/*
* 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.beam.runners.core;
import org.apache.beam.sdk.util.common.ElementByteSizeObserver;
/**
* An interface for things that allow observing the size in bytes of
* encoded values of type {@code T}.
*
* @param <T> the type of the values being observed
*/
public interface ElementByteSizeObservable<T> {
/**
* Returns whether {@link #registerByteSizeObserver} is cheap enough
* to call for every element, that is, if this
* {@code ElementByteSizeObservable} can calculate the byte size of
* the element to be coded in roughly constant time (or lazily).
*/
boolean isRegisterByteSizeObserverCheap(T value);
/**
* Notifies the {@code ElementByteSizeObserver} about the byte size
* of the encoded value using this {@code ElementByteSizeObservable}.
*/
void registerByteSizeObserver(T value, ElementByteSizeObserver observer)
throws Exception;
}