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 // At least Irix needs this
35 #ifdef SG_HAVE_NATIVE_SGI_COMPILERS
36 #include <char_traits.h>
39 #ifdef SG_HAVE_STD_INCLUDES
43 # include <iostream.h>
44 # include <simgear/fg_traits.hxx>
47 #include <simgear/debug/debug_types.h>
49 #ifndef SG_HAVE_NATIVE_SGI_COMPILERS
50 SG_USING_STD(streambuf);
51 SG_USING_STD(ostream);
55 SG_USING_STD(char_traits);
59 SG_USING_STD(iostream);
65 // 1. Change output destination. Done.
66 // 2. Make logbuf thread safe.
67 // 3. Read environment for default debugClass and debugPriority.
70 //-----------------------------------------------------------------------------
72 // logbuf is an output-only streambuf with the ability to disable sets of
73 // messages at runtime. Only messages with priority >= logbuf::logPriority
74 // and debugClass == logbuf::logClass are output.
76 class logbuf : public streambuf
80 #ifndef SG_HAVE_STD_INCLUDES
81 typedef char_traits<char> traits_type;
82 typedef char_traits<char>::int_type int_type;
83 // typedef char_traits<char>::pos_type pos_type;
84 // typedef char_traits<char>::off_type off_type;
86 // logbuf( streambuf* sb ) : sbuf(sb) {}
90 // Is logging enabled?
91 bool enabled() { return logging_enabled; }
93 // Set the logging level of subsequent messages.
94 void set_log_state( fgDebugClass c, fgDebugPriority p );
96 // Set the global logging level.
97 static void set_log_level( fgDebugClass c, fgDebugPriority p );
100 void set_sb( streambuf* sb );
104 inline virtual int sync();
105 int_type overflow( int ch );
106 // int xsputn( const char* s, istreamsize n );
110 // The streambuf used for actual output. Defaults to cerr.rdbuf().
111 static streambuf* sbuf;
113 static bool logging_enabled;
114 static fgDebugClass logClass;
115 static fgDebugPriority logPriority;
120 logbuf( const logbuf& );
121 void operator= ( const logbuf& );
127 #ifdef SG_HAVE_STD_INCLUDES
128 return sbuf->pubsync();
135 logbuf::set_log_state( fgDebugClass c, fgDebugPriority p )
137 logging_enabled = ((c & logClass) != 0 && p >= logPriority);
140 inline logbuf::int_type
141 logbuf::overflow( int c )
143 return logging_enabled ? sbuf->sputc(c) : (EOF == 0 ? 1: 0);
146 //-----------------------------------------------------------------------------
148 // logstream manipulator for setting the log level of a message.
152 loglevel( fgDebugClass c, fgDebugPriority p )
153 : logClass(c), logPriority(p) {}
155 fgDebugClass logClass;
156 fgDebugPriority logPriority;
159 //-----------------------------------------------------------------------------
161 // A helper class that ensures a streambuf and ostream are constructed and
162 // destroyed in the correct order. The streambuf must be created before the
163 // ostream but bases are constructed before members. Thus, making this class
164 // a private base of logstream, declared to the left of ostream, we ensure the
165 // correct order of construction and destruction.
167 struct logstream_base
169 // logstream_base( streambuf* sb ) : lbuf(sb) {}
175 //-----------------------------------------------------------------------------
179 class logstream : private logstream_base, public ostream
182 // The default is to send messages to cerr.
183 logstream( ostream& out )
184 // : logstream_base(out.rdbuf()),
186 ostream(&lbuf) { lbuf.set_sb(out.rdbuf());}
188 void set_output( ostream& out ) { lbuf.set_sb( out.rdbuf() ); }
190 // Set the global log class and priority level.
191 void setLogLevels( fgDebugClass c, fgDebugPriority p );
193 // Output operator to capture the debug level and priority of a message.
194 inline ostream& operator<< ( const loglevel& l );
198 logstream::operator<< ( const loglevel& l )
200 lbuf.set_log_state( l.logClass, l.logPriority );
204 //-----------------------------------------------------------------------------
206 // Return the one and only logstream instance.
207 // We use a function instead of a global object so we are assured that cerr
208 // has been initialised.
213 static logstream logstrm( cerr );
218 # define FG_LOG(C,P,M)
219 #elif defined( __MWERKS__ )
220 # define FG_LOG(C,P,M) ::fglog() << ::loglevel(C,P) << M << std::endl
222 # define FG_LOG(C,P,M) fglog() << loglevel(C,P) << M << endl
225 #endif // _LOGSTREAM_H