ExternalLogger.h

// This file is part of Cantera. See License.txt in the top-level directory or
// at https://cantera.org/license.txt for license and copyright information.
 
#ifndef CT_EXTERNAL_LOGGER_H
#define CT_EXTERNAL_LOGGER_H
 
#include "logger.h"
 
namespace Cantera {
 
//! Logger that delegates to an external source via a callback to produce log output.
//! @ingroup logGroup
class ExternalLogger : public Logger
{
public:
    explicit ExternalLogger(LogCallback writer) {
        if (writer == nullptr) {
            throw CanteraError("ExternalLogger::ExternalLogger",
                "Argument “writer” must not be null!");
        }
 
        m_writer = writer;
    }
 
    void write(const string& msg) override {
        m_writeBuffer.append(msg);
 
        if (!m_writeBuffer.empty() && m_writeBuffer.back() == '\n') {
            // This is a bit strange, but the terminal new line is interpreted to mean
            // “end of message”, so we want to pop it from the message itself.
            // The other side of the logger will be in charge of deciding whether
            // “messages” will have a terminal new line or not.
            m_writeBuffer.pop_back();
 
            m_writer(LogLevel::INFO, "Info", m_writeBuffer.c_str());
 
            m_writeBuffer.erase();
        }
    }
 
    void writeendl() override {
        m_writer(LogLevel::INFO, "Info", m_writeBuffer.c_str());
 
        m_writeBuffer.erase();
    }
 
    void warn(const string& warning, const string& msg) override {
        m_writer(LogLevel::WARN, warning.c_str(), msg.c_str());
    }
 
    void error(const string& msg) override {
        m_writer(LogLevel::ERROR, "Error", msg.c_str());
    }
 
private:
    string m_writeBuffer;
 
    LogCallback m_writer = nullptr;
};
 
}
 
#endif