implement message counter feature

adds %i logger pattern for printing log message sequence ID

include/spdlog/details/async_log_helper.h

@@ -51,6 +51,7 @@ class async_log_helper
         size_t thread_id;
         std::string txt;
         async_msg_type msg_type;
+        size_t msg_id;
 
         async_msg() = default;
         ~async_msg() = default;
@@ -62,13 +63,15 @@ async_msg(async_msg&& other) SPDLOG_NOEXCEPT:
             time(std::move(other.time)),
             thread_id(other.thread_id),
             txt(std::move(other.txt)),
-                    msg_type(std::move(other.msg_type))
+            msg_type(std::move(other.msg_type)),
+            msg_id(other.msg_id)
         {}
 
         async_msg(async_msg_type m_type):
             level(level::info),
             thread_id(0),
-            msg_type(m_type)
+            msg_type(m_type),
+            msg_id(0)
         {}
 
         async_msg& operator=(async_msg&& other) SPDLOG_NOEXCEPT
@@ -79,6 +82,7 @@ async_msg(async_msg&& other) SPDLOG_NOEXCEPT:
             thread_id = other.thread_id;
             txt = std::move(other.txt);
             msg_type = other.msg_type;
+            msg_id = other.msg_id;
             return *this;
         }
 
@@ -92,7 +96,8 @@ async_msg(async_msg&& other) SPDLOG_NOEXCEPT:
             time(m.time),
             thread_id(m.thread_id),
             txt(m.raw.data(), m.raw.size()),
-            msg_type(async_msg_type::log)
+            msg_type(async_msg_type::log),
+            msg_id(m.msg_id)
         {
 #ifndef SPDLOG_NO_NAME
             logger_name = *m.logger_name;
@@ -108,6 +113,7 @@ async_msg(async_msg&& other) SPDLOG_NOEXCEPT:
             msg.time = time;
             msg.thread_id = thread_id;
             msg.raw << txt;
+            msg.msg_id = msg_id;
         }
     };
 

include/spdlog/details/log_msg.h

@@ -41,6 +41,8 @@ struct log_msg
     size_t thread_id;
     fmt::MemoryWriter raw;
     fmt::MemoryWriter formatted;
+    size_t msg_id;
+
 };
 }
 }

include/spdlog/details/logger_impl.h

@@ -21,7 +21,8 @@ inline spdlog::logger::logger(const std::string& logger_name, const It& begin, c
     _formatter(std::make_shared<pattern_formatter>("%+")),
     _level(level::info),
     _flush_level(level::off),
-    _last_err_time(0)
+    _last_err_time(0),
+    _msg_counter(1)  // message counter will start from 1. 0-message id will be reserved for controll messages
 {
     _err_handler = [this](const std::string &msg)
     {
@@ -37,10 +38,7 @@ inline spdlog::logger::logger(const std::string& logger_name, sinks_init_list si
 
 // ctor with single sink
 inline spdlog::logger::logger(const std::string& logger_name, spdlog::sink_ptr single_sink):
-    logger(logger_name,
-{
-    single_sink
-})
+    logger(logger_name, { single_sink })
 {}
 
 
@@ -67,6 +65,7 @@ inline void spdlog::logger::log(level::level_enum lvl, const char* fmt, const Ar
     {
         details::log_msg log_msg(&_name, lvl);
         log_msg.raw.write(fmt, args...);
+        log_msg.msg_id = _msg_counter.fetch_add(1, std::memory_order_relaxed);
         _sink_it(log_msg);
     }
     catch (const std::exception &ex)
@@ -87,6 +86,7 @@ inline void spdlog::logger::log(level::level_enum lvl, const char* msg)
     {
         details::log_msg log_msg(&_name, lvl);
         log_msg.raw << msg;
+        log_msg.msg_id = _msg_counter.fetch_add(1, std::memory_order_relaxed);
         _sink_it(log_msg);
     }
     catch (const std::exception &ex)
@@ -108,6 +108,7 @@ inline void spdlog::logger::log(level::level_enum lvl, const T& msg)
     {
         details::log_msg log_msg(&_name, lvl);
         log_msg.raw << msg;
+        log_msg.msg_id = _msg_counter.fetch_add(1, std::memory_order_relaxed);
         _sink_it(log_msg);
     }
     catch (const std::exception &ex)

include/spdlog/details/pattern_formatter_impl.h

@@ -92,7 +92,14 @@ class a_formatter:public flag_formatter
         msg.formatted << days()[tm_time.tm_wday];
     }
 };
-
+// message counter formatter
+class i_formatter SPDLOG_FINAL:public flag_formatter
+{
+    void format(details::log_msg& msg, const std::tm& tm_time) override
+    {
+        msg.formatted << '#' << msg.msg_id;
+    }
+};
 //Full weekday name
 static const days_array& full_days()
 {
@@ -645,6 +652,10 @@ inline void spdlog::pattern_formatter::handle_flag(char flag)
         _formatters.push_back(std::unique_ptr<details::flag_formatter>(new details::pid_formatter()));
         break;
 
+    case ('i'):
+        _formatters.push_back(std::unique_ptr<details::flag_formatter>(new details::i_formatter()));
+        break;
+
     default: //Unknown flag appears as is
         _formatters.push_back(std::unique_ptr<details::flag_formatter>(new details::ch_formatter('%')));
         _formatters.push_back(std::unique_ptr<details::flag_formatter>(new details::ch_formatter(flag)));

include/spdlog/logger.h

@@ -98,6 +98,7 @@ protected:
     spdlog::level_t _flush_level;
     log_err_handler _err_handler;
     std::atomic<time_t> _last_err_time;
+    std::atomic<size_t> _msg_counter;
 };
 }