connection.h

// ------------------------------------------------------------------
//
//				   Client/Server communication package
//
//						 Connection header file
//
// Change log
//	950323	RH	Initial version
//	951212	RH	Modified to allow subclassing of class Connection
//	970127	RH	Changed "private" to "protected"
//	990125	PH	Changed function names: Read -> read, etc.
//	000114	PH	int -> bool, virtual destructors, other minor changes
//	010129	PH	added void type to initConnection
//	011212	PH	changed char* arguments to const char*
//				changed connection closed handling to exception
//				unsigned char instead of char/int in write/read
//	020102	PH	split into separate file for each class
//	040421	PH	added namespace, new casts, cleaned up a lot
//	050113	PH	added deregisterConnection, new registration (vector),
//				added check for server shutdown, many more changes
//  130515  PH  removed namespace
//
// ------------------------------------------------------------------

#ifndef CONNECTION_H
#define CONNECTION_H

class Server;

/* A Connection object represents a connection (a socket)  */
class Connection {
	friend class Server;
public:
	/* Establishes a connection to the computer 'host' via
	   the port 'port' */
	Connection(const char* host, int port);
	
	/* Creates a Connection object which will be initialized
	   by the server */
	Connection();
	
	/* Closes the connection */
	virtual ~Connection();
	
	/* Returns true if the connection has been established */
	bool isConnected() const;
	
	/* Writes a character */
	void write(unsigned char ch) const;
	
	/* Reads a character */
	unsigned char read() const;
	
protected:
	/* The socket number that this connections communicates on */
	int my_socket;
	
	/* Set to true when the constructor has called signal()
	   to ignore broken pipe. See comment in the constructor */
	static bool ignoresPipeSignals;
	
	/* Initialization from server, receives socket number s */
	void initConnection(int s);
	
	/* Server fetches the socket number */
	int getSocket() const;
	
	/* Prints error message and exits */
	void error(const char* msg) const;
};

#endif