/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed 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 com.google.common.hash;
import com.google.common.annotations.Beta;
import java.io.Serializable;
/**
* An object which can send data from an object of type {@code T} into a {@code PrimitiveSink}.
* Implementations for common types can be found in {@link Funnels}.
*
* <p>Note that serialization of {@linkplain BloomFilter bloom filters} requires the proper
* serialization of funnels. When possible, it is recommended that funnels be implemented as a
* single-element enum to maintain serialization guarantees. See Effective Java (2nd Edition),
* Item 3: "Enforce the singleton property with a private constructor or an enum type". For example:
* <pre> {@code
* public enum PersonFunnel implements Funnel<Person> {
* INSTANCE;
* public void funnel(Person person, PrimitiveSink into) {
* into.putUnencodedChars(person.getFirstName())
* .putUnencodedChars(person.getLastName())
* .putInt(person.getAge());
* }
* }}</pre>
*
* @author Dimitris Andreou
* @since 11.0
*/
@Beta
public interface Funnel<T> extends Serializable {
/**
* Sends a stream of data from the {@code from} object into the sink {@code into}. There
* is no requirement that this data be complete enough to fully reconstitute the object
* later.
*
* @since 12.0 (in Guava 11.0, {@code PrimitiveSink} was named {@code Sink})
*/
void funnel(T from, PrimitiveSink into);
}