/*----------------------------------------------------------------------------*
* This file is part of Pitaya. *
* Copyright (C) 2012-2014 Osman KOCAK <kocakosm@gmail.com> *
* *
* This program is free software: you can redistribute it and/or modify it *
* under the terms of the GNU Lesser General Public License as published by *
* the Free Software Foundation, either version 3 of the License, or (at your *
* option) any later version. *
* This program is distributed in the hope that it will be useful, but *
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public *
* License for more details. *
* You should have received a copy of the GNU Lesser General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/>. *
*----------------------------------------------------------------------------*/
package org.kocakosm.pitaya.io;
import org.kocakosm.pitaya.util.Parameters;
import java.io.IOException;
import java.io.Reader;
import java.util.concurrent.atomic.AtomicLong;
/**
* A decorating {@link Reader} that counts the number of characters that have
* been read from its underlying {@link Reader}. Characters read multiple times
* are counted as many times they have been read. Also, skipped characters are
* not counted.
*
* @author Osman KOCAK
*/
public final class CountingReader extends Reader
{
private final Reader reader;
private final AtomicLong counter;
/**
* Creates a new {@code CountingReader}.
*
* @param reader the underlying reader.
*
* @throws NullPointerException if {@code reader} is {@code null}.
*/
public CountingReader(Reader reader)
{
Parameters.checkNotNull(reader);
this.reader = reader;
this.counter = new AtomicLong();
}
/**
* Returns the number of characters that have been read so far.
*
* @return the number of characters that have been read so far.
*/
public long getCount()
{
return counter.get();
}
/**
* Sets the counter to 0 and returns its value before resetting it.
*
* @return the number of characters that have been read so far.
*/
public long resetCount()
{
return counter.getAndSet(0);
}
@Override
public boolean ready() throws IOException
{
return reader.ready();
}
@Override
public int read() throws IOException
{
int b = reader.read();
count(b != -1 ? 1 : -1);
return b;
}
@Override
public int read(char[] buf) throws IOException
{
int n = reader.read(buf);
count(n);
return n;
}
@Override
public int read(char[] buf, int off, int len) throws IOException
{
int n = reader.read(buf, off, len);
count(n);
return n;
}
@Override
public boolean markSupported()
{
return reader.markSupported();
}
@Override
public void mark(int readLimit) throws IOException
{
reader.mark(readLimit);
}
@Override
public void reset() throws IOException
{
reader.reset();
}
@Override
public long skip(long n) throws IOException
{
return reader.skip(n);
}
@Override
public void close() throws IOException
{
reader.close();
}
private void count(int n)
{
if (n != -1) {
counter.addAndGet(n);
}
}
}