/*
 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed 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 io.airlift.slice;

import javax.annotation.Nullable;

import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;

/**
 * An OutputStream that counts the number of bytes written.
 *
 * @author Chris Nokleberg
 */
final class CountingOutputStream
        extends FilterOutputStream
{
    private long count;

    /**
     * Wraps another output stream, counting the number of bytes written.
     *
     * @param out the output stream to be wrapped
     */
    public CountingOutputStream(@Nullable OutputStream out)
    {
        super(out);
    }

    /**
     * Returns the number of bytes written.
     */
    public long getCount()
    {
        return count;
    }

    @Override
    public void write(byte[] b, int off, int len)
            throws IOException
    {
        out.write(b, off, len);
        count += len;
    }

    @Override
    public void write(int b)
            throws IOException
    {
        out.write(b);
        count++;
    }
}
