Ramblings++

Been quiet the last week because I’ve just moved house. Got everything sorted and up and running now though so I should be able to get some stuff done. I still plan to take a look at some of the bots on the market currently, but have just been so busy lately, and with Mimic already being half-way into their grave I didn’t really think it was urgent to push them in all the way, I think they can take care of that themselves.

Anyway, I figured I may as well post something of use so here’s a C++ logging class I posted on GD that may be of use to people*:

* I’ll post a version with some of the outlined problems fixed Soon. Just gotta get back into the swing of things, moving always shakes me up for a few days.

This is a C++ logging class designed to be both generic and portable. Currently needs fixes in order to be truly portable but I havn’t had time to reinstall G++ or Intel to test, I’ve outlined the minor issues though. If you want to fix the issues it’s a 10 minute job at most, I’m just lazy.

The idea is that you can redirect the standard output streams to a file using a generic class template (so when new character types are added like the ones in C++0x it will be much easier to add support).

This should work across operating systems (Linux, Mac, etc).. Anything with Boost support (which is all major OS’s) SHOULD work, but is untested. Obviously you’ll need to remove the MSVC specific pragmas.

Notes:
* Boost dependency. This will not work without Boost. No I will not help you install Boost, it’s not hard, just read the documentation. If you can’t get it working you probably shouldn’t be using C++.
* Minor modifications needed for it to be truly portable. (See below)
* Relative log file path is hardcoded to “../Logs/Hades-%s.log”. Simply change that to a relative path from your module.
* Compiler is assumed to be MSVC. I am using VS 2008 Team Edition with code analysis enabled. If you get an error about warning “6328″ not being valid simply remove the pragma line with that in it.
* If you are using a compiler other than MSVC you’ll want to remove the ‘pragma warning’ stuff, I’ll fix that later.
* Makes heavy use of templates. Unless you know what you’re doing its probably best to just leave all the typedefs and template stuff alone.

Usage:
Makes use of templates and the standard output streams.
For example:
// Logging objects
Logger<char>::Stream m_AnsiStream;
Logger<wchar_t>::Stream m_WideStream;
// Initialize logger
m_AnsiStream.open(Logger<char>());
std::cout.rdbuf(m_AnsiStream.rdbuf());
m_WideStream.open(Logger<wchar_t>());
std::wcout.rdbuf(m_WideStream.rdbuf());

Now, whenever you use cout or wcout like so:
std::cout << “Look ma, I’m using the standard output stream!” << std::endl;
std::wcout << L”Wide output too!”"<< std::endl;

The output will be redirected to your file rather than to the screen or wherever the standard output was aimed at previously.

Obviously your Logger objects need to remain valid whilst ever your program is running unless you manually reset the standard output stream buffers. This means that you should store them as static objects somewhere. If you store them as a local object then they will be destructed when they move out of scope and you’ll get an access violation.

An alternative to the above is to just heap-allocate the object. Its destructor will never be called but this is probably not a problem. The reason this may be better is that you avoid race conditions implicit in the order of destruction of static objects. Obviously do NOT use a smart pointer because at that point it WILL be deleted and you’re back where you started.

Misc:
You are free to use this for whatever, as long as you agree that Kynox’s sister is a nympho.

Code:

// Preprocessor header guard to stop multiple includes

#ifndef HADES__LOGGER_H

#define HADES__LOGGER_H

// C++ Standard Library

#include <iostream>

#include <string>

#include <vector>

#include <fstream>

// Boost C++ Libraries

#pragma warning(push, 1)

#pragma warning(disable: 6328)

#pragma warning(disable: 4996)

#pragma warning(disable: 4702)

#include <boost/iostreams/categories.hpp>

#include <boost/iostreams/stream.hpp>

#include <boost/date_time/posix_time/posix_time.hpp>

#include <boost/format.hpp>

#include <boost/filesystem.hpp>

#pragma warning(pop)

// Logging class

template <typename _charT>

class Logger

{

public:

// Sink information

typedef _charT char_type;

typedef boost::iostreams::sink_tag category;

// STL typedefs

typedef std::basic_ofstream<char_type> tofstream;

typedef std::basic_string<char_type> tstring;

// Boost typedefs

typedef boost::basic_format<char_type> tformat;

struct path_traits;

typedef boost::filesystem::basic_path<tstring, path_traits> tpath;

struct path_traits

{

typedef tstring internal_string_type;

typedef tstring external_string_type;

static external_string_type to_external( const tpath &,

const internal_string_type & src ) { return src; }

static internal_string_type to_internal(

const external_string_type & src ) { return src; }

};

// Stream typedef

typedef boost::iostreams::stream< Logger<_charT> > Stream;

// Constructor

Logger() : m_LogPath(GeneratePath())

{ }

// Generate path to log file.

tstring GeneratePath()

{

// For boost

using namespace boost::posix_time;

using namespace boost::filesystem;

using boost::str;

// For STL

using std::string;

using std::wstring;

// Get local time

ptime Time(second_clock::local_time());

// Convert time to string YYYY-MM-DDTHH:MM:SS

tstring TimeStr(to_iso_extended_string_type<char_type>(Time));

// Reformat time YYYY-MM-DD_HH-MM-SS

TimeStr[10] = ‘_’;

TimeStr[13] = ‘-’;

TimeStr[16] = ‘-’;

// Generate file path relative to initial directory

wstring WideFormat(L”../Logs/Hades-%s.log”);

tstring AnyFormat(WideFormat.begin(), WideFormat.end());

tstring RelPath(str(tformat(AnyFormat) %TimeStr));

// Make full path to log file

tpath Current(initial_path<tpath>());

Current /= RelPath;

// Return path to log file

return Current.string();

}

// Writes n characters from s

std::streamsize write(const char_type* s, std::streamsize n)

{

// For boost

using namespace boost::posix_time;

// Get time

ptime Time(second_clock::local_time());

tstring TimeStr = to_simple_string_type<char_type>(Time);

// Open file

tofstream Out(m_LogPath.c_str(), tofstream::out | tofstream::app );

if(Out.is_open() && Out.good())

{

// Write time as string

Out << ‘[' << TimeStr << "]: “;

// Write data

Out.write(s, n);

}

// Return size

return n;

}

private:

// Path to log file

tstring m_LogPath;

};

#endif // HADES__LOGGER_H

// Preprocessor header guard to stop multiple includes

#ifndef HADES__LOGGER_H

#define HADES__LOGGER_H

// C++ Standard Library

#include <iostream>

#include <string>

#include <vector>

#include <fstream>

// Boost C++ Libraries

#pragma warning(push, 1)

#pragma warning(disable: 6328)

#pragma warning(disable: 4996)

#pragma warning(disable: 4702)

#include <boost/iostreams/categories.hpp>

#include <boost/iostreams/stream.hpp>

#include <boost/date_time/posix_time/posix_time.hpp>

#include <boost/format.hpp>

#include <boost/filesystem.hpp>

#pragma warning(pop)

// Logging class

template <typename _charT>

class Logger

{

public:

// Sink information

typedef _charT char_type;

typedef boost::iostreams::sink_tag category;

// STL typedefs

typedef std::basic_ofstream<char_type> tofstream;

typedef std::basic_string<char_type> tstring;

// Boost typedefs

typedef boost::basic_format<char_type> tformat;

struct path_traits;

typedef boost::filesystem::basic_path<tstring, path_traits> tpath;

struct path_traits

{

typedef tstring internal_string_type;

typedef tstring external_string_type;

static external_string_type to_external( const tpath &,

const internal_string_type & src ) { return src; }

static internal_string_type to_internal(

const external_string_type & src ) { return src; }

};

// Stream typedef

typedef boost::iostreams::stream< Logger<_charT> > Stream;

// Constructor

Logger() : m_LogPath(GeneratePath())

{ }

// Generate path to log file.

tstring GeneratePath()

{

// For boost

using namespace boost::posix_time;

using namespace boost::filesystem;

using boost::str;

// For STL

using std::string;

using std::wstring;

// Get local time

ptime Time(second_clock::local_time());

// Convert time to string YYYY-MM-DDTHH:MM:SS

tstring TimeStr(to_iso_extended_string_type<char_type>(Time));

// Reformat time YYYY-MM-DD_HH-MM-SS

TimeStr[10] = ‘_’;

TimeStr[13] = ‘-’;

TimeStr[16] = ‘-’;

// Generate file path relative to initial directory

wstring WideFormat(L”../Logs/Hades-%s.log”);

tstring AnyFormat(WideFormat.begin(), WideFormat.end());

tstring RelPath(str(tformat(AnyFormat) %TimeStr));

// Make full path to log file

tpath Current(initial_path<tpath>());

Current /= RelPath;

// Return path to log file

return Current.string();

}

// Writes n characters from s

std::streamsize write(const char_type* s, std::streamsize n)

{

// For boost

using namespace boost::posix_time;

// Get time

ptime Time(second_clock::local_time());

tstring TimeStr = to_simple_string_type<char_type>(Time);

// Open file

tofstream Out(m_LogPath.c_str(), tofstream::out | tofstream::app );

if(Out.is_open() && Out.good())

{

// Write time as string

Out << ‘[' << TimeStr << "]: “;

// Write data

Out.write(s, n);

}

// Return size

return n;

}

private:

// Path to log file

tstring m_LogPath;

};

#endif // HADES__LOGGER_H