use spdlog for logging in ws + unittest + remove un-needed mutex

third_party/spdlog/include/spdlog/sinks/basic_file_sink.h

@@ -0,0 +1,70 @@
+//
+// Copyright(c) 2015-2018 Gabi Melman.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+//
+
+#pragma once
+
+#ifndef SPDLOG_H
+#include "spdlog/spdlog.h"
+#endif
+
+#include "spdlog/details/file_helper.h"
+#include "spdlog/details/null_mutex.h"
+#include "spdlog/sinks/base_sink.h"
+
+#include <mutex>
+#include <string>
+
+namespace spdlog {
+namespace sinks {
+/*
+ * Trivial file sink with single file as target
+ */
+template<typename Mutex>
+class basic_file_sink final : public base_sink<Mutex>
+{
+public:
+    explicit basic_file_sink(const filename_t &filename, bool truncate = false)
+    {
+        file_helper_.open(filename, truncate);
+    }
+
+protected:
+    void sink_it_(const details::log_msg &msg) override
+    {
+        fmt::memory_buffer formatted;
+        sink::formatter_->format(msg, formatted);
+        file_helper_.write(formatted);
+    }
+
+    void flush_() override
+    {
+        file_helper_.flush();
+    }
+
+private:
+    details::file_helper file_helper_;
+};
+
+using basic_file_sink_mt = basic_file_sink<std::mutex>;
+using basic_file_sink_st = basic_file_sink<details::null_mutex>;
+
+} // namespace sinks
+
+//
+// factory functions
+//
+template<typename Factory = default_factory>
+inline std::shared_ptr<logger> basic_logger_mt(const std::string &logger_name, const filename_t &filename, bool truncate = false)
+{
+    return Factory::template create<sinks::basic_file_sink_mt>(logger_name, filename, truncate);
+}
+
+template<typename Factory = default_factory>
+inline std::shared_ptr<logger> basic_logger_st(const std::string &logger_name, const filename_t &filename, bool truncate = false)
+{
+    return Factory::template create<sinks::basic_file_sink_st>(logger_name, filename, truncate);
+}
+
+} // namespace spdlog