rotating file logger callback

include/spdlog/common.h

@@ -67,6 +67,9 @@ using level_t = std::atomic<int>;
 
 using log_err_handler = std::function<void(const std::string &err_msg)>;
 
+using rotating_logger_cb = std::function<void(std::vector<std::string>)>;
+using daily_logger_cb = std::function<void(std::string)>;
+
 //Log level enum
 namespace level
 {

include/spdlog/details/spdlog_impl.h

@@ -59,25 +59,25 @@ inline std::shared_ptr<spdlog::logger> spdlog::basic_logger_st(const std::string
 }
 
 // Create multi/single threaded rotating file logger
-inline std::shared_ptr<spdlog::logger> spdlog::rotating_logger_mt(const std::string& logger_name, const filename_t& filename, size_t max_file_size, size_t max_files)
+inline std::shared_ptr<spdlog::logger> spdlog::rotating_logger_mt(const std::string& logger_name, const filename_t& filename, size_t max_file_size, size_t max_files, rotating_logger_cb cb /*= nullptr*/)
 {
-    return create<spdlog::sinks::rotating_file_sink_mt>(logger_name, filename, max_file_size, max_files);
+    return create<spdlog::sinks::rotating_file_sink_mt>(logger_name, filename, max_file_size, max_files, cb);
 }
 
-inline std::shared_ptr<spdlog::logger> spdlog::rotating_logger_st(const std::string& logger_name, const filename_t& filename, size_t max_file_size, size_t max_files)
+inline std::shared_ptr<spdlog::logger> spdlog::rotating_logger_st(const std::string& logger_name, const filename_t& filename, size_t max_file_size, size_t max_files, rotating_logger_cb cb /*= nullptr*/)
 {
-    return create<spdlog::sinks::rotating_file_sink_st>(logger_name, filename, max_file_size, max_files);
+    return create<spdlog::sinks::rotating_file_sink_st>(logger_name, filename, max_file_size, max_files, cb);
 }
 
 // Create file logger which creates new file at midnight):
-inline std::shared_ptr<spdlog::logger> spdlog::daily_logger_mt(const std::string& logger_name, const filename_t& filename, int hour, int minute)
+inline std::shared_ptr<spdlog::logger> spdlog::daily_logger_mt(const std::string& logger_name, const filename_t& filename, int hour, int minute, daily_logger_cb cb /*= nullptr*/)
 {
-    return create<spdlog::sinks::daily_file_sink_mt>(logger_name, filename, hour, minute);
+    return create<spdlog::sinks::daily_file_sink_mt>(logger_name, filename, hour, minute, cb);
 }
 
-inline std::shared_ptr<spdlog::logger> spdlog::daily_logger_st(const std::string& logger_name, const filename_t& filename, int hour, int minute)
+inline std::shared_ptr<spdlog::logger> spdlog::daily_logger_st(const std::string& logger_name, const filename_t& filename, int hour, int minute, daily_logger_cb cb /*= nullptr*/)
 {
-    return create<spdlog::sinks::daily_file_sink_st>(logger_name, filename, hour, minute);
+    return create<spdlog::sinks::daily_file_sink_st>(logger_name, filename, hour, minute, cb);
 }
 
 

include/spdlog/sinks/file_sinks.h

@@ -66,12 +66,13 @@ class rotating_file_sink SPDLOG_FINAL : public base_sink < Mutex >
 {
 public:
     rotating_file_sink(const filename_t &base_filename,
-                       std::size_t max_size, std::size_t max_files) :
+                       std::size_t max_size, std::size_t max_files, rotating_logger_cb cb) :
         _base_filename(base_filename),
         _max_size(max_size),
         _max_files(max_files),
         _current_size(0),
-        _file_helper()
+        _file_helper(),
+        _on_finish_cb(cb)
     {
         _file_helper.open(calc_filename(_base_filename, 0));
         _current_size = _file_helper.size(); //expensive. called only once
@@ -115,7 +116,10 @@ private:
     void _rotate()
     {
         using details::os::filename_to_str;
+        std::vector<filename_t> files;
         _file_helper.close();
+
+
         for (auto i = _max_files; i > 0; --i)
         {
             filename_t src = calc_filename(_base_filename, i - 1);
@@ -128,18 +132,31 @@ private:
                     throw spdlog_ex("rotating_file_sink: failed removing " + filename_to_str(target), errno);
                 }
             }
-            if (details::file_helper::file_exists(src) && details::os::rename(src, target))
+            if (details::file_helper::file_exists(src))
+            {
+                if (details::os::rename(src, target))
                 {
                     throw spdlog_ex("rotating_file_sink: failed renaming " + filename_to_str(src) + " to " + filename_to_str(target), errno);
                 }
+                if (_on_finish_cb)
+                {
+                    files.push_back(target);
+                }
+            }
         }
         _file_helper.reopen(true);
+        
+        if (_on_finish_cb)
+        {
+            _on_finish_cb(files);
+        }
     }
     filename_t _base_filename;
     std::size_t _max_size;
     std::size_t _max_files;
     std::size_t _current_size;
     details::file_helper _file_helper;
+    rotating_logger_cb _on_finish_cb;
 };
 
 typedef rotating_file_sink<std::mutex> rotating_file_sink_mt;
@@ -186,9 +203,11 @@ public:
     daily_file_sink(
         const filename_t& base_filename,
         int rotation_hour,
-        int rotation_minute) : _base_filename(base_filename),
+        int rotation_minute,
+        daily_logger_cb cb) : _base_filename(base_filename),
         _rotation_h(rotation_hour),
-        _rotation_m(rotation_minute)
+        _rotation_m(rotation_minute),
+        _daily_cb(cb)
     {
         if (rotation_hour < 0 || rotation_hour > 23 || rotation_minute < 0 || rotation_minute > 59)
             throw spdlog_ex("daily_file_sink: Invalid rotation time in ctor");
@@ -202,8 +221,13 @@ protected:
     {
         if (std::chrono::system_clock::now() >= _rotation_tp)
         {
+            auto old_file_name = _file_helper.filename();
             _file_helper.open(FileNameCalc::calc_filename(_base_filename));
             _rotation_tp = _next_rotation_tp();
+            if (_daily_cb)
+            {
+                _daily_cb(old_file_name);
+            }
         }
         _file_helper.write(msg);
     }
@@ -234,6 +258,7 @@ private:
     int _rotation_m;
     std::chrono::system_clock::time_point _rotation_tp;
     details::file_helper _file_helper;
+    daily_logger_cb _daily_cb;
 };
 
 typedef daily_file_sink<std::mutex> daily_file_sink_mt;

include/spdlog/spdlog.h

@@ -77,14 +77,14 @@ std::shared_ptr<logger> basic_logger_st(const std::string& logger_name, const fi
 //
 // Create and register multi/single threaded rotating file logger
 //
-std::shared_ptr<logger> rotating_logger_mt(const std::string& logger_name, const filename_t& filename, size_t max_file_size, size_t max_files);
+std::shared_ptr<logger> rotating_logger_mt(const std::string& logger_name, const filename_t& filename, size_t max_file_size, size_t max_files, rotating_logger_cb cb = nullptr);
-std::shared_ptr<logger> rotating_logger_st(const std::string& logger_name, const filename_t& filename, size_t max_file_size, size_t max_files);
+std::shared_ptr<logger> rotating_logger_st(const std::string& logger_name, const filename_t& filename, size_t max_file_size, size_t max_files, rotating_logger_cb cb = nullptr);
 
 //
 // Create file logger which creates new file on the given time (default in  midnight):
 //
-std::shared_ptr<logger> daily_logger_mt(const std::string& logger_name, const filename_t& filename, int hour=0, int minute=0);
+std::shared_ptr<logger> daily_logger_mt(const std::string& logger_name, const filename_t& filename, int hour=0, int minute=0, daily_logger_cb cb = nullptr);
-std::shared_ptr<logger> daily_logger_st(const std::string& logger_name, const filename_t& filename, int hour=0, int minute=0);
+std::shared_ptr<logger> daily_logger_st(const std::string& logger_name, const filename_t& filename, int hour=0, int minute=0, daily_logger_cb cb = nullptr);
 
 //
 // Create and register stdout/stderr loggers

tests/file_log.cpp

@@ -75,6 +75,31 @@ TEST_CASE("rotating_file_logger2", "[rotating_logger]]")
     REQUIRE(get_filesize(filename1) <= 1024);
 }
 
+TEST_CASE("rotating_file_logger_cb", "[rotating_logger]]")
+{
+    return;
+    prepare_logdir();
+    std::string basename = "logs/rotating_log_cb";
+    std::vector<std::string> file_names;
+    auto cb_fun = [&file_names](std::vector<std::string> _file_names) mutable
+    {
+        file_names = _file_names;
+    };
+
+    auto logger = spdlog::rotating_logger_mt("logger", basename, 120, 3, cb_fun);
+    for (int i = 0; i < 100; ++i)
+        logger->info("0123456789");
+    logger->flush();
+
+    REQUIRE(file_names.size() == 3);
+
+    REQUIRE(get_filesize(basename) <= 120);
+    for (auto i = 1; i < 3; i++)
+    {
+        auto filename1 = basename + "." + std::to_string(i);
+        REQUIRE(get_filesize(filename1) <= 120);
+    }
+}
 
 TEST_CASE("daily_logger", "[daily_logger]]")
 {
@@ -108,7 +133,7 @@ TEST_CASE("daily_logger with dateonly calculator", "[daily_logger_dateonly]]")
     fmt::MemoryWriter w;
     w.write("{}_{:04d}-{:02d}-{:02d}", basename, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
 
-    auto logger = spdlog::create<sink_type>("logger", basename, 0, 0);
+    auto logger = spdlog::create<sink_type>("logger", basename, 0, 0, nullptr);
     for (int i = 0; i < 10; ++i)
         logger->info("Test message {}", i);
     logger->flush();
@@ -140,7 +165,7 @@ TEST_CASE("daily_logger with custom calculator", "[daily_logger_custom]]")
     fmt::MemoryWriter w;
     w.write("{}{:04d}{:02d}{:02d}", basename, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
 
-    auto logger = spdlog::create<sink_type>("logger", basename, 0, 0);
+    auto logger = spdlog::create<sink_type>("logger", basename, 0, 0, nullptr);
     for (int i = 0; i < 10; ++i)
         logger->info("Test message {}", i);