Add daily_rotating_file_sink

A sink combined with daily_file_sink and rotating_file_sink, which creates new file each day and also when the file size exceeds. In addition, no limit of file number.

include/spdlog/sinks/daily_rotating_file_sink.h

@@ -0,0 +1,212 @@
+//
+// Copyright(c) 2015 Gabi Melman.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+//
+
+#pragma once
+#include "spdlog/details/file_helper.h"
+#include "spdlog/details/null_mutex.h"
+#include "spdlog/fmt/fmt.h"
+#include "spdlog/sinks/base_sink.h"
+#include "spdlog/spdlog.h"
+
+#include <cerrno>
+#include <chrono>
+#include <cstdio>
+#include <ctime>
+#include <mutex>
+#include <string>
+#include <tuple>
+
+
+namespace spdlog {
+namespace sinks {
+
+/*
+ * Generator of daily log file names in format basename.YYYY-MM-DD.ext
+ */
+struct daily_filename_calculator
+{
+    // Create filename for the form basename.YYYY-MM-DD
+    static filename_t calc_filename(const filename_t &filename, const tm &now_tm)
+    {
+        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::memory_buffer, fmt::wmemory_buffer>::type w;
+        fmt::format_to(
+            w, SPDLOG_FILENAME_T("{}_{:04d}-{:02d}-{:02d}{}"), basename, now_tm.tm_year + 1900, now_tm.tm_mon + 1, now_tm.tm_mday, ext);
+        return fmt::to_string(w);
+    }
+};
+
+/*
+ * Rotating file sink based on date. rotates at midnight
+ */
+template<typename Mutex, typename FileNameCalc = daily_filename_calculator>
+class daily_rotating_file_sink final : public base_sink<Mutex>
+{
+public:
+    // create daily file sink which rotates on given time
+	daily_rotating_file_sink(filename_t base_filename, std::size_t max_size, int rotation_hour, int rotation_minute, bool truncate = false)
+        : base_filename_(std::move(base_filename))
+		, max_size_(max_size)
+        , rotation_h_(rotation_hour)
+        , rotation_m_(rotation_minute)
+        , truncate_(truncate)
+    {
+        if (rotation_hour < 0 || rotation_hour > 23 || rotation_minute < 0 || rotation_minute > 59)
+        {
+            throw spdlog_ex("daily_file_sink: Invalid rotation time in ctor");
+        }
+        auto now = log_clock::now();
+        file_helper_.open(FileNameCalc::calc_filename(base_filename_, now_tm(now)), truncate_);
+        rotation_tp_ = next_rotation_tp_();
+		current_size_ = file_helper_.size(); // expensive. called only once
+    }
+
+protected:
+    void sink_it_(const details::log_msg &msg) override
+    {
+		today_filename_ = FileNameCalc::calc_filename(base_filename_, now_tm(msg.time));
+
+        if (msg.time >= rotation_tp_)
+        {
+            file_helper_.open(today_filename_, truncate_);
+            rotation_tp_ = next_rotation_tp_();
+        }
+
+        fmt::memory_buffer formatted;
+        sink::formatter_->format(msg, formatted);
+
+		current_size_ += formatted.size();
+		if (current_size_ > max_size_)
+		{
+			rotate_();
+			current_size_ = formatted.size();
+		}
+
+        file_helper_.write(formatted);
+    }
+
+    void flush_() override
+    {
+        file_helper_.flush();
+    }
+
+private:
+    tm now_tm(log_clock::time_point tp)
+    {
+        time_t tnow = log_clock::to_time_t(tp);
+        return spdlog::details::os::localtime(tnow);
+    }
+
+    log_clock::time_point next_rotation_tp_()
+    {
+        auto now = log_clock::now();
+        tm date = now_tm(now);
+        date.tm_hour = rotation_h_;
+        date.tm_min = rotation_m_;
+        date.tm_sec = 0;
+        auto rotation_time = log_clock::from_time_t(std::mktime(&date));
+        if (rotation_time > now)
+        {
+            return rotation_time;
+        }
+        return {rotation_time + std::chrono::hours(24)};
+    }
+
+	// Rotate files:
+	// log.txt -> log.1.txt
+	// log.1.txt -> log.2.txt
+	// log.2.txt -> log.3.txt
+	// log.3.txt -> log.4.txt
+	void rotate_()
+	{
+		using details::os::filename_to_str;
+		file_helper_.close();
+		for (auto i = max_files_; i >= 0; --i)
+		{
+			filename_t src = calc_filename(today_filename_, i);
+			if (!details::file_helper::file_exists(src))
+			{
+				continue;
+			}
+			filename_t target = calc_filename(today_filename_, i + 1);
+
+			if (!rename_file(src, target))
+			{
+				// if failed try again after a small delay.
+				// this is a workaround to a windows issue, where very high rotation
+				// rates can cause the rename to fail with permission denied (because of antivirus?).
+				details::os::sleep_for_millis(100);
+				if (!rename_file(src, target))
+				{
+					file_helper_.reopen(true); // truncate the log file anyway to prevent it to grow beyond its limit!
+					throw spdlog_ex(
+						"rotating_file_sink: failed renaming " + filename_to_str(src) + " to " + filename_to_str(target), errno);
+				}
+			}
+		}
+		++max_files_;
+		file_helper_.reopen(true);
+	}
+
+	// delete the target if exists, and rename the src file  to target
+	// return true on success, false otherwise.
+	bool rename_file(const filename_t &src_filename, const filename_t &target_filename)
+	{
+		// try to delete the target file in case it already exists.
+		(void)details::os::remove(target_filename);
+		return details::os::rename(src_filename, target_filename) == 0;
+	}
+
+	static filename_t calc_filename(const filename_t &filename, std::size_t index)
+	{
+		typename std::conditional<std::is_same<filename_t::value_type, char>::value, fmt::memory_buffer, fmt::wmemory_buffer>::type w;
+		if (index != 0u)
+		{
+			filename_t basename, ext;
+			std::tie(basename, ext) = details::file_helper::split_by_extenstion(filename);
+			fmt::format_to(w, SPDLOG_FILENAME_T("{}.{}{}"), basename, index, ext);
+		}
+		else
+		{
+			fmt::format_to(w, SPDLOG_FILENAME_T("{}"), filename);
+		}
+		return fmt::to_string(w);
+	}
+
+	std::size_t max_size_;
+	std::size_t max_files_;
+	std::size_t current_size_;
+	filename_t today_filename_;
+    filename_t base_filename_;
+    int rotation_h_;
+    int rotation_m_;
+    log_clock::time_point rotation_tp_;
+    details::file_helper file_helper_;
+    bool truncate_;
+};
+
+using daily_rotating_file_sink_mt = daily_rotating_file_sink<std::mutex>;
+using daily_rotating_file_sink_st = daily_rotating_file_sink<details::null_mutex>;
+
+} // namespace sinks
+
+//
+// factory functions
+//
+template<typename Factory = default_factory>
+inline std::shared_ptr<logger> daily_rotating_logger_mt(
+    const std::string &logger_name, const filename_t &filename, std::size_t max_size, int hour = 0, int minute = 0, bool truncate = false)
+{
+    return Factory::template create<sinks::daily_rotating_file_sink_mt>(logger_name, filename, max_size, hour, minute, truncate);
+}
+
+template<typename Factory = default_factory>
+inline std::shared_ptr<logger> daily_rotating_logger_st(
+    const std::string &logger_name, const filename_t &filename, std::size_t max_size, int hour = 0, int minute = 0, bool truncate = false)
+{
+    return Factory::template create<sinks::daily_rotating_file_sink_st>(logger_name, filename, max_size, hour, minute, truncate);
+}
+} // namespace spdlog