1 // Stream based logging mechanism.
3 // Written by Bernie Bright, 1998
5 // Copyright (C) 1998 Bernie Bright - bbright@c031.aone.net.au
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 // (Log is kept at end of this file)
27 #include "Include/compiler.h"
29 #ifdef FG_HAVE_STD_INCLUDES
33 # include <iostream.h>
34 # include "Include/fg_traits.hxx"
37 #include "debug_types.h"
42 // 1. Change output destination. Done.
43 // 2. Make logbuf thread safe.
44 // 3. Read environment for default debugClass and debugPriority.
47 //-----------------------------------------------------------------------------
49 // logbuf is an output-only streambuf with the ability to disable sets of
50 // messages at runtime. Only messages with priority >= logbuf::logPriority
51 // and debugClass == logbuf::logClass are output.
53 class logbuf : public streambuf
57 #ifndef FG_HAVE_STD_INCLUDES
58 typedef char_traits<char> traits_type;
59 typedef char_traits<char>::int_type int_type;
60 typedef char_traits<char>::pos_type pos_type;
61 typedef char_traits<char>::off_type off_type;
63 // logbuf( streambuf* sb ) : sbuf(sb) {}
67 // Is logging enabled?
68 bool enabled() { return logging_enabled; }
70 // Set the logging level of subsequent messages.
71 void set_log_state( fgDebugClass c, fgDebugPriority p );
73 // Set the global logging level.
74 static void set_log_level( fgDebugClass c, fgDebugPriority p );
77 void set_sb( streambuf* sb );
81 int sync() { return sbuf->sync(); }
82 int_type overflow( int ch );
83 // int xsputn( const char* s, istreamsize n );
87 // The streambuf used for actual output. Defaults to cerr.rdbuf().
88 static streambuf* sbuf;
90 static bool logging_enabled;
91 static fgDebugClass logClass;
92 static fgDebugPriority logPriority;
97 logbuf( const logbuf& );
98 void operator= ( const logbuf& );
102 logbuf::set_log_state( fgDebugClass c, fgDebugPriority p )
104 logging_enabled = ((c & logClass) != 0 && p >= logPriority);
107 inline logbuf::int_type
108 logbuf::overflow( int c )
110 return logging_enabled ? sbuf->sputc(c) : (EOF == 0 ? 1: 0);
113 //-----------------------------------------------------------------------------
115 // logstream manipulator for setting the log level of a message.
119 loglevel( fgDebugClass c, fgDebugPriority p )
120 : logClass(c), logPriority(p) {}
122 fgDebugClass logClass;
123 fgDebugPriority logPriority;
126 //-----------------------------------------------------------------------------
128 // A helper class that ensures a streambuf and ostream are constructed and
129 // destroyed in the correct order. The streambuf must be created before the
130 // ostream but bases are constructed before members. Thus, making this class
131 // a private base of logstream, declared to the left of ostream, we ensure the
132 // correct order of construction and destruction.
134 struct logstream_base
136 // logstream_base( streambuf* sb ) : lbuf(sb) {}
142 //-----------------------------------------------------------------------------
146 class logstream : private logstream_base, public ostream
149 // The default is to send messages to cerr.
150 logstream( ostream& out )
151 // : logstream_base(out.rdbuf()),
153 ostream(&lbuf) { lbuf.set_sb(out.rdbuf());}
155 void set_output( ostream& out ) { lbuf.set_sb( out.rdbuf() ); }
157 // Set the global log class and priority level.
158 void setLogLevels( fgDebugClass c, fgDebugPriority p );
160 // Output operator to capture the debug level and priority of a message.
161 inline ostream& operator<< ( const loglevel& l );
165 logstream::operator<< ( const loglevel& l )
167 lbuf.set_log_state( l.logClass, l.logPriority );
171 //-----------------------------------------------------------------------------
173 // Return the one and only logstream instance.
174 // We use a function instead of a global object so we are assured that cerr
175 // has been initialised.
180 static logstream logstrm( cerr );
185 # define FG_LOG(C,P,M)
187 # define FG_LOG(C,P,M) fglog() << loglevel(C,P) << M << endl
190 #endif // _LOGSTREAM_H
193 // Revision 1.1 1998/11/06 21:20:42 curt