/******************************************************************************
 * QUANTA - A toolkit for High Performance Data Sharing
 * Copyright (C) 2003 Electronic Visualization Laboratory,  
 * University of Illinois at Chicago
 *
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above
 *    copyright notice, this list of conditions and the following disclaimer
 *    in the documentation and/or other materials provided with the distribution.
 *  * Neither the name of the University of Illinois at Chicago nor
 *    the names of its contributors may be used to endorse or promote
 *    products derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Direct questions, comments etc about Quanta to cavern@evl.uic.edu
 *****************************************************************************/

#ifndef _QUANTAPLUS_PERF_DAEMON_C
#define _QUANTAPLUS_PERF_DAEMON_C

#ifndef __HAVE_STDIO_H
#include <stdio.h>
#define __HAVE_STDIO_H
#endif

#include "QUANTAnet_perfClient_c.hxx"

class QUANTAnet_tcpServer_c;

struct PerfDaemonClient
{
    QUANTAnet_perfDaemonClient_c *Client;
    int IsPerfClient;
    int Started;
};

/** QUANTA performance monitoring daemon class. This class treats TCP 
streams as discrete packets/messages that can be reflected to multiple 
connected performance monitoring clients. Clients must be created using 
QUANTAnet_perfDaemonClient_c. Hence do NOT attempt to use 
QUANTAnet_tcpClient_c to connect to a perf daemon class. This class has 
2 main functions: checkForNewClients() and process(). checkForNewClients, 
as the name suggests, checks to see if any new clients wish to connect 
to the reflector. Process() does the actual work of data reflection.

checkForNewClients is called everytime process() is called. If you want 
the check to be done more frequently you need to do it yourself. Similarly 
if you want the process() call done more frequently it is up to you to do it. 
I recommend threading those two off and setting up a mutex so that you do 
not do process() and checkForNewClients() at the same time.

@author cavern@evl.uic.edu
@version 3/28/2000

*/
class QUANTAnet_perfDaemon_c
{
public:
        /**
        Constructor of performance monitoring daemon class. 
      
        @param File
        Optional parameter. If file pointer is given here, it will be used 
        to save all log information.
        */
	QUANTAnet_perfDaemon_c(FILE* File = NULL);
	~QUANTAnet_perfDaemon_c();

	//@{
	/// Status ok.
	static const int OK/* = 0*/;

	/// Status failed.
	static const int FAILED/* = 1*/;

	/// Memory allocation error.
	static const int MEM_ALLOC_ERR/* = 2*/;

	/// New client has been connected.
	static const int NEW_CONNECTION_ESTABLISHED/* = 4*/;

	/// Reflector cannot handle any more connections
	static const int TOO_MANY_CLIENTS/* = 5*/;

	/// No new connection.
	static const int NO_NEW_CONNECTION/* = 6*/;

	/// A non-blocking read had no data available to read.
	static const int NON_BLOCKING_HAS_NO_DATA/* = 7*/;

	/// Skip the data distribution process. Used in user callback. See intercept().
	static const int SKIP_DISTRIBUTION/* = 8*/;

	static const int DEFAULT_PORT/* = 9500*/;
	//@}

	/** Initialize the reflector.
	    @param incomingPort is listening port for incoming connections. Default is 7000.
	    @param maxClients is the max number of clients the reflector will manage.
	    @return Either QUANTAnet_perfDaemon_c::OK,FAILED,MEM_ALLOC_ERR.
	 */
	int init(int incomingPort=PERF_DAEMON_DEFAULT_PORT, int maxClients = 64);

	/** Call this within a while loop to let the reflector continuously
	    do its processing.
	    @return Either QUANTAnet_perfDaemon_c::OK,MEM_ALLOC_ERR
	*/
	int process();

	/** Call this as often as you wish to check for new clients.
	    Note. If you do this in a separate thread then you must set up a mutex
	    so that you do not call the proces() call and this call at the same time.
	    The process() call itself has imbedded in it 1 check for each time you
	    call it.
	    @return Either QUANTAnet_perfDaemon_c::NEW_CONNECTION_ESTABLISHED, NO_NEW_CONNECTION, TOO_MANY_CLIENTS.
	*/
	int checkForNewClients();

	/** Intercept incoming messages and call a user-defined callback function.
	    If you want you can also alter the buffer completely so that the reflector will reflect an
	    entirely different message. You can do this by changing the contents of the buffer or
	    by replacing the buffer entirely by allocating memory for a new buffer and stuffing it
	    with your own data. If you choose to allocate a totally new buffer you must remember
	    to deallocate memory for the original
	    buffer before substituting it with yours.

	    If after your callback function exits you do not wish the reflector to forward
	    the contents of the buffer, return with QUANTA_tcpReflector_c::SKIP_DISTRIBUTION. Otherwise
	    just return QUANTA_tcpReflector_c::OK.

	    Note also that the callback function will also be given a pointer to a
	    QUANTAnet_perfDaemonClient_c object that
	    can then be used to send data directly to the client that originally sent the message.
	*/
	void intercept(int (*callback) (QUANTAnet_perfDaemonClient_c *client, char** buffer, 
		                            int *bufferSize,  void *userData), void* userData);

	/** Intercept any new connections that are formed.
	    This allows you to send private data to the newly formed connection before it assumes its data
	    reflection duties.
	    Callback function will be given a pointer to the QUANTAnet_perfDaemonClient_c object that
	    can then be used to send data directly to the client.
	*/
	void interceptNewConnection(void (*callback) (QUANTAnet_perfDaemonClient_c *newClient, void* userData), void *userData);

        int sendToAll(char* buf, int incomingSize);

private:
	PerfDaemonClient **clients;
	QUANTAnet_tcpServer_c *server;
	unsigned short incomingPort;
	FILE* LogFile;

	int (*interceptCallback) (QUANTAnet_perfDaemonClient_c *newClient, char** buffer, 
		                      int* bufsize, void *userData);
	void *interceptUserData;

	void (*interceptNewConnectionCallback) (QUANTAnet_perfDaemonClient_c *newClient, void *userData);
	void *interceptNewConnectionUserData;

	// Distribute the data to all connected performance monitoring clients.
	// Specify -1 if want to send to all.
	int distributeDataToPerfClients(char* buf, int incomingSize);

	// Remove a client from the client array.
	void removeClient(int clientNum);

	// Close all client sockets and remove them. Used by destructor.
	// Also closes down and deallocates the server.
	void closeDownSockets();
	int maxNumClients;
};

#endif