Merge pull request #683 from Puasonych/master

Let's add a new type of logger 'step_logger' :)

.gitignore

 # Auto generated files
-build/*
+build/*
 *.slo
 *.lo
 *.o
@@ -65,4 +65,7 @@ install_manifest.txt
 /tests/logs/*
 
 # idea
-.idea/
\ No newline at end of file
+.idea/
+
+# vscode
+.vscode/
\ No newline at end of file

include/spdlog/contrib/sinks/step_file_sink.h

+#pragma once
+
+#include "../../details/file_helper.h"
+#include "../../details/null_mutex.h"
+#include "../../fmt/fmt.h"
+#include "../../sinks/base_sink.h"
+
+#include <algorithm>
+#include <cerrno>
+#include <chrono>
+#include <cstdio>
+#include <ctime>
+#include <mutex>
+#include <string>
+
+// Example for spdlog.h
+//
+// 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, const filename_t &tmp_ext = ".tmp", unsigned max_file_size = std::numeric_limits<unsigned>::max());
+// std::shared_ptr<logger> step_logger_st(const std::string &logger_name, const filename_t &filename, unsigned seconds = 60, const filename_t &tmp_ext = ".tmp", unsigned max_file_size = std::numeric_limits<unsigned>::max();;
+
+// Example for spdlog_impl.h
+// 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, const filename_t &tmp_ext, unsigned max_file_size)
+// {
+//     return create<spdlog::sinks::step_file_sink_mt>(logger_name, filename_fmt, seconds, tmp_ext, 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, const filename_t &tmp_ext, unsigned max_file_size)
+// {
+//     return create<spdlog::sinks::step_file_sink_st>(logger_name, filename_fmt, seconds, tmp_ext, max_file_size);
+// }
+
+namespace spdlog {
+namespace sinks {
+
+/*
+ * 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, const filename_t &tmp_ext)
+    {
+        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, tmp_ext);
+        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, filename_t tmp_ext, unsigned max_size)
+        : _base_filename(std::move(base_filename))
+        , _tmp_ext(std::move(tmp_ext))
+        , _step_seconds(step_seconds)
+        , _max_size(max_size)
+    {
+        if (step_seconds == 0)
+        {
+            throw spdlog_ex("step_file_sink: Invalid time step in ctor");
+        }
+        if (max_size == 0)
+        {
+            throw spdlog_ex("step_file_sink: Invalid max log size in ctor");
+        }
+        
+        _tp = _next_tp();
+        std::tie(_current_filename, _ext) = FileNameCalc::calc_filename(_base_filename, _tmp_ext);
+
+        if (_tmp_ext == _ext)
+        {
+            throw spdlog_ex("step_file_sink: The temporary extension matches the specified in ctor");
+        }
+
+        _file_helper.open(_current_filename);
+        _current_size = _file_helper.size(); // expensive. called only once
+    }
+    
+    ~step_file_sink()
+    {
+        using details::os::filename_to_str;
+
+        filename_t src =_current_filename, target;
+        std::tie(target, std::ignore) = details::file_helper::split_by_extenstion(src);
+        target += _ext;
+        
+        details::os::rename(src, target);
+    }
+
+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, _tmp_ext);
+            _file_helper.open(_current_filename);
+            _tp = _next_tp();
+            _current_size = msg.formatted.size();
+        }
+        _file_helper.write(msg);
+    }
+
+    void _flush() override
+    {
+        _file_helper.flush();
+    }
+
+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, target;
+        std::tie(target, std::ignore) = details::file_helper::split_by_extenstion(src);
+        target += _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);
+        }
+    }
+
+    const filename_t _base_filename;
+    const filename_t _tmp_ext;
+    const std::chrono::seconds _step_seconds;
+    const unsigned _max_size;
+
+    std::chrono::system_clock::time_point _tp;
+    filename_t _current_filename;
+    filename_t _ext;
+    unsigned _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