3 * High level IO channel base class.
6 // Written by Curtis Olson, started November 1999.
8 // Copyright (C) 1999 Curtis L. Olson - curt@flightgear.org
10 // This program is free software; you can redistribute it and/or
11 // modify it under the terms of the GNU General Public License as
12 // published by the Free Software Foundation; either version 2 of the
13 // License, or (at your option) any later version.
15 // This program is distributed in the hope that it will be useful, but
16 // WITHOUT ANY WARRANTY; without even the implied warranty of
17 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 // General Public License for more details.
20 // You should have received a copy of the GNU General Public License
21 // along with this program; if not, write to the Free Software
22 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
27 #ifndef _IOCHANNEL_HXX
28 #define _IOCHANNEL_HXX
31 #include <simgear/compiler.h>
33 // #include "protocol.hxx"
42 #define SG_IO_MAX_MSG_SIZE 16384
45 * Specify if this is a read (IN), write (OUT), or r/w (BI) directional
56 * Specify the channel type
66 * The SGIOChannel base class provides a consistent method for
67 * applications to communication through various mediums. By providing
68 * a base class with multiple derived classes, and application such as
69 * FlightGear can implement a way to speak any protocol via any kind
72 * All of the SGIOChannel derived classes have exactly the same usage
73 * interface once an instance has been created.
88 virtual ~SGIOChannel();
91 * @param d channel communication "direction"
92 * Direction can be one of:
93 * - SG_IO_IN - data will be flowing into this object to the application.
94 * - SG_IO_OUT - data will be flowing out of this object from the
96 * - SG_IO_BI - data will be flowing in both directions.
97 * - SG_IO_NONE - data will not be flowing in either direction.
98 * This is here for the sake of completeness.
100 virtual bool open( const SGProtocolDir d );
103 * The read() method is modeled after the read() Unix system
104 * call. You must provide a pointer to a character buffer that has
105 * enough allocated space for your potential read. You can also
106 * specify the maximum number of bytes allowed for this particular
107 * read. The actual number of bytes read is returned. You are
108 * responsible to ensure that the size of buf is large enough to
109 * accomodate your input message
110 * @param buf a char pointer to your input buffer
111 * @param length max number of bytes to read
113 virtual int read( char *buf, int length );
116 * The readline() method is similar to read() except that it will
117 * stop at the first end of line encountered in the input buffer.
118 * @param buf a char pointer to your input buffer
119 * @param length max number of bytes to read
121 virtual int readline( char *buf, int length );
122 virtual int write( const char *buf, const int length );
123 virtual int writestring( const char *str );
124 virtual bool close();
126 inline void set_type( SGChannelType t ) { type = t; }
127 inline SGChannelType get_type() const { return type; }
129 inline void set_dir( const SGProtocolDir d ) { dir = d; }
130 inline SGProtocolDir get_dir() const { return dir; }
131 inline bool isvalid() const { return valid; }
135 #endif // _IOCHANNEL_HXX