ceph/src/boost/libs/log/example/doc/extension_system_uptime_attr.cpp

   1 /*
   2  *          Copyright Andrey Semashev 2007 - 2015.
   3  * Distributed under the Boost Software License, Version 1.0.
   4  *    (See accompanying file LICENSE_1_0.txt or copy at
   5  *          http://www.boost.org/LICENSE_1_0.txt)
   6  */
   7
   8 #include <string>
   9 #include <iostream>
  10 #include <stdexcept>
  11 #include <boost/config.hpp>
  12 #include <boost/smart_ptr/shared_ptr.hpp>
  13 #include <boost/core/null_deleter.hpp>
  14 #include <boost/log/core.hpp>
  15 #include <boost/log/expressions.hpp>
  16 #include <boost/log/sinks/sync_frontend.hpp>
  17 #include <boost/log/sinks/text_ostream_backend.hpp>
  18 #include <boost/log/sources/logger.hpp>
  19 #include <boost/log/sources/record_ostream.hpp>
  20 #include <boost/log/attributes/attribute.hpp>
  21 #include <boost/log/attributes/attribute_value.hpp>
  22 #include <boost/log/attributes/attribute_value_impl.hpp>
  23 #include <boost/log/attributes/attribute_cast.hpp>
  24
  25 // Includes for get_uptime()
  26 #include <boost/throw_exception.hpp>
  27 #if defined(BOOST_WINDOWS)
  28 #include <windows.h>
  29 #elif defined(__linux__) || defined(__linux) || defined(linux)
  30 #include <sys/sysinfo.h>
  31 #elif defined(macintosh) || defined(__APPLE__) || defined(__APPLE_CC__)
  32 #include <time.h>
  33 #include <errno.h>
  34 #include <sys/sysctl.h>
  35 #elif defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
  36 #include <time.h>
  37 #endif
  38
  39 namespace logging = boost::log;
  40 namespace attrs = boost::log::attributes;
  41 namespace src = boost::log::sources;
  42 namespace expr = boost::log::expressions;
  43 namespace sinks = boost::log::sinks;
  44 namespace keywords = boost::log::keywords;
  45
  46 //[ example_extension_system_uptime_attr_impl
  47 // The function returns the system uptime, in seconds
  48 unsigned int get_uptime();
  49
  50 // Attribute implementation class
  51 class system_uptime_impl :
  52     public logging::attribute::impl
  53 {
  54 public:
  55     // The method generates a new attribute value
  56     logging::attribute_value get_value()
  57     {
  58         return attrs::make_attribute_value(get_uptime());
  59     }
  60 };
  61 //]
  62
  63 //[ example_extension_system_uptime_attr
  64 // Attribute interface class
  65 class system_uptime :
  66     public logging::attribute
  67 {
  68 public:
  69     system_uptime() : logging::attribute(new system_uptime_impl())
  70     {
  71     }
  72     // Attribute casting support
  73     explicit system_uptime(attrs::cast_source const& source) : logging::attribute(source.as< system_uptime_impl >())
  74     {
  75     }
  76 };
  77 //]
  78
  79 //[ example_extension_system_uptime_use
  80 void init_logging()
  81 {
  82     boost::shared_ptr< logging::core > core = logging::core::get();
  83
  84     //<-
  85     // Initialize the sink
  86     typedef sinks::synchronous_sink< sinks::text_ostream_backend > sink_t;
  87     boost::shared_ptr< sink_t > sink(new sink_t());
  88     sink->locked_backend()->add_stream(boost::shared_ptr< std::ostream >(&std::clog, boost::null_deleter()));
  89     sink->set_formatter(expr::stream << expr::attr< unsigned int >("SystemUptime") << ": " << expr::smessage);
  90     core->add_sink(sink);
  91     //->
  92     // ...
  93
  94     // Add the uptime attribute to the core
  95     core->add_global_attribute("SystemUptime", system_uptime());
  96 }
  97 //]
  98
  99 unsigned int get_uptime()
 100 {
 101 #if defined(BOOST_WINDOWS)
 102     return GetTickCount() / 1000u;
 103 #elif defined(__linux__) || defined(__linux) || defined(linux)
 104     struct sysinfo info;
 105     if (sysinfo(&info) != 0)
 106         BOOST_THROW_EXCEPTION(std::runtime_error("Could not acquire uptime"));
 107     return info.uptime;
 108 #elif defined(macintosh) || defined(__APPLE__) || defined(__APPLE_CC__)
 109     struct timeval boottime;
 110     std::size_t len = sizeof(boottime);
 111     int mib[2] = { CTL_KERN, KERN_BOOTTIME };
 112     if (sysctl(mib, 2, &boottime, &len, NULL, 0) < 0)
 113         BOOST_THROW_EXCEPTION(std::runtime_error("Could not acquire uptime"));
 114     return time(NULL) - boottime.tv_sec;
 115 #elif (defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)) && defined(CLOCK_UPTIME)
 116     struct timespec ts;
 117     if (clock_gettime(CLOCK_UPTIME, &ts) != 0)
 118         BOOST_THROW_EXCEPTION(std::runtime_error("Could not acquire uptime"));
 119     return ts.tv_sec;
 120 #else
 121     return 0;
 122 #endif
 123 }
 124
 125 int main(int, char*[])
 126 {
 127     init_logging();
 128
 129     src::logger lg;
 130     BOOST_LOG(lg) << "Hello, world with uptime!";
 131
 132     return 0;
 133 }