/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.commons.io.input;
import java.io.IOException;
import java.io.InputStream;
/**
* A decorating input stream that counts the number of bytes that have passed
* through the stream so far.
* <p>
* A typical use case would be during debugging, to ensure that data is being
* read as expected.
*
* @author Marcelo Liberato
* @version $Id: CountingInputStream.java 471628 2006-11-06 04:06:45Z bayard $
*/
public class CountingInputStream extends ProxyInputStream {
/** The count of bytes that have passed. */
private long count;
/**
* Constructs a new CountingInputStream.
*
* @param in the InputStream to delegate to
*/
public CountingInputStream(InputStream in) {
super(in);
}
//-----------------------------------------------------------------------
/**
* Reads a number of bytes into the byte array, keeping count of the
* number read.
*
* @param b the buffer into which the data is read, not null
* @return the total number of bytes read into the buffer, -1 if end of stream
* @throws IOException if an I/O error occurs
* @see java.io.InputStream#read(byte[])
*/
public int read(byte[] b) throws IOException {
int found = super.read(b);
this.count += (found >= 0) ? found : 0;
return found;
}
/**
* Reads a number of bytes into the byte array at a specific offset,
* keeping count of the number read.
*
* @param b the buffer into which the data is read, not null
* @param off the start offset in the buffer
* @param len the maximum number of bytes to read
* @return the total number of bytes read into the buffer, -1 if end of stream
* @throws IOException if an I/O error occurs
* @see java.io.InputStream#read(byte[], int, int)
*/
public int read(byte[] b, int off, int len) throws IOException {
int found = super.read(b, off, len);
this.count += (found >= 0) ? found : 0;
return found;
}
/**
* Reads the next byte of data adding to the count of bytes received
* if a byte is successfully read.
*
* @return the byte read, -1 if end of stream
* @throws IOException if an I/O error occurs
* @see java.io.InputStream#read()
*/
public int read() throws IOException {
int found = super.read();
this.count += (found >= 0) ? 1 : 0;
return found;
}
/**
* Skips the stream over the specified number of bytes, adding the skipped
* amount to the count.
*
* @param length the number of bytes to skip
* @return the actual number of bytes skipped
* @throws IOException if an I/O error occurs
* @see java.io.InputStream#skip(long)
*/
public long skip(final long length) throws IOException {
final long skip = super.skip(length);
this.count += skip;
return skip;
}
//-----------------------------------------------------------------------
/**
* The number of bytes that have passed through this stream.
* <p>
* NOTE: From v1.3 this method throws an ArithmeticException if the
* count is greater than can be expressed by an <code>int</code>.
* See {@link #getByteCount()} for a method using a <code>long</code>.
*
* @return the number of bytes accumulated
* @throws ArithmeticException if the byte count is too large
*/
public synchronized int getCount() {
long result = getByteCount();
if (result > Integer.MAX_VALUE) {
throw new ArithmeticException("The byte count " + result + " is too large to be converted to an int");
}
return (int) result;
}
/**
* Set the byte count back to 0.
* <p>
* NOTE: From v1.3 this method throws an ArithmeticException if the
* count is greater than can be expressed by an <code>int</code>.
* See {@link #resetByteCount()} for a method using a <code>long</code>.
*
* @return the count previous to resetting
* @throws ArithmeticException if the byte count is too large
*/
public synchronized int resetCount() {
long result = resetByteCount();
if (result > Integer.MAX_VALUE) {
throw new ArithmeticException("The byte count " + result + " is too large to be converted to an int");
}
return (int) result;
}
/**
* The number of bytes that have passed through this stream.
* <p>
* NOTE: This method is an alternative for <code>getCount()</code>
* and was added because that method returns an integer which will
* result in incorrect count for files over 2GB.
*
* @return the number of bytes accumulated
* @since Commons IO 1.3
*/
public synchronized long getByteCount() {
return this.count;
}
/**
* Set the byte count back to 0.
* <p>
* NOTE: This method is an alternative for <code>resetCount()</code>
* and was added because that method returns an integer which will
* result in incorrect count for files over 2GB.
*
* @return the count previous to resetting
* @since Commons IO 1.3
*/
public synchronized long resetByteCount() {
long tmp = this.count;
this.count = 0;
return tmp;
}
}