Java tutorial
/* * Copyright (c) 2016 Uber Technologies, Inc. (hoodie-dev-group@uber.com) * * 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.uber.hoodie.io.storage; import org.apache.hadoop.fs.FSDataOutputStream; import java.io.IOException; import java.util.concurrent.atomic.AtomicLong; /** * Wrapper over <code>FSDataOutputStream</code> to keep track of the size of the written bytes. * This gives a cheap way to check on the underlying file size. */ public class SizeAwareFSDataOutputStream extends FSDataOutputStream { // A callback to call when the output stream is closed. private final Runnable closeCallback; // Keep track of the bytes written private final AtomicLong bytesWritten = new AtomicLong(0L); public SizeAwareFSDataOutputStream(FSDataOutputStream out, Runnable closeCallback) throws IOException { super(out); this.closeCallback = closeCallback; } @Override public synchronized void write(byte[] b, int off, int len) throws IOException { bytesWritten.addAndGet(len); super.write(b, off, len); } @Override public void write(byte[] b) throws IOException { bytesWritten.addAndGet(b.length); super.write(b); } @Override public void close() throws IOException { super.close(); closeCallback.run(); } public long getBytesWritten() { return bytesWritten.get(); } }