<java.util.Map<K,V>> getAllAsync(java.util.Collection<K> keys,
                                                                               java.lang.Object... args)

Asynchronously fetch the table records for specified keys and additional arguments. This method must be thread-safe.

Parameters:

keys - keys for the table records

args - additional arguments

Returns:

CompletableFuture for the get request

readAsync

default <T> java.util.concurrent.CompletableFuture<T> readAsync(int opId,
                                                                java.lang.Object... args)

Asynchronously read data from table for specified opId and additional arguments. This method must be thread-safe.

Type Parameters:

T - return type

Parameters:

opId - operation identifier

args - additional arguments

Returns:

CompletableFuture for the read request