tri_logger.cpp

//
// Copyright (c) 2005 - 2010
// Seweryn Habdank-Wojewodzki
//
// Distributed under the Boost Software License, Version 1.0.
// ( copy at http://www.boost.org/LICENSE_1_0.txt )

#include "tri_logger.hpp"
#include <memory>

#if !defined(CLEANTLOG)

#if defined (FTLOG)
#include <fstream>
#include <cctype>

#else
#include <iostream>
#include "nullstream.hpp"
#endif

namespace trivial_logger
{
	namespace detail
	{
		class tri_logger_impl
		{
		public:
			// true if logger is activated 
			static bool is_activated_;

			// auto pointer helps manage resources;
			static ::std::auto_ptr < ::std::ostream > outstream_helper_ptr_;

			// pointer to the output stream of the logger
			static ::std::ostream * outstream_;
		};

		// activate logger by default
		bool tri_logger_impl::is_activated_ = true;

		void init_tri_logger_impl();
	}

	std::auto_ptr<detail::tri_logger_impl> 
		tri_logger_t::tl_impl ( std::auto_ptr<detail::tri_logger_impl> ( new detail::tri_logger_impl ) );

	tri_logger_t::tri_logger_t()
	{
		if (tl_impl.get() == NULL)
		{
			tri_logger_t::tl_impl.reset ( new detail::tri_logger_impl );
		}
		detail::init_tri_logger_impl();
	}

	tri_logger_t::~tri_logger_t()
	{
	}

	bool tri_logger_t::is_activated()
	{
		return tl_impl->is_activated_;
	}

	void tri_logger_t::activate ( bool const activate )
	{
		tl_impl->is_activated_ = activate;
	}

	::std::ostream *& tri_logger_t::ostream_ptr()
	{
		return tl_impl->outstream_;
	}

#if defined(TLOG)
	// set auto pointer to the null stream
	// reason: ::std::cout can not be created in runtime, so
	// the auto pointer has nothing to do with its resources
	::std::auto_ptr < ::std::ostream > 
		detail::tri_logger_impl::outstream_helper_ptr_
		= ::std::auto_ptr < ::std::ostream > ( new null_stream );
	::std::ostream * detail::tri_logger_impl::outstream_ = &::std::cout;

	void detail::init_tri_logger_impl()
	{ 
		detail::tri_logger_impl::outstream_helper_ptr_.reset ( new null_stream );
		detail::tri_logger_impl::outstream_ = &::std::cout;
	}

#elif defined (ETLOG)
	// look to the TLOG comments
	::std::auto_ptr < ::std::ostream >
		detail::tri_logger_impl::outstream_helper_ptr_
		= ::std::auto_ptr < ::std::ostream > ( new null_stream );
	::std::ostream * detail::tri_logger_impl::outstream_ = &::std::cerr;

	void detail::init_tri_logger_impl()
	{ 
		detail::tri_logger_impl::outstream_helper_ptr_.reset ( new null_stream );
		detail::tri_logger_impl::outstream_ = &::std::cerr;
	}


#elif defined (FTLOG)


#define XSTR(s) STR(s)
#define STR(s) #s

#define MAX(x,y) ( (x) < (y) ? (y) : (x) )

	namespace detail
	{
		/// Function paste rhs C string to the lhs C string.
		/// lhs should be long enough for that operation.
		/// Additionally coping is stared from the point which
		/// points lhs.
		template < typename Char_type >
		size_t const str_cat ( Char_type *& lhs, Char_type const * rhs )
		{
			size_t len = 0;
			while ( *rhs != '\0' )
			{
				*lhs = *rhs;
				++rhs;
				++lhs;
				++len;
			}
			return len;
		}

		/// Function calculates length of C string
		/// It can be used with wide characters
		template < typename Char_type >
		size_t const str_len ( Char_type const * str )
		{
			size_t len = 0;
			while ( *str != '\0' )
			{
				++str;
				++len;
			}
			return len;
		}

		/// Function copy rhs C string in to the lhs.
		/// It do not check size of target C string
		/// It starts to copy from the beginning of the C string,
		/// but it begins put characters at the point where lhs points,
		/// so there can be a problem when lhs points on the end of lhs
		/// C string.
		template < typename Char_type >
		size_t const str_cpy ( Char_type *& lhs, Char_type const * rhs )
		{
			size_t len = 0;
			while ( *rhs != '\0' )
			{
				*lhs = *rhs;
				++rhs;
				++lhs;
				++len;
			}
			*lhs = '\0';
			return len+1;
		}

		/// Function converts existing file name to the file name
		/// which has no non-printable signs and 
		/// at the end is added extension.
		/// The space sign in file name is converted to the underscore.
		/// Lengths of C strings has to be proper.
		template < typename Char_type >
		size_t const 
			createfilename ( Char_type * result, 
			Char_type const * filename,
			Char_type const * ext,
			Char_type const * helper )
		{
			size_t len = 0; 
			if ( str_len ( filename ) > 1 )
			{
				while ( *filename != '\0' )
				{
					// check if characters have grapnical
					// reprasentation
					if ( 0 != ::std::isgraph( *filename ) )
					{
						*result = *filename;
						++result;
						++len;
					}
					else
					{
						// convert space to underscore
						if ( *filename == ' ' )
						{
							*result = '_';
							++result;
							++len;
						}
					}
					++filename;
				}
				// add extension
				str_cat ( result, ext ); 
				*result = '\0';
			}
			else
			{
				result = &result[0];
				len = str_cpy ( result, helper );
			}
			return len;
		}

		template < typename T >
		T const max ( T const x, T const y )
		{
			return ( x < y ? y : x );
		}

		char_type* const get_xstr()
		{
			return XSTR(FTLOG);
		}
		// extension C string
		char_type* const get_ext()
		{
			return ".log";
		}

		char_type* const get_logger_file_name()
		{
			return "_logger.log";
		}


	} // namespace detail

	typedef char char_type;

	// convert definition of the TLOGFILE
	// to the C string
	char_type* const tlogfilename = detail::get_xstr();
	// extension C string
	char_type* const ext = detail::get_ext();

	char_type* const helper_name = detail::get_logger_file_name();

	// container for final file name
	char_type filename[(MAX(sizeof(tlogfilename),sizeof(helper_name))+sizeof(ext))/sizeof(char_type)];
	// create file name
	size_t const len = detail::createfilename ( filename, detail::get_xstr(), detail::get_ext(), detail::get_logger_file_name() );

#undef MAX
#undef STR
#undef XSTR

	// new file is opened and its destruction is managed by auto_ptr
	::std::auto_ptr < ::std::ostream >
		detail::tri_logger_impl::outstream_helper_ptr_
		= ::std::auto_ptr < ::std::ostream > 
		( new ::std::ofstream ( filename ));
	// set pointer output stream
	::std::ostream * detail::tri_logger_impl::outstream_ = outstream_helper_ptr_.get();

	void detail::init_tri_logger_impl()
	{ 
		detail::tri_logger_impl::outstream_helper_ptr_.reset( new ::std::ofstream ( filename ));
		// set pointer output stream
		detail::tri_logger_impl::outstream_ = detail::tri_logger_impl::outstream_helper_ptr_.get();
	}

	// here is a place for user defined output stream and flag

	// ...

#else
	::std::auto_ptr < ::std::ostream >
		detail::tri_logger_impl::outstream_helper_ptr_ 
		= ::std::auto_ptr < ::std::ostream > ( new null_stream );
	::std::ostream * detail::tri_logger_impl::outstream_ = outstream_helper_ptr_.get();

	void detail::init_tri_logger_impl()
	{ 
		detail::tri_logger_impl::outstream_helper_ptr_ .reset ( new null_stream );
		detail::tri_logger_impl::outstream_ = outstream_helper_ptr_.get();
	}


#endif

	::std::auto_ptr<tri_logger_t> detail::tri_logger_out_ptr ( new tri_logger_t() );

	tri_logger_t& tri_logger()
	{
		if  (detail::tri_logger_out_ptr.get() == NULL)
		{
			detail::tri_logger_out_ptr.reset ( new tri_logger_t() );
		}
		return *detail::tri_logger_out_ptr;
	}

} // namespace trivial_logger

#endif // !CLEANTLOG