Add new logger: step_logger

include/spdlog/details/spdlog_impl.h

@@ -83,6 +83,19 @@ inline std::shared_ptr<spdlog::logger> spdlog::daily_logger_st(
     return create<spdlog::sinks::daily_file_sink_st>(logger_name, filename, hour, minute);
 }
 
+// Create a file logger that creates new files with a specified increment
+inline std::shared_ptr<spdlog::logger> spdlog::step_logger_mt(
+    const std::string &logger_name, const filename_t &filename_fmt, unsigned seconds, size_t max_file_size)
+{
+    return create<spdlog::sinks::step_file_sink_mt>(logger_name, filename_fmt, seconds, max_file_size);
+}
+
+inline std::shared_ptr<spdlog::logger> spdlog::step_logger_st(
+    const std::string &logger_name, const filename_t &filename_fmt, unsigned seconds, size_t max_file_size)
+{
+    return create<spdlog::sinks::step_file_sink_st>(logger_name, filename_fmt, seconds, max_file_size);
+}
+
 //
 // stdout/stderr loggers
 //

include/spdlog/sinks/file_sinks.h

@@ -251,5 +251,97 @@ private:
 using daily_file_sink_mt = daily_file_sink<std::mutex>;
 using daily_file_sink_st = daily_file_sink<details::null_mutex>;
 
+/*
+ * Default generator of step log file names.
+ */
+struct default_step_file_name_calculator
+{
+    // Create filename for the form filename_YYYY-MM-DD_hh-mm-ss.ext
+    static std::tuple<filename_t, filename_t> calc_filename(const filename_t &filename)
+    {
+        std::tm tm = spdlog::details::os::localtime();
+        filename_t basename, ext;
+        std::tie(basename, ext) = details::file_helper::split_by_extenstion(filename);
+        std::conditional<std::is_same<filename_t::value_type, char>::value, fmt::MemoryWriter, fmt::WMemoryWriter>::type w;
+        w.write(SPDLOG_FILENAME_T("{}_{:04d}-{:02d}-{:02d}_{:02d}-{:02d}-{:02d}"), basename, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+            tm.tm_hour, tm.tm_min, tm.tm_sec);
+        return std::make_tuple(w.str(), ext);
+    }
+};
+
+/*
+ * Rotating file sink based on size and a specified time step
+ */
+template<class Mutex, class FileNameCalc = default_step_file_name_calculator>
+class step_file_sink SPDLOG_FINAL : public base_sink<Mutex>
+{
+public:
+    step_file_sink(filename_t base_filename, unsigned step_seconds, std::size_t max_size)
+        : _base_filename(std::move(base_filename))
+        , _step_seconds(step_seconds)
+        , _max_size(max_size)
+    {
+        _tp = _next_tp();
+        std::tie(_current_filename, _ext) = FileNameCalc::calc_filename(_base_filename);
+        _file_helper.open(_current_filename);
+        _current_size = _file_helper.size(); // expensive. called only once
+    }
+
+protected:
+    void _sink_it(const details::log_msg &msg) override
+    {
+        _current_size += msg.formatted.size();
+        if (std::chrono::system_clock::now() >= _tp || _current_size > _max_size)
+        {
+            close_current_file();
+
+            std::tie(_current_filename, std::ignore) = FileNameCalc::calc_filename(_base_filename);
+            _file_helper.open(_current_filename);
+            _tp = _next_tp();
+            _current_size = msg.formatted.size();
+        }
+        _file_helper.write(msg);
+    }
+
+    void _flush() override
+    {
+        _file_helper.flush();
+        close_current_file();
+    }
+
+private:
+    std::chrono::system_clock::time_point _next_tp()
+    {
+        return std::chrono::system_clock::now() + _step_seconds;
+    }
+
+    void close_current_file()
+    {
+        using details::os::filename_to_str;
+
+        filename_t src =_current_filename;
+        filename_t target = _current_filename + _ext;
+
+        if (details::file_helper::file_exists(src) && details::os::rename(src, target) != 0)
+        {
+            throw spdlog_ex("step_file_sink: failed renaming " + filename_to_str(src) + " to " + filename_to_str(target), errno);
+        }
+    }
+
+    filename_t _base_filename;
+    std::chrono::seconds _step_seconds;
+    std::size_t _max_size;
+
+    std::chrono::system_clock::time_point _tp;
+    filename_t _current_filename;
+    filename_t _ext;
+    std::size_t _current_size;
+    
+    details::file_helper _file_helper;
+};
+
+using step_file_sink_mt = step_file_sink<std::mutex>;
+using step_file_sink_st = step_file_sink<details::null_mutex>;
+
 } // namespace sinks
 } // namespace spdlog

include/spdlog/spdlog.h

@@ -91,6 +91,12 @@ std::shared_ptr<logger> rotating_logger_st(
 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_st(const std::string &logger_name, const filename_t &filename, int hour = 0, int minute = 0);
 
+//
+// Create a file logger which creates new files with a specified time step and fixed file size:
+//
+std::shared_ptr<logger> step_logger_mt(const std::string &logger_name, const filename_t &filename, unsigned seconds = 60, size_t max_file_size = std::numeric_limits<int>::max());
+std::shared_ptr<logger> step_logger_st(const std::string &logger_name, const filename_t &filename, unsigned seconds = 60, size_t max_file_size = std::numeric_limits<int>::max());
+
 //
 // Create and register stdout/stderr loggers
 //

tests/file_log.cpp

@@ -179,6 +179,71 @@ TEST_CASE("daily_logger with custom calculator", "[daily_logger_custom]]")
     REQUIRE(count_lines(filename) == 10);
 }
 
+TEST_CASE("step_logger", "[step_logger]]")
+{
+    prepare_logdir();
+    // calculate filename (time based)
+    std::string basename = "logs/step_log";
+    std::tm tm = spdlog::details::os::localtime();
+    fmt::MemoryWriter w;
+    w.write("{}_{:04d}-{:02d}-{:02d}_{:02d}-{:02d}-{:02d}", basename, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
+
+    auto logger = spdlog::step_logger_mt("logger", basename, 60);
+    logger->flush_on(spdlog::level::info);
+    for (int i = 0; i < 10; ++i)
+    {
+#if !defined(SPDLOG_FMT_PRINTF)
+        logger->info("Test message {}", i);
+#else
+        logger->info("Test message %d", i);
+#endif
+    }
+
+    auto filename = w.str();
+    REQUIRE(count_lines(filename) == 10);
+}
+
+struct custom_step_file_name_calculator
+{
+    static std::tuple<spdlog::filename_t, spdlog::filename_t> calc_filename(const spdlog::filename_t &filename)
+    {
+        std::tm tm = spdlog::details::os::localtime();
+        spdlog::filename_t basename, ext;
+        std::tie(basename, ext) = spdlog::details::file_helper::split_by_extenstion(filename);
+        std::conditional<std::is_same<spdlog::filename_t::value_type, char>::value, fmt::MemoryWriter, fmt::WMemoryWriter>::type w;
+        w.write(SPDLOG_FILENAME_T("{}.{:04d}:{:02d}:{:02d}.{:02d}:{:02d}:{:02d}"), basename, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+            tm.tm_hour, tm.tm_min, tm.tm_sec);
+        return std::make_tuple(w.str(), ext);
+    }
+};
+
+TEST_CASE("step_logger with custom calculator", "[step_logger_custom]]")
+{
+    using sink_type = spdlog::sinks::step_file_sink<std::mutex, custom_step_file_name_calculator>;
+
+    prepare_logdir();
+
+    std::string basename = "logs/step_log_custom";
+    std::tm tm = spdlog::details::os::localtime();
+    fmt::MemoryWriter w;
+    w.write("{}.{:04d}:{:02d}:{:02d}.{:02d}:{:02d}:{:02d}", basename, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+            tm.tm_hour, tm.tm_min, tm.tm_sec);
+
+    auto logger = spdlog::create<sink_type>("logger", basename, 60, std::numeric_limits<int>::max());
+    for (int i = 0; i < 10; ++i)
+    {
+#if !defined(SPDLOG_FMT_PRINTF)
+        logger->info("Test message {}", i);
+#else
+        logger->info("Test message %d", i);
+#endif
+    }
+
+    logger->flush();
+    auto filename = w.str();
+    REQUIRE(count_lines(filename) == 10);
+}
+
 /*
  * File name calculations
  */