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	/*
	* Copyright (c) 1996, 2012, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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 General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/
	package sun.rmi.transport.proxy;

	import java.io.*;

	import sun.rmi.runtime.Log;

	/**
	* The HttpInputStream class assists the HttpSendSocket and HttpReceiveSocket
	* classes by filtering out the header for the message as well as any
	* data after its proper content length.
	*/
	class HttpInputStream extends FilterInputStream {

	/** bytes remaining to be read from proper content of message */
	protected int bytesLeft;

	/** bytes remaining to be read at time of last mark */
	protected int bytesLeftAtMark;

	/**
	* Create new filter on a given input stream.
	* @param in the InputStream to filter from
	*/
	public HttpInputStream(InputStream in) throws IOException
	{
	super(in);

	if (in.markSupported())
	in.mark(0); // prevent resetting back to old marks

	// pull out header, looking for content length

	DataInputStream dis = new DataInputStream(in);
	String key = "Content-length:".toLowerCase();
	boolean contentLengthFound = false;
	String line;
	do {
	line = dis.readLine();

	if (RMIMasterSocketFactory.proxyLog.isLoggable(Log.VERBOSE)) {
	RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
	"received header line: \"" + line + "\"");
	}

	if (line == null)
	throw new EOFException();

	if (line.toLowerCase().startsWith(key)) {
	if (contentLengthFound) {
	throw new IOException(
	"Multiple Content-length entries found.");
	} else {
	bytesLeft =
	Integer.parseInt(line.substring(key.length()).trim());
	contentLengthFound = true;
	}
	}

	// The idea here is to go past the first blank line.
	// Some DataInputStream.readLine() documentation specifies that
	// it does include the line-terminating character(s) in the
	// returned string, but it actually doesn't, so we'll cover
	// all cases here...
	} while ((line.length() != 0) &&
	(line.charAt(0) != '\r') && (line.charAt(0) != '\n'));

	if (!contentLengthFound \|\| bytesLeft < 0) {
	// This really shouldn't happen, but if it does, shoud we fail??
	// For now, just give up and let a whole lot of bytes through...
	bytesLeft = Integer.MAX_VALUE;
	}
	bytesLeftAtMark = bytesLeft;

	if (RMIMasterSocketFactory.proxyLog.isLoggable(Log.VERBOSE)) {
	RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
	"content length: " + bytesLeft);
	}
	}

	/**
	* Returns the number of bytes that can be read with blocking.
	* Make sure that this does not exceed the number of bytes remaining
	* in the proper content of the message.
	*/
	public int available() throws IOException
	{
	int bytesAvailable = in.available();
	if (bytesAvailable > bytesLeft)
	bytesAvailable = bytesLeft;

	return bytesAvailable;
	}

	/**
	* Read a byte of data from the stream. Make sure that one is available
	* from the proper content of the message, else -1 is returned to
	* indicate to the user that the end of the stream has been reached.
	*/
	public int read() throws IOException
	{
	if (bytesLeft > 0) {
	int data = in.read();
	if (data != -1)
	-- bytesLeft;

	if (RMIMasterSocketFactory.proxyLog.isLoggable(Log.VERBOSE)) {
	RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
	"received byte: '" +
	((data & 0x7F) < ' ' ? " " : String.valueOf((char) data)) +
	"' " + data);
	}

	return data;
	}
	else {
	RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
	"read past content length");

	return -1;
	}
	}

	public int read(byte b[], int off, int len) throws IOException
	{
	if (bytesLeft == 0 && len > 0) {
	RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
	"read past content length");

	return -1;
	}
	if (len > bytesLeft)
	len = bytesLeft;
	int bytesRead = in.read(b, off, len);
	bytesLeft -= bytesRead;

	if (RMIMasterSocketFactory.proxyLog.isLoggable(Log.VERBOSE)) {
	RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
	"read " + bytesRead + " bytes, " + bytesLeft + " remaining");
	}

	return bytesRead;
	}

	/**
	* Mark the current position in the stream (for future calls to reset).
	* Remember where we are within the proper content of the message, so
	* that a reset method call can recreate our state properly.
	* @param readlimit how many bytes can be read before mark becomes invalid
	*/
	public void mark(int readlimit)
	{
	in.mark(readlimit);
	if (in.markSupported())
	bytesLeftAtMark = bytesLeft;
	}

	/**
	* Repositions the stream to the last marked position. Make sure to
	* adjust our position within the proper content accordingly.
	*/
	public void reset() throws IOException
	{
	in.reset();
	bytesLeft = bytesLeftAtMark;
	}

	/**
	* Skips bytes of the stream. Make sure to adjust our
	* position within the proper content accordingly.
	* @param n number of bytes to be skipped
	*/
	public long skip(long n) throws IOException
	{
	if (n > bytesLeft)
	n = bytesLeft;
	long bytesSkipped = in.skip(n);
	bytesLeft -= bytesSkipped;
	return bytesSkipped;
	}
	}

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