1bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook/*
2bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * Licensed to the Apache Software Foundation (ASF) under one or more
3bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * contributor license agreements.  See the NOTICE file distributed with
4bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * this work for additional information regarding copyright ownership.
5bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * The ASF licenses this file to You under the Apache License, Version 2.0
6bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * (the "License"); you may not use this file except in compliance with
7bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * the License.  You may obtain a copy of the License at
8bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook *
9bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook *      http://www.apache.org/licenses/LICENSE-2.0
10bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook *
11bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * Unless required by applicable law or agreed to in writing, software
12bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * distributed under the License is distributed on an "AS IS" BASIS,
13bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * See the License for the specific language governing permissions and
15bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * limitations under the License.
16bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook */
17bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrookpackage org.apache.commons.io.input;
18bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook
19bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrookimport java.io.IOException;
20bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrookimport java.io.InputStream;
21bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook
22bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook/**
23bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * A decorating input stream that counts the number of bytes that have passed
24bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * through the stream so far.
25bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * <p>
26bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * A typical use case would be during debugging, to ensure that data is being
27bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * read as expected.
28bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook *
29bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * @author Marcelo Liberato
30bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook * @version $Id: CountingInputStream.java 471628 2006-11-06 04:06:45Z bayard $
31bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook */
32bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrookpublic class CountingInputStream extends ProxyInputStream {
33bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook
34bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    /** The count of bytes that have passed. */
35bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    private long count;
36bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook
37bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    /**
38bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * Constructs a new CountingInputStream.
39bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     *
40bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @param in  the InputStream to delegate to
41bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     */
42bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    public CountingInputStream(InputStream in) {
43bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        super(in);
44bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    }
45bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook
46bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    //-----------------------------------------------------------------------
47bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    /**
48bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * Reads a number of bytes into the byte array, keeping count of the
49bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * number read.
50bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     *
51bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @param b  the buffer into which the data is read, not null
52bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @return the total number of bytes read into the buffer, -1 if end of stream
53bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @throws IOException if an I/O error occurs
54bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @see java.io.InputStream#read(byte[])
55bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     */
56bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    public int read(byte[] b) throws IOException {
57bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        int found = super.read(b);
58bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        this.count += (found >= 0) ? found : 0;
59bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        return found;
60bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    }
61bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook
62bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    /**
63bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * Reads a number of bytes into the byte array at a specific offset,
64bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * keeping count of the number read.
65bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     *
66bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @param b  the buffer into which the data is read, not null
67bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @param off  the start offset in the buffer
68bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @param len  the maximum number of bytes to read
69bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @return the total number of bytes read into the buffer, -1 if end of stream
70bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @throws IOException if an I/O error occurs
71bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @see java.io.InputStream#read(byte[], int, int)
72bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     */
73bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    public int read(byte[] b, int off, int len) throws IOException {
74bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        int found = super.read(b, off, len);
75bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        this.count += (found >= 0) ? found : 0;
76bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        return found;
77bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    }
78bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook
79bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    /**
80bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * Reads the next byte of data adding to the count of bytes received
81bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * if a byte is successfully read.
82bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     *
83bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @return the byte read, -1 if end of stream
84bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @throws IOException if an I/O error occurs
85bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @see java.io.InputStream#read()
86bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     */
87bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    public int read() throws IOException {
88bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        int found = super.read();
89bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        this.count += (found >= 0) ? 1 : 0;
90bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        return found;
91bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    }
92bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook
93bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    /**
94bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * Skips the stream over the specified number of bytes, adding the skipped
95bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * amount to the count.
96bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     *
97bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @param length  the number of bytes to skip
98bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @return the actual number of bytes skipped
99bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @throws IOException if an I/O error occurs
100bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @see java.io.InputStream#skip(long)
101bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     */
102bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    public long skip(final long length) throws IOException {
103bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        final long skip = super.skip(length);
104bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        this.count += skip;
105bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        return skip;
106bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    }
107bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook
108bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    //-----------------------------------------------------------------------
109bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    /**
110bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * The number of bytes that have passed through this stream.
111bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * <p>
112bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * NOTE: From v1.3 this method throws an ArithmeticException if the
113bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * count is greater than can be expressed by an <code>int</code>.
114bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * See {@link #getByteCount()} for a method using a <code>long</code>.
115bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     *
116bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @return the number of bytes accumulated
117bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @throws ArithmeticException if the byte count is too large
118bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     */
119bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    public synchronized int getCount() {
120bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        long result = getByteCount();
121bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        if (result > Integer.MAX_VALUE) {
122bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook            throw new ArithmeticException("The byte count " + result + " is too large to be converted to an int");
123bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        }
124bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        return (int) result;
125bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    }
126bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook
127bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    /**
128bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * Set the byte count back to 0.
129bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * <p>
130bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * NOTE: From v1.3 this method throws an ArithmeticException if the
131bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * count is greater than can be expressed by an <code>int</code>.
132bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * See {@link #resetByteCount()} for a method using a <code>long</code>.
133bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     *
134bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @return the count previous to resetting
135bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @throws ArithmeticException if the byte count is too large
136bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     */
137bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    public synchronized int resetCount() {
138bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        long result = resetByteCount();
139bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        if (result > Integer.MAX_VALUE) {
140bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook            throw new ArithmeticException("The byte count " + result + " is too large to be converted to an int");
141bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        }
142bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        return (int) result;
143bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    }
144bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook
145bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    /**
146bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * The number of bytes that have passed through this stream.
147bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * <p>
148bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * NOTE: This method is an alternative for <code>getCount()</code>
149bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * and was added because that method returns an integer which will
150bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * result in incorrect count for files over 2GB.
151bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     *
152bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @return the number of bytes accumulated
153bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @since Commons IO 1.3
154bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     */
155bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    public synchronized long getByteCount() {
156bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        return this.count;
157bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    }
158bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook
159bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    /**
160bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * Set the byte count back to 0.
161bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * <p>
162bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * NOTE: This method is an alternative for <code>resetCount()</code>
163bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * and was added because that method returns an integer which will
164bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * result in incorrect count for files over 2GB.
165bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     *
166bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @return the count previous to resetting
167bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     * @since Commons IO 1.3
168bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook     */
169bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    public synchronized long resetByteCount() {
170bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        long tmp = this.count;
171bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        this.count = 0;
172bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook        return tmp;
173bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook    }
174bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook
175bc47398187c6ffd132435e51d8d61e6ec79a79dbPaul Westbrook}
176