source: trunk/src/logger.cc @ 5

// Copyright (C) 2011 Kornel Kisielewicz
// This file is part of NV Libraries.
// For conditions of distribution and use, see copyright notice in nv.hh

#include "nv/logger.hh"

#include <iostream>
#include <utility>
#include <algorithm>
#include <fstream>
#include <nv/exception.hh>

using namespace nv;

// log level names
const char *log_level_names[] =
{
        "NONE",
        "FATAL",
        "CRITICAL",
        "ERROR",
        "WARNING",
        "NOTICE",
        "INFO",
        "INFO",
        "DEBUG",
        "DEBUG2",
        "TRACE"
};

// helper macro to access log_level_names
#define NV_LOG_LEVEL_NAME(level) (log_level_names[ (level) / 10 ])

// log function
void logger::log( log_level level, const std::string& message )
{
        // get the iterator to the beginning of the log_sink list
        log_sink_list::reverse_iterator it = m_log_sinks.rbegin();

        // iterate
        while ( it != m_log_sinks.rend() )
        {
                // if we have a log sink with high enough level...
                if ( it->first >= level )
                {
                        // log and iterate
                        it->second->log( level, message );
                }
                else 
                {
                        // otherwise return, the list is sorted by log level
                        return;
                }
                ++it;
        }
}

// add a new sink
void logger::add_sink( log_sink* sink, int level )
{
        // add a sink
        m_log_sinks.push_back( std::make_pair( log_level(level), sink ) );
        // and sort the list (default sort of pairs is by first element)
        m_log_sinks.sort();
}

// remove existing sink
bool logger::remove_sink( log_sink* sink )
{
        // get the iterator to the beginning of the log_sink list
        log_sink_list::iterator it = m_log_sinks.begin();

        // iterate
        while ( it != m_log_sinks.end() )
        {
                // found?
                if ( it->second == sink ) 
                {
                        // erase and return true to report success
                        m_log_sinks.erase(it);
                        return true;
                }
                ++it;
        }

        // not found, return false
        return false;
}

// destructor
logger::~logger()
{
        // while we have sinks
        while ( !m_log_sinks.empty() )
        {
                // delete the last one
                delete m_log_sinks.back().second;
                // and pop it
                m_log_sinks.pop_back();
        }
}


// console logging
void log_console_sink::log( log_level level, const std::string& message )
{
        std::cout << "[" << NV_LOG_LEVEL_NAME(level) << "] " << message << std::endl;
}

// stream logging
void log_stream_sink::log( log_level level, const std::string& message )
{
        // if flushing is enabled
        if ( m_flush )
        {
                // write and flush using std::endl
                *m_stream << "[" << NV_LOG_LEVEL_NAME(level) << "] " << message << std::endl;
        }
        else
        {
                // write and end with "\n" (no flush)
                *m_stream << "[" << NV_LOG_LEVEL_NAME(level) << "] " << message << "\n";
        }
}

// file logging
log_file_sink::log_file_sink( const std::string file_name, bool flush_always /*= true */ )
        : log_stream_sink( nullptr, flush_always )
{
        // create the stream manually
        std::ofstream* fstream = new std::ofstream( file_name );

        // check if it's open
        if ( !fstream->is_open() )
        {
                // throw if not open
                throw runtime_error( "Could not open file \""+file_name+"\" for logging!" );
        }

        m_stream = fstream;
}

// file logger destructor
log_file_sink::~log_file_sink()
{
        // close the file
        dynamic_cast< std::ofstream* >(m_stream)->close();
        // dispose of the stream
        delete m_stream;
}