Log.h

/*
GRT MIT License
Copyright (c) <2012> <Nicholas Gillian, Media Lab, MIT>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
and associated documentation files (the "Software"), to deal in the Software without restriction, 
including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, 
and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, 
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial 
portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT 
LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE 
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#ifndef GRT_LOG_HEADER
#define GRT_LOG_HEADER

#include "GRTTypedefs.h"
//Only include the C++ 11 code if C++11 support it is enabled
#ifdef GRT_CXX11_ENABLED
#include <atomic>
#include <thread>
#include <mutex>
#endif //GRT_CXX11_ENABLED

GRT_BEGIN_NAMESPACE

class GRT_API Log{
public:
    typedef std::basic_ostream<char, std::char_traits<char> > CoutType; 
    typedef CoutType& (*StandardEndLine)(CoutType&); 

    Log(const std::string &key = ""){
        setKey(key);
        instanceLoggingEnabled = true;
        writeKey = true;
        loggingEnabledPtr = &instanceLoggingEnabled;
        writeKeyPtr = &writeKey;
        lastMessagePtr = &lastMessage;
    }

    Log(const Log &rhs){
        this->key = rhs.key;
        this->writeKey = rhs.writeKey;
        this->lastMessage = rhs.lastMessage;
        this->instanceLoggingEnabled = rhs.instanceLoggingEnabled;
        this->loggingEnabledPtr = &(this->instanceLoggingEnabled);
        this->writeKeyPtr = &(this->writeKey);
        this->lastMessagePtr = &(this->lastMessage);
    }

    virtual ~Log(){}

    Log& operator=(const Log &rhs){
        if( this != &rhs ){
            this->key = rhs.key;
            this->writeKey = rhs.writeKey;
            this->lastMessage = rhs.lastMessage;
            this->instanceLoggingEnabled = rhs.instanceLoggingEnabled;
            this->loggingEnabledPtr = &(this->instanceLoggingEnabled);
            this->writeKeyPtr = &(this->writeKey);
            this->lastMessagePtr = &(this->lastMessage);
        }
        return *this;
    }

    template < class T >
    const Log& operator<< (const T &val ) const{

#ifdef GRT_CXX11_ENABLED
        std::unique_lock<std::mutex> lock( logMutex );
#endif
        if( !baseLoggingEnabled ) return *this; //If the base class global logging is disabled, then there is nothing to do
        
        if( *loggingEnabledPtr && instanceLoggingEnabled ){
            if( *writeKeyPtr ){
                *writeKeyPtr = false;
                std::cout << key.c_str();
                std::cout << " ";
                *lastMessagePtr = ""; //Reset the last message
            }
            std::cout << val;
            std::stringstream stream;
            stream << val;
            *lastMessagePtr += stream.str(); //Update the last message
        }
        return *this;
    }

    const Log& operator<<(const StandardEndLine manip) const{

#ifdef GRT_CXX11_ENABLED
        std::unique_lock<std::mutex> lock( logMutex );
#endif
        if( !baseLoggingEnabled ) return *this; //If the base class global logging is disabled, then there is nothing to do

        if( *loggingEnabledPtr && instanceLoggingEnabled ){
            // call the function, but we cannot return it's value
            manip(std::cout);
            *writeKeyPtr = true; //The message is now complete, so toggle back the key
            
            //Trigger any logging callbacks
            triggerCallback( lastMessage );
        }
        
        return *this;
    }
    
    virtual bool getInstanceLoggingEnabled() const { 
        return instanceLoggingEnabled; 
    }

    virtual std::string getKey() const {
        return key;
    }

    virtual std::string getLastMessage() const{ 
        return lastMessage; 
    }
    
    virtual bool setKey(const std::string &key){
        if( key.length() == 0 ) this->key = "";
        else this->key = key;
        return true;
    }

    static bool getLoggingEnabled() { 
        return baseLoggingEnabled; 
    }

    virtual bool getInstanceLoggingEnabled(){
        return this->instanceLoggingEnabled;
    }

    static bool setLoggingEnabled(const bool enabled) { 
        baseLoggingEnabled = enabled; 
        return true; 
    }

    virtual bool setInstanceLoggingEnabled(const bool loggingEnabled){
        this->instanceLoggingEnabled = loggingEnabled;
        return true;
    }

    GRT_DEPRECATED_MSG("setProceedingText is deprecated, use setKey instead", void setProceedingText(std::string proceedingText) );
    GRT_DEPRECATED_MSG("getProceedingText is deprecated, use getKey instead", std::string getProceedingText() const );
    GRT_DEPRECATED_MSG("setEnableInstanceLogging is deprecated, use setInstanceLoggingEnabled instead", bool setEnableInstanceLogging(const bool loggingEnabled) );

protected:
    virtual void triggerCallback( const std::string &message ) const{ return; }
    
    std::string key;                
    std::string lastMessage;        
    bool writeKey;                  
    bool instanceLoggingEnabled;    

    bool *loggingEnabledPtr;        
    bool *writeKeyPtr;              
    std::string *lastMessagePtr;    

    static bool baseLoggingEnabled; 

#ifdef GRT_CXX11_ENABLED
    static std::mutex logMutex;
#endif
};

GRT_END_NAMESPACE

#endif //GRT_LOG_HEADER