ClickHouse/base/poco/Foundation/include/Poco/LogStream.h

//
// LogStream.h
//
// Library: Foundation
// Package: Logging
// Module:  LogStream
//
// Definition of the LogStream class.
//
// Copyright (c) 2006-2007, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef Foundation_LogStream_INCLUDED
#define Foundation_LogStream_INCLUDED


#include <istream>
#include "Poco/Foundation.h"
#include "Poco/Logger.h"
#include "Poco/UnbufferedStreamBuf.h"


namespace Poco
{


class Foundation_API LogStreamBuf : public UnbufferedStreamBuf
/// This class implements a streambuf interface
/// to a Logger.
///
/// The streambuf appends all characters written to it
/// to a string. As soon as a CR or LF (std::endl) is written,
/// the string is sent to the Logger, with the set
/// priority.
{
public:
    LogStreamBuf(Logger & logger, Message::Priority priority);
    /// Creates the LogStream.

    ~LogStreamBuf();
    /// Destroys the LogStream.

    void setPriority(Message::Priority priority);
    /// Sets the priority for log messages.

    Message::Priority getPriority() const;
    /// Returns the priority for log messages.

    Logger & logger() const;
    /// Returns a reference to the Logger.

private:
    int writeToDevice(char c);

private:
    Logger & _logger;
    Message::Priority _priority;
    std::string _message;
};


class Foundation_API LogIOS : public virtual std::ios
/// The base class for LogStream.
///
/// This class is needed to ensure the correct initialization
/// order of the stream buffer and base classes.
{
public:
    LogIOS(Logger & logger, Message::Priority priority);
    ~LogIOS();
    LogStreamBuf * rdbuf();

protected:
    LogStreamBuf _buf;
};


class Foundation_API LogStream : public LogIOS, public std::ostream
/// This class implements an ostream interface
/// to a Logger.
///
/// The stream's buffer appends all characters written to it
/// to a string. As soon as a CR or LF (std::endl) is written,
/// the string is sent to the Logger, with the current
/// priority.
///
/// Usage example:
///     LogStream ls(someLogger);
///     ls << "Some informational message" << std::endl;
///     ls.error() << "Some error message" << std::endl;
{
public:
    LogStream(Logger & logger, Message::Priority priority = Message::PRIO_INFORMATION);
    /// Creates the LogStream, using the given logger and priority.

    LogStream(const std::string & loggerName, Message::Priority priority = Message::PRIO_INFORMATION);
    /// Creates the LogStream, using the logger identified
    /// by loggerName, and sets the priority.

    ~LogStream();
    /// Destroys the LogStream.

    LogStream & fatal();
    /// Sets the priority for log messages to Message::PRIO_FATAL.

    LogStream & fatal(const std::string & message);
    /// Sets the priority for log messages to Message::PRIO_FATAL
    /// and writes the given message.

    LogStream & critical();
    /// Sets the priority for log messages to Message::PRIO_CRITICAL.

    LogStream & critical(const std::string & message);
    /// Sets the priority for log messages to Message::PRIO_CRITICAL
    /// and writes the given message.

    LogStream & error();
    /// Sets the priority for log messages to Message::PRIO_ERROR.

    LogStream & error(const std::string & message);
    /// Sets the priority for log messages to Message::PRIO_ERROR
    /// and writes the given message.

    LogStream & warning();
    /// Sets the priority for log messages to Message::PRIO_WARNING.

    LogStream & warning(const std::string & message);
    /// Sets the priority for log messages to Message::PRIO_WARNING
    /// and writes the given message.

    LogStream & notice();
    /// Sets the priority for log messages to Message::PRIO_NOTICE.

    LogStream & notice(const std::string & message);
    /// Sets the priority for log messages to Message::PRIO_NOTICE
    /// and writes the given message.

    LogStream & information();
    /// Sets the priority for log messages to Message::PRIO_INFORMATION.

    LogStream & information(const std::string & message);
    /// Sets the priority for log messages to Message::PRIO_INFORMATION
    /// and writes the given message.

    LogStream & debug();
    /// Sets the priority for log messages to Message::PRIO_DEBUG.

    LogStream & debug(const std::string & message);
    /// Sets the priority for log messages to Message::PRIO_DEBUG
    /// and writes the given message.

    LogStream & trace();
    /// Sets the priority for log messages to Message::PRIO_TRACE.

    LogStream & trace(const std::string & message);
    /// Sets the priority for log messages to Message::PRIO_TRACE
    /// and writes the given message.

    LogStream & test();
    /// Sets the priority for log messages to Message::PRIO_TEST.

    LogStream & test(const std::string & message);
    /// Sets the priority for log messages to Message::PRIO_TEST
    /// and writes the given message.

    LogStream & priority(Message::Priority priority);
    /// Sets the priority for log messages.
};


//
// inlines
//
inline Message::Priority LogStreamBuf::getPriority() const
{
    return _priority;
}


inline Logger & LogStreamBuf::logger() const
{
    return _logger;
}


} // namespace Poco


#endif // Foundation_LogStream_INCLUDED