logstream.hxx

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// Written by Bernie Bright, 1998
//
// Copyright (C) 1998  Bernie Bright - bbright@c031.aone.net.au
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Library General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
// $Id: logstream_8hxx_source.html,v 1.3 2010/02/23 22:10:14 curt Exp $

#ifndef _LOGSTREAM_H
#define _LOGSTREAM_H

#include <simgear/compiler.h>

#ifdef _WIN32
#  include <windows.h>
#endif

#include <streambuf>
#include <ostream>
#include <cstdio>

#include <simgear/debug/debug_types.h>

using std::streambuf;
using std::ostream;

//
// TODO:
//
// 1. Change output destination. Done.
// 2. Make logbuf thread safe.
// 3. Read environment for default debugClass and debugPriority.
//

#ifdef SG_NEED_STREAMBUF_HACK
class logbuf : public __streambuf
#else
class logbuf : public std::streambuf
#endif
{
public:
    // logbuf( streambuf* sb ) : sbuf(sb) {}
    logbuf();

    ~logbuf();

    bool enabled() { return logging_enabled; }

    void set_log_state( sgDebugClass c, sgDebugPriority p );

    bool would_log( sgDebugClass c, sgDebugPriority p ) const;

    static void set_log_level( sgDebugClass c, sgDebugPriority p );


    static void set_log_classes (sgDebugClass c);


    static sgDebugClass get_log_classes ();


    static void set_log_priority (sgDebugPriority p);


    static sgDebugPriority get_log_priority ();


    void set_sb( std::streambuf* sb );

#ifdef _WIN32
    static void has_no_console() { has_console = false; }
#endif

protected:

    inline virtual int sync();

    int_type overflow( int ch );
    // int xsputn( const char* s, istreamsize n );

private:

    // The streambuf used for actual output. Defaults to cerr.rdbuf().
    static std::streambuf* sbuf;

    static bool logging_enabled;
#ifdef _WIN32
    static bool has_console;
#endif
    static sgDebugClass logClass;
    static sgDebugPriority logPriority;

private:

    // Not defined.
    logbuf( const logbuf& );
    void operator= ( const logbuf& );
};

inline int
logbuf::sync()
{
        return sbuf->pubsync();
}

inline void
logbuf::set_log_state( sgDebugClass c, sgDebugPriority p )
{
    logging_enabled = ((c & logClass) != 0 && p >= logPriority);
}

inline bool
logbuf::would_log( sgDebugClass c, sgDebugPriority p ) const
{
    return ((c & logClass) != 0 && p >= logPriority);
}

inline logbuf::int_type
logbuf::overflow( int c )
{
#ifdef _WIN32
    if ( logging_enabled ) {
        if ( !has_console ) {
            AllocConsole();
            freopen("conin$", "r", stdin);
            freopen("conout$", "w", stdout);
            freopen("conout$", "w", stderr);
            has_console = true;
        }
        return sbuf->sputc(c);
    }
    else
        return EOF == 0 ? 1: 0;
#else
    return logging_enabled ? sbuf->sputc(c) : (EOF == 0 ? 1: 0);
#endif
}

struct loglevel
{
    loglevel( sgDebugClass c, sgDebugPriority p )
        : logClass(c), logPriority(p) {}

    sgDebugClass logClass;
    sgDebugPriority logPriority;
};

struct logstream_base
{
    // logstream_base( streambuf* sb ) : lbuf(sb) {}
    logstream_base() {}

    logbuf lbuf;
};

class logstream : private logstream_base, public std::ostream
{
public:
    logstream( std::ostream& out )
        // : logstream_base(out.rdbuf()),
        : logstream_base(),
          std::ostream(&lbuf) { lbuf.set_sb(out.rdbuf());}

    void set_output( std::ostream& out ) { lbuf.set_sb( out.rdbuf() ); }

    void setLogLevels( sgDebugClass c, sgDebugPriority p );

    bool would_log(  sgDebugClass c, sgDebugPriority p ) const
    {
        return lbuf.would_log( c, p );
    };

    inline std::ostream& operator<< ( const loglevel& l );
    friend logstream& sglog();
    static logstream *initGlobalLogstream();
protected:
    static logstream *global_logstream;
};

inline std::ostream&
logstream::operator<< ( const loglevel& l )
{
    lbuf.set_log_state( l.logClass, l.logPriority );
    return *this;
}

inline logstream&
sglog()
{
    return *logstream::initGlobalLogstream();
}


#ifdef FG_NDEBUG
# define SG_LOG(C,P,M)
#else
# define SG_LOG(C,P,M) do {                     \
        logstream& __tmplogstreamref(sglog());                      \
        if(__tmplogstreamref.would_log(C,P)) {                      \
        __tmplogstreamref << loglevel(C,P) << M << std::endl; } \
        } while(0)
#endif

#define SG_ORIGIN __FILE__ ":" SG_STRINGIZE(__LINE__)

#endif // _LOGSTREAM_H

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