001/*
002 * ModeShape (http://www.modeshape.org)
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *       http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.modeshape.common.util;
017
018import java.io.IOException;
019import java.io.InputStream;
020import java.util.concurrent.atomic.AtomicLong;
021
022/**
023 * An {@link InputStream} implementation that can wrap another input stream and determine the number of bytes read.
024 */
025public class SizeMeasuringInputStream extends InputStream {
026    private final InputStream stream;
027    private final AtomicLong size;
028
029    public SizeMeasuringInputStream( InputStream stream,
030                                     AtomicLong size ) {
031        this.stream = stream;
032        this.size = size;
033    }
034
035    @Override
036    public int read() throws IOException {
037        int result = stream.read();
038        if (result != -1) {
039            size.addAndGet(1);
040        }
041        return result;
042    }
043
044    @Override
045    public int read( byte[] b,
046                     int off,
047                     int len ) throws IOException {
048        // Read from the stream ...
049        int n = stream.read(b, off, len);
050        if (n != -1) {
051            size.addAndGet(n);
052        }
053        return n;
054    }
055
056    @Override
057    public int read( byte[] b ) throws IOException {
058        int n = stream.read(b);
059        if (n != -1) {
060            size.addAndGet(n);
061        }
062        return n;
063    }
064
065    @Override
066    public synchronized void mark( int readlimit ) {
067        stream.mark(readlimit);
068    }
069
070    @Override
071    public boolean markSupported() {
072        return stream.markSupported();
073    }
074
075    @Override
076    public int available() throws IOException {
077        return stream.available();
078    }
079
080    @Override
081    public synchronized void reset() throws IOException {
082        stream.reset();
083    }
084
085    @Override
086    public void close() throws IOException {
087        stream.close();
088    }
089}