dlib C++ Library - logger_kernel_1.cpp

    // Copyright (C) 2006  Davis E. King (davis@dlib.net)
    // License: Boost Software License   See LICENSE.txt for the full license.
    #ifndef DLIB_LOGGER_KERNEL_1_CPp_
    #define DLIB_LOGGER_KERNEL_1_CPp_

    #include "logger_kernel_1.h"
    #include <iostream>
    #include <sstream>

    namespace dlib
    {

    // ----------------------------------------------------------------------------------------

        void set_all_logging_output_streams (
            std::ostream& out_
        )
        {
            logger::global_data& gd = logger::get_global_data();
            auto_mutex M(gd.m);
            gd.loggers.reset();
            while (gd.loggers.move_next())
            {
                gd.loggers.element()->out.rdbuf(out_.rdbuf());
                gd.loggers.element()->hook.clear();
            }

            gd.set_output_stream("",out_);

            // set the default hook to be an empty member function pointer
            logger::hook_mfp hook;
            gd.set_output_hook("",hook);
        }

        void set_all_logging_levels (
            const log_level& new_level
        )
        {
            logger::global_data& gd = logger::get_global_data();
            auto_mutex M(gd.m);
            gd.loggers.reset();
            while (gd.loggers.move_next())
            {
                gd.loggers.element()->cur_level = new_level;
            }

            gd.set_level("",new_level);
        }

        void set_all_logging_headers (
            const print_header_type& new_header
        )
        {
            logger::global_data& gd = logger::get_global_data();
            auto_mutex M(gd.m);
            gd.loggers.reset();
            while (gd.loggers.move_next())
            {
                gd.loggers.element()->print_header = new_header;
            }

            gd.set_logger_header("",new_header);
        }

    // ----------------------------------------------------------------------------------------

        namespace logger_helper_stuff
        {
            class helper
            {
            public:
                helper()
                {
                    std::ostringstream sout;
                    print_default_logger_header(sout,"some_name",LDEBUG,0);
                }
            };
            // do this to make sure all the static members of print_default_logger_header get
            // initialized when the program turns on.
            static helper a;
            // make a logger to make extra sure the static global_data object gets
            // initialized before any threads start up.  Also do this so that there is always
            // at least one logger so that the global data won't be deleted until the
            // program is terminating.
            static logger log("dlib");
        }

    // ----------------------------------------------------------------------------------------

        void print_default_logger_header (
            std::ostream& out,
            const std::string& logger_name,
            const log_level& l,
            const uint64 thread_id
        )
        {
            using namespace std;
            static timestamper ts;
            static const uint64 first_time = ts.get_timestamp();

            const uint64 cur_time = (ts.get_timestamp() - first_time)/1000;
            streamsize old_width = out.width(); out.width(5);
            out << cur_time << " " << l.name;
            out.width(old_width);

            out << " [" << thread_id << "] " << logger_name << ": ";
        }

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
    //                 global_data stuff
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        logger::global_data::
        ~global_data (
        )
        {
            unregister_thread_end_handler(*this,&global_data::thread_end_handler);
        }

    // ----------------------------------------------------------------------------------------

        logger::global_data::
        global_data(
        ) :
            next_thread_name(1)
        {
            // make sure the main program thread always has id 0.  Since there is
            // a global logger object declared in this file we should expect that
            // the global_data object will be initialized in the main program thread
            // so if we call get_thread_id() now we should get the main thread id.
            thread_id_type main_id = get_thread_id();
            uint64 id_zero = 0;
            thread_names.add(main_id,id_zero);

            // set up the defaults
            auto_flush_table.val = true;
            streambuf_table.val = std::cout.rdbuf();
            header_table.val = print_default_logger_header;

            // also allocate an initial buffer for hook based logging
            hookbuf.buffer.reserve(1000);
        }

        logger::global_data::level_container::
        level_container (
        ) : val(300,"ERROR") {}

    // ----------------------------------------------------------------------------------------

        template <typename T>
        const T& search_tables (
            const T& c,
            const std::string& name
        )
        {
            if (c.table.size() == 0 || name.size() == 0)
                return c;

            const std::string::size_type pos = name.find_first_of(".");
            const std::string first = name.substr(0,pos);
            std::string last;
            if (pos != std::string::npos)
                last = name.substr(pos+1);

            if (c.table.is_in_domain(first))
            {
                return search_tables(*c.table[first], last);
            }
            else
            {
                return c;
            }
        }

    // ----------------------------------------------------------------------------------------

        template <typename T, typename U>
        void assign_tables (
            T& c,
            const std::string& name,
            const U& val
        )
        {
            if (name.size() == 0)
            {
                c.val = val;
                c.table.clear();
                return;
            }

            const std::string::size_type pos = name.find_first_of(".");
            std::string first = name.substr(0,pos);
            std::string last;
            if (pos != std::string::npos)
                last = name.substr(pos+1);

            if (c.table.is_in_domain(first))
            {
                assign_tables(*c.table[first], last, val);
            }
            else
            {
                std::unique_ptr<T> temp (new T);
                temp->val = c.val;
                assign_tables(*temp, last, val);
                c.table.add(first,temp);
            }
        }

    // ----------------------------------------------------------------------------------------

        const log_level logger::global_data::
        level (
            const std::string& name
        ) const
        {
            auto_mutex M(m);
            return search_tables(level_table, name).val;
        }

    // ----------------------------------------------------------------------------------------

        void logger::global_data::
        set_level (
            const std::string& name,
            const log_level& new_level
        )
        {
            auto_mutex M(m);
            assign_tables(level_table, name, new_level);
        }

    // ----------------------------------------------------------------------------------------

        bool logger::global_data::
        auto_flush (
            const std::string& name
        ) const
        {
            auto_mutex M(m);
            return search_tables(auto_flush_table, name).val;
        }

    // ----------------------------------------------------------------------------------------

        void logger::global_data::
        set_auto_flush (
            const std::string& name,
            bool enabled
        )
        {
            auto_mutex M(m);
            assign_tables(auto_flush_table, name, enabled);
        }

    // ----------------------------------------------------------------------------------------

        std::streambuf* logger::global_data::
        output_streambuf (
            const std::string& name
        )
        {
            auto_mutex M(m);
            return search_tables(streambuf_table, name).val;
        }

    // ----------------------------------------------------------------------------------------

        void logger::global_data::
        set_output_stream (
            const std::string& name,
            std::ostream& out_
        )
        {
            auto_mutex M(m);
            assign_tables( streambuf_table, name, out_.rdbuf());
        }

    // ----------------------------------------------------------------------------------------

        void logger::global_data::
        set_output_stream (
            const std::string& name,
            std::streambuf& buf
        )
        {
            auto_mutex M(m);
            assign_tables( streambuf_table, name, &buf);
        }

    // ----------------------------------------------------------------------------------------

        logger::hook_mfp logger::global_data::
        output_hook (
            const std::string& name
        )
        {
            auto_mutex M(m);
            return search_tables(hook_table, name).val;
        }

    // ----------------------------------------------------------------------------------------

        void logger::global_data::
        set_output_hook (
            const std::string& name,
            const hook_mfp& hook
        )
        {
            auto_mutex M(m);
            assign_tables( hook_table, name, hook);
        }

    // ----------------------------------------------------------------------------------------

        print_header_type logger::global_data::
        logger_header (
            const std::string& name
        )
        {
            auto_mutex M(m);
            return search_tables(header_table, name).val;
        }

    // ----------------------------------------------------------------------------------------

        void logger::global_data::
        set_logger_header (
            const std::string& name,
            print_header_type ph
        )
        {
            auto_mutex M(m);
            assign_tables(header_table, name, ph);
        }

    // ----------------------------------------------------------------------------------------

        logger::global_data& logger::get_global_data()
        {
            // Allocate the global_data on the heap rather than on the stack because
            // we want to guard against the case where this static object would be destroyed
            // during program termination BEFORE all logger objects are destroyed.
            static global_data* gd = new global_data;
            return *gd;
        }

    // ----------------------------------------------------------------------------------------

        void logger::global_data::
        thread_end_handler (
        )
        {
            auto_mutex M(m);
            thread_id_type id = get_thread_id();
            thread_id_type junkd;
            uint64 junkr;
            thread_names.remove(id,junkd,junkr);
        }

    // ----------------------------------------------------------------------------------------

        uint64 logger::global_data::
        get_thread_name (
        )
        {
            thread_id_type id = get_thread_id();
            uint64 thread_name;
            if (thread_names.is_in_domain(id))
            {
                thread_name = thread_names[id];
            }
            else
            {
                if (is_dlib_thread(id))
                    register_thread_end_handler(*this,&global_data::thread_end_handler);
                thread_name = next_thread_name;
                thread_names.add(id,thread_name);
                thread_name = next_thread_name;
                ++next_thread_name;
            }
            return thread_name;
        }

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
    //               logger_stream stuff
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        void logger::logger_stream::
        print_header_and_stuff (
        )
        {
            if (!been_used)
            {
                log.gd.m.lock();

                // Check if the output hook is setup.  If it isn't then we print the logger
                // header like normal.  Otherwise we need to remember to clear out the output
                // stringstream we always write to.
                if (log.hook.is_set() == false)
                {
                    log.logger_header()(log.out,log.name(),l,log.gd.get_thread_name());
                }
                else
                {
                    // Make sure the hook buffer doesn't have any old data in it before we start
                    // logging a new message into it.
                    log.gd.hookbuf.buffer.resize(0);
                }
                been_used = true;
            }
        }

    // ----------------------------------------------------------------------------------------

        void logger::logger_stream::
        print_end_of_line (
        )
        {
            auto_unlock M(log.gd.m);

            if (log.hook.is_set() == false)
            {
                if (log.auto_flush_enabled)
                    log.out << std::endl;
                else
                    log.out << "\n";
            }
            else
            {
                // Make sure the buffer is a proper C-string
                log.gd.hookbuf.buffer.push_back('\0');
                // call the output hook with all the info regarding this log message.
                log.hook(log.name(), l, log.gd.get_thread_name(), &log.gd.hookbuf.buffer[0]);
            }
        }

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
    //         logger stuff
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        logger::
        logger (
            const std::string& name_
        ) :
            gd(get_global_data()),
            logger_name(name_),
            out(gd.output_streambuf(logger_name)),
            cur_level(gd.level(logger_name))
        {
            DLIB_ASSERT(name_[0] != '\0',
                        "\tlogger::logger()"
                        << "\n\tYou can't make a logger with an empty name"
                        << "\n\tthis: " << this
            );

            auto_mutex M(gd.m);
            logger* temp = this;
            gd.loggers.add(temp);

            // load the appropriate settings
            print_header        = gd.logger_header(logger_name);
            auto_flush_enabled  = gd.auto_flush(logger_name);
            hook                = gd.output_hook(logger_name);
        }

    // ----------------------------------------------------------------------------------------

        logger::
        ~logger (
        )
        {
            gd.m.lock();
            gd.loggers.destroy(this);
            // if this was the last logger then delete the global data
            if (gd.loggers.size() == 0)
            {
                gd.m.unlock();
                delete &gd;
            }
            else
            {
                gd.m.unlock();
            }
        }

    // ----------------------------------------------------------------------------------------

    }

    #endif // DLIB_LOGGER_KERNEL_1_CPp_