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 */ 019package org.apache.commons.compress.utils; 020 021import java.io.FilterInputStream; 022import java.io.IOException; 023import java.io.InputStream; 024 025/** 026 * Input stream that tracks the number of bytes read. 027 * @since 1.3 028 * @NotThreadSafe 029 */ 030public class CountingInputStream extends FilterInputStream { 031 private long bytesRead; 032 033 public CountingInputStream(final InputStream in) { 034 super(in); 035 } 036 037 /** 038 * Increments the counter of already read bytes. 039 * Doesn't increment if the EOF has been hit (read == -1) 040 * 041 * @param read the number of bytes read 042 */ 043 protected final void count(final long read) { 044 if (read != -1) { 045 bytesRead += read; 046 } 047 } 048 049 /** 050 * Returns the current number of bytes read from this stream. 051 * @return the number of read bytes 052 */ 053 public long getBytesRead() { 054 return bytesRead; 055 } 056 057 @Override 058 public int read() throws IOException { 059 final int r = in.read(); 060 if (r >= 0) { 061 count(1); 062 } 063 return r; 064 } 065 066 @Override 067 public int read(final byte[] b) throws IOException { 068 return read(b, 0, b.length); 069 } 070 071 @Override 072 public int read(final byte[] b, final int off, final int len) throws IOException { 073 if (len == 0) { 074 return 0; 075 } 076 final int r = in.read(b, off, len); 077 if (r >= 0) { 078 count(r); 079 } 080 return r; 081 } 082}