logger.h

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/* -*- c++ -*- */
/*
 * Copyright 2012-2013 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * GNU Radio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3, or (at your option)
 * any later version.
 *
 * GNU Radio is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#ifndef INCLUDED_GR_LOGGER_H
#define INCLUDED_GR_LOGGER_H

/*!
 * \ingroup logging
 * \brief GNU Radio logging wrapper for log4cpp library (C++ port of log4j)
 *
 */

#ifdef _MSC_VER
typedef int mode_t;
#else
#include <sys/types.h>
#endif

#include <gnuradio/api.h>
#include <assert.h>
#include <log4cpp/Category.hh>
#include <log4cpp/FileAppender.hh>
#include <log4cpp/OstreamAppender.hh>
#include <log4cpp/PatternLayout.hh>
#include <log4cpp/PropertyConfigurator.hh>
#include <log4cpp/RollingFileAppender.hh>
#include <pmt/pmt.h>
#include <time.h>
#include <boost/filesystem.hpp>
#include <boost/format.hpp>
#include <boost/thread.hpp>
#include <iostream>

namespace gr {

/*!
 * \brief GR_LOG macros
 * \ingroup logging
 *
 * These macros wrap the standard LOG4CPP_LEVEL macros.  The availablie macros
 * are:
 *  LOG_DEBUG
 *  LOG_INFO
 *  LOG_WARN
 *  LOG_TRACE
 *  LOG_ERROR
 *  LOG_ALERT
 *  LOG_CRIT
 *  LOG_FATAL
 *  LOG_EMERG
 */
typedef log4cpp::Category* logger_ptr;

} /* namespace gr */

/* Macros for Programmatic Configuration */
#define GR_LOG_DECLARE_LOGPTR(logger) gr::logger_ptr logger

#define GR_LOG_ASSIGN_LOGPTR(logger, name) logger = gr::logger_get_logger(name)

#define GR_CONFIG_LOGGER(config) gr::logger_config::load_config(config)

#define GR_CONFIG_AND_WATCH_LOGGER(config, period) \
    gr::logger_config::load_config(config, period)

#define GR_LOG_GETLOGGER(logger, name) gr::logger_ptr logger = gr::logger_get_logger(name)

#define GR_SET_LEVEL(name, level)                            \
    {                                                        \
        gr::logger_ptr logger = gr::logger_get_logger(name); \
        gr::logger_set_level(logger, level);                 \
    }

#define GR_LOG_SET_LEVEL(logger, level) gr::logger_set_level(logger, level)

#define GR_GET_LEVEL(name, level)                            \
    {                                                        \
        gr::logger_ptr logger = gr::logger_get_logger(name); \
        gr::logger_get_level(logger, level);                 \
    }

#define GR_LOG_GET_LEVEL(logger, level) gr::logger_get_level(logger, level)

#define GR_ADD_CONSOLE_APPENDER(name, target, pattern)            \
    {                                                             \
        gr::logger_ptr logger = gr::logger_get_logger(name);      \
        gr::logger_add_console_appender(logger, target, pattern); \
    }

#define GR_LOG_ADD_CONSOLE_APPENDER(logger, target, pattern)      \
    {                                                             \
        gr::logger_add_console_appender(logger, target, pattern); \
    }

#define GR_SET_CONSOLE_APPENDER(name, target, pattern)            \
    {                                                             \
        gr::logger_ptr logger = gr::logger_get_logger(name);      \
        gr::logger_set_console_appender(logger, target, pattern); \
    }

#define GR_LOG_SET_CONSOLE_APPENDER(logger, target, pattern)      \
    {                                                             \
        gr::logger_set_console_appender(logger, target, pattern); \
    }

#define GR_ADD_FILE_APPENDER(name, filename, append, pattern)            \
    {                                                                    \
        gr::logger_ptr logger = gr::logger_get_logger(name);             \
        gr::logger_add_file_appender(logger, filename, append, pattern); \
    }

#define GR_LOG_ADD_FILE_APPENDER(logger, filename, append, pattern)      \
    {                                                                    \
        gr::logger_add_file_appender(logger, filename, append, pattern); \
    }

#define GR_SET_FILE_APPENDER(name, filename, append, pattern)            \
    {                                                                    \
        gr::logger_ptr logger = gr::logger_get_logger(name);             \
        gr::logger_set_file_appender(logger, filename, append, pattern); \
    }

#define GR_LOG_SET_FILE_APPENDER(logger, filename, append, pattern)      \
    {                                                                    \
        gr::logger_set_file_appender(logger, filename, append, pattern); \
    }

#define GR_ADD_ROLLINGFILE_APPENDER(                                        \
    name, filename, filesize, bkup_index, append, mode, pattern)            \
    {                                                                       \
        gr::logger_ptr logger = gr::logger_get_logger(name);                \
        gr::logger_add_rollingfile_appender(                                \
            logger, filename, filesize, bkup_index, append, mode, pattern); \
    }

#define GR_LOG_ADD_ROLLINGFILE_APPENDER(                                    \
    logger, filename, filesize, bkup_index, append, mode, pattern)          \
    {                                                                       \
        gr::logger_add_rollingfile_appender(                                \
            logger, filename, filesize, bkup_index, append, mode, pattern); \
    }

#define GR_GET_LOGGER_NAMES(names)             \
    {                                          \
        names = gr::logger_get_logger_names(); \
    }

#define GR_RESET_CONFIGURATION() gr::logger_config::reset_config();

/* Logger name referenced macros */
#define GR_DEBUG(name, msg)                                         \
    {                                                               \
        gr::logger_ptr logger = gr::logger_get_logger(name);        \
        *logger << log4cpp::Priority::DEBUG << msg << log4cpp::eol; \
    }

#define GR_INFO(name, msg)                                         \
    {                                                              \
        gr::logger_ptr logger = gr::logger_get_logger(name);       \
        *logger << log4cpp::Priority::INFO << msg << log4cpp::eol; \
    }

#define GR_NOTICE(name, msg)                                 \
    {                                                        \
        gr::logger_ptr logger = gr::logger_get_logger(name); \
        *logger << log4cpp::Priority::NOTICE << msg;         \
    }

#define GR_WARN(name, msg)                                         \
    {                                                              \
        gr::logger_ptr logger = gr::logger_get_logger(name);       \
        *logger << log4cpp::Priority::WARN << msg << log4cpp::eol; \
    }

#define GR_ERROR(name, msg)                                         \
    {                                                               \
        gr::logger_ptr logger = gr::logger_get_logger(name);        \
        *logger << log4cpp::Priority::ERROR << msg << log4cpp::eol; \
    }

#define GR_CRIT(name, msg)                                         \
    {                                                              \
        gr::logger_ptr logger = gr::logger_get_logger(name);       \
        *logger << log4cpp::Priority::CRIT << msg << log4cpp::eol; \
    }

#define GR_ALERT(name, msg)                                         \
    {                                                               \
        gr::logger_ptr logger = gr::logger_get_logger(name);        \
        *logger << log4cpp::Priority::ALERT << msg << log4cpp::eol; \
    }

#define GR_FATAL(name, msg)                                         \
    {                                                               \
        gr::logger_ptr logger = gr::logger_get_logger(name);        \
        *logger << log4cpp::Priority::FATAL << msg << log4cpp::eol; \
    }

#define GR_EMERG(name, msg)                                         \
    {                                                               \
        gr::logger_ptr logger = gr::logger_get_logger(name);        \
        *logger << log4cpp::Priority::EMERG << msg << log4cpp::eol; \
    }

#define GR_ERRORIF(name, cond, msg)                                     \
    {                                                                   \
        if ((cond)) {                                                   \
            gr::logger_ptr logger = gr::logger_get_logger(name);        \
            *logger << log4cpp::Priority::ERROR << msg << log4cpp::eol; \
        }                                                               \
    }

#define GR_ASSERT(name, cond, msg)                                      \
    {                                                                   \
        if (!(cond)) {                                                  \
            gr::logger_ptr logger = gr::logger_get_logger(name);        \
            *logger << log4cpp::Priority::EMERG << msg << log4cpp::eol; \
        }                                                               \
        assert(0);                                                      \
    }

/* LoggerPtr Referenced Macros */
#define GR_LOG_DEBUG(logger, msg)                                   \
    {                                                               \
        *logger << log4cpp::Priority::DEBUG << msg << log4cpp::eol; \
    }

#define GR_LOG_INFO(logger, msg)                                   \
    {                                                              \
        *logger << log4cpp::Priority::INFO << msg << log4cpp::eol; \
    }

#define GR_LOG_NOTICE(logger, msg)                                   \
    {                                                                \
        *logger << log4cpp::Priority::NOTICE << msg << log4cpp::eol; \
    }

#define GR_LOG_WARN(logger, msg)                                   \
    {                                                              \
        *logger << log4cpp::Priority::WARN << msg << log4cpp::eol; \
    }

#define GR_LOG_ERROR(logger, msg)                                   \
    {                                                               \
        *logger << log4cpp::Priority::ERROR << msg << log4cpp::eol; \
    }

#define GR_LOG_CRIT(logger, msg)                                   \
    {                                                              \
        *logger << log4cpp::Priority::CRIT << msg << log4cpp::eol; \
    }

#define GR_LOG_ALERT(logger, msg)                                   \
    {                                                               \
        *logger << log4cpp::Priority::ALERT << msg << log4cpp::eol; \
    }

#define GR_LOG_FATAL(logger, msg)                                   \
    {                                                               \
        *logger << log4cpp::Priority::FATAL << msg << log4cpp::eol; \
    }

#define GR_LOG_EMERG(logger, msg)                                   \
    {                                                               \
        *logger << log4cpp::Priority::EMERG << msg << log4cpp::eol; \
    }

#define GR_LOG_ERRORIF(logger, cond, msg)                               \
    {                                                                   \
        if ((cond)) {                                                   \
            *logger << log4cpp::Priority::ERROR << msg << log4cpp::eol; \
        }                                                               \
    }

#define GR_LOG_ASSERT(logger, cond, msg)                                \
    {                                                                   \
        if (!(cond)) {                                                  \
            *logger << log4cpp::Priority::EMERG << msg << log4cpp::eol; \
            assert(0);                                                  \
        }                                                               \
    }

namespace gr {

/*!
 * \brief Class to control configuration of logger.
 * This is a singleton that can launch a thread to watch a config file for changes
 * \ingroup logging
 */
class GR_RUNTIME_API logger_config
{
private:
    /*! \brief filename of logger config file */
    std::string filename;
    /*! \brief Period (seconds) over which watcher thread checks config file for changes
     */
    unsigned int watch_period;
    /*! \brief Pointer to watch thread for config file changes */
    boost::thread* watch_thread;

    /*! \brief Watcher thread method
     * /param filename Name of configuration file
     * /param watch_period Seconds between checks for changes in config file
     */
    static void watch_file(std::string filename, unsigned int watch_period);

    static bool logger_configured;

    logger_config() /*:
     rpc_get_filename("logger_config", "filename", &logger_config::get_filename4rpc,
       pmt::mp(""), pmt::mp(""), pmt::mp(""),
       "", "filename", RPC_PRIVLVL_MIN,
       DISPTIME | DISPOPTSTRIP),
     rpc_get_watchperiod("logger_config", "watch_period",
     &logger_config::get_watchperiod4rpc, pmt::mp(0), pmt::mp(32768), pmt::mp(0),
       "", "watch_period", RPC_PRIVLVL_MIN,
       DISPTIME | DISPOPTSTRIP),
     rpc_get_config("logger_config", "config", &logger_config::get_config4rpc,
       pmt::mp(""), pmt::mp(""), pmt::mp(""),
       "", "filename", RPC_PRIVLVL_MIN,
       DISPTIME | DISPOPTSTRIP),
     rpc_set_config("logger_config","config", &logger_config::set_config4rpc,
       pmt::mp(""), pmt::mp(""), pmt::mp(""),
       "", "filename", RPC_PRIVLVL_MIN,
       DISPTIME | DISPOPTSTRIP)
                    */
    {
    } //!< Constructor

    /*
      rpcbasic_register_get<logger_config,std::string> rpc_get_filename;
      rpcbasic_register_get<logger_config,int> rpc_get_watchperiod;
      rpcbasic_register_get<logger_config,std::string> rpc_get_config;
      rpcbasic_register_set<logger_config,std::string> rpc_set_config;
    */

    logger_config(logger_config const&);  //!< Copy constructor
    void operator=(logger_config const&); //!< Assignment Operator

    std::string get_filename4rpc() { return filename; }
    int get_watchperiod4rpc() { return watch_period; };

    std::string get_config4rpc() { return filename; }

    void set_config4rpc(std::string set) { printf("Set string was:%s\n", set.c_str()); }

    /*! \brief destructor stops watch thread before exits */
    ~logger_config() { stop_watch(); }

    /*! \brief Instance getter for singleton. Only used by class. */
    static logger_config& get_instance(void);

public:
    /*! \brief Getter for config filename */
    static std::string get_filename();
    /*! \brief Getter for watch period */
    static unsigned int get_watch_period();
    /*! \brief Method to load configuration
     * /param filename Name of configuration file
     * /param watch_period Seconds between checks for changes in config file
     */
    static void load_config(std::string filename, unsigned int watch_period = 0);
    /*! \brief Method to stop watcher thread */
    static void stop_watch();
    /*! \brief method to reset logger configuration */
    static void reset_config(void);
};

/*!
 * \brief Retrieve a pointer to a logger by name
 *
 * Retrieves a logger pointer
 * \p name.
 *
 * \param name Name of the logger for which a pointer is requested
 */
GR_RUNTIME_API logger_ptr logger_get_logger(std::string name);

/*!
 * \brief Load logger's configuration file.
 *
 * Initialize the GNU Radio logger by loading the configuration file
 * \p config_filename.
 *
 * \param config_filename The configuration file. Set to "" for the
 *        basic logger that outputs to the console.
 */
GR_RUNTIME_API bool logger_load_config(const std::string& config_filename = "");

/*!
 * \brief Reset logger's configuration file.
 *
 * Remove all appenders from loggers
 */
GR_RUNTIME_API void logger_reset_config(void);

/*!
 * \brief Set the logger's output level.
 *
 * Sets the level of the logger. This takes a string that is
 * translated to the standard levels and can be (case insensitive):
 *
 * \li off , notset
 * \li debug
 * \li info
 * \li notice
 * \li warn
 * \li error
 * \li crit
 * \li alert
 * \li fatal
 * \li emerg
 *
 * \param logger the logger to set the level of.
 * \param level  string to set the level to.
 */
GR_RUNTIME_API void logger_set_level(logger_ptr logger, const std::string& level);

/*!
 * \brief Set the logger's output level.
 *
 * Sets the level of the logger. This takes the actual Log4cpp::Priority
 * data type, which can be:
 *
 * \li log4cpp::Priority::NOTSET
 * \li log4cpp::Priority::DEBUG
 * \li log4cpp::Priority::INFO
 * \li log4cpp::Priority::NOTICE
 * \li log4cpp::Priority::WARN
 * \li log4cpp::Priority::ERROR
 * \li log4cpp::Priority::CRIT
 * \li log4cpp::Priority::ALERT
 * \li log4cpp::Priority::FATAL
 * \li log4cpp::Priority::EMERG
 *
 * \param logger the logger to set the level of.
 * \param level  new logger level of type Log4cpp::Priority
 */
GR_RUNTIME_API void logger_set_level(logger_ptr logger, log4cpp::Priority::Value level);

/*!
 * \brief Get the logger's output level.
 *
 * Gets the level of the logger. This returns a string that
 * corresponds to the standard levels and can be (case insensitive):
 *
 * \li notset
 * \li debug
 * \li info
 * \li notice
 * \li warn
 * \li error
 * \li crit
 * \li alert
 * \li fatal
 * \li emerg
 *
 * \param logger the logger to get the level of.
 * \param level  string to get the level into.
 */
GR_RUNTIME_API void logger_get_level(logger_ptr logger, std::string& level);

/*!
 * \brief Get the logger's output level.
 *
 * Gets the level of the logger. This returns the actual Log4cpp::Level
 * data type, which can be:
 *
 * \li log4cpp::Priority::NOTSET
 * \li log4cpp::Priority::DEBUG
 * \li log4cpp::Priority::INFO
 * \li log4cpp::Priority::NOTICE
 * \li log4cpp::Priority::WARN
 * \li log4cpp::Priority::ERROR
 * \li log4cpp::Priority::CRIT
 * \li log4cpp::Priority::ALERT
 * \li log4cpp::Priority::FATAL
 * \li log4cpp::Priority::EMERG
 *
 * \param logger the logger to get the level of.
 * \param level of the logger.
 */
GR_RUNTIME_API void logger_get_level(logger_ptr logger, log4cpp::Priority::Value& level);

/*!
 * \brief Add console appender to a given logger
 *
 * Add console appender to a given logger
 *
 * \param logger Logger to which appender will be added
 * \param appender Name of appender to add to logger
 */
GR_RUNTIME_API void logger_add_appender(logger_ptr logger, std::string appender);

/*!
 * \brief Sets a console appender to a given logger. Deletes any
 * existing appenders and adds a new one. To add an additional
 * appender, use logger_add_appender.
 *
 * \param logger Logger to which appender will be added
 * \param appender Name of appender to add to logger
 */
GR_RUNTIME_API void logger_set_appender(logger_ptr logger, std::string appender);

/*!
 * \brief Add console appender to a given logger
 *
 * Add console appender to a given logger
 *
 * \param logger Logger to which appender will be added
 * \param target Std target to write 'cout' or 'cerr' (default is cout)
 * \param pattern Formatting pattern for log messages
 */
GR_RUNTIME_API void
logger_add_console_appender(logger_ptr logger, std::string target, std::string pattern);

/*!
 * \brief Sets a new console appender to a given logger after
 * removing all others. Use logger_add_console_appender to add
 * another.
 *
 * \param logger Logger to which appender will be added
 * \param target Std target to write 'cout' or 'cerr' (default is cout)
 * \param pattern Formatting pattern for log messages
 */
GR_RUNTIME_API void
logger_set_console_appender(logger_ptr logger, std::string target, std::string pattern);

/*!
 * \brief Add file appender to a given logger
 *
 * Add file appender to a given logger
 *
 * \param logger Logger to which appender will be added
 * \param filename File to which log will be written
 * \param append Overwrite or append to log file
 * \param pattern Formatting pattern for log messages
 */
GR_RUNTIME_API void logger_add_file_appender(logger_ptr logger,
                                             std::string filename,
                                             bool append,
                                             std::string pattern);

/*!
 * \brief Set a file appender to a given logger. To add another file
 * appender, use logger_add_file_appender.
 *
 * \param logger Logger to which appender will be added
 * \param filename File to which log will be written
 * \param append Overwrite or append to log file
 * \param pattern Formatting pattern for log messages
 */
GR_RUNTIME_API void logger_set_file_appender(logger_ptr logger,
                                             std::string filename,
                                             bool append,
                                             std::string pattern);

/*!
 * \brief Add rolling file appender to a given logger
 *
 * Add rolling file appender to a given logger
 *
 * \param logger Logger to which appender will be added
 * \param filename File to which log will be written
 * \param filesize Sizez of files to write
 * \param bkup_index Number of files to write
 * \param append Overwrite or append to log file
 * \param mode Permissions to set on log file
 * \param pattern Formatting pattern for log messages
 */
GR_RUNTIME_API void logger_add_rollingfile_appender(logger_ptr logger,
                                                    std::string filename,
                                                    size_t filesize,
                                                    int bkup_index,
                                                    bool append,
                                                    mode_t mode,
                                                    std::string pattern);

/*!
 * \brief Add rolling file appender to a given logger
 *
 * Add rolling file appender to a given logger
 *
 * \return vector of string names of loggers
 */
GR_RUNTIME_API std::vector<std::string> logger_get_logger_names(void);

} /* namespace gr */

// If Logger disable do nothing
namespace gr {

/********************* Start  Classes and Methods for Python ******************/
/*!
 * \brief Logger class for referencing loggers in python.  Not
 * needed in C++ (use macros) Wraps and manipulates loggers for
 * python as python has no macros
 * \ingroup logging
 *
 */
class GR_RUNTIME_API logger
{
private:
    /*! \brief logger pointer to logger associated wiith this wrapper class */
    GR_LOG_DECLARE_LOGPTR(d_logger);

public:
    /*!
     * \brief constructor Provide name of logger to associate with this class
     * \param logger_name Name of logger associated with class
     */
    logger(std::string logger_name) { GR_LOG_ASSIGN_LOGPTR(d_logger, logger_name); };

    /*! \brief Destructor */
    ~logger() { ; }

    // Wrappers for logging macros
    /*! \brief inline function, wrapper to set the logger level */
    void set_level(std::string level) { GR_LOG_SET_LEVEL(d_logger, level); }

    /*! \brief inline function, wrapper to get the logger level */
    void get_level(std::string& level) { GR_LOG_GET_LEVEL(d_logger, level); }

    /*! \brief inline function, wrapper for LOG4CPP_DEBUG for DEBUG message */
    void debug(std::string msg) { GR_LOG_DEBUG(d_logger, msg); };

    /*! \brief inline function, wrapper for LOG4CPP_INFO for INFO message */
    void info(std::string msg) { GR_LOG_INFO(d_logger, msg); }

    /*! \brief inline function, wrapper for NOTICE message */
    void notice(std::string msg) { GR_LOG_NOTICE(d_logger, msg); }

    /*! \brief inline function, wrapper for LOG4CPP_WARN for WARN message */
    void warn(std::string msg) { GR_LOG_WARN(d_logger, msg); }

    /*! \brief inline function, wrapper for LOG4CPP_ERROR for ERROR message */
    void error(std::string msg) { GR_LOG_ERROR(d_logger, msg); }

    /*! \brief inline function, wrapper for NOTICE message */
    void crit(std::string msg) { GR_LOG_CRIT(d_logger, msg); }

    /*! \brief inline function, wrapper for ALERT message */
    void alert(std::string msg) { GR_LOG_ALERT(d_logger, msg); }

    /*! \brief inline function, wrapper for FATAL message */
    void fatal(std::string msg) { GR_LOG_FATAL(d_logger, msg); }

    /*! \brief inline function, wrapper for EMERG message */
    void emerg(std::string msg) { GR_LOG_EMERG(d_logger, msg); }

    /*! \brief inline function, wrapper for LOG4CPP_ASSERT for conditional ERROR message
     */
    void errorIF(bool cond, std::string msg) { GR_LOG_ERRORIF(d_logger, cond, msg); }

    /*! \brief inline function, wrapper for LOG4CPP_ASSERT for conditional ERROR message
     */
    void log_assert(bool cond, std::string msg) { GR_LOG_ASSERT(d_logger, cond, msg); }

    /*! \brief inline function, Method to add console appender to logger */
    void add_console_appender(std::string target, std::string pattern)
    {
        GR_LOG_ADD_CONSOLE_APPENDER(d_logger, target, pattern);
    }

    /*! \brief inline function, Method to set a console appender to logger */
    void set_console_appender(std::string target, std::string pattern)
    {
        GR_LOG_SET_CONSOLE_APPENDER(d_logger, target, pattern);
    }

    /*! \brief inline function, Method to add file appender to logger */
    void add_file_appender(std::string filename, bool append, std::string pattern)
    {
        GR_LOG_ADD_FILE_APPENDER(d_logger, filename, append, pattern);
    }

    /*! \brief inline function, Method to set a file appender to logger */
    void set_file_appender(std::string filename, bool append, std::string pattern)
    {
        GR_LOG_SET_FILE_APPENDER(d_logger, filename, append, pattern);
    }

    /*! \brief inline function, Method to add rolling file appender to logger */
    void add_rollingfile_appender(std::string filename,
                                  size_t filesize,
                                  int bkup_index,
                                  bool append,
                                  mode_t mode,
                                  std::string pattern)
    {
        GR_LOG_ADD_ROLLINGFILE_APPENDER(
            d_logger, filename, filesize, bkup_index, append, mode, pattern);
    }
};

} /* namespace gr */

/**************** Start Configuration Class and Methods for Python ************/
/*!
 * \brief Function to call configuration macro from python.
 *        Note: Configuration is only updated if filename or watch_period has changed.
 * \param config_filename  Name of configuration file
 * \param watch_period Seconds to wait between checking for changes in conf file.
 *        Watch_period defaults to 0 in which case the file is not watched for changes
 */
GR_RUNTIME_API void gr_logger_config(const std::string config_filename,
                                     unsigned int watch_period = 0);

/*!
 * \brief Function to return logger names to python
 * \return Vector of name strings
 *
 */
GR_RUNTIME_API std::vector<std::string> gr_logger_get_logger_names(void);

/*!
 * \brief Function to reset logger configuration from python
 *
 */
GR_RUNTIME_API void gr_logger_reset_config(void);


namespace gr {
/*!
 * Function to use the GR prefs files to get and setup the two
 * default loggers defined there. The loggers are unique to the
 * class in which they are called, and we pass it the \p name to
 * identify where the log message originates from. For a GNU Radio
 * block, we use 'alias()' for this value, and this is set up for us
 * automatically in gr::block.
 */
GR_RUNTIME_API bool
configure_default_loggers(gr::logger_ptr& l, gr::logger_ptr& d, const std::string name);

GR_RUNTIME_API bool update_logger_alias(const std::string& name,
                                        const std::string& alias);

} /* namespace gr */

#endif /* INCLUDED_GR_LOGGER_H */