marley::Logger::Message Class Reference

Temporary object used for forming logger messages. More...

#include <Logger.hh>

Public Member Functions
	Message (Message &&other)=default
	Message (std::vector< std::ostream * > &vec, std::mutex *mtx)
	operator bool () const
template<typename OutputType>
Message &	operator<< (const OutputType &out)
Message &	operator<< (std::ios_base &(*manip)(std::ios_base &))
	Backup overload for extra output manipulators.
Message &	operator<< (std::ostream &(*manip)(std::ostream &))
	Allows the Message to accept standard stream manipulators (like std::endl) via operator<<.
Message &	operator= (Message &&other)=default

Protected Attributes
std::ostringstream	buffer_
std::mutex *	mtx_
std::vector< std::ostream * >	osvec_
	Active output streams that should receive the Message.

Detailed Description

Temporary object used for forming logger messages.

Upon destruction, a newline is appended to the message. This is based on a trick from https://stackoverflow.com/a/57553824

Definition at line 172 of file Logger.hh.

Constructor & Destructor Documentation

Message()

marley::Logger::Message::Message ( std::vector< std::ostream * > & vec, std::mutex * mtx )

inline

Definition at line 176 of file Logger.hh.

            : osvec_( vec ), mtx_( mtx ) {}

~Message()

marley::Logger::Message::~Message ( )

inline

Definition at line 190 of file Logger.hh.

                            {
            // If we have no active OutStreams, then just destroy the Message
            // without any output
            if ( osvec_.empty() ) return;
            // Otherwise, append a new line, apply a lock to protect against
            // activity from other threads, and write to each active OutStream
            buffer_ << '\n';
            std::string msg = buffer_.str();
            std::lock_guard< std::mutex > lock( *mtx_ );
            for ( auto& s : osvec_ ) *s << msg;
          }

Member Function Documentation

operator bool()

marley::Logger::Message::operator bool ( ) const

inlineexplicit

Definition at line 188 of file Logger.hh.

{ return true; }

operator<<() [1/3]

template<typename OutputType>

Message & marley::Logger::Message::operator<< ( const OutputType & out )

inline

Definition at line 202 of file Logger.hh.

          {
            // If we have no active OutStreams, then don't both to store the
            // streaming output (since it will not be sent anywhere by the
            // destructor
            if ( !osvec_.empty() ) buffer_ << out;
            return *this;
          }

operator<<() [2/3]

marley::Logger::Message & marley::Logger::Message::operator<<

(

std::ios_base &(*

manip )(std::ios_base &)

)

Backup overload for extra output manipulators.

Definition at line 326 of file Logger.cc.

{
  buffer_ << manip;
  return *this;
}

References buffer_.

operator<<() [3/3]

marley::Logger::Message & marley::Logger::Message::operator<<

(

std::ostream &(*

manip )(std::ostream &)

)

Allows the Message to accept standard stream manipulators (like std::endl) via operator<<.

Note

Code for this function is based on a trick discussed here: http://www.cplusplus.com/forum/general/54588/#msg294798

Definition at line 319 of file Logger.cc.

{
  buffer_ << manip;
  return *this;
}

References buffer_.

Member Data Documentation

buffer_

std::ostringstream marley::Logger::Message::buffer_

protected

Used to cache output from multiple calls to operator<< until we have the full message. Then we just emit it in a single-step for each active OutStream, all at once. This together with a std::mutex prevents splitting logging messages due to race conditions between parallel threads.

Definition at line 228 of file Logger.hh.

Referenced by operator<<(), and operator<<().

mtx_

std::mutex* marley::Logger::Message::mtx_

protected

std::mutex to use to lock streaming output when emitting the final message

Definition at line 235 of file Logger.hh.

osvec_

std::vector< std::ostream* > marley::Logger::Message::osvec_

protected

Active output streams that should receive the Message.

Definition at line 231 of file Logger.hh.

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The documentation for this class was generated from the following files:

• /home/sjg/Desktop/marley/include/marley/Logger.hh
• /home/sjg/Desktop/marley/src/Logger.cc