/*
 * ====================================================================
 * 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.InputStream;

import org.apache.http.io.BufferInfo;
import org.apache.http.io.SessionInputBuffer;
import org.apache.http.util.Args;

Input stream that reads 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, it will read until the end of the stream (until -1 is returned). 
Since:
4.0/**
 * Input stream that reads 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, it will read until the end of the stream (until
 * {@code -1} is returned).
 *
 * @since 4.0
 */
public class IdentityInputStream extends InputStream {

    private final SessionInputBuffer in;

    private boolean closed = false;

    
Wraps session input stream and reads input until the the end of stream.
Params:
in – The session input buffer/**
     * Wraps session input stream and reads input until the the end of stream.
     *
     * @param in The session input buffer
     */
    public IdentityInputStream(final SessionInputBuffer in) {
        super();
        this.in = Args.notNull(in, "Session input buffer");
    }

    @Override
    public int available() throws IOException {
        if (this.in instanceof BufferInfo) {
            return ((BufferInfo) this.in).length();
        }
        return 0;
    }

    @Override
    public void close() throws IOException {
        this.closed = true;
    }

    @Override
    public int read() throws IOException {
        return this.closed ? -1 : this.in.read();
    }

    @Override
    public int read(final byte[] b, final int off, final int len) throws IOException {
        return this.closed ? -1 : this.in.read(b, off, len);
    }

}