1 // Stream based logging mechanism.
3 // Written by Bernie Bright, 1998
5 // Copyright (C) 1998 Bernie Bright - bbright@c031.aone.net.au
7 // This library is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU Library General Public
9 // License as published by the Free Software Foundation; either
10 // version 2 of the License, or (at your option) any later version.
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // Library General Public License for more details.
17 // You should have received a copy of the GNU Library General Public
18 // License along with this library; if not, write to the
19 // Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 // Boston, MA 02111-1307, USA.
32 #include <simgear/compiler.h>
34 #ifdef FG_HAVE_STD_INCLUDES
38 # include <iostream.h>
39 # include <simgear/fg_traits.hxx>
42 #include <simgear/debug/debug_types.h>
44 #ifndef FG_HAVE_NATIVE_SGI_COMPILERS
45 FG_USING_STD(streambuf);
46 FG_USING_STD(ostream);
52 # define cerr std::cerr
53 # define endl std::endl
54 FG_USING_STD(iostream);
60 // 1. Change output destination. Done.
61 // 2. Make logbuf thread safe.
62 // 3. Read environment for default debugClass and debugPriority.
65 //-----------------------------------------------------------------------------
67 // logbuf is an output-only streambuf with the ability to disable sets of
68 // messages at runtime. Only messages with priority >= logbuf::logPriority
69 // and debugClass == logbuf::logClass are output.
71 class logbuf : public streambuf
75 #ifndef FG_HAVE_STD_INCLUDES
76 typedef char_traits<char> traits_type;
77 typedef char_traits<char>::int_type int_type;
78 typedef char_traits<char>::pos_type pos_type;
79 typedef char_traits<char>::off_type off_type;
81 // logbuf( streambuf* sb ) : sbuf(sb) {}
85 // Is logging enabled?
86 bool enabled() { return logging_enabled; }
88 // Set the logging level of subsequent messages.
89 void set_log_state( fgDebugClass c, fgDebugPriority p );
91 // Set the global logging level.
92 static void set_log_level( fgDebugClass c, fgDebugPriority p );
95 void set_sb( streambuf* sb );
99 inline virtual int sync();
100 int_type overflow( int ch );
101 // int xsputn( const char* s, istreamsize n );
105 // The streambuf used for actual output. Defaults to cerr.rdbuf().
106 static streambuf* sbuf;
108 static bool logging_enabled;
109 static fgDebugClass logClass;
110 static fgDebugPriority logPriority;
115 logbuf( const logbuf& );
116 void operator= ( const logbuf& );
122 #ifdef FG_HAVE_STD_INCLUDES
123 return sbuf->pubsync();
130 logbuf::set_log_state( fgDebugClass c, fgDebugPriority p )
132 logging_enabled = ((c & logClass) != 0 && p >= logPriority);
135 inline logbuf::int_type
136 logbuf::overflow( int c )
138 return logging_enabled ? sbuf->sputc(c) : (EOF == 0 ? 1: 0);
141 //-----------------------------------------------------------------------------
143 // logstream manipulator for setting the log level of a message.
147 loglevel( fgDebugClass c, fgDebugPriority p )
148 : logClass(c), logPriority(p) {}
150 fgDebugClass logClass;
151 fgDebugPriority logPriority;
154 //-----------------------------------------------------------------------------
156 // A helper class that ensures a streambuf and ostream are constructed and
157 // destroyed in the correct order. The streambuf must be created before the
158 // ostream but bases are constructed before members. Thus, making this class
159 // a private base of logstream, declared to the left of ostream, we ensure the
160 // correct order of construction and destruction.
162 struct logstream_base
164 // logstream_base( streambuf* sb ) : lbuf(sb) {}
170 //-----------------------------------------------------------------------------
174 class logstream : private logstream_base, public ostream
177 // The default is to send messages to cerr.
178 logstream( ostream& out )
179 // : logstream_base(out.rdbuf()),
181 ostream(&lbuf) { lbuf.set_sb(out.rdbuf());}
183 void set_output( ostream& out ) { lbuf.set_sb( out.rdbuf() ); }
185 // Set the global log class and priority level.
186 void setLogLevels( fgDebugClass c, fgDebugPriority p );
188 // Output operator to capture the debug level and priority of a message.
189 inline ostream& operator<< ( const loglevel& l );
193 logstream::operator<< ( const loglevel& l )
195 lbuf.set_log_state( l.logClass, l.logPriority );
199 //-----------------------------------------------------------------------------
201 // Return the one and only logstream instance.
202 // We use a function instead of a global object so we are assured that cerr
203 // has been initialised.
208 static logstream logstrm( cerr );
213 # define FG_LOG(C,P,M)
214 #elif defined( __MWERKS__ )
215 # define FG_LOG(C,P,M) ::fglog() << ::loglevel(C,P) << M << std::endl
217 # define FG_LOG(C,P,M) fglog() << loglevel(C,P) << M << endl
220 #endif // _LOGSTREAM_H