org.apache.flink.runtime.state.gemini.engine.GeminiKV Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.runtime.state.gemini.engine;
import java.util.Map;
/**
* GeminiKV.
* K is type of key.
* V is type of value.
*/
public interface GeminiKV {
/**
* Associates the given value with the given key in the storage.
* If the storage previously contains a value for the given key,
* the old value will be replaced with the new value.
*
* @param key The key with which the given value is to be associated.
* @param value The value to be associated with the given key.
*/
void put(K key, V value);
/**
* Returns the value associated with the given key in the state.
* Null will be returned if this state contains no value for the key.
*
* @param key The key of the value to be retrieved.
* @return The value associated with the given key.
*/
V get(K key);
/**
* Returns the value associated with the key in the state, or
* {@code defaultValue} if the key does not exist in the state.
*
* @param key The key whose associated value is to be returned.
* @param defaultValue The default value of the key.
* @return The value to which the specified key is mapped, or
* {@code defaultValue} if the key does not exist in the state.
*/
V getOrDefault(K key, V defaultValue);
/**
* Removes the value for the given key from the storage if it is present.
*
* @param key The key of the value to be removed.
*/
void remove(K key);
/**
* Returns all the key/value map in the state.
*
* @return The key/value map in the state.
*/
Map getAll();
/**
* Put all the key/value of the state into map.
*/
void getAll(Map results);
/**
* Remove all the items in the state.
*/
void removeAll();
/**
* Returns an iterable over all of the keys in the state.
*
* @return The iterable of all the keys in the state.
*/
Iterable keys();
/**
* Returns true if the state contains a pair whose key is equal to the given
* object.
*
* @param key The key whose presence in the state to be tested.
* @return True if the state contains the pair for the given key.
*/
boolean contains(K key);
}