// Copyright (C) 1999-2005 Open Source Telecom Corporation.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
//
// This exception applies only to the code released under the name GNU
// Common C++.  If you copy code from other releases into a copy of GNU
// Common C++, as the General Public License permits, the exception does
// not apply to the code that you add in this way.  To avoid misleading
// anyone as to the status of such modified files, you must delete
// this exception notice from them.
//
// If you write modifications of your own for GNU Common C++, it is your choice
// whether to permit this exception to apply to your modifications.
// If you do not wish that, delete this exception notice.
//

/**
 * @file unix.h
 * @short UNIX domain sockets, streams and sessions.
 **/

#ifndef	CCXX_UNIX_H_
#define	CCXX_UNIX_H_

#ifndef CCXX_MISSING_H_
#include <cc++/missing.h>
#endif

#ifndef	CCXX_SOCKET_H_
#include <cc++/socket.h>
#endif

#ifdef	CCXX_NAMESPACES
namespace ost {
#endif

#ifndef WIN32

 /**
  * Unix domain sockets are used for stream based connected sessions between
  * processes on the same machine.

  * An implicit and unique UnixSocket object exists in Common C++ to represent
  * a bound Unix domain socket acting as a "server" for receiving connection requests.
  * This class is not part of UnixStream because such objects normally perform
  * no physical I/O (read or write operations) other than to specify a listen
  * backlog queue and perform "accept" operations for pending connections.
  *
  * @author Alex Pavloff <alex@pavloff.net>
  * @short bound server for Unix domain streams and sessions.
  */
 class UnixSocket : protected Socket {
 protected:
 	friend class UnixStream;
 	friend class SocketPort;
 	friend class unixstream;

	void close(void);
	char *path;

 public:
 	/**
 	 * A Unix domain "server" is created as a Unix domain socket that is bound
 	 * to a pathname and that has a backlog queue to listen for connection
 	 * requests.  If the server cannot be created, an exception is thrown.
 	 *
 	 * @param pathname pathname to socket file
 	 * @param backlog size of connection request queue.
 	 */
 	UnixSocket(const char* pathname, int backlog = 5);

 	/**
 	 * Used to wait for pending connection requests.
 	 */
 	inline bool isPendingConnection(timeout_t timeout = TIMEOUT_INF) /** not const -- jfc */
 		{return Socket::isPending(pendingInput, timeout);}

 	/**
 	 * Use base socket handler for ending this socket.
 	 */
 	virtual ~UnixSocket();
 };

 /**
  * Unix streams are used to represent Unix domain client connections to a
  * local server for accepting client connections.  The Unix
  * stream is a C++ "stream" class, and can accept streaming of data to
  * and from other C++ objects using the << and >> operators.
  *
  * Unix Stream itself can be formed either by connecting to a bound network
  * address of a Unix domain server, or can be created when "accepting" a
  * network connection from a Unix domain server.
  *
  * @author Alex Pavloff <alex@pavloff.net>
  * @short streamable Unix domain socket connection.
  */
 class UnixStream : public Socket, public std::streambuf, public std::iostream {
 private:
 	int doallocate();

 protected:
 	timeout_t timeout;
 	int bufsize;
 	char *gbuf, *pbuf;

 	/**
 	 * The constructor required for "unixstream", a more C++ style
 	 * version of the TCPStream class.
 	 */
 	UnixStream(bool throwflag = true);

 	/**
 	 * Used to allocate the buffer space needed for iostream
 	 * operations.  This function is called by the constructor.
 	 *
 	 * @param size of stream buffers from constructor.
 	 */
 	void allocate(int size);

 	/**
 	 * Used to terminate the buffer space and cleanup the socket
 	 * connection.  This fucntion is called by the destructor.
 	 */
 	void endStream(void);

 	/**
 	 * This streambuf method is used to load the input buffer
 	 * through the established unix domain socket connection.
 	 *
 	 * @return char from get buffer, EOF if not connected.
 	 */
 	virtual int underflow(void);

 	/**
 	 * This streambuf method is used for doing unbuffered reads
 	 * through the established unix domain socket connection when in interactive mode.
 	 * Also this method will handle proper use of buffers if not in
 	 * interative mode.
 	 *
 	 * @return char from unix domain socket connection, EOF if not connected.
 	 */
 	int uflow(void);

 	/**
 	 * This streambuf method is used to write the output
 	 * buffer through the established unix domain connection.
 	 *
 	 * @param ch char to push through.
 	 * @return char pushed through.
 	 */
 	int overflow(int ch);

 	/**
 	 * Create a Unix domain stream by connecting to a Unix domain socket
 	 *
 	 * @param pathname path to socket
 	 * @param size of streaming input and output buffers.
 	 */
 	void connect(const char* pathname, int size);

 	/**
 	 * Used in derived classes to refer to the current object via
 	 * it's iostream.  For example, to send a set of characters
 	 * in a derived method, one might use *tcp() << "test".
 	 *
 	 * @return stream pointer of this object.
 	 */
 	std::iostream *unixstr(void)
 		{return ((std::iostream *)this);};

 public:
 	/**
 	 * Create a Unix domain stream by accepting a connection from a bound
 	 * Unix domain socket acting as a server.  This performs an "accept"
 	 * call.
 	 *
	 * @param server socket listening.
 	 * @param size of streaming input and output buffers.
 	 * @param throwflag flag to throw errors.
 	 * @param timeout for all operations.
 	 */
 	UnixStream(UnixSocket &server, int size = 512, bool throwflag = true, timeout_t timeout = 0);

 	/**
 	 * Create a Unix domain stream by connecting to a Unix domain socket
 	 *
 	 * @param pathname path to socket
 	 * @param size of streaming input and output buffers.
 	 * @param throwflag flag to throw errors.
 	 * @param to timeout for all operations.
 	 */
 	UnixStream(const char* pathname, int size = 512, bool throwflag = true, timeout_t to = 0);

 	/**
 	 * Set the I/O operation timeout for socket I/O operations.
 	 *
 	 * @param to timeout to set.
 	 */
 	inline void setTimeout(timeout_t to)
 		{timeout = to;};

 	/**
 	 * A copy constructor creates a new stream buffer.
 	 *
 	 * @param source of copy.
 	 *
 	 */
 	UnixStream(const UnixStream &source);

 	/**
 	 * Flush and empty all buffers, and then remove the allocated
 	 * buffers.
 	 */
 	virtual ~UnixStream();

 	/**
 	 * Flushes the stream input and output buffers, writes
 	 * pending output.
 	 *
 	 * @return 0 on success.
 	 */
 	int sync(void);

 	/**
 	 * Get the status of pending stream data.  This can be used to
 	 * examine if input or output is waiting, or if an error or
 	 * disconnect has occured on the stream.  If a read buffer
 	 * contains data then input is ready and if write buffer
 	 * contains data it is first flushed and then checked.
 	 */
 	bool isPending(Pending pend, timeout_t timeout = TIMEOUT_INF);

 	/**
 	 * Return the size of the current stream buffering used.
 	 *
 	 * @return size of stream buffers.
 	 */
 	int getBufferSize(void) const
 		{return bufsize;};
 };

 /**
  * A more natural C++ "unixstream" class for use by non-threaded
  * applications.  This class behaves a lot more like fstream and
  * similar classes.
  *
  * @author Alex Pavloff <alex@pavloff.net>
  * @short C++ "fstream" style unixstream class.
  */
 class unixstream : public UnixStream {
 public:
 	/**
 	 * Construct an unopened "tcpstream" object.
 	 */
 	unixstream();

 	/**
 	 * Construct and "open" (connect) the tcp stream to a remote
 	 * socket.
 	 *
 	 * @param pathname pathname to socket file
 	 * @param buffer size for streaming (optional).
 	 */
 	unixstream(const char *pathname, int buffer = 512);

 	/**
 	 * Construct and "accept" (connect) the tcp stream through
 	 * a server.
 	 *
 	 * @param unixsock socket to accept from.
 	 * @param buffer size for streaming (optional).
 	 */
 	unixstream(UnixSocket &unixsock, int buffer = 512);

 	/**
 	 * Open a tcp stream connection.  This will close the currently
 	 * active connection first.
 	 *
 	 * @param pathname pathname to socket file
 	 * @param buffer size for streaming (optional)
 	 */
 	void open(const char *pathname, int buffer = 512)
 		{ UnixStream::connect( pathname, buffer ); }

 	/**
 	 * Open a tcp stream connection by accepting a tcp socket.
 	 *
 	 * @param unixsock socket to accept from.
 	 * @param buffer size for streaming (optional)
 	 */
 	void open(UnixSocket &unixsock, int buffer = 512);

 	/**
 	 * Close the active tcp stream connection.
 	 */
 	void close(void);

 	/**
 	 * Test to see if stream is open.
 	 */
 	bool operator!() const;
 };

 /**
  * The Unix domain session is used to primarily to represent a client connection
  * that can be managed on a seperate thread.  The Unix domain session also supports
  * a non-blocking connection scheme which prevents blocking during the
  * constructor and moving the process of completing a connection into the
  * thread that executes for the session.
  *
  * @author Alex Pavloff <alex@pavloff.net>
  * @short Threaded streamable unix domain socket with non-blocking constructor.
  */
 class __EXPORT UnixSession : public Thread, public UnixStream {
 protected:
 	/**
 	 * Normally called during the thread Initial() method by default,
 	 * this will wait for the socket connection to complete when
 	 * connecting to a remote socket.  One might wish to use
 	 * setCompletion() to change the socket back to blocking I/O
 	 * calls after the connection completes.  To implement the
 	 * session one must create a derived class which implements
 	 * Run().
 	 *
 	 * @return 0 if successful, -1 if timed out.
 	 * @param timeout to wait for completion in milliseconds.
 	 */
 	int waitConnection(timeout_t timeout = TIMEOUT_INF);

 	/**
 	 * The initial method is used to esablish a connection when
 	 * delayed completion is used.  This assures the constructor
 	 * terminates without having to wait for a connection request
 	 * to complete.
 	 */
 	void initial(void);

 public:
 	/**
 	 * Create a Unix domain socket that will be connected to a local server
 	 * server and that will execute under it's own thread.
 	 *
 	 * @param pathname path to socket
 	 * @param size of streaming buffer.
 	 * @param pri execution priority relative to parent.
 	 * @param stack allocation needed on some platforms.
 	 */
 	UnixSession(const char* pathname, int size = 512, int pri = 0, int stack = 0);

 	/**
 	 * Create a Unix domain socket from a bound Unix domain server by accepting a pending
 	 * connection from that server and execute a thread for the accepted connection.
 	 *
 	 * @param server unix domain socket to accept a connection from.
 	 * @param size of streaming buffer.
 	 * @param pri execution priority relative to parent.
 	 * @param stack allocation needed on some platforms.
 	 */
 	UnixSession(UnixSocket &server, int size = 512,
 		   int pri = 0, int stack = 0);

	/**
	 * Virtual destructor.
	 */
	virtual ~UnixSession();
 };

#endif // ndef WIN32

#ifdef	CCXX_NAMESPACES
}
#endif

#endif