Merge pull request #279 from facontidavide/loglevel_per_sink

Loglevel per sink. Thanks @facontidavide

.gitignore

@@ -45,6 +45,7 @@ example/*
 !example/example.sln
 !example/example.vcxproj
 !example/CMakeLists.txt
+!example/multisink.cpp
 
 # generated files
 generated

example/CMakeLists.txt

@@ -40,6 +40,9 @@ target_link_libraries(example spdlog::spdlog ${CMAKE_THREAD_LIBS_INIT})
 add_executable(benchmark bench.cpp)
 target_link_libraries(benchmark spdlog::spdlog ${CMAKE_THREAD_LIBS_INIT})
 
+add_executable(multisink multisink.cpp)
+target_link_libraries(multisink spdlog::spdlog ${CMAKE_THREAD_LIBS_INIT})
+
 enable_testing()
 file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/logs")
 add_test(NAME RunExample COMMAND example)

example/multisink.cpp

@@ -0,0 +1,47 @@
+#include "spdlog/spdlog.h"
+
+#include <iostream>
+#include <memory>
+
+namespace spd = spdlog;
+int main(int, char*[])
+{
+    bool enable_debug = true;
+    try
+    {
+        // This other example use a single logger with multiple sinks.
+        // This means that the same log_msg is forwarded to multiple sinks;
+        // Each sink can have it's own log level and a message will be logged.
+        std::vector<spdlog::sink_ptr> sinks;
+        sinks.push_back( std::make_shared<spdlog::sinks::stdout_sink_mt>() );
+        sinks.push_back( std::make_shared<spdlog::sinks::simple_file_sink_mt>("./log_regular_file.txt") );
+        sinks.push_back( std::make_shared<spdlog::sinks::simple_file_sink_mt>("./log_debug_file.txt") );
+
+        spdlog::logger console_multisink("multisink",  sinks.begin(), sinks.end() );
+        console_multisink.set_level( spdlog::level::warn);
+
+        sinks[0]->set_level( spdlog::level::trace);  // console. Allow everything.  Default value
+        sinks[1]->set_level( spdlog::level::trace);  //  regular file. Allow everything.  Default value
+        sinks[2]->set_level( spdlog::level::off);    //  regular file. Ignore everything.
+
+        console_multisink.warn("warn: will print only on console and regular file");
+
+        if( enable_debug )
+        {
+            console_multisink.set_level( spdlog::level::debug); // level of the logger
+            sinks[1]->set_level( spdlog::level::debug);  // regular file
+            sinks[2]->set_level( spdlog::level::debug);  // debug file
+        }
+        console_multisink.debug("Debug: you should see this on console and both files");
+
+        // Release and close all loggers
+        spdlog::drop_all();
+    }
+    // Exceptions will only be thrown upon failed logger or sink construction (not during logging)
+    catch (const spd::spdlog_ex& ex)
+    {
+        std::cout << "Log init failed: " << ex.what() << std::endl;
+        return 1;
+    }
+}
+

include/spdlog/details/async_log_helper.h

@@ -303,9 +303,12 @@ inline bool spdlog::details::async_log_helper::process_next_msg(log_clock::time_
             log_msg incoming_log_msg;
             incoming_async_msg.fill_log_msg(incoming_log_msg);
             _formatter->format(incoming_log_msg);
-            for (auto &s : _sinks)
+            for (auto &s : _sinks){
+                if(s->should_log( incoming_log_msg.level)){
                     s->log(incoming_log_msg);
                 }
+            }
+        }
         return true;
     }
 
@@ -317,7 +320,6 @@ inline bool spdlog::details::async_log_helper::process_next_msg(log_clock::time_
         handle_flush_interval(now, last_flush);
         sleep_or_yield(now, last_pop);
         return !_terminate_requested;
-
     }
 }
 

include/spdlog/details/logger_impl.h

@@ -245,8 +245,11 @@ inline bool spdlog::logger::should_log(spdlog::level::level_enum msg_level) cons
 inline void spdlog::logger::_sink_it(details::log_msg& msg)
 {
     _formatter->format(msg);
-    for (auto &sink : _sinks)
+    for (auto &sink : _sinks){
+        if( sink->should_log( msg.level)){
             sink->log(msg);
+        }
+    }
 
     if(_should_flush_on(msg))
         flush();

include/spdlog/sinks/dist_sink.h

@@ -35,10 +35,12 @@ protected:
 
     void _sink_it(const details::log_msg& msg) override
     {
-        for (auto &sink : _sinks)
+        for (auto &sink : _sinks){
+            if( sink->should_log( msg.level)){
                 sink->log(msg);
             }
-
+        }
+    }
 
 public:
     void flush() override

include/spdlog/sinks/sink.h

@@ -15,10 +15,33 @@ namespace sinks
 class sink
 {
 public:
+    sink(): _level( level::trace ) {}
+
     virtual ~sink() {}
     virtual void log(const details::log_msg& msg) = 0;
     virtual void flush() = 0;
+
+    bool should_log(level::level_enum msg_level) const;
+    void set_level(level::level_enum log_level);
+    level::level_enum level() const;
+
+private:
+    level_t _level;
+
 };
+
+inline bool sink::should_log(level::level_enum msg_level) const {
+    return msg_level >= _level.load(std::memory_order_relaxed);
+}
+
+inline void sink::set_level(level::level_enum log_level) {
+    _level.store(log_level);
+}
+
+inline level::level_enum sink::level() const {
+    return static_cast<spdlog::level::level_enum>(_level.load(std::memory_order_relaxed));
+}
+
 }
 }