/*
 * ====================================================================
 * 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.http.impl.io;

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

import org.apache.http.io.SessionOutputBuffer;
import org.apache.http.util.Args;

Output stream that writes data without any transformation. The end of
the content entity is demarcated by closing the underlying connection
(EOF condition). Entities transferred using this input stream can be of
unlimited length.

Note that this class NEVER closes the underlying stream, even when close
gets called.  Instead, the stream will be marked as closed and no further
output will be permitted.
Since:
4.0/**
 * Output stream that writes data without any transformation. The end of
 * the content entity is demarcated by closing the underlying connection
 * (EOF condition). Entities transferred using this input stream can be of
 * unlimited length.
 * <p>
 * Note that this class NEVER closes the underlying stream, even when close
 * gets called.  Instead, the stream will be marked as closed and no further
 * output will be permitted.
 *
 * @since 4.0
 */
public class IdentityOutputStream extends OutputStream {

    
Wrapped session output buffer.
/**
     * Wrapped session output buffer.
     */
    private final SessionOutputBuffer out;

    
True if the stream is closed. /** True if the stream is closed. */
    private boolean closed = false;

    public IdentityOutputStream(final SessionOutputBuffer out) {
        super();
        this.out = Args.notNull(out, "Session output buffer");
    }

    
Does not close the underlying socket output.
Throws:
IOException – If an I/O problem occurs./**
     * <p>Does not close the underlying socket output.</p>
     *
     * @throws IOException If an I/O problem occurs.
     */
    @Override
    public void close() throws IOException {
        if (!this.closed) {
            this.closed = true;
            this.out.flush();
        }
    }

    @Override
    public void flush() throws IOException {
        this.out.flush();
    }

    @Override
    public void write(final byte[] b, final int off, final int len) throws IOException {
        if (this.closed) {
            throw new IOException("Attempted write to closed stream.");
        }
        this.out.write(b, off, len);
    }

    @Override
    public void write(final byte[] b) throws IOException {
        write(b, 0, b.length);
    }

    @Override
    public void write(final int b) throws IOException {
        if (this.closed) {
            throw new IOException("Attempted write to closed stream.");
        }
        this.out.write(b);
    }

}