001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     * http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing,
013     * software distributed under the License is distributed on an
014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     * KIND, either express or implied.  See the License for the
016     * specific language governing permissions and limitations
017     * under the License.
018     */
019    package org.apache.commons.compress.utils;
020    
021    import java.io.FilterInputStream;
022    import java.io.IOException;
023    import java.io.InputStream;
024    
025    /**
026     * Stream that tracks the number of bytes read.
027     * @since Apache Commons Compress 1.3
028     * @NotThreadSafe
029     */
030    public class CountingInputStream extends FilterInputStream {
031        private long bytesRead;
032    
033        public CountingInputStream(final InputStream in) {
034            super(in);
035        }
036    
037        @Override
038        public int read() throws IOException {
039            int r = in.read();
040            if (r >= 0) {
041                count(1);
042            }
043            return r;
044        }
045        @Override
046        public int read(byte[] b) throws IOException {
047            return read(b, 0, b.length);
048        }
049        @Override
050        public int read(byte[] b, int off, int len) throws IOException {
051            int r = in.read(b, off, len);
052            if (r >= 0) {
053                count(r);
054            }
055            return r;
056        }
057        /**
058         * Increments the counter of already read bytes.
059         * Doesn't increment if the EOF has been hit (read == -1)
060         * 
061         * @param read the number of bytes read
062         */
063        protected final void count(long read) {
064            if (read != -1) {
065                bytesRead += read;
066            }
067        }
068        
069        /**
070         * Returns the current number of bytes read from this stream.
071         * @return the number of read bytes
072         */
073        public long getBytesRead() {
074            return bytesRead;
075        }
076    }