org.apache.flink.statefun.sdk.state

Class PersistedTable<K,V>

java.lang.Object

org.apache.flink.statefun.sdk.state.PersistedTable<K,V>

Type Parameters:

K - type of the key - Please note that the key have a meaningful Object.hashCode() and Object.equals(Object) implemented.

V - type of the value.

public final class PersistedTable<K,V>
extends java.lang.Object

A PersistedTable is a table (collection of keys and values) registered within StatefulFunctions and is persisted and maintained by the system for fault-tolerance.

Created persisted tables must be registered by using the Persisted annotation. Please see the class-level Javadoc of StatefulFunction for an example on how to do that.

See Also:

StatefulFunction

Method Summary

Modifier and Type	Method and Description
void	clear() Clears all elements in the persisted buffer.
java.lang.Iterable<java.util.Map.Entry<K,V>>	entries() Gets an Iterable over all the entries of the persisted table.
Expiration	expiration()
V	get(K key) Returns a persisted table's value.
java.lang.Iterable<K>	keys() Gets an Iterable over all keys of the persisted table.
java.lang.Class<K>	keyType() Returns the type of the persisted tables keys.
java.lang.String	name() Returns the unique name of the persisted table.
static <K,V> PersistedTable<K,V>	of(java.lang.String name, java.lang.Class<K> keyType, java.lang.Class<V> valueType) Creates a PersistedTable instance that may be used to access persisted state managed by the system.
static <K,V> PersistedTable<K,V>	of(java.lang.String name, java.lang.Class<K> keyType, java.lang.Class<V> valueType, Expiration expiration) Creates a PersistedTable instance that may be used to access persisted state managed by the system.
void	remove(K key) Removes the value associated with key.
void	set(K key, V value) Updates the persisted table.
java.lang.String	toString()
java.lang.Iterable<V>	values() Gets an Iterable over all values of the persisted table.
java.lang.Class<V>	valueType() Returns the type of the persisted tables values.

Methods inherited from class java.lang.Object

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

Method Detail

of

public static <K,V> PersistedTable<K,V> of(java.lang.String name,
                                           java.lang.Class<K> keyType,
                                           java.lang.Class<V> valueType)

Creates a PersistedTable instance that may be used to access persisted state managed by the system. Access to the persisted table is identified by an unique name, type of the key, and type of the value. These may not change across multiple executions of the application.

Type Parameters:

K - the type of the state keys.

V - the type of the state values.

Parameters:

name - the unique name of the persisted state.

keyType - the type of the state keys of this PersistedTable.

valueType - the type of the state values of this PersistedTale.

Returns:

a PersistedTable instance.

of

public static <K,V> PersistedTable<K,V> of(java.lang.String name,
                                           java.lang.Class<K> keyType,
                                           java.lang.Class<V> valueType,
                                           Expiration expiration)

Creates a PersistedTable instance that may be used to access persisted state managed by the system. Access to the persisted table is identified by an unique name, type of the key, and type of the value. These may not change across multiple executions of the application.

Type Parameters:

K - the type of the state keys.

V - the type of the state values.

Parameters:

name - the unique name of the persisted state.

keyType - the type of the state keys of this PersistedTable.

valueType - the type of the state values of this PersistedTale.

expiration - state expiration configuration.

Returns:

a PersistedTable instance.

name

public java.lang.String name()

Returns the unique name of the persisted table.

Returns:

unique name of the persisted table.

keyType

public java.lang.Class<K> keyType()

Returns the type of the persisted tables keys.

Returns:

the type of the persisted tables keys.

valueType

public java.lang.Class<V> valueType()

Returns the type of the persisted tables values.

Returns:

the type of the persisted tables values.

expiration

public Expiration expiration()

get

public V get(K key)

Returns a persisted table's value.

Returns:

the persisted table value associated with key.

set

public void set(K key,
                V value)

Updates the persisted table.

Parameters:

key - the to associate the value with.

value - the new value.

remove

public void remove(K key)

Removes the value associated with key.

Parameters:

key - the key to remove.

entries

public java.lang.Iterable<java.util.Map.Entry<K,V>> entries()

Gets an Iterable over all the entries of the persisted table.

Returns:

An Iterable of the elements of the persisted table.

keys

public java.lang.Iterable<K> keys()

Gets an Iterable over all keys of the persisted table.

Returns:

An Iterable of keys in the persisted table.

values

public java.lang.Iterable<V> values()

Gets an Iterable over all values of the persisted table.

Returns:

An Iterable of values in the persisted table.

clear

public void clear()

Clears all elements in the persisted buffer.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object