feature: enables basic framework for spdlogs

Related-To: NEO-10510

Signed-off-by: Kulkarni, Ashwin Kumar <ashwin.kumar.kulkarni@intel.com>

third_party/spdlog_headers/.version

@@ -0,0 +1 @@
+1.13.0

third_party/spdlog_headers/LICENSE

@@ -0,0 +1,26 @@
+The MIT License (MIT)
+
+Copyright (c) 2016 Gabi Melman.                                       
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+-- NOTE: Third party dependency used by this software --
+This software depends on the fmt lib (MIT License),
+and users must comply to its license: https://raw.githubusercontent.com/fmtlib/fmt/master/LICENSE
+

third_party/spdlog_headers/README.md

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+# Source locations of interface headers
+
+https://github.com/gabime/spdlog/tree/v1.x/include/

third_party/spdlog_headers/spdlog/common-inl.h

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+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#ifndef SPDLOG_HEADER_ONLY
+    #include <spdlog/common.h>
+#endif
+
+#include <algorithm>
+#include <iterator>
+
+namespace spdlog {
+namespace level {
+
+#if __cplusplus >= 201703L
+constexpr
+#endif
+    static string_view_t level_string_views[] SPDLOG_LEVEL_NAMES;
+
+static const char *short_level_names[] SPDLOG_SHORT_LEVEL_NAMES;
+
+SPDLOG_INLINE const string_view_t &to_string_view(spdlog::level::level_enum l) SPDLOG_NOEXCEPT {
+    return level_string_views[l];
+}
+
+SPDLOG_INLINE const char *to_short_c_str(spdlog::level::level_enum l) SPDLOG_NOEXCEPT {
+    return short_level_names[l];
+}
+
+SPDLOG_INLINE spdlog::level::level_enum from_str(const std::string &name) SPDLOG_NOEXCEPT {
+    auto it = std::find(std::begin(level_string_views), std::end(level_string_views), name);
+    if (it != std::end(level_string_views))
+        return static_cast<level::level_enum>(std::distance(std::begin(level_string_views), it));
+
+    // check also for "warn" and "err" before giving up..
+    if (name == "warn") {
+        return level::warn;
+    }
+    if (name == "err") {
+        return level::err;
+    }
+    return level::off;
+}
+}  // namespace level
+
+SPDLOG_INLINE spdlog_ex::spdlog_ex(std::string msg)
+    : msg_(std::move(msg)) {}
+
+SPDLOG_INLINE spdlog_ex::spdlog_ex(const std::string &msg, int last_errno) {
+#ifdef SPDLOG_USE_STD_FORMAT
+    msg_ = std::system_error(std::error_code(last_errno, std::generic_category()), msg).what();
+#else
+    memory_buf_t outbuf;
+    fmt::format_system_error(outbuf, last_errno, msg.c_str());
+    msg_ = fmt::to_string(outbuf);
+#endif
+}
+
+SPDLOG_INLINE const char *spdlog_ex::what() const SPDLOG_NOEXCEPT { return msg_.c_str(); }
+
+SPDLOG_INLINE void throw_spdlog_ex(const std::string &msg, int last_errno) {
+    SPDLOG_THROW(spdlog_ex(msg, last_errno));
+}
+
+SPDLOG_INLINE void throw_spdlog_ex(std::string msg) { SPDLOG_THROW(spdlog_ex(std::move(msg))); }
+
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/common.h

@@ -0,0 +1,411 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <spdlog/details/null_mutex.h>
+#include <spdlog/tweakme.h>
+
+#include <atomic>
+#include <chrono>
+#include <cstdio>
+#include <exception>
+#include <functional>
+#include <initializer_list>
+#include <memory>
+#include <string>
+#include <type_traits>
+
+#ifdef SPDLOG_USE_STD_FORMAT
+    #include <version>
+    #if __cpp_lib_format >= 202207L
+        #include <format>
+    #else
+        #include <string_view>
+    #endif
+#endif
+
+#ifdef SPDLOG_COMPILED_LIB
+    #undef SPDLOG_HEADER_ONLY
+    #if defined(SPDLOG_SHARED_LIB)
+        #if defined(_WIN32)
+            #ifdef spdlog_EXPORTS
+                #define SPDLOG_API __declspec(dllexport)
+            #else  // !spdlog_EXPORTS
+                #define SPDLOG_API __declspec(dllimport)
+            #endif
+        #else  // !defined(_WIN32)
+            #define SPDLOG_API __attribute__((visibility("default")))
+        #endif
+    #else  // !defined(SPDLOG_SHARED_LIB)
+        #define SPDLOG_API
+    #endif
+    #define SPDLOG_INLINE
+#else  // !defined(SPDLOG_COMPILED_LIB)
+    #define SPDLOG_API
+    #define SPDLOG_HEADER_ONLY
+    #define SPDLOG_INLINE inline
+#endif  // #ifdef SPDLOG_COMPILED_LIB
+
+#include <spdlog/fmt/fmt.h>
+
+#if !defined(SPDLOG_USE_STD_FORMAT) && \
+    FMT_VERSION >= 80000  // backward compatibility with fmt versions older than 8
+    #define SPDLOG_FMT_RUNTIME(format_string) fmt::runtime(format_string)
+    #define SPDLOG_FMT_STRING(format_string) FMT_STRING(format_string)
+    #if defined(SPDLOG_WCHAR_FILENAMES) || defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT)
+        #include <spdlog/fmt/xchar.h>
+    #endif
+#else
+    #define SPDLOG_FMT_RUNTIME(format_string) format_string
+    #define SPDLOG_FMT_STRING(format_string) format_string
+#endif
+
+// visual studio up to 2013 does not support noexcept nor constexpr
+#if defined(_MSC_VER) && (_MSC_VER < 1900)
+    #define SPDLOG_NOEXCEPT _NOEXCEPT
+    #define SPDLOG_CONSTEXPR
+#else
+    #define SPDLOG_NOEXCEPT noexcept
+    #define SPDLOG_CONSTEXPR constexpr
+#endif
+
+// If building with std::format, can just use constexpr, otherwise if building with fmt
+// SPDLOG_CONSTEXPR_FUNC needs to be set the same as FMT_CONSTEXPR to avoid situations where
+// a constexpr function in spdlog could end up calling a non-constexpr function in fmt
+// depending on the compiler
+// If fmt determines it can't use constexpr, we should inline the function instead
+#ifdef SPDLOG_USE_STD_FORMAT
+    #define SPDLOG_CONSTEXPR_FUNC constexpr
+#else  // Being built with fmt
+    #if FMT_USE_CONSTEXPR
+        #define SPDLOG_CONSTEXPR_FUNC FMT_CONSTEXPR
+    #else
+	#define SPDLOG_CONSTEXPR_FUNC inline
+    #endif
+#endif
+
+#if defined(__GNUC__) || defined(__clang__)
+    #define SPDLOG_DEPRECATED __attribute__((deprecated))
+#elif defined(_MSC_VER)
+    #define SPDLOG_DEPRECATED __declspec(deprecated)
+#else
+    #define SPDLOG_DEPRECATED
+#endif
+
+// disable thread local on msvc 2013
+#ifndef SPDLOG_NO_TLS
+    #if (defined(_MSC_VER) && (_MSC_VER < 1900)) || defined(__cplusplus_winrt)
+        #define SPDLOG_NO_TLS 1
+    #endif
+#endif
+
+#ifndef SPDLOG_FUNCTION
+    #define SPDLOG_FUNCTION static_cast<const char *>(__FUNCTION__)
+#endif
+
+#ifdef SPDLOG_NO_EXCEPTIONS
+    #define SPDLOG_TRY
+    #define SPDLOG_THROW(ex)                               \
+        do {                                               \
+            printf("spdlog fatal error: %s\n", ex.what()); \
+            std::abort();                                  \
+        } while (0)
+    #define SPDLOG_CATCH_STD
+#else
+    #define SPDLOG_TRY try
+    #define SPDLOG_THROW(ex) throw(ex)
+    #define SPDLOG_CATCH_STD             \
+        catch (const std::exception &) { \
+        }
+#endif
+
+namespace spdlog {
+
+class formatter;
+
+namespace sinks {
+class sink;
+}
+
+#if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
+using filename_t = std::wstring;
+    // allow macro expansion to occur in SPDLOG_FILENAME_T
+    #define SPDLOG_FILENAME_T_INNER(s) L##s
+    #define SPDLOG_FILENAME_T(s) SPDLOG_FILENAME_T_INNER(s)
+#else
+using filename_t = std::string;
+    #define SPDLOG_FILENAME_T(s) s
+#endif
+
+using log_clock = std::chrono::system_clock;
+using sink_ptr = std::shared_ptr<sinks::sink>;
+using sinks_init_list = std::initializer_list<sink_ptr>;
+using err_handler = std::function<void(const std::string &err_msg)>;
+#ifdef SPDLOG_USE_STD_FORMAT
+namespace fmt_lib = std;
+
+using string_view_t = std::string_view;
+using memory_buf_t = std::string;
+
+template <typename... Args>
+    #if __cpp_lib_format >= 202207L
+using format_string_t = std::format_string<Args...>;
+    #else
+using format_string_t = std::string_view;
+    #endif
+
+template <class T, class Char = char>
+struct is_convertible_to_basic_format_string
+    : std::integral_constant<bool, std::is_convertible<T, std::basic_string_view<Char>>::value> {};
+
+    #if defined(SPDLOG_WCHAR_FILENAMES) || defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT)
+using wstring_view_t = std::wstring_view;
+using wmemory_buf_t = std::wstring;
+
+template <typename... Args>
+        #if __cpp_lib_format >= 202207L
+using wformat_string_t = std::wformat_string<Args...>;
+        #else
+using wformat_string_t = std::wstring_view;
+        #endif
+    #endif
+    #define SPDLOG_BUF_TO_STRING(x) x
+#else  // use fmt lib instead of std::format
+namespace fmt_lib = fmt;
+
+using string_view_t = fmt::basic_string_view<char>;
+using memory_buf_t = fmt::basic_memory_buffer<char, 250>;
+
+template <typename... Args>
+using format_string_t = fmt::format_string<Args...>;
+
+template <class T>
+using remove_cvref_t = typename std::remove_cv<typename std::remove_reference<T>::type>::type;
+
+template <typename Char>
+    #if FMT_VERSION >= 90101
+using fmt_runtime_string = fmt::runtime_format_string<Char>;
+    #else
+using fmt_runtime_string = fmt::basic_runtime<Char>;
+    #endif
+
+// clang doesn't like SFINAE disabled constructor in std::is_convertible<> so have to repeat the
+// condition from basic_format_string here, in addition, fmt::basic_runtime<Char> is only
+// convertible to basic_format_string<Char> but not basic_string_view<Char>
+template <class T, class Char = char>
+struct is_convertible_to_basic_format_string
+    : std::integral_constant<bool,
+                             std::is_convertible<T, fmt::basic_string_view<Char>>::value ||
+                                 std::is_same<remove_cvref_t<T>, fmt_runtime_string<Char>>::value> {
+};
+
+    #if defined(SPDLOG_WCHAR_FILENAMES) || defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT)
+using wstring_view_t = fmt::basic_string_view<wchar_t>;
+using wmemory_buf_t = fmt::basic_memory_buffer<wchar_t, 250>;
+
+template <typename... Args>
+using wformat_string_t = fmt::wformat_string<Args...>;
+    #endif
+    #define SPDLOG_BUF_TO_STRING(x) fmt::to_string(x)
+#endif
+
+#ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
+    #ifndef _WIN32
+        #error SPDLOG_WCHAR_TO_UTF8_SUPPORT only supported on windows
+    #endif  // _WIN32
+#endif      // SPDLOG_WCHAR_TO_UTF8_SUPPORT
+
+template <class T>
+struct is_convertible_to_any_format_string
+    : std::integral_constant<bool,
+                             is_convertible_to_basic_format_string<T, char>::value ||
+                                 is_convertible_to_basic_format_string<T, wchar_t>::value> {};
+
+#if defined(SPDLOG_NO_ATOMIC_LEVELS)
+using level_t = details::null_atomic_int;
+#else
+using level_t = std::atomic<int>;
+#endif
+
+#define SPDLOG_LEVEL_TRACE 0
+#define SPDLOG_LEVEL_DEBUG 1
+#define SPDLOG_LEVEL_INFO 2
+#define SPDLOG_LEVEL_WARN 3
+#define SPDLOG_LEVEL_ERROR 4
+#define SPDLOG_LEVEL_CRITICAL 5
+#define SPDLOG_LEVEL_OFF 6
+
+#if !defined(SPDLOG_ACTIVE_LEVEL)
+    #define SPDLOG_ACTIVE_LEVEL SPDLOG_LEVEL_INFO
+#endif
+
+// Log level enum
+namespace level {
+enum level_enum : int {
+    trace = SPDLOG_LEVEL_TRACE,
+    debug = SPDLOG_LEVEL_DEBUG,
+    info = SPDLOG_LEVEL_INFO,
+    warn = SPDLOG_LEVEL_WARN,
+    err = SPDLOG_LEVEL_ERROR,
+    critical = SPDLOG_LEVEL_CRITICAL,
+    off = SPDLOG_LEVEL_OFF,
+    n_levels
+};
+
+#define SPDLOG_LEVEL_NAME_TRACE spdlog::string_view_t("trace", 5)
+#define SPDLOG_LEVEL_NAME_DEBUG spdlog::string_view_t("debug", 5)
+#define SPDLOG_LEVEL_NAME_INFO spdlog::string_view_t("info", 4)
+#define SPDLOG_LEVEL_NAME_WARNING spdlog::string_view_t("warning", 7)
+#define SPDLOG_LEVEL_NAME_ERROR spdlog::string_view_t("error", 5)
+#define SPDLOG_LEVEL_NAME_CRITICAL spdlog::string_view_t("critical", 8)
+#define SPDLOG_LEVEL_NAME_OFF spdlog::string_view_t("off", 3)
+
+#if !defined(SPDLOG_LEVEL_NAMES)
+    #define SPDLOG_LEVEL_NAMES                                                                  \
+        {                                                                                       \
+            SPDLOG_LEVEL_NAME_TRACE, SPDLOG_LEVEL_NAME_DEBUG, SPDLOG_LEVEL_NAME_INFO,           \
+                SPDLOG_LEVEL_NAME_WARNING, SPDLOG_LEVEL_NAME_ERROR, SPDLOG_LEVEL_NAME_CRITICAL, \
+                SPDLOG_LEVEL_NAME_OFF                                                           \
+        }
+#endif
+
+#if !defined(SPDLOG_SHORT_LEVEL_NAMES)
+
+    #define SPDLOG_SHORT_LEVEL_NAMES \
+        { "T", "D", "I", "W", "E", "C", "O" }
+#endif
+
+SPDLOG_API const string_view_t &to_string_view(spdlog::level::level_enum l) SPDLOG_NOEXCEPT;
+SPDLOG_API const char *to_short_c_str(spdlog::level::level_enum l) SPDLOG_NOEXCEPT;
+SPDLOG_API spdlog::level::level_enum from_str(const std::string &name) SPDLOG_NOEXCEPT;
+
+}  // namespace level
+
+//
+// Color mode used by sinks with color support.
+//
+enum class color_mode { always, automatic, never };
+
+//
+// Pattern time - specific time getting to use for pattern_formatter.
+// local time by default
+//
+enum class pattern_time_type {
+    local,  // log localtime
+    utc     // log utc
+};
+
+//
+// Log exception
+//
+class SPDLOG_API spdlog_ex : public std::exception {
+public:
+    explicit spdlog_ex(std::string msg);
+    spdlog_ex(const std::string &msg, int last_errno);
+    const char *what() const SPDLOG_NOEXCEPT override;
+
+private:
+    std::string msg_;
+};
+
+[[noreturn]] SPDLOG_API void throw_spdlog_ex(const std::string &msg, int last_errno);
+[[noreturn]] SPDLOG_API void throw_spdlog_ex(std::string msg);
+
+struct source_loc {
+    SPDLOG_CONSTEXPR source_loc() = default;
+    SPDLOG_CONSTEXPR source_loc(const char *filename_in, int line_in, const char *funcname_in)
+        : filename{filename_in},
+          line{line_in},
+          funcname{funcname_in} {}
+
+    SPDLOG_CONSTEXPR bool empty() const SPDLOG_NOEXCEPT { return line == 0; }
+    const char *filename{nullptr};
+    int line{0};
+    const char *funcname{nullptr};
+};
+
+struct file_event_handlers {
+    file_event_handlers()
+        : before_open(nullptr),
+          after_open(nullptr),
+          before_close(nullptr),
+          after_close(nullptr) {}
+
+    std::function<void(const filename_t &filename)> before_open;
+    std::function<void(const filename_t &filename, std::FILE *file_stream)> after_open;
+    std::function<void(const filename_t &filename, std::FILE *file_stream)> before_close;
+    std::function<void(const filename_t &filename)> after_close;
+};
+
+namespace details {
+
+// to_string_view
+
+SPDLOG_CONSTEXPR_FUNC spdlog::string_view_t to_string_view(const memory_buf_t &buf)
+    SPDLOG_NOEXCEPT {
+    return spdlog::string_view_t{buf.data(), buf.size()};
+}
+
+SPDLOG_CONSTEXPR_FUNC spdlog::string_view_t to_string_view(spdlog::string_view_t str)
+    SPDLOG_NOEXCEPT {
+    return str;
+}
+
+#if defined(SPDLOG_WCHAR_FILENAMES) || defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT)
+SPDLOG_CONSTEXPR_FUNC spdlog::wstring_view_t to_string_view(const wmemory_buf_t &buf)
+    SPDLOG_NOEXCEPT {
+    return spdlog::wstring_view_t{buf.data(), buf.size()};
+}
+
+SPDLOG_CONSTEXPR_FUNC spdlog::wstring_view_t to_string_view(spdlog::wstring_view_t str)
+    SPDLOG_NOEXCEPT {
+    return str;
+}
+#endif
+
+#ifndef SPDLOG_USE_STD_FORMAT
+template <typename T, typename... Args>
+inline fmt::basic_string_view<T> to_string_view(fmt::basic_format_string<T, Args...> fmt) {
+    return fmt;
+}
+#elif __cpp_lib_format >= 202207L
+template <typename T, typename... Args>
+SPDLOG_CONSTEXPR_FUNC std::basic_string_view<T> to_string_view(
+    std::basic_format_string<T, Args...> fmt) SPDLOG_NOEXCEPT {
+    return fmt.get();
+}
+#endif
+
+// make_unique support for pre c++14
+#if __cplusplus >= 201402L  // C++14 and beyond
+using std::enable_if_t;
+using std::make_unique;
+#else
+template <bool B, class T = void>
+using enable_if_t = typename std::enable_if<B, T>::type;
+
+template <typename T, typename... Args>
+std::unique_ptr<T> make_unique(Args &&...args) {
+    static_assert(!std::is_array<T>::value, "arrays not supported");
+    return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
+}
+#endif
+
+// to avoid useless casts (see https://github.com/nlohmann/json/issues/2893#issuecomment-889152324)
+template <typename T, typename U, enable_if_t<!std::is_same<T, U>::value, int> = 0>
+constexpr T conditional_static_cast(U value) {
+    return static_cast<T>(value);
+}
+
+template <typename T, typename U, enable_if_t<std::is_same<T, U>::value, int> = 0>
+constexpr T conditional_static_cast(U value) {
+    return value;
+}
+
+}  // namespace details
+}  // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "common-inl.h"
+#endif

third_party/spdlog_headers/spdlog/details/backtracer-inl.h

@@ -0,0 +1,63 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#ifndef SPDLOG_HEADER_ONLY
+    #include <spdlog/details/backtracer.h>
+#endif
+namespace spdlog {
+namespace details {
+SPDLOG_INLINE backtracer::backtracer(const backtracer &other) {
+    std::lock_guard<std::mutex> lock(other.mutex_);
+    enabled_ = other.enabled();
+    messages_ = other.messages_;
+}
+
+SPDLOG_INLINE backtracer::backtracer(backtracer &&other) SPDLOG_NOEXCEPT {
+    std::lock_guard<std::mutex> lock(other.mutex_);
+    enabled_ = other.enabled();
+    messages_ = std::move(other.messages_);
+}
+
+SPDLOG_INLINE backtracer &backtracer::operator=(backtracer other) {
+    std::lock_guard<std::mutex> lock(mutex_);
+    enabled_ = other.enabled();
+    messages_ = std::move(other.messages_);
+    return *this;
+}
+
+SPDLOG_INLINE void backtracer::enable(size_t size) {
+    std::lock_guard<std::mutex> lock{mutex_};
+    enabled_.store(true, std::memory_order_relaxed);
+    messages_ = circular_q<log_msg_buffer>{size};
+}
+
+SPDLOG_INLINE void backtracer::disable() {
+    std::lock_guard<std::mutex> lock{mutex_};
+    enabled_.store(false, std::memory_order_relaxed);
+}
+
+SPDLOG_INLINE bool backtracer::enabled() const { return enabled_.load(std::memory_order_relaxed); }
+
+SPDLOG_INLINE void backtracer::push_back(const log_msg &msg) {
+    std::lock_guard<std::mutex> lock{mutex_};
+    messages_.push_back(log_msg_buffer{msg});
+}
+
+SPDLOG_INLINE bool backtracer::empty() const {
+    std::lock_guard<std::mutex> lock{mutex_};
+    return messages_.empty();
+}
+
+// pop all items in the q and apply the given fun on each of them.
+SPDLOG_INLINE void backtracer::foreach_pop(std::function<void(const details::log_msg &)> fun) {
+    std::lock_guard<std::mutex> lock{mutex_};
+    while (!messages_.empty()) {
+        auto &front_msg = messages_.front();
+        fun(front_msg);
+        messages_.pop_front();
+    }
+}
+}  // namespace details
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/details/backtracer.h

@@ -0,0 +1,45 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <spdlog/details/circular_q.h>
+#include <spdlog/details/log_msg_buffer.h>
+
+#include <atomic>
+#include <functional>
+#include <mutex>
+
+// Store log messages in circular buffer.
+// Useful for storing debug data in case of error/warning happens.
+
+namespace spdlog {
+namespace details {
+class SPDLOG_API backtracer {
+    mutable std::mutex mutex_;
+    std::atomic<bool> enabled_{false};
+    circular_q<log_msg_buffer> messages_;
+
+public:
+    backtracer() = default;
+    backtracer(const backtracer &other);
+
+    backtracer(backtracer &&other) SPDLOG_NOEXCEPT;
+    backtracer &operator=(backtracer other);
+
+    void enable(size_t size);
+    void disable();
+    bool enabled() const;
+    void push_back(const log_msg &msg);
+    bool empty() const;
+
+    // pop all items in the q and apply the given fun on each of them.
+    void foreach_pop(std::function<void(const details::log_msg &)> fun);
+};
+
+}  // namespace details
+}  // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "backtracer-inl.h"
+#endif

third_party/spdlog_headers/spdlog/details/circular_q.h

@@ -0,0 +1,113 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+// circular q view of std::vector.
+#pragma once
+
+#include <cassert>
+#include <vector>
+
+namespace spdlog {
+namespace details {
+template <typename T>
+class circular_q {
+    size_t max_items_ = 0;
+    typename std::vector<T>::size_type head_ = 0;
+    typename std::vector<T>::size_type tail_ = 0;
+    size_t overrun_counter_ = 0;
+    std::vector<T> v_;
+
+public:
+    using value_type = T;
+
+    // empty ctor - create a disabled queue with no elements allocated at all
+    circular_q() = default;
+
+    explicit circular_q(size_t max_items)
+        : max_items_(max_items + 1)  // one item is reserved as marker for full q
+          ,
+          v_(max_items_) {}
+
+    circular_q(const circular_q &) = default;
+    circular_q &operator=(const circular_q &) = default;
+
+    // move cannot be default,
+    // since we need to reset head_, tail_, etc to zero in the moved object
+    circular_q(circular_q &&other) SPDLOG_NOEXCEPT { copy_moveable(std::move(other)); }
+
+    circular_q &operator=(circular_q &&other) SPDLOG_NOEXCEPT {
+        copy_moveable(std::move(other));
+        return *this;
+    }
+
+    // push back, overrun (oldest) item if no room left
+    void push_back(T &&item) {
+        if (max_items_ > 0) {
+            v_[tail_] = std::move(item);
+            tail_ = (tail_ + 1) % max_items_;
+
+            if (tail_ == head_)  // overrun last item if full
+            {
+                head_ = (head_ + 1) % max_items_;
+                ++overrun_counter_;
+            }
+        }
+    }
+
+    // Return reference to the front item.
+    // If there are no elements in the container, the behavior is undefined.
+    const T &front() const { return v_[head_]; }
+
+    T &front() { return v_[head_]; }
+
+    // Return number of elements actually stored
+    size_t size() const {
+        if (tail_ >= head_) {
+            return tail_ - head_;
+        } else {
+            return max_items_ - (head_ - tail_);
+        }
+    }
+
+    // Return const reference to item by index.
+    // If index is out of range 0…size()-1, the behavior is undefined.
+    const T &at(size_t i) const {
+        assert(i < size());
+        return v_[(head_ + i) % max_items_];
+    }
+
+    // Pop item from front.
+    // If there are no elements in the container, the behavior is undefined.
+    void pop_front() { head_ = (head_ + 1) % max_items_; }
+
+    bool empty() const { return tail_ == head_; }
+
+    bool full() const {
+        // head is ahead of the tail by 1
+        if (max_items_ > 0) {
+            return ((tail_ + 1) % max_items_) == head_;
+        }
+        return false;
+    }
+
+    size_t overrun_counter() const { return overrun_counter_; }
+
+    void reset_overrun_counter() { overrun_counter_ = 0; }
+
+private:
+    // copy from other&& and reset it to disabled state
+    void copy_moveable(circular_q &&other) SPDLOG_NOEXCEPT {
+        max_items_ = other.max_items_;
+        head_ = other.head_;
+        tail_ = other.tail_;
+        overrun_counter_ = other.overrun_counter_;
+        v_ = std::move(other.v_);
+
+        // put &&other in disabled, but valid state
+        other.max_items_ = 0;
+        other.head_ = other.tail_ = 0;
+        other.overrun_counter_ = 0;
+    }
+};
+}  // namespace details
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/details/console_globals.h

@@ -0,0 +1,28 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <mutex>
+#include <spdlog/details/null_mutex.h>
+
+namespace spdlog {
+namespace details {
+
+struct console_mutex {
+    using mutex_t = std::mutex;
+    static mutex_t &mutex() {
+        static mutex_t s_mutex;
+        return s_mutex;
+    }
+};
+
+struct console_nullmutex {
+    using mutex_t = null_mutex;
+    static mutex_t &mutex() {
+        static mutex_t s_mutex;
+        return s_mutex;
+    }
+};
+}  // namespace details
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/details/file_helper-inl.h

@@ -0,0 +1,152 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#ifndef SPDLOG_HEADER_ONLY
+    #include <spdlog/details/file_helper.h>
+#endif
+
+#include <spdlog/common.h>
+#include <spdlog/details/os.h>
+
+#include <cerrno>
+#include <chrono>
+#include <cstdio>
+#include <string>
+#include <thread>
+#include <tuple>
+
+namespace spdlog {
+namespace details {
+
+SPDLOG_INLINE file_helper::file_helper(const file_event_handlers &event_handlers)
+    : event_handlers_(event_handlers) {}
+
+SPDLOG_INLINE file_helper::~file_helper() { close(); }
+
+SPDLOG_INLINE void file_helper::open(const filename_t &fname, bool truncate) {
+    close();
+    filename_ = fname;
+
+    auto *mode = SPDLOG_FILENAME_T("ab");
+    auto *trunc_mode = SPDLOG_FILENAME_T("wb");
+
+    if (event_handlers_.before_open) {
+        event_handlers_.before_open(filename_);
+    }
+    for (int tries = 0; tries < open_tries_; ++tries) {
+        // create containing folder if not exists already.
+        os::create_dir(os::dir_name(fname));
+        if (truncate) {
+            // Truncate by opening-and-closing a tmp file in "wb" mode, always
+            // opening the actual log-we-write-to in "ab" mode, since that
+            // interacts more politely with eternal processes that might
+            // rotate/truncate the file underneath us.
+            std::FILE *tmp;
+            if (os::fopen_s(&tmp, fname, trunc_mode)) {
+                continue;
+            }
+            std::fclose(tmp);
+        }
+        if (!os::fopen_s(&fd_, fname, mode)) {
+            if (event_handlers_.after_open) {
+                event_handlers_.after_open(filename_, fd_);
+            }
+            return;
+        }
+
+        details::os::sleep_for_millis(open_interval_);
+    }
+
+    throw_spdlog_ex("Failed opening file " + os::filename_to_str(filename_) + " for writing",
+                    errno);
+}
+
+SPDLOG_INLINE void file_helper::reopen(bool truncate) {
+    if (filename_.empty()) {
+        throw_spdlog_ex("Failed re opening file - was not opened before");
+    }
+    this->open(filename_, truncate);
+}
+
+SPDLOG_INLINE void file_helper::flush() {
+    if (std::fflush(fd_) != 0) {
+        throw_spdlog_ex("Failed flush to file " + os::filename_to_str(filename_), errno);
+    }
+}
+
+SPDLOG_INLINE void file_helper::sync() {
+    if (!os::fsync(fd_)) {
+        throw_spdlog_ex("Failed to fsync file " + os::filename_to_str(filename_), errno);
+    }
+}
+
+SPDLOG_INLINE void file_helper::close() {
+    if (fd_ != nullptr) {
+        if (event_handlers_.before_close) {
+            event_handlers_.before_close(filename_, fd_);
+        }
+
+        std::fclose(fd_);
+        fd_ = nullptr;
+
+        if (event_handlers_.after_close) {
+            event_handlers_.after_close(filename_);
+        }
+    }
+}
+
+SPDLOG_INLINE void file_helper::write(const memory_buf_t &buf) {
+    if(fd_ == nullptr) return;
+    size_t msg_size = buf.size();
+    auto data = buf.data();
+    if (std::fwrite(data, 1, msg_size, fd_) != msg_size) {
+        throw_spdlog_ex("Failed writing to file " + os::filename_to_str(filename_), errno);
+    }
+}
+
+SPDLOG_INLINE size_t file_helper::size() const {
+    if (fd_ == nullptr) {
+        throw_spdlog_ex("Cannot use size() on closed file " + os::filename_to_str(filename_));
+    }
+    return os::filesize(fd_);
+}
+
+SPDLOG_INLINE const filename_t &file_helper::filename() const { return filename_; }
+
+//
+// return file path and its extension:
+//
+// "mylog.txt" => ("mylog", ".txt")
+// "mylog" => ("mylog", "")
+// "mylog." => ("mylog.", "")
+// "/dir1/dir2/mylog.txt" => ("/dir1/dir2/mylog", ".txt")
+//
+// the starting dot in filenames is ignored (hidden files):
+//
+// ".mylog" => (".mylog". "")
+// "my_folder/.mylog" => ("my_folder/.mylog", "")
+// "my_folder/.mylog.txt" => ("my_folder/.mylog", ".txt")
+SPDLOG_INLINE std::tuple<filename_t, filename_t> file_helper::split_by_extension(
+    const filename_t &fname) {
+    auto ext_index = fname.rfind('.');
+
+    // no valid extension found - return whole path and empty string as
+    // extension
+    if (ext_index == filename_t::npos || ext_index == 0 || ext_index == fname.size() - 1) {
+        return std::make_tuple(fname, filename_t());
+    }
+
+    // treat cases like "/etc/rc.d/somelogfile or "/abc/.hiddenfile"
+    auto folder_index = fname.find_last_of(details::os::folder_seps_filename);
+    if (folder_index != filename_t::npos && folder_index >= ext_index - 1) {
+        return std::make_tuple(fname, filename_t());
+    }
+
+    // finally - return a valid base and extension tuple
+    return std::make_tuple(fname.substr(0, ext_index), fname.substr(ext_index));
+}
+
+}  // namespace details
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/details/file_helper.h

@@ -0,0 +1,61 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <spdlog/common.h>
+#include <tuple>
+
+namespace spdlog {
+namespace details {
+
+// Helper class for file sinks.
+// When failing to open a file, retry several times(5) with a delay interval(10 ms).
+// Throw spdlog_ex exception on errors.
+
+class SPDLOG_API file_helper {
+public:
+    file_helper() = default;
+    explicit file_helper(const file_event_handlers &event_handlers);
+
+    file_helper(const file_helper &) = delete;
+    file_helper &operator=(const file_helper &) = delete;
+    ~file_helper();
+
+    void open(const filename_t &fname, bool truncate = false);
+    void reopen(bool truncate);
+    void flush();
+    void sync();
+    void close();
+    void write(const memory_buf_t &buf);
+    size_t size() const;
+    const filename_t &filename() const;
+
+    //
+    // return file path and its extension:
+    //
+    // "mylog.txt" => ("mylog", ".txt")
+    // "mylog" => ("mylog", "")
+    // "mylog." => ("mylog.", "")
+    // "/dir1/dir2/mylog.txt" => ("/dir1/dir2/mylog", ".txt")
+    //
+    // the starting dot in filenames is ignored (hidden files):
+    //
+    // ".mylog" => (".mylog". "")
+    // "my_folder/.mylog" => ("my_folder/.mylog", "")
+    // "my_folder/.mylog.txt" => ("my_folder/.mylog", ".txt")
+    static std::tuple<filename_t, filename_t> split_by_extension(const filename_t &fname);
+
+private:
+    const int open_tries_ = 5;
+    const unsigned int open_interval_ = 10;
+    std::FILE *fd_{nullptr};
+    filename_t filename_;
+    file_event_handlers event_handlers_;
+};
+}  // namespace details
+}  // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "file_helper-inl.h"
+#endif

third_party/spdlog_headers/spdlog/details/fmt_helper.h

@@ -0,0 +1,141 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+#pragma once
+
+#include <chrono>
+#include <iterator>
+#include <spdlog/common.h>
+#include <spdlog/fmt/fmt.h>
+#include <type_traits>
+
+#ifdef SPDLOG_USE_STD_FORMAT
+    #include <charconv>
+    #include <limits>
+#endif
+
+// Some fmt helpers to efficiently format and pad ints and strings
+namespace spdlog {
+namespace details {
+namespace fmt_helper {
+
+inline void append_string_view(spdlog::string_view_t view, memory_buf_t &dest) {
+    auto *buf_ptr = view.data();
+    dest.append(buf_ptr, buf_ptr + view.size());
+}
+
+#ifdef SPDLOG_USE_STD_FORMAT
+template <typename T>
+inline void append_int(T n, memory_buf_t &dest) {
+    // Buffer should be large enough to hold all digits (digits10 + 1) and a sign
+    SPDLOG_CONSTEXPR const auto BUF_SIZE = std::numeric_limits<T>::digits10 + 2;
+    char buf[BUF_SIZE];
+
+    auto [ptr, ec] = std::to_chars(buf, buf + BUF_SIZE, n, 10);
+    if (ec == std::errc()) {
+        dest.append(buf, ptr);
+    } else {
+        throw_spdlog_ex("Failed to format int", static_cast<int>(ec));
+    }
+}
+#else
+template <typename T>
+inline void append_int(T n, memory_buf_t &dest) {
+    fmt::format_int i(n);
+    dest.append(i.data(), i.data() + i.size());
+}
+#endif
+
+template <typename T>
+SPDLOG_CONSTEXPR_FUNC unsigned int count_digits_fallback(T n) {
+    // taken from fmt: https://github.com/fmtlib/fmt/blob/8.0.1/include/fmt/format.h#L899-L912
+    unsigned int count = 1;
+    for (;;) {
+        // Integer division is slow so do it for a group of four digits instead
+        // of for every digit. The idea comes from the talk by Alexandrescu
+        // "Three Optimization Tips for C++". See speed-test for a comparison.
+        if (n < 10) return count;
+        if (n < 100) return count + 1;
+        if (n < 1000) return count + 2;
+        if (n < 10000) return count + 3;
+        n /= 10000u;
+        count += 4;
+    }
+}
+
+template <typename T>
+inline unsigned int count_digits(T n) {
+    using count_type =
+        typename std::conditional<(sizeof(T) > sizeof(uint32_t)), uint64_t, uint32_t>::type;
+#ifdef SPDLOG_USE_STD_FORMAT
+    return count_digits_fallback(static_cast<count_type>(n));
+#else
+    return static_cast<unsigned int>(fmt::
+    // fmt 7.0.0 renamed the internal namespace to detail.
+    // See: https://github.com/fmtlib/fmt/issues/1538
+    #if FMT_VERSION < 70000
+                                         internal
+    #else
+                                         detail
+    #endif
+                                     ::count_digits(static_cast<count_type>(n)));
+#endif
+}
+
+inline void pad2(int n, memory_buf_t &dest) {
+    if (n >= 0 && n < 100)  // 0-99
+    {
+        dest.push_back(static_cast<char>('0' + n / 10));
+        dest.push_back(static_cast<char>('0' + n % 10));
+    } else  // unlikely, but just in case, let fmt deal with it
+    {
+        fmt_lib::format_to(std::back_inserter(dest), SPDLOG_FMT_STRING("{:02}"), n);
+    }
+}
+
+template <typename T>
+inline void pad_uint(T n, unsigned int width, memory_buf_t &dest) {
+    static_assert(std::is_unsigned<T>::value, "pad_uint must get unsigned T");
+    for (auto digits = count_digits(n); digits < width; digits++) {
+        dest.push_back('0');
+    }
+    append_int(n, dest);
+}
+
+template <typename T>
+inline void pad3(T n, memory_buf_t &dest) {
+    static_assert(std::is_unsigned<T>::value, "pad3 must get unsigned T");
+    if (n < 1000) {
+        dest.push_back(static_cast<char>(n / 100 + '0'));
+        n = n % 100;
+        dest.push_back(static_cast<char>((n / 10) + '0'));
+        dest.push_back(static_cast<char>((n % 10) + '0'));
+    } else {
+        append_int(n, dest);
+    }
+}
+
+template <typename T>
+inline void pad6(T n, memory_buf_t &dest) {
+    pad_uint(n, 6, dest);
+}
+
+template <typename T>
+inline void pad9(T n, memory_buf_t &dest) {
+    pad_uint(n, 9, dest);
+}
+
+// return fraction of a second of the given time_point.
+// e.g.
+// fraction<std::milliseconds>(tp) -> will return the millis part of the second
+template <typename ToDuration>
+inline ToDuration time_fraction(log_clock::time_point tp) {
+    using std::chrono::duration_cast;
+    using std::chrono::seconds;
+    auto duration = tp.time_since_epoch();
+    auto secs = duration_cast<seconds>(duration);
+    return duration_cast<ToDuration>(duration) - duration_cast<ToDuration>(secs);
+}
+
+}  // namespace fmt_helper
+}  // namespace details
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/details/log_msg-inl.h

@@ -0,0 +1,44 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#ifndef SPDLOG_HEADER_ONLY
+    #include <spdlog/details/log_msg.h>
+#endif
+
+#include <spdlog/details/os.h>
+
+namespace spdlog {
+namespace details {
+
+SPDLOG_INLINE log_msg::log_msg(spdlog::log_clock::time_point log_time,
+                               spdlog::source_loc loc,
+                               string_view_t a_logger_name,
+                               spdlog::level::level_enum lvl,
+                               spdlog::string_view_t msg)
+    : logger_name(a_logger_name),
+      level(lvl),
+      time(log_time)
+#ifndef SPDLOG_NO_THREAD_ID
+      ,
+      thread_id(os::thread_id())
+#endif
+      ,
+      source(loc),
+      payload(msg) {
+}
+
+SPDLOG_INLINE log_msg::log_msg(spdlog::source_loc loc,
+                               string_view_t a_logger_name,
+                               spdlog::level::level_enum lvl,
+                               spdlog::string_view_t msg)
+    : log_msg(os::now(), loc, a_logger_name, lvl, msg) {}
+
+SPDLOG_INLINE log_msg::log_msg(string_view_t a_logger_name,
+                               spdlog::level::level_enum lvl,
+                               spdlog::string_view_t msg)
+    : log_msg(os::now(), source_loc{}, a_logger_name, lvl, msg) {}
+
+}  // namespace details
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/details/log_msg.h

@@ -0,0 +1,40 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <spdlog/common.h>
+#include <string>
+
+namespace spdlog {
+namespace details {
+struct SPDLOG_API log_msg {
+    log_msg() = default;
+    log_msg(log_clock::time_point log_time,
+            source_loc loc,
+            string_view_t logger_name,
+            level::level_enum lvl,
+            string_view_t msg);
+    log_msg(source_loc loc, string_view_t logger_name, level::level_enum lvl, string_view_t msg);
+    log_msg(string_view_t logger_name, level::level_enum lvl, string_view_t msg);
+    log_msg(const log_msg &other) = default;
+    log_msg &operator=(const log_msg &other) = default;
+
+    string_view_t logger_name;
+    level::level_enum level{level::off};
+    log_clock::time_point time;
+    size_t thread_id{0};
+
+    // wrapping the formatted text with color (updated by pattern_formatter).
+    mutable size_t color_range_start{0};
+    mutable size_t color_range_end{0};
+
+    source_loc source;
+    string_view_t payload;
+};
+}  // namespace details
+}  // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "log_msg-inl.h"
+#endif

third_party/spdlog_headers/spdlog/details/log_msg_buffer-inl.h

@@ -0,0 +1,54 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#ifndef SPDLOG_HEADER_ONLY
+    #include <spdlog/details/log_msg_buffer.h>
+#endif
+
+namespace spdlog {
+namespace details {
+
+SPDLOG_INLINE log_msg_buffer::log_msg_buffer(const log_msg &orig_msg)
+    : log_msg{orig_msg} {
+    buffer.append(logger_name.begin(), logger_name.end());
+    buffer.append(payload.begin(), payload.end());
+    update_string_views();
+}
+
+SPDLOG_INLINE log_msg_buffer::log_msg_buffer(const log_msg_buffer &other)
+    : log_msg{other} {
+    buffer.append(logger_name.begin(), logger_name.end());
+    buffer.append(payload.begin(), payload.end());
+    update_string_views();
+}
+
+SPDLOG_INLINE log_msg_buffer::log_msg_buffer(log_msg_buffer &&other) SPDLOG_NOEXCEPT
+    : log_msg{other},
+      buffer{std::move(other.buffer)} {
+    update_string_views();
+}
+
+SPDLOG_INLINE log_msg_buffer &log_msg_buffer::operator=(const log_msg_buffer &other) {
+    log_msg::operator=(other);
+    buffer.clear();
+    buffer.append(other.buffer.data(), other.buffer.data() + other.buffer.size());
+    update_string_views();
+    return *this;
+}
+
+SPDLOG_INLINE log_msg_buffer &log_msg_buffer::operator=(log_msg_buffer &&other) SPDLOG_NOEXCEPT {
+    log_msg::operator=(other);
+    buffer = std::move(other.buffer);
+    update_string_views();
+    return *this;
+}
+
+SPDLOG_INLINE void log_msg_buffer::update_string_views() {
+    logger_name = string_view_t{buffer.data(), logger_name.size()};
+    payload = string_view_t{buffer.data() + logger_name.size(), payload.size()};
+}
+
+}  // namespace details
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/details/log_msg_buffer.h

@@ -0,0 +1,32 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <spdlog/details/log_msg.h>
+
+namespace spdlog {
+namespace details {
+
+// Extend log_msg with internal buffer to store its payload.
+// This is needed since log_msg holds string_views that points to stack data.
+
+class SPDLOG_API log_msg_buffer : public log_msg {
+    memory_buf_t buffer;
+    void update_string_views();
+
+public:
+    log_msg_buffer() = default;
+    explicit log_msg_buffer(const log_msg &orig_msg);
+    log_msg_buffer(const log_msg_buffer &other);
+    log_msg_buffer(log_msg_buffer &&other) SPDLOG_NOEXCEPT;
+    log_msg_buffer &operator=(const log_msg_buffer &other);
+    log_msg_buffer &operator=(log_msg_buffer &&other) SPDLOG_NOEXCEPT;
+};
+
+}  // namespace details
+}  // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "log_msg_buffer-inl.h"
+#endif

third_party/spdlog_headers/spdlog/details/null_mutex.h

@@ -0,0 +1,35 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <atomic>
+#include <utility>
+// null, no cost dummy "mutex" and dummy "atomic" int
+
+namespace spdlog {
+namespace details {
+struct null_mutex {
+    void lock() const {}
+    void unlock() const {}
+};
+
+struct null_atomic_int {
+    int value;
+    null_atomic_int() = default;
+
+    explicit null_atomic_int(int new_value)
+        : value(new_value) {}
+
+    int load(std::memory_order = std::memory_order_relaxed) const { return value; }
+
+    void store(int new_value, std::memory_order = std::memory_order_relaxed) { value = new_value; }
+
+    int exchange(int new_value, std::memory_order = std::memory_order_relaxed) {
+        std::swap(new_value, value);
+        return new_value;  // return value before the call
+    }
+};
+
+}  // namespace details
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/details/os-inl.h

@@ -0,0 +1,585 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#ifndef SPDLOG_HEADER_ONLY
+    #include <spdlog/details/os.h>
+#endif
+
+#include <spdlog/common.h>
+
+#include <algorithm>
+#include <array>
+#include <chrono>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <ctime>
+#include <string>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <thread>
+
+#ifdef _WIN32
+    #include <spdlog/details/windows_include.h>
+    #include <fileapi.h>  // for FlushFileBuffers
+    #include <io.h>       // for _get_osfhandle, _isatty, _fileno
+    #include <process.h>  // for _get_pid
+
+    #ifdef __MINGW32__
+        #include <share.h>
+    #endif
+
+    #if defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)
+        #include <cassert>
+        #include <limits>
+    #endif
+
+    #include <direct.h>  // for _mkdir/_wmkdir
+
+#else  // unix
+
+    #include <fcntl.h>
+    #include <unistd.h>
+
+    #ifdef __linux__
+        #include <sys/syscall.h>  //Use gettid() syscall under linux to get thread id
+
+    #elif defined(_AIX)
+        #include <pthread.h>  // for pthread_getthrds_np
+
+    #elif defined(__DragonFly__) || defined(__FreeBSD__)
+        #include <pthread_np.h>  // for pthread_getthreadid_np
+
+    #elif defined(__NetBSD__)
+        #include <lwp.h>  // for _lwp_self
+
+    #elif defined(__sun)
+        #include <thread.h>  // for thr_self
+    #endif
+
+#endif  // unix
+
+#if defined __APPLE__
+    #include <AvailabilityMacros.h>
+#endif
+
+#ifndef __has_feature           // Clang - feature checking macros.
+    #define __has_feature(x) 0  // Compatibility with non-clang compilers.
+#endif
+
+namespace spdlog {
+namespace details {
+namespace os {
+
+SPDLOG_INLINE spdlog::log_clock::time_point now() SPDLOG_NOEXCEPT {
+#if defined __linux__ && defined SPDLOG_CLOCK_COARSE
+    timespec ts;
+    ::clock_gettime(CLOCK_REALTIME_COARSE, &ts);
+    return std::chrono::time_point<log_clock, typename log_clock::duration>(
+        std::chrono::duration_cast<typename log_clock::duration>(
+            std::chrono::seconds(ts.tv_sec) + std::chrono::nanoseconds(ts.tv_nsec)));
+
+#else
+    return log_clock::now();
+#endif
+}
+SPDLOG_INLINE std::tm localtime(const std::time_t &time_tt) SPDLOG_NOEXCEPT {
+#ifdef _WIN32
+    std::tm tm;
+    ::localtime_s(&tm, &time_tt);
+#else
+    std::tm tm;
+    ::localtime_r(&time_tt, &tm);
+#endif
+    return tm;
+}
+
+SPDLOG_INLINE std::tm localtime() SPDLOG_NOEXCEPT {
+    std::time_t now_t = ::time(nullptr);
+    return localtime(now_t);
+}
+
+SPDLOG_INLINE std::tm gmtime(const std::time_t &time_tt) SPDLOG_NOEXCEPT {
+#ifdef _WIN32
+    std::tm tm;
+    ::gmtime_s(&tm, &time_tt);
+#else
+    std::tm tm;
+    ::gmtime_r(&time_tt, &tm);
+#endif
+    return tm;
+}
+
+SPDLOG_INLINE std::tm gmtime() SPDLOG_NOEXCEPT {
+    std::time_t now_t = ::time(nullptr);
+    return gmtime(now_t);
+}
+
+// fopen_s on non windows for writing
+SPDLOG_INLINE bool fopen_s(FILE **fp, const filename_t &filename, const filename_t &mode) {
+#ifdef _WIN32
+    #ifdef SPDLOG_WCHAR_FILENAMES
+    *fp = ::_wfsopen((filename.c_str()), mode.c_str(), _SH_DENYNO);
+    #else
+    *fp = ::_fsopen((filename.c_str()), mode.c_str(), _SH_DENYNO);
+    #endif
+    #if defined(SPDLOG_PREVENT_CHILD_FD)
+    if (*fp != nullptr) {
+        auto file_handle = reinterpret_cast<HANDLE>(_get_osfhandle(::_fileno(*fp)));
+        if (!::SetHandleInformation(file_handle, HANDLE_FLAG_INHERIT, 0)) {
+            ::fclose(*fp);
+            *fp = nullptr;
+        }
+    }
+    #endif
+#else  // unix
+    #if defined(SPDLOG_PREVENT_CHILD_FD)
+    const int mode_flag = mode == SPDLOG_FILENAME_T("ab") ? O_APPEND : O_TRUNC;
+    const int fd =
+        ::open((filename.c_str()), O_CREAT | O_WRONLY | O_CLOEXEC | mode_flag, mode_t(0644));
+    if (fd == -1) {
+        return true;
+    }
+    *fp = ::fdopen(fd, mode.c_str());
+    if (*fp == nullptr) {
+        ::close(fd);
+    }
+    #else
+    *fp = ::fopen((filename.c_str()), mode.c_str());
+    #endif
+#endif
+
+    return *fp == nullptr;
+}
+
+SPDLOG_INLINE int remove(const filename_t &filename) SPDLOG_NOEXCEPT {
+#if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
+    return ::_wremove(filename.c_str());
+#else
+    return std::remove(filename.c_str());
+#endif
+}
+
+SPDLOG_INLINE int remove_if_exists(const filename_t &filename) SPDLOG_NOEXCEPT {
+    return path_exists(filename) ? remove(filename) : 0;
+}
+
+SPDLOG_INLINE int rename(const filename_t &filename1, const filename_t &filename2) SPDLOG_NOEXCEPT {
+#if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
+    return ::_wrename(filename1.c_str(), filename2.c_str());
+#else
+    return std::rename(filename1.c_str(), filename2.c_str());
+#endif
+}
+
+// Return true if path exists (file or directory)
+SPDLOG_INLINE bool path_exists(const filename_t &filename) SPDLOG_NOEXCEPT {
+#ifdef _WIN32
+    struct _stat buffer;
+    #ifdef SPDLOG_WCHAR_FILENAMES
+    return (::_wstat(filename.c_str(), &buffer) == 0);
+    #else
+    return (::_stat(filename.c_str(), &buffer) == 0);
+    #endif
+#else  // common linux/unix all have the stat system call
+    struct stat buffer;
+    return (::stat(filename.c_str(), &buffer) == 0);
+#endif
+}
+
+#ifdef _MSC_VER
+    // avoid warning about unreachable statement at the end of filesize()
+    #pragma warning(push)
+    #pragma warning(disable : 4702)
+#endif
+
+// Return file size according to open FILE* object
+SPDLOG_INLINE size_t filesize(FILE *f) {
+    if (f == nullptr) {
+        throw_spdlog_ex("Failed getting file size. fd is null");
+    }
+#if defined(_WIN32) && !defined(__CYGWIN__)
+    int fd = ::_fileno(f);
+    #if defined(_WIN64)  // 64 bits
+    __int64 ret = ::_filelengthi64(fd);
+    if (ret >= 0) {
+        return static_cast<size_t>(ret);
+    }
+
+    #else  // windows 32 bits
+    long ret = ::_filelength(fd);
+    if (ret >= 0) {
+        return static_cast<size_t>(ret);
+    }
+    #endif
+
+#else  // unix
+    // OpenBSD and AIX doesn't compile with :: before the fileno(..)
+    #if defined(__OpenBSD__) || defined(_AIX)
+    int fd = fileno(f);
+    #else
+    int fd = ::fileno(f);
+    #endif
+    // 64 bits(but not in osx, linux/musl or cygwin, where fstat64 is deprecated)
+    #if ((defined(__linux__) && defined(__GLIBC__)) || defined(__sun) || defined(_AIX)) && \
+        (defined(__LP64__) || defined(_LP64))
+    struct stat64 st;
+    if (::fstat64(fd, &st) == 0) {
+        return static_cast<size_t>(st.st_size);
+    }
+    #else  // other unix or linux 32 bits or cygwin
+    struct stat st;
+    if (::fstat(fd, &st) == 0) {
+        return static_cast<size_t>(st.st_size);
+    }
+    #endif
+#endif
+    throw_spdlog_ex("Failed getting file size from fd", errno);
+    return 0;  // will not be reached.
+}
+
+#ifdef _MSC_VER
+    #pragma warning(pop)
+#endif
+
+// Return utc offset in minutes or throw spdlog_ex on failure
+SPDLOG_INLINE int utc_minutes_offset(const std::tm &tm) {
+#ifdef _WIN32
+    #if _WIN32_WINNT < _WIN32_WINNT_WS08
+    TIME_ZONE_INFORMATION tzinfo;
+    auto rv = ::GetTimeZoneInformation(&tzinfo);
+    #else
+    DYNAMIC_TIME_ZONE_INFORMATION tzinfo;
+    auto rv = ::GetDynamicTimeZoneInformation(&tzinfo);
+    #endif
+    if (rv == TIME_ZONE_ID_INVALID) throw_spdlog_ex("Failed getting timezone info. ", errno);
+
+    int offset = -tzinfo.Bias;
+    if (tm.tm_isdst) {
+        offset -= tzinfo.DaylightBias;
+    } else {
+        offset -= tzinfo.StandardBias;
+    }
+    return offset;
+#else
+
+    #if defined(sun) || defined(__sun) || defined(_AIX) || \
+        (defined(__NEWLIB__) && !defined(__TM_GMTOFF)) ||  \
+        (!defined(_BSD_SOURCE) && !defined(_GNU_SOURCE))
+    // 'tm_gmtoff' field is BSD extension and it's missing on SunOS/Solaris
+    struct helper {
+        static long int calculate_gmt_offset(const std::tm &localtm = details::os::localtime(),
+                                             const std::tm &gmtm = details::os::gmtime()) {
+            int local_year = localtm.tm_year + (1900 - 1);
+            int gmt_year = gmtm.tm_year + (1900 - 1);
+
+            long int days = (
+                // difference in day of year
+                localtm.tm_yday -
+                gmtm.tm_yday
+
+                // + intervening leap days
+                + ((local_year >> 2) - (gmt_year >> 2)) - (local_year / 100 - gmt_year / 100) +
+                ((local_year / 100 >> 2) - (gmt_year / 100 >> 2))
+
+                // + difference in years * 365 */
+                + static_cast<long int>(local_year - gmt_year) * 365);
+
+            long int hours = (24 * days) + (localtm.tm_hour - gmtm.tm_hour);
+            long int mins = (60 * hours) + (localtm.tm_min - gmtm.tm_min);
+            long int secs = (60 * mins) + (localtm.tm_sec - gmtm.tm_sec);
+
+            return secs;
+        }
+    };
+
+    auto offset_seconds = helper::calculate_gmt_offset(tm);
+    #else
+    auto offset_seconds = tm.tm_gmtoff;
+    #endif
+
+    return static_cast<int>(offset_seconds / 60);
+#endif
+}
+
+// Return current thread id as size_t
+// It exists because the std::this_thread::get_id() is much slower(especially
+// under VS 2013)
+SPDLOG_INLINE size_t _thread_id() SPDLOG_NOEXCEPT {
+#ifdef _WIN32
+    return static_cast<size_t>(::GetCurrentThreadId());
+#elif defined(__linux__)
+    #if defined(__ANDROID__) && defined(__ANDROID_API__) && (__ANDROID_API__ < 21)
+        #define SYS_gettid __NR_gettid
+    #endif
+    return static_cast<size_t>(::syscall(SYS_gettid));
+#elif defined(_AIX)
+    struct __pthrdsinfo buf;
+    int reg_size = 0;
+    pthread_t pt = pthread_self();
+    int retval = pthread_getthrds_np(&pt, PTHRDSINFO_QUERY_TID, &buf, sizeof(buf), NULL, &reg_size);
+    int tid = (!retval) ? buf.__pi_tid : 0;
+    return static_cast<size_t>(tid);
+#elif defined(__DragonFly__) || defined(__FreeBSD__)
+    return static_cast<size_t>(::pthread_getthreadid_np());
+#elif defined(__NetBSD__)
+    return static_cast<size_t>(::_lwp_self());
+#elif defined(__OpenBSD__)
+    return static_cast<size_t>(::getthrid());
+#elif defined(__sun)
+    return static_cast<size_t>(::thr_self());
+#elif __APPLE__
+    uint64_t tid;
+    // There is no pthread_threadid_np prior to Mac OS X 10.6, and it is not supported on any PPC,
+    // including 10.6.8 Rosetta. __POWERPC__ is Apple-specific define encompassing ppc and ppc64.
+    #ifdef MAC_OS_X_VERSION_MAX_ALLOWED
+    {
+        #if (MAC_OS_X_VERSION_MAX_ALLOWED < 1060) || defined(__POWERPC__)
+        tid = pthread_mach_thread_np(pthread_self());
+        #elif MAC_OS_X_VERSION_MIN_REQUIRED < 1060
+        if (&pthread_threadid_np) {
+            pthread_threadid_np(nullptr, &tid);
+        } else {
+            tid = pthread_mach_thread_np(pthread_self());
+        }
+        #else
+        pthread_threadid_np(nullptr, &tid);
+        #endif
+    }
+    #else
+    pthread_threadid_np(nullptr, &tid);
+    #endif
+    return static_cast<size_t>(tid);
+#else  // Default to standard C++11 (other Unix)
+    return static_cast<size_t>(std::hash<std::thread::id>()(std::this_thread::get_id()));
+#endif
+}
+
+// Return current thread id as size_t (from thread local storage)
+SPDLOG_INLINE size_t thread_id() SPDLOG_NOEXCEPT {
+#if defined(SPDLOG_NO_TLS)
+    return _thread_id();
+#else  // cache thread id in tls
+    static thread_local const size_t tid = _thread_id();
+    return tid;
+#endif
+}
+
+// This is avoid msvc issue in sleep_for that happens if the clock changes.
+// See https://github.com/gabime/spdlog/issues/609
+SPDLOG_INLINE void sleep_for_millis(unsigned int milliseconds) SPDLOG_NOEXCEPT {
+#if defined(_WIN32)
+    ::Sleep(milliseconds);
+#else
+    std::this_thread::sleep_for(std::chrono::milliseconds(milliseconds));
+#endif
+}
+
+// wchar support for windows file names (SPDLOG_WCHAR_FILENAMES must be defined)
+#if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
+SPDLOG_INLINE std::string filename_to_str(const filename_t &filename) {
+    memory_buf_t buf;
+    wstr_to_utf8buf(filename, buf);
+    return SPDLOG_BUF_TO_STRING(buf);
+}
+#else
+SPDLOG_INLINE std::string filename_to_str(const filename_t &filename) { return filename; }
+#endif
+
+SPDLOG_INLINE int pid() SPDLOG_NOEXCEPT {
+#ifdef _WIN32
+    return conditional_static_cast<int>(::GetCurrentProcessId());
+#else
+    return conditional_static_cast<int>(::getpid());
+#endif
+}
+
+// Determine if the terminal supports colors
+// Based on: https://github.com/agauniyal/rang/
+SPDLOG_INLINE bool is_color_terminal() SPDLOG_NOEXCEPT {
+#ifdef _WIN32
+    return true;
+#else
+
+    static const bool result = []() {
+        const char *env_colorterm_p = std::getenv("COLORTERM");
+        if (env_colorterm_p != nullptr) {
+            return true;
+        }
+
+        static constexpr std::array<const char *, 16> terms = {
+            {"ansi", "color", "console", "cygwin", "gnome", "konsole", "kterm", "linux", "msys",
+             "putty", "rxvt", "screen", "vt100", "xterm", "alacritty", "vt102"}};
+
+        const char *env_term_p = std::getenv("TERM");
+        if (env_term_p == nullptr) {
+            return false;
+        }
+
+        return std::any_of(terms.begin(), terms.end(), [&](const char *term) {
+            return std::strstr(env_term_p, term) != nullptr;
+        });
+    }();
+
+    return result;
+#endif
+}
+
+// Determine if the terminal attached
+// Source: https://github.com/agauniyal/rang/
+SPDLOG_INLINE bool in_terminal(FILE *file) SPDLOG_NOEXCEPT {
+#ifdef _WIN32
+    return ::_isatty(_fileno(file)) != 0;
+#else
+    return ::isatty(fileno(file)) != 0;
+#endif
+}
+
+#if (defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)) && defined(_WIN32)
+SPDLOG_INLINE void wstr_to_utf8buf(wstring_view_t wstr, memory_buf_t &target) {
+    if (wstr.size() > static_cast<size_t>((std::numeric_limits<int>::max)()) / 2 - 1) {
+        throw_spdlog_ex("UTF-16 string is too big to be converted to UTF-8");
+    }
+
+    int wstr_size = static_cast<int>(wstr.size());
+    if (wstr_size == 0) {
+        target.resize(0);
+        return;
+    }
+
+    int result_size = static_cast<int>(target.capacity());
+    if ((wstr_size + 1) * 2 > result_size) {
+        result_size =
+            ::WideCharToMultiByte(CP_UTF8, 0, wstr.data(), wstr_size, NULL, 0, NULL, NULL);
+    }
+
+    if (result_size > 0) {
+        target.resize(result_size);
+        result_size = ::WideCharToMultiByte(CP_UTF8, 0, wstr.data(), wstr_size, target.data(),
+                                            result_size, NULL, NULL);
+
+        if (result_size > 0) {
+            target.resize(result_size);
+            return;
+        }
+    }
+
+    throw_spdlog_ex(
+        fmt_lib::format("WideCharToMultiByte failed. Last error: {}", ::GetLastError()));
+}
+
+SPDLOG_INLINE void utf8_to_wstrbuf(string_view_t str, wmemory_buf_t &target) {
+    if (str.size() > static_cast<size_t>((std::numeric_limits<int>::max)()) - 1) {
+        throw_spdlog_ex("UTF-8 string is too big to be converted to UTF-16");
+    }
+
+    int str_size = static_cast<int>(str.size());
+    if (str_size == 0) {
+        target.resize(0);
+        return;
+    }
+
+    // find the size to allocate for the result buffer
+    int result_size =
+        ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, str.data(), str_size, NULL, 0);
+
+    if (result_size > 0) {
+        target.resize(result_size);
+        result_size = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, str.data(), str_size,
+                                            target.data(), result_size);
+        if (result_size > 0) {
+            assert(result_size == target.size());
+            return;
+        }
+    }
+
+    throw_spdlog_ex(
+        fmt_lib::format("MultiByteToWideChar failed. Last error: {}", ::GetLastError()));
+}
+#endif  // (defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)) &&
+        // defined(_WIN32)
+
+// return true on success
+static SPDLOG_INLINE bool mkdir_(const filename_t &path) {
+#ifdef _WIN32
+    #ifdef SPDLOG_WCHAR_FILENAMES
+    return ::_wmkdir(path.c_str()) == 0;
+    #else
+    return ::_mkdir(path.c_str()) == 0;
+    #endif
+#else
+    return ::mkdir(path.c_str(), mode_t(0755)) == 0;
+#endif
+}
+
+// create the given directory - and all directories leading to it
+// return true on success or if the directory already exists
+SPDLOG_INLINE bool create_dir(const filename_t &path) {
+    if (path_exists(path)) {
+        return true;
+    }
+
+    if (path.empty()) {
+        return false;
+    }
+
+    size_t search_offset = 0;
+    do {
+        auto token_pos = path.find_first_of(folder_seps_filename, search_offset);
+        // treat the entire path as a folder if no folder separator not found
+        if (token_pos == filename_t::npos) {
+            token_pos = path.size();
+        }
+
+        auto subdir = path.substr(0, token_pos);
+
+        if (!subdir.empty() && !path_exists(subdir) && !mkdir_(subdir)) {
+            return false;  // return error if failed creating dir
+        }
+        search_offset = token_pos + 1;
+    } while (search_offset < path.size());
+
+    return true;
+}
+
+// Return directory name from given path or empty string
+// "abc/file" => "abc"
+// "abc/" => "abc"
+// "abc" => ""
+// "abc///" => "abc//"
+SPDLOG_INLINE filename_t dir_name(const filename_t &path) {
+    auto pos = path.find_last_of(folder_seps_filename);
+    return pos != filename_t::npos ? path.substr(0, pos) : filename_t{};
+}
+
+std::string SPDLOG_INLINE getenv(const char *field) {
+#if defined(_MSC_VER)
+    #if defined(__cplusplus_winrt)
+    return std::string{};  // not supported under uwp
+    #else
+    size_t len = 0;
+    char buf[128];
+    bool ok = ::getenv_s(&len, buf, sizeof(buf), field) == 0;
+    return ok ? buf : std::string{};
+    #endif
+#else  // revert to getenv
+    char *buf = ::getenv(field);
+    return buf ? buf : std::string{};
+#endif
+}
+
+// Do fsync by FILE handlerpointer
+// Return true on success
+SPDLOG_INLINE bool fsync(FILE *fp) {
+#ifdef _WIN32
+    return FlushFileBuffers(reinterpret_cast<HANDLE>(_get_osfhandle(_fileno(fp)))) != 0;
+#else
+    return ::fsync(fileno(fp)) == 0;
+#endif
+}
+
+}  // namespace os
+}  // namespace details
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/details/os.h

@@ -0,0 +1,123 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <ctime>  // std::time_t
+#include <spdlog/common.h>
+
+namespace spdlog {
+namespace details {
+namespace os {
+
+SPDLOG_API spdlog::log_clock::time_point now() SPDLOG_NOEXCEPT;
+
+SPDLOG_API std::tm localtime(const std::time_t &time_tt) SPDLOG_NOEXCEPT;
+
+SPDLOG_API std::tm localtime() SPDLOG_NOEXCEPT;
+
+SPDLOG_API std::tm gmtime(const std::time_t &time_tt) SPDLOG_NOEXCEPT;
+
+SPDLOG_API std::tm gmtime() SPDLOG_NOEXCEPT;
+
+// eol definition
+#if !defined(SPDLOG_EOL)
+    #ifdef _WIN32
+        #define SPDLOG_EOL "\r\n"
+    #else
+        #define SPDLOG_EOL "\n"
+    #endif
+#endif
+
+SPDLOG_CONSTEXPR static const char *default_eol = SPDLOG_EOL;
+
+// folder separator
+#if !defined(SPDLOG_FOLDER_SEPS)
+    #ifdef _WIN32
+        #define SPDLOG_FOLDER_SEPS "\\/"
+    #else
+        #define SPDLOG_FOLDER_SEPS "/"
+    #endif
+#endif
+
+SPDLOG_CONSTEXPR static const char folder_seps[] = SPDLOG_FOLDER_SEPS;
+SPDLOG_CONSTEXPR static const filename_t::value_type folder_seps_filename[] =
+    SPDLOG_FILENAME_T(SPDLOG_FOLDER_SEPS);
+
+// fopen_s on non windows for writing
+SPDLOG_API bool fopen_s(FILE **fp, const filename_t &filename, const filename_t &mode);
+
+// Remove filename. return 0 on success
+SPDLOG_API int remove(const filename_t &filename) SPDLOG_NOEXCEPT;
+
+// Remove file if exists. return 0 on success
+// Note: Non atomic (might return failure to delete if concurrently deleted by other process/thread)
+SPDLOG_API int remove_if_exists(const filename_t &filename) SPDLOG_NOEXCEPT;
+
+SPDLOG_API int rename(const filename_t &filename1, const filename_t &filename2) SPDLOG_NOEXCEPT;
+
+// Return if file exists.
+SPDLOG_API bool path_exists(const filename_t &filename) SPDLOG_NOEXCEPT;
+
+// Return file size according to open FILE* object
+SPDLOG_API size_t filesize(FILE *f);
+
+// Return utc offset in minutes or throw spdlog_ex on failure
+SPDLOG_API int utc_minutes_offset(const std::tm &tm = details::os::localtime());
+
+// Return current thread id as size_t
+// It exists because the std::this_thread::get_id() is much slower(especially
+// under VS 2013)
+SPDLOG_API size_t _thread_id() SPDLOG_NOEXCEPT;
+
+// Return current thread id as size_t (from thread local storage)
+SPDLOG_API size_t thread_id() SPDLOG_NOEXCEPT;
+
+// This is avoid msvc issue in sleep_for that happens if the clock changes.
+// See https://github.com/gabime/spdlog/issues/609
+SPDLOG_API void sleep_for_millis(unsigned int milliseconds) SPDLOG_NOEXCEPT;
+
+SPDLOG_API std::string filename_to_str(const filename_t &filename);
+
+SPDLOG_API int pid() SPDLOG_NOEXCEPT;
+
+// Determine if the terminal supports colors
+// Source: https://github.com/agauniyal/rang/
+SPDLOG_API bool is_color_terminal() SPDLOG_NOEXCEPT;
+
+// Determine if the terminal attached
+// Source: https://github.com/agauniyal/rang/
+SPDLOG_API bool in_terminal(FILE *file) SPDLOG_NOEXCEPT;
+
+#if (defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)) && defined(_WIN32)
+SPDLOG_API void wstr_to_utf8buf(wstring_view_t wstr, memory_buf_t &target);
+
+SPDLOG_API void utf8_to_wstrbuf(string_view_t str, wmemory_buf_t &target);
+#endif
+
+// Return directory name from given path or empty string
+// "abc/file" => "abc"
+// "abc/" => "abc"
+// "abc" => ""
+// "abc///" => "abc//"
+SPDLOG_API filename_t dir_name(const filename_t &path);
+
+// Create a dir from the given path.
+// Return true if succeeded or if this dir already exists.
+SPDLOG_API bool create_dir(const filename_t &path);
+
+// non thread safe, cross platform getenv/getenv_s
+// return empty string if field not found
+SPDLOG_API std::string getenv(const char *field);
+
+// Do fsync by FILE objectpointer.
+// Return true on success.
+SPDLOG_API bool fsync(FILE *fp);
+
+}  // namespace os
+}  // namespace details
+}  // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "os-inl.h"
+#endif

third_party/spdlog_headers/spdlog/details/periodic_worker-inl.h

@@ -0,0 +1,26 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#ifndef SPDLOG_HEADER_ONLY
+    #include <spdlog/details/periodic_worker.h>
+#endif
+
+namespace spdlog {
+namespace details {
+
+// stop the worker thread and join it
+SPDLOG_INLINE periodic_worker::~periodic_worker() {
+    if (worker_thread_.joinable()) {
+        {
+            std::lock_guard<std::mutex> lock(mutex_);
+            active_ = false;
+        }
+        cv_.notify_one();
+        worker_thread_.join();
+    }
+}
+
+}  // namespace details
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/details/periodic_worker.h

@@ -0,0 +1,58 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+// periodic worker thread - periodically executes the given callback function.
+//
+// RAII over the owned thread:
+//    creates the thread on construction.
+//    stops and joins the thread on destruction (if the thread is executing a callback, wait for it
+//    to finish first).
+
+#include <chrono>
+#include <condition_variable>
+#include <functional>
+#include <mutex>
+#include <thread>
+namespace spdlog {
+namespace details {
+
+class SPDLOG_API periodic_worker {
+public:
+    template <typename Rep, typename Period>
+    periodic_worker(const std::function<void()> &callback_fun,
+                    std::chrono::duration<Rep, Period> interval) {
+        active_ = (interval > std::chrono::duration<Rep, Period>::zero());
+        if (!active_) {
+            return;
+        }
+
+        worker_thread_ = std::thread([this, callback_fun, interval]() {
+            for (;;) {
+                std::unique_lock<std::mutex> lock(this->mutex_);
+                if (this->cv_.wait_for(lock, interval, [this] { return !this->active_; })) {
+                    return;  // active_ == false, so exit this thread
+                }
+                callback_fun();
+            }
+        });
+    }
+    std::thread &get_thread() { return worker_thread_; }
+    periodic_worker(const periodic_worker &) = delete;
+    periodic_worker &operator=(const periodic_worker &) = delete;
+    // stop the worker thread and join it
+    ~periodic_worker();
+
+private:
+    bool active_;
+    std::thread worker_thread_;
+    std::mutex mutex_;
+    std::condition_variable cv_;
+};
+}  // namespace details
+}  // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "periodic_worker-inl.h"
+#endif

third_party/spdlog_headers/spdlog/details/registry-inl.h

@@ -0,0 +1,281 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#ifndef SPDLOG_HEADER_ONLY
+    #include <spdlog/details/registry.h>
+#endif
+
+#include <spdlog/common.h>
+#include <spdlog/details/periodic_worker.h>
+#include <spdlog/logger.h>
+#include <spdlog/pattern_formatter.h>
+
+#ifndef SPDLOG_DISABLE_DEFAULT_LOGGER
+    // support for the default stdout color logger
+    #ifdef _WIN32
+        #include <spdlog/sinks/wincolor_sink.h>
+    #else
+        #include <spdlog/sinks/ansicolor_sink.h>
+    #endif
+#endif  // SPDLOG_DISABLE_DEFAULT_LOGGER
+
+#include <chrono>
+#include <functional>
+#include <memory>
+#include <string>
+#include <unordered_map>
+
+namespace spdlog {
+namespace details {
+
+SPDLOG_INLINE registry::registry()
+    : formatter_(new pattern_formatter()) {
+#ifndef SPDLOG_DISABLE_DEFAULT_LOGGER
+    // create default logger (ansicolor_stdout_sink_mt or wincolor_stdout_sink_mt in windows).
+    #ifdef _WIN32
+    auto color_sink = std::make_shared<sinks::wincolor_stdout_sink_mt>();
+    #else
+    auto color_sink = std::make_shared<sinks::ansicolor_stdout_sink_mt>();
+    #endif
+
+    const char *default_logger_name = "";
+    default_logger_ = std::make_shared<spdlog::logger>(default_logger_name, std::move(color_sink));
+    loggers_[default_logger_name] = default_logger_;
+
+#endif  // SPDLOG_DISABLE_DEFAULT_LOGGER
+}
+
+SPDLOG_INLINE registry::~registry() = default;
+
+SPDLOG_INLINE void registry::register_logger(std::shared_ptr<logger> new_logger) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    register_logger_(std::move(new_logger));
+}
+
+SPDLOG_INLINE void registry::initialize_logger(std::shared_ptr<logger> new_logger) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    new_logger->set_formatter(formatter_->clone());
+
+    if (err_handler_) {
+        new_logger->set_error_handler(err_handler_);
+    }
+
+    // set new level according to previously configured level or default level
+    auto it = log_levels_.find(new_logger->name());
+    auto new_level = it != log_levels_.end() ? it->second : global_log_level_;
+    new_logger->set_level(new_level);
+
+    new_logger->flush_on(flush_level_);
+
+    if (backtrace_n_messages_ > 0) {
+        new_logger->enable_backtrace(backtrace_n_messages_);
+    }
+
+    if (automatic_registration_) {
+        register_logger_(std::move(new_logger));
+    }
+}
+
+SPDLOG_INLINE std::shared_ptr<logger> registry::get(const std::string &logger_name) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    auto found = loggers_.find(logger_name);
+    return found == loggers_.end() ? nullptr : found->second;
+}
+
+#if __cplusplus >= 201703L  // C++17
+SPDLOG_INLINE std::shared_ptr<logger> registry::get(std::string_view logger_name) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    for (const auto &[key, val] : loggers_) {
+        if (key == logger_name) {
+            return val;
+        }
+    }
+    return nullptr;
+}
+
+SPDLOG_INLINE std::shared_ptr<logger> registry::get(const char *logger_name) {
+    return get(std::string_view(logger_name));
+}
+#endif
+
+SPDLOG_INLINE std::shared_ptr<logger> registry::default_logger() {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    return default_logger_;
+}
+
+// Return raw ptr to the default logger.
+// To be used directly by the spdlog default api (e.g. spdlog::info)
+// This make the default API faster, but cannot be used concurrently with set_default_logger().
+// e.g do not call set_default_logger() from one thread while calling spdlog::info() from another.
+SPDLOG_INLINE logger *registry::get_default_raw() { return default_logger_.get(); }
+
+// set default logger.
+// default logger is stored in default_logger_ (for faster retrieval) and in the loggers_ map.
+SPDLOG_INLINE void registry::set_default_logger(std::shared_ptr<logger> new_default_logger) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    // remove previous default logger from the map
+    if (default_logger_ != nullptr) {
+        loggers_.erase(default_logger_->name());
+    }
+    if (new_default_logger != nullptr) {
+        loggers_[new_default_logger->name()] = new_default_logger;
+    }
+    default_logger_ = std::move(new_default_logger);
+}
+
+SPDLOG_INLINE void registry::set_tp(std::shared_ptr<thread_pool> tp) {
+    std::lock_guard<std::recursive_mutex> lock(tp_mutex_);
+    tp_ = std::move(tp);
+}
+
+SPDLOG_INLINE std::shared_ptr<thread_pool> registry::get_tp() {
+    std::lock_guard<std::recursive_mutex> lock(tp_mutex_);
+    return tp_;
+}
+
+// Set global formatter. Each sink in each logger will get a clone of this object
+SPDLOG_INLINE void registry::set_formatter(std::unique_ptr<formatter> formatter) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    formatter_ = std::move(formatter);
+    for (auto &l : loggers_) {
+        l.second->set_formatter(formatter_->clone());
+    }
+}
+
+SPDLOG_INLINE void registry::enable_backtrace(size_t n_messages) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    backtrace_n_messages_ = n_messages;
+
+    for (auto &l : loggers_) {
+        l.second->enable_backtrace(n_messages);
+    }
+}
+
+SPDLOG_INLINE void registry::disable_backtrace() {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    backtrace_n_messages_ = 0;
+    for (auto &l : loggers_) {
+        l.second->disable_backtrace();
+    }
+}
+
+SPDLOG_INLINE void registry::set_level(level::level_enum log_level) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    for (auto &l : loggers_) {
+        l.second->set_level(log_level);
+    }
+    global_log_level_ = log_level;
+}
+
+SPDLOG_INLINE void registry::flush_on(level::level_enum log_level) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    for (auto &l : loggers_) {
+        l.second->flush_on(log_level);
+    }
+    flush_level_ = log_level;
+}
+
+SPDLOG_INLINE void registry::set_error_handler(err_handler handler) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    for (auto &l : loggers_) {
+        l.second->set_error_handler(handler);
+    }
+    err_handler_ = std::move(handler);
+}
+
+SPDLOG_INLINE void registry::apply_all(
+    const std::function<void(const std::shared_ptr<logger>)> &fun) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    for (auto &l : loggers_) {
+        fun(l.second);
+    }
+}
+
+SPDLOG_INLINE void registry::flush_all() {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    for (auto &l : loggers_) {
+        l.second->flush();
+    }
+}
+
+SPDLOG_INLINE void registry::drop(const std::string &logger_name) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    auto is_default_logger = default_logger_ && default_logger_->name() == logger_name;
+    loggers_.erase(logger_name);
+    if (is_default_logger) {
+        default_logger_.reset();
+    }
+}
+
+SPDLOG_INLINE void registry::drop_all() {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    loggers_.clear();
+    default_logger_.reset();
+}
+
+// clean all resources and threads started by the registry
+SPDLOG_INLINE void registry::shutdown() {
+    {
+        std::lock_guard<std::mutex> lock(flusher_mutex_);
+        periodic_flusher_.reset();
+    }
+
+    drop_all();
+
+    {
+        std::lock_guard<std::recursive_mutex> lock(tp_mutex_);
+        tp_.reset();
+    }
+}
+
+SPDLOG_INLINE std::recursive_mutex &registry::tp_mutex() { return tp_mutex_; }
+
+SPDLOG_INLINE void registry::set_automatic_registration(bool automatic_registration) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    automatic_registration_ = automatic_registration;
+}
+
+SPDLOG_INLINE void registry::set_levels(log_levels levels, level::level_enum *global_level) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    log_levels_ = std::move(levels);
+    auto global_level_requested = global_level != nullptr;
+    global_log_level_ = global_level_requested ? *global_level : global_log_level_;
+
+    for (auto &logger : loggers_) {
+        auto logger_entry = log_levels_.find(logger.first);
+        if (logger_entry != log_levels_.end()) {
+            logger.second->set_level(logger_entry->second);
+        } else if (global_level_requested) {
+            logger.second->set_level(*global_level);
+        }
+    }
+}
+
+SPDLOG_INLINE registry &registry::instance() {
+    static registry s_instance;
+    return s_instance;
+}
+
+SPDLOG_INLINE void registry::apply_logger_env_levels(std::shared_ptr<logger> new_logger) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    auto it = log_levels_.find(new_logger->name());
+    auto new_level = it != log_levels_.end() ? it->second : global_log_level_;
+    new_logger->set_level(new_level);
+}
+
+SPDLOG_INLINE void registry::throw_if_exists_(const std::string &logger_name) {
+    if (loggers_.find(logger_name) != loggers_.end()) {
+        throw_spdlog_ex("logger with name '" + logger_name + "' already exists");
+    }
+}
+
+SPDLOG_INLINE void registry::register_logger_(std::shared_ptr<logger> new_logger) {
+    auto logger_name = new_logger->name();
+    throw_if_exists_(logger_name);
+    loggers_[logger_name] = std::move(new_logger);
+}
+
+}  // namespace details
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/details/registry.h

@@ -0,0 +1,135 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+// Loggers registry of unique name->logger pointer
+// An attempt to create a logger with an already existing name will result with spdlog_ex exception.
+// If user requests a non existing logger, nullptr will be returned
+// This class is thread safe
+
+#include <spdlog/common.h>
+#include <spdlog/details/periodic_worker.h>
+
+#include <chrono>
+#include <functional>
+#include <memory>
+#include <mutex>
+#include <string>
+#include <unordered_map>
+
+#if __cplusplus >= 201703L  // C++17
+    #include <string_view>
+#endif
+
+namespace spdlog {
+class logger;
+
+namespace details {
+class thread_pool;
+
+class SPDLOG_API registry {
+public:
+    using log_levels = std::unordered_map<std::string, level::level_enum>;
+    registry(const registry &) = delete;
+    registry &operator=(const registry &) = delete;
+
+    void register_logger(std::shared_ptr<logger> new_logger);
+    void initialize_logger(std::shared_ptr<logger> new_logger);
+    std::shared_ptr<logger> get(const std::string &logger_name);
+#if __cplusplus >= 201703L  // C++17
+    std::shared_ptr<logger> get(std::string_view logger_name);
+    std::shared_ptr<logger> get(const char *logger_name);
+#endif
+    std::shared_ptr<logger> default_logger();
+
+    // Return raw ptr to the default logger.
+    // To be used directly by the spdlog default api (e.g. spdlog::info)
+    // This make the default API faster, but cannot be used concurrently with set_default_logger().
+    // e.g do not call set_default_logger() from one thread while calling spdlog::info() from
+    // another.
+    logger *get_default_raw();
+
+    // set default logger.
+    // default logger is stored in default_logger_ (for faster retrieval) and in the loggers_ map.
+    void set_default_logger(std::shared_ptr<logger> new_default_logger);
+
+    void set_tp(std::shared_ptr<thread_pool> tp);
+
+    std::shared_ptr<thread_pool> get_tp();
+
+    // Set global formatter. Each sink in each logger will get a clone of this object
+    void set_formatter(std::unique_ptr<formatter> formatter);
+
+    void enable_backtrace(size_t n_messages);
+
+    void disable_backtrace();
+
+    void set_level(level::level_enum log_level);
+
+    void flush_on(level::level_enum log_level);
+
+    template <typename Rep, typename Period>
+    void flush_every(std::chrono::duration<Rep, Period> interval) {
+        std::lock_guard<std::mutex> lock(flusher_mutex_);
+        auto clbk = [this]() { this->flush_all(); };
+        periodic_flusher_ = details::make_unique<periodic_worker>(clbk, interval);
+    }
+
+    std::unique_ptr<periodic_worker> &get_flusher() {
+        std::lock_guard<std::mutex> lock(flusher_mutex_); 
+        return periodic_flusher_; 
+    }
+
+    void set_error_handler(err_handler handler);
+
+    void apply_all(const std::function<void(const std::shared_ptr<logger>)> &fun);
+
+    void flush_all();
+
+    void drop(const std::string &logger_name);
+
+    void drop_all();
+
+    // clean all resources and threads started by the registry
+    void shutdown();
+
+    std::recursive_mutex &tp_mutex();
+
+    void set_automatic_registration(bool automatic_registration);
+
+    // set levels for all existing/future loggers. global_level can be null if should not set.
+    void set_levels(log_levels levels, level::level_enum *global_level);
+
+    static registry &instance();
+
+    void apply_logger_env_levels(std::shared_ptr<logger> new_logger);
+
+private:
+    registry();
+    ~registry();
+
+    void throw_if_exists_(const std::string &logger_name);
+    void register_logger_(std::shared_ptr<logger> new_logger);
+    bool set_level_from_cfg_(logger *logger);
+    std::mutex logger_map_mutex_, flusher_mutex_;
+    std::recursive_mutex tp_mutex_;
+    std::unordered_map<std::string, std::shared_ptr<logger>> loggers_;
+    log_levels log_levels_;
+    std::unique_ptr<formatter> formatter_;
+    spdlog::level::level_enum global_log_level_ = level::info;
+    level::level_enum flush_level_ = level::off;
+    err_handler err_handler_;
+    std::shared_ptr<thread_pool> tp_;
+    std::unique_ptr<periodic_worker> periodic_flusher_;
+    std::shared_ptr<logger> default_logger_;
+    bool automatic_registration_ = true;
+    size_t backtrace_n_messages_ = 0;
+};
+
+}  // namespace details
+}  // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "registry-inl.h"
+#endif

third_party/spdlog_headers/spdlog/details/synchronous_factory.h

@@ -0,0 +1,22 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include "registry.h"
+
+namespace spdlog {
+
+// Default logger factory-  creates synchronous loggers
+class logger;
+
+struct synchronous_factory {
+    template <typename Sink, typename... SinkArgs>
+    static std::shared_ptr<spdlog::logger> create(std::string logger_name, SinkArgs &&...args) {
+        auto sink = std::make_shared<Sink>(std::forward<SinkArgs>(args)...);
+        auto new_logger = std::make_shared<spdlog::logger>(std::move(logger_name), std::move(sink));
+        details::registry::instance().initialize_logger(new_logger);
+        return new_logger;
+    }
+};
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/fmt/fmt.h

@@ -0,0 +1,34 @@
+//
+// Copyright(c) 2016-2018 Gabi Melman.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+//
+
+#pragma once
+
+//
+// Include a bundled header-only copy of fmtlib or an external one.
+// By default spdlog include its own copy.
+//
+#include <spdlog/tweakme.h>
+
+#if defined(SPDLOG_USE_STD_FORMAT)  // SPDLOG_USE_STD_FORMAT is defined - use std::format
+    #include <format>
+#elif !defined(SPDLOG_FMT_EXTERNAL)
+    #if !defined(SPDLOG_COMPILED_LIB) && !defined(FMT_HEADER_ONLY)
+        #define FMT_HEADER_ONLY
+    #endif
+    #ifndef FMT_USE_WINDOWS_H
+        #define FMT_USE_WINDOWS_H 0
+    #endif
+    // enable the 'n' flag in for backward compatibility with fmt 6.x
+    #define FMT_DEPRECATED_N_SPECIFIER
+    // enable ostream formatting for backward compatibility with fmt 8.x
+    #define FMT_DEPRECATED_OSTREAM
+
+    #include <spdlog/fmt/bundled/core.h>
+    #include <spdlog/fmt/bundled/format.h>
+
+#else  // SPDLOG_FMT_EXTERNAL is defined - use external fmtlib
+    #include <fmt/core.h>
+    #include <fmt/format.h>
+#endif

third_party/spdlog_headers/spdlog/formatter.h

@@ -0,0 +1,17 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <spdlog/details/log_msg.h>
+#include <spdlog/fmt/fmt.h>
+
+namespace spdlog {
+
+class formatter {
+public:
+    virtual ~formatter() = default;
+    virtual void format(const details::log_msg &msg, memory_buf_t &dest) = 0;
+    virtual std::unique_ptr<formatter> clone() const = 0;
+};
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/logger-inl.h

@@ -0,0 +1,198 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#ifndef SPDLOG_HEADER_ONLY
+    #include <spdlog/logger.h>
+#endif
+
+#include <spdlog/details/backtracer.h>
+#include <spdlog/pattern_formatter.h>
+#include <spdlog/sinks/sink.h>
+
+#include <cstdio>
+
+namespace spdlog {
+
+// public methods
+SPDLOG_INLINE logger::logger(const logger &other)
+    : name_(other.name_),
+      sinks_(other.sinks_),
+      level_(other.level_.load(std::memory_order_relaxed)),
+      flush_level_(other.flush_level_.load(std::memory_order_relaxed)),
+      custom_err_handler_(other.custom_err_handler_),
+      tracer_(other.tracer_) {}
+
+SPDLOG_INLINE logger::logger(logger &&other) SPDLOG_NOEXCEPT
+    : name_(std::move(other.name_)),
+      sinks_(std::move(other.sinks_)),
+      level_(other.level_.load(std::memory_order_relaxed)),
+      flush_level_(other.flush_level_.load(std::memory_order_relaxed)),
+      custom_err_handler_(std::move(other.custom_err_handler_)),
+      tracer_(std::move(other.tracer_))
+
+{}
+
+SPDLOG_INLINE logger &logger::operator=(logger other) SPDLOG_NOEXCEPT {
+    this->swap(other);
+    return *this;
+}
+
+SPDLOG_INLINE void logger::swap(spdlog::logger &other) SPDLOG_NOEXCEPT {
+    name_.swap(other.name_);
+    sinks_.swap(other.sinks_);
+
+    // swap level_
+    auto other_level = other.level_.load();
+    auto my_level = level_.exchange(other_level);
+    other.level_.store(my_level);
+
+    // swap flush level_
+    other_level = other.flush_level_.load();
+    my_level = flush_level_.exchange(other_level);
+    other.flush_level_.store(my_level);
+
+    custom_err_handler_.swap(other.custom_err_handler_);
+    std::swap(tracer_, other.tracer_);
+}
+
+SPDLOG_INLINE void swap(logger &a, logger &b) { a.swap(b); }
+
+SPDLOG_INLINE void logger::set_level(level::level_enum log_level) { level_.store(log_level); }
+
+SPDLOG_INLINE level::level_enum logger::level() const {
+    return static_cast<level::level_enum>(level_.load(std::memory_order_relaxed));
+}
+
+SPDLOG_INLINE const std::string &logger::name() const { return name_; }
+
+// set formatting for the sinks in this logger.
+// each sink will get a separate instance of the formatter object.
+SPDLOG_INLINE void logger::set_formatter(std::unique_ptr<formatter> f) {
+    for (auto it = sinks_.begin(); it != sinks_.end(); ++it) {
+        if (std::next(it) == sinks_.end()) {
+            // last element - we can be move it.
+            (*it)->set_formatter(std::move(f));
+            break;  // to prevent clang-tidy warning
+        } else {
+            (*it)->set_formatter(f->clone());
+        }
+    }
+}
+
+SPDLOG_INLINE void logger::set_pattern(std::string pattern, pattern_time_type time_type) {
+    auto new_formatter = details::make_unique<pattern_formatter>(std::move(pattern), time_type);
+    set_formatter(std::move(new_formatter));
+}
+
+// create new backtrace sink and move to it all our child sinks
+SPDLOG_INLINE void logger::enable_backtrace(size_t n_messages) { tracer_.enable(n_messages); }
+
+// restore orig sinks and level and delete the backtrace sink
+SPDLOG_INLINE void logger::disable_backtrace() { tracer_.disable(); }
+
+SPDLOG_INLINE void logger::dump_backtrace() { dump_backtrace_(); }
+
+// flush functions
+SPDLOG_INLINE void logger::flush() { flush_(); }
+
+SPDLOG_INLINE void logger::flush_on(level::level_enum log_level) { flush_level_.store(log_level); }
+
+SPDLOG_INLINE level::level_enum logger::flush_level() const {
+    return static_cast<level::level_enum>(flush_level_.load(std::memory_order_relaxed));
+}
+
+// sinks
+SPDLOG_INLINE const std::vector<sink_ptr> &logger::sinks() const { return sinks_; }
+
+SPDLOG_INLINE std::vector<sink_ptr> &logger::sinks() { return sinks_; }
+
+// error handler
+SPDLOG_INLINE void logger::set_error_handler(err_handler handler) {
+    custom_err_handler_ = std::move(handler);
+}
+
+// create new logger with same sinks and configuration.
+SPDLOG_INLINE std::shared_ptr<logger> logger::clone(std::string logger_name) {
+    auto cloned = std::make_shared<logger>(*this);
+    cloned->name_ = std::move(logger_name);
+    return cloned;
+}
+
+// protected methods
+SPDLOG_INLINE void logger::log_it_(const spdlog::details::log_msg &log_msg,
+                                   bool log_enabled,
+                                   bool traceback_enabled) {
+    if (log_enabled) {
+        sink_it_(log_msg);
+    }
+    if (traceback_enabled) {
+        tracer_.push_back(log_msg);
+    }
+}
+
+SPDLOG_INLINE void logger::sink_it_(const details::log_msg &msg) {
+    for (auto &sink : sinks_) {
+        if (sink->should_log(msg.level)) {
+            SPDLOG_TRY { sink->log(msg); }
+            SPDLOG_LOGGER_CATCH(msg.source)
+        }
+    }
+
+    if (should_flush_(msg)) {
+        flush_();
+    }
+}
+
+SPDLOG_INLINE void logger::flush_() {
+    for (auto &sink : sinks_) {
+        SPDLOG_TRY { sink->flush(); }
+        SPDLOG_LOGGER_CATCH(source_loc())
+    }
+}
+
+SPDLOG_INLINE void logger::dump_backtrace_() {
+    using details::log_msg;
+    if (tracer_.enabled() && !tracer_.empty()) {
+        sink_it_(
+            log_msg{name(), level::info, "****************** Backtrace Start ******************"});
+        tracer_.foreach_pop([this](const log_msg &msg) { this->sink_it_(msg); });
+        sink_it_(
+            log_msg{name(), level::info, "****************** Backtrace End ********************"});
+    }
+}
+
+SPDLOG_INLINE bool logger::should_flush_(const details::log_msg &msg) {
+    auto flush_level = flush_level_.load(std::memory_order_relaxed);
+    return (msg.level >= flush_level) && (msg.level != level::off);
+}
+
+SPDLOG_INLINE void logger::err_handler_(const std::string &msg) {
+    if (custom_err_handler_) {
+        custom_err_handler_(msg);
+    } else {
+        using std::chrono::system_clock;
+        static std::mutex mutex;
+        static std::chrono::system_clock::time_point last_report_time;
+        static size_t err_counter = 0;
+        std::lock_guard<std::mutex> lk{mutex};
+        auto now = system_clock::now();
+        err_counter++;
+        if (now - last_report_time < std::chrono::seconds(1)) {
+            return;
+        }
+        last_report_time = now;
+        auto tm_time = details::os::localtime(system_clock::to_time_t(now));
+        char date_buf[64];
+        std::strftime(date_buf, sizeof(date_buf), "%Y-%m-%d %H:%M:%S", &tm_time);
+#if defined(USING_R) && defined(R_R_H)  // if in R environment
+        REprintf("[*** LOG ERROR #%04zu ***] [%s] [%s] %s\n", err_counter, date_buf, name().c_str(),
+                 msg.c_str());
+#else
+        std::fprintf(stderr, "[*** LOG ERROR #%04zu ***] [%s] [%s] %s\n", err_counter, date_buf,
+                     name().c_str(), msg.c_str());
+#endif
+    }
+}
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/logger.h

@@ -0,0 +1,379 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+// Thread safe logger (except for set_error_handler())
+// Has name, log level, vector of std::shared sink pointers and formatter
+// Upon each log write the logger:
+// 1. Checks if its log level is enough to log the message and if yes:
+// 2. Call the underlying sinks to do the job.
+// 3. Each sink use its own private copy of a formatter to format the message
+// and send to its destination.
+//
+// The use of private formatter per sink provides the opportunity to cache some
+// formatted data, and support for different format per sink.
+
+#include <spdlog/common.h>
+#include <spdlog/details/backtracer.h>
+#include <spdlog/details/log_msg.h>
+
+#ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
+    #ifndef _WIN32
+        #error SPDLOG_WCHAR_TO_UTF8_SUPPORT only supported on windows
+    #endif
+    #include <spdlog/details/os.h>
+#endif
+
+#include <vector>
+
+#ifndef SPDLOG_NO_EXCEPTIONS
+    #define SPDLOG_LOGGER_CATCH(location)                                                 \
+        catch (const std::exception &ex) {                                                \
+            if (location.filename) {                                                      \
+                err_handler_(fmt_lib::format(SPDLOG_FMT_STRING("{} [{}({})]"), ex.what(), \
+                                             location.filename, location.line));          \
+            } else {                                                                      \
+                err_handler_(ex.what());                                                  \
+            }                                                                             \
+        }                                                                                 \
+        catch (...) {                                                                     \
+            err_handler_("Rethrowing unknown exception in logger");                       \
+            throw;                                                                        \
+        }
+#else
+    #define SPDLOG_LOGGER_CATCH(location)
+#endif
+
+namespace spdlog {
+
+class SPDLOG_API logger {
+public:
+    // Empty logger
+    explicit logger(std::string name)
+        : name_(std::move(name)),
+          sinks_() {}
+
+    // Logger with range on sinks
+    template <typename It>
+    logger(std::string name, It begin, It end)
+        : name_(std::move(name)),
+          sinks_(begin, end) {}
+
+    // Logger with single sink
+    logger(std::string name, sink_ptr single_sink)
+        : logger(std::move(name), {std::move(single_sink)}) {}
+
+    // Logger with sinks init list
+    logger(std::string name, sinks_init_list sinks)
+        : logger(std::move(name), sinks.begin(), sinks.end()) {}
+
+    virtual ~logger() = default;
+
+    logger(const logger &other);
+    logger(logger &&other) SPDLOG_NOEXCEPT;
+    logger &operator=(logger other) SPDLOG_NOEXCEPT;
+    void swap(spdlog::logger &other) SPDLOG_NOEXCEPT;
+
+    template <typename... Args>
+    void log(source_loc loc, level::level_enum lvl, format_string_t<Args...> fmt, Args &&...args) {
+        log_(loc, lvl, details::to_string_view(fmt), std::forward<Args>(args)...);
+    }
+
+    template <typename... Args>
+    void log(level::level_enum lvl, format_string_t<Args...> fmt, Args &&...args) {
+        log(source_loc{}, lvl, fmt, std::forward<Args>(args)...);
+    }
+
+    template <typename T>
+    void log(level::level_enum lvl, const T &msg) {
+        log(source_loc{}, lvl, msg);
+    }
+
+    // T cannot be statically converted to format string (including string_view/wstring_view)
+    template <class T,
+              typename std::enable_if<!is_convertible_to_any_format_string<const T &>::value,
+                                      int>::type = 0>
+    void log(source_loc loc, level::level_enum lvl, const T &msg) {
+        log(loc, lvl, "{}", msg);
+    }
+
+    void log(log_clock::time_point log_time,
+             source_loc loc,
+             level::level_enum lvl,
+             string_view_t msg) {
+        bool log_enabled = should_log(lvl);
+        bool traceback_enabled = tracer_.enabled();
+        if (!log_enabled && !traceback_enabled) {
+            return;
+        }
+
+        details::log_msg log_msg(log_time, loc, name_, lvl, msg);
+        log_it_(log_msg, log_enabled, traceback_enabled);
+    }
+
+    void log(source_loc loc, level::level_enum lvl, string_view_t msg) {
+        bool log_enabled = should_log(lvl);
+        bool traceback_enabled = tracer_.enabled();
+        if (!log_enabled && !traceback_enabled) {
+            return;
+        }
+
+        details::log_msg log_msg(loc, name_, lvl, msg);
+        log_it_(log_msg, log_enabled, traceback_enabled);
+    }
+
+    void log(level::level_enum lvl, string_view_t msg) { log(source_loc{}, lvl, msg); }
+
+    template <typename... Args>
+    void trace(format_string_t<Args...> fmt, Args &&...args) {
+        log(level::trace, fmt, std::forward<Args>(args)...);
+    }
+
+    template <typename... Args>
+    void debug(format_string_t<Args...> fmt, Args &&...args) {
+        log(level::debug, fmt, std::forward<Args>(args)...);
+    }
+
+    template <typename... Args>
+    void info(format_string_t<Args...> fmt, Args &&...args) {
+        log(level::info, fmt, std::forward<Args>(args)...);
+    }
+
+    template <typename... Args>
+    void warn(format_string_t<Args...> fmt, Args &&...args) {
+        log(level::warn, fmt, std::forward<Args>(args)...);
+    }
+
+    template <typename... Args>
+    void error(format_string_t<Args...> fmt, Args &&...args) {
+        log(level::err, fmt, std::forward<Args>(args)...);
+    }
+
+    template <typename... Args>
+    void critical(format_string_t<Args...> fmt, Args &&...args) {
+        log(level::critical, fmt, std::forward<Args>(args)...);
+    }
+
+#ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
+    template <typename... Args>
+    void log(source_loc loc, level::level_enum lvl, wformat_string_t<Args...> fmt, Args &&...args) {
+        log_(loc, lvl, details::to_string_view(fmt), std::forward<Args>(args)...);
+    }
+
+    template <typename... Args>
+    void log(level::level_enum lvl, wformat_string_t<Args...> fmt, Args &&...args) {
+        log(source_loc{}, lvl, fmt, std::forward<Args>(args)...);
+    }
+
+    void log(log_clock::time_point log_time,
+             source_loc loc,
+             level::level_enum lvl,
+             wstring_view_t msg) {
+        bool log_enabled = should_log(lvl);
+        bool traceback_enabled = tracer_.enabled();
+        if (!log_enabled && !traceback_enabled) {
+            return;
+        }
+
+        memory_buf_t buf;
+        details::os::wstr_to_utf8buf(wstring_view_t(msg.data(), msg.size()), buf);
+        details::log_msg log_msg(log_time, loc, name_, lvl, string_view_t(buf.data(), buf.size()));
+        log_it_(log_msg, log_enabled, traceback_enabled);
+    }
+
+    void log(source_loc loc, level::level_enum lvl, wstring_view_t msg) {
+        bool log_enabled = should_log(lvl);
+        bool traceback_enabled = tracer_.enabled();
+        if (!log_enabled && !traceback_enabled) {
+            return;
+        }
+
+        memory_buf_t buf;
+        details::os::wstr_to_utf8buf(wstring_view_t(msg.data(), msg.size()), buf);
+        details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
+        log_it_(log_msg, log_enabled, traceback_enabled);
+    }
+
+    void log(level::level_enum lvl, wstring_view_t msg) { log(source_loc{}, lvl, msg); }
+
+    template <typename... Args>
+    void trace(wformat_string_t<Args...> fmt, Args &&...args) {
+        log(level::trace, fmt, std::forward<Args>(args)...);
+    }
+
+    template <typename... Args>
+    void debug(wformat_string_t<Args...> fmt, Args &&...args) {
+        log(level::debug, fmt, std::forward<Args>(args)...);
+    }
+
+    template <typename... Args>
+    void info(wformat_string_t<Args...> fmt, Args &&...args) {
+        log(level::info, fmt, std::forward<Args>(args)...);
+    }
+
+    template <typename... Args>
+    void warn(wformat_string_t<Args...> fmt, Args &&...args) {
+        log(level::warn, fmt, std::forward<Args>(args)...);
+    }
+
+    template <typename... Args>
+    void error(wformat_string_t<Args...> fmt, Args &&...args) {
+        log(level::err, fmt, std::forward<Args>(args)...);
+    }
+
+    template <typename... Args>
+    void critical(wformat_string_t<Args...> fmt, Args &&...args) {
+        log(level::critical, fmt, std::forward<Args>(args)...);
+    }
+#endif
+
+    template <typename T>
+    void trace(const T &msg) {
+        log(level::trace, msg);
+    }
+
+    template <typename T>
+    void debug(const T &msg) {
+        log(level::debug, msg);
+    }
+
+    template <typename T>
+    void info(const T &msg) {
+        log(level::info, msg);
+    }
+
+    template <typename T>
+    void warn(const T &msg) {
+        log(level::warn, msg);
+    }
+
+    template <typename T>
+    void error(const T &msg) {
+        log(level::err, msg);
+    }
+
+    template <typename T>
+    void critical(const T &msg) {
+        log(level::critical, msg);
+    }
+
+    // return true logging is enabled for the given level.
+    bool should_log(level::level_enum msg_level) const {
+        return msg_level >= level_.load(std::memory_order_relaxed);
+    }
+
+    // return true if backtrace logging is enabled.
+    bool should_backtrace() const { return tracer_.enabled(); }
+
+    void set_level(level::level_enum log_level);
+
+    level::level_enum level() const;
+
+    const std::string &name() const;
+
+    // set formatting for the sinks in this logger.
+    // each sink will get a separate instance of the formatter object.
+    void set_formatter(std::unique_ptr<formatter> f);
+
+    // set formatting for the sinks in this logger.
+    // equivalent to
+    //     set_formatter(make_unique<pattern_formatter>(pattern, time_type))
+    // Note: each sink will get a new instance of a formatter object, replacing the old one.
+    void set_pattern(std::string pattern, pattern_time_type time_type = pattern_time_type::local);
+
+    // backtrace support.
+    // efficiently store all debug/trace messages in a circular buffer until needed for debugging.
+    void enable_backtrace(size_t n_messages);
+    void disable_backtrace();
+    void dump_backtrace();
+
+    // flush functions
+    void flush();
+    void flush_on(level::level_enum log_level);
+    level::level_enum flush_level() const;
+
+    // sinks
+    const std::vector<sink_ptr> &sinks() const;
+
+    std::vector<sink_ptr> &sinks();
+
+    // error handler
+    void set_error_handler(err_handler);
+
+    // create new logger with same sinks and configuration.
+    virtual std::shared_ptr<logger> clone(std::string logger_name);
+
+protected:
+    std::string name_;
+    std::vector<sink_ptr> sinks_;
+    spdlog::level_t level_{level::info};
+    spdlog::level_t flush_level_{level::off};
+    err_handler custom_err_handler_{nullptr};
+    details::backtracer tracer_;
+
+    // common implementation for after templated public api has been resolved
+    template <typename... Args>
+    void log_(source_loc loc, level::level_enum lvl, string_view_t fmt, Args &&...args) {
+        bool log_enabled = should_log(lvl);
+        bool traceback_enabled = tracer_.enabled();
+        if (!log_enabled && !traceback_enabled) {
+            return;
+        }
+        SPDLOG_TRY {
+            memory_buf_t buf;
+#ifdef SPDLOG_USE_STD_FORMAT
+            fmt_lib::vformat_to(std::back_inserter(buf), fmt, fmt_lib::make_format_args(args...));
+#else
+            fmt::vformat_to(fmt::appender(buf), fmt, fmt::make_format_args(args...));
+#endif
+
+            details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
+            log_it_(log_msg, log_enabled, traceback_enabled);
+        }
+        SPDLOG_LOGGER_CATCH(loc)
+    }
+
+#ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
+    template <typename... Args>
+    void log_(source_loc loc, level::level_enum lvl, wstring_view_t fmt, Args &&...args) {
+        bool log_enabled = should_log(lvl);
+        bool traceback_enabled = tracer_.enabled();
+        if (!log_enabled && !traceback_enabled) {
+            return;
+        }
+        SPDLOG_TRY {
+            // format to wmemory_buffer and convert to utf8
+            wmemory_buf_t wbuf;
+            fmt_lib::vformat_to(std::back_inserter(wbuf), fmt,
+                                fmt_lib::make_format_args<fmt_lib::wformat_context>(args...));
+
+            memory_buf_t buf;
+            details::os::wstr_to_utf8buf(wstring_view_t(wbuf.data(), wbuf.size()), buf);
+            details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
+            log_it_(log_msg, log_enabled, traceback_enabled);
+        }
+        SPDLOG_LOGGER_CATCH(loc)
+    }
+#endif  // SPDLOG_WCHAR_TO_UTF8_SUPPORT
+
+    // log the given message (if the given log level is high enough),
+    // and save backtrace (if backtrace is enabled).
+    void log_it_(const details::log_msg &log_msg, bool log_enabled, bool traceback_enabled);
+    virtual void sink_it_(const details::log_msg &msg);
+    virtual void flush_();
+    void dump_backtrace_();
+    bool should_flush_(const details::log_msg &msg);
+
+    // handle errors during logging.
+    // default handler prints the error to stderr at max rate of 1 message/sec.
+    void err_handler_(const std::string &msg);
+};
+
+void swap(logger &a, logger &b);
+
+}  // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "logger-inl.h"
+#endif

third_party/spdlog_headers/spdlog/pattern_formatter.h

@@ -0,0 +1,118 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <spdlog/common.h>
+#include <spdlog/details/log_msg.h>
+#include <spdlog/details/os.h>
+#include <spdlog/formatter.h>
+
+#include <chrono>
+#include <ctime>
+#include <memory>
+
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+namespace spdlog {
+namespace details {
+
+// padding information.
+struct padding_info {
+    enum class pad_side { left, right, center };
+
+    padding_info() = default;
+    padding_info(size_t width, padding_info::pad_side side, bool truncate)
+        : width_(width),
+          side_(side),
+          truncate_(truncate),
+          enabled_(true) {}
+
+    bool enabled() const { return enabled_; }
+    size_t width_ = 0;
+    pad_side side_ = pad_side::left;
+    bool truncate_ = false;
+    bool enabled_ = false;
+};
+
+class SPDLOG_API flag_formatter {
+public:
+    explicit flag_formatter(padding_info padinfo)
+        : padinfo_(padinfo) {}
+    flag_formatter() = default;
+    virtual ~flag_formatter() = default;
+    virtual void format(const details::log_msg &msg,
+                        const std::tm &tm_time,
+                        memory_buf_t &dest) = 0;
+
+protected:
+    padding_info padinfo_;
+};
+
+}  // namespace details
+
+class SPDLOG_API custom_flag_formatter : public details::flag_formatter {
+public:
+    virtual std::unique_ptr<custom_flag_formatter> clone() const = 0;
+
+    void set_padding_info(const details::padding_info &padding) {
+        flag_formatter::padinfo_ = padding;
+    }
+};
+
+class SPDLOG_API pattern_formatter final : public formatter {
+public:
+    using custom_flags = std::unordered_map<char, std::unique_ptr<custom_flag_formatter>>;
+
+    explicit pattern_formatter(std::string pattern,
+                               pattern_time_type time_type = pattern_time_type::local,
+                               std::string eol = spdlog::details::os::default_eol,
+                               custom_flags custom_user_flags = custom_flags());
+
+    // use default pattern is not given
+    explicit pattern_formatter(pattern_time_type time_type = pattern_time_type::local,
+                               std::string eol = spdlog::details::os::default_eol);
+
+    pattern_formatter(const pattern_formatter &other) = delete;
+    pattern_formatter &operator=(const pattern_formatter &other) = delete;
+
+    std::unique_ptr<formatter> clone() const override;
+    void format(const details::log_msg &msg, memory_buf_t &dest) override;
+
+    template <typename T, typename... Args>
+    pattern_formatter &add_flag(char flag, Args &&...args) {
+        custom_handlers_[flag] = details::make_unique<T>(std::forward<Args>(args)...);
+        return *this;
+    }
+    void set_pattern(std::string pattern);
+    void need_localtime(bool need = true);
+
+private:
+    std::string pattern_;
+    std::string eol_;
+    pattern_time_type pattern_time_type_;
+    bool need_localtime_;
+    std::tm cached_tm_;
+    std::chrono::seconds last_log_secs_;
+    std::vector<std::unique_ptr<details::flag_formatter>> formatters_;
+    custom_flags custom_handlers_;
+
+    std::tm get_time_(const details::log_msg &msg);
+    template <typename Padder>
+    void handle_flag_(char flag, details::padding_info padding);
+
+    // Extract given pad spec (e.g. %8X)
+    // Advance the given it pass the end of the padding spec found (if any)
+    // Return padding.
+    static details::padding_info handle_padspec_(std::string::const_iterator &it,
+                                                 std::string::const_iterator end);
+
+    void compile_pattern_(const std::string &pattern);
+};
+}  // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "pattern_formatter-inl.h"
+#endif

third_party/spdlog_headers/spdlog/sinks/ansicolor_sink-inl.h

@@ -0,0 +1,135 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#ifndef SPDLOG_HEADER_ONLY
+    #include <spdlog/sinks/ansicolor_sink.h>
+#endif
+
+#include <spdlog/details/os.h>
+#include <spdlog/pattern_formatter.h>
+
+namespace spdlog {
+namespace sinks {
+
+template <typename ConsoleMutex>
+SPDLOG_INLINE ansicolor_sink<ConsoleMutex>::ansicolor_sink(FILE *target_file, color_mode mode)
+    : target_file_(target_file),
+      mutex_(ConsoleMutex::mutex()),
+      formatter_(details::make_unique<spdlog::pattern_formatter>())
+
+{
+    set_color_mode(mode);
+    colors_.at(level::trace) = to_string_(white);
+    colors_.at(level::debug) = to_string_(cyan);
+    colors_.at(level::info) = to_string_(green);
+    colors_.at(level::warn) = to_string_(yellow_bold);
+    colors_.at(level::err) = to_string_(red_bold);
+    colors_.at(level::critical) = to_string_(bold_on_red);
+    colors_.at(level::off) = to_string_(reset);
+}
+
+template <typename ConsoleMutex>
+SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::set_color(level::level_enum color_level,
+                                                           string_view_t color) {
+    std::lock_guard<mutex_t> lock(mutex_);
+    colors_.at(static_cast<size_t>(color_level)) = to_string_(color);
+}
+
+template <typename ConsoleMutex>
+SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::log(const details::log_msg &msg) {
+    // Wrap the originally formatted message in color codes.
+    // If color is not supported in the terminal, log as is instead.
+    std::lock_guard<mutex_t> lock(mutex_);
+    msg.color_range_start = 0;
+    msg.color_range_end = 0;
+    memory_buf_t formatted;
+    formatter_->format(msg, formatted);
+    if (should_do_colors_ && msg.color_range_end > msg.color_range_start) {
+        // before color range
+        print_range_(formatted, 0, msg.color_range_start);
+        // in color range
+        print_ccode_(colors_.at(static_cast<size_t>(msg.level)));
+        print_range_(formatted, msg.color_range_start, msg.color_range_end);
+        print_ccode_(reset);
+        // after color range
+        print_range_(formatted, msg.color_range_end, formatted.size());
+    } else  // no color
+    {
+        print_range_(formatted, 0, formatted.size());
+    }
+    fflush(target_file_);
+}
+
+template <typename ConsoleMutex>
+SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::flush() {
+    std::lock_guard<mutex_t> lock(mutex_);
+    fflush(target_file_);
+}
+
+template <typename ConsoleMutex>
+SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::set_pattern(const std::string &pattern) {
+    std::lock_guard<mutex_t> lock(mutex_);
+    formatter_ = std::unique_ptr<spdlog::formatter>(new pattern_formatter(pattern));
+}
+
+template <typename ConsoleMutex>
+SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::set_formatter(
+    std::unique_ptr<spdlog::formatter> sink_formatter) {
+    std::lock_guard<mutex_t> lock(mutex_);
+    formatter_ = std::move(sink_formatter);
+}
+
+template <typename ConsoleMutex>
+SPDLOG_INLINE bool ansicolor_sink<ConsoleMutex>::should_color() {
+    return should_do_colors_;
+}
+
+template <typename ConsoleMutex>
+SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::set_color_mode(color_mode mode) {
+    switch (mode) {
+        case color_mode::always:
+            should_do_colors_ = true;
+            return;
+        case color_mode::automatic:
+            should_do_colors_ =
+                details::os::in_terminal(target_file_) && details::os::is_color_terminal();
+            return;
+        case color_mode::never:
+            should_do_colors_ = false;
+            return;
+        default:
+            should_do_colors_ = false;
+    }
+}
+
+template <typename ConsoleMutex>
+SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::print_ccode_(const string_view_t &color_code) {
+    fwrite(color_code.data(), sizeof(char), color_code.size(), target_file_);
+}
+
+template <typename ConsoleMutex>
+SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::print_range_(const memory_buf_t &formatted,
+                                                              size_t start,
+                                                              size_t end) {
+    fwrite(formatted.data() + start, sizeof(char), end - start, target_file_);
+}
+
+template <typename ConsoleMutex>
+SPDLOG_INLINE std::string ansicolor_sink<ConsoleMutex>::to_string_(const string_view_t &sv) {
+    return std::string(sv.data(), sv.size());
+}
+
+// ansicolor_stdout_sink
+template <typename ConsoleMutex>
+SPDLOG_INLINE ansicolor_stdout_sink<ConsoleMutex>::ansicolor_stdout_sink(color_mode mode)
+    : ansicolor_sink<ConsoleMutex>(stdout, mode) {}
+
+// ansicolor_stderr_sink
+template <typename ConsoleMutex>
+SPDLOG_INLINE ansicolor_stderr_sink<ConsoleMutex>::ansicolor_stderr_sink(color_mode mode)
+    : ansicolor_sink<ConsoleMutex>(stderr, mode) {}
+
+}  // namespace sinks
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/sinks/ansicolor_sink.h

@@ -0,0 +1,115 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <array>
+#include <memory>
+#include <mutex>
+#include <spdlog/details/console_globals.h>
+#include <spdlog/details/null_mutex.h>
+#include <spdlog/sinks/sink.h>
+#include <string>
+
+namespace spdlog {
+namespace sinks {
+
+/**
+ * This sink prefixes the output with an ANSI escape sequence color code
+ * depending on the severity
+ * of the message.
+ * If no color terminal detected, omit the escape codes.
+ */
+
+template <typename ConsoleMutex>
+class ansicolor_sink : public sink {
+public:
+    using mutex_t = typename ConsoleMutex::mutex_t;
+    ansicolor_sink(FILE *target_file, color_mode mode);
+    ~ansicolor_sink() override = default;
+
+    ansicolor_sink(const ansicolor_sink &other) = delete;
+    ansicolor_sink(ansicolor_sink &&other) = delete;
+
+    ansicolor_sink &operator=(const ansicolor_sink &other) = delete;
+    ansicolor_sink &operator=(ansicolor_sink &&other) = delete;
+
+    void set_color(level::level_enum color_level, string_view_t color);
+    void set_color_mode(color_mode mode);
+    bool should_color();
+
+    void log(const details::log_msg &msg) override;
+    void flush() override;
+    void set_pattern(const std::string &pattern) final;
+    void set_formatter(std::unique_ptr<spdlog::formatter> sink_formatter) override;
+
+    // Formatting codes
+    const string_view_t reset = "\033[m";
+    const string_view_t bold = "\033[1m";
+    const string_view_t dark = "\033[2m";
+    const string_view_t underline = "\033[4m";
+    const string_view_t blink = "\033[5m";
+    const string_view_t reverse = "\033[7m";
+    const string_view_t concealed = "\033[8m";
+    const string_view_t clear_line = "\033[K";
+
+    // Foreground colors
+    const string_view_t black = "\033[30m";
+    const string_view_t red = "\033[31m";
+    const string_view_t green = "\033[32m";
+    const string_view_t yellow = "\033[33m";
+    const string_view_t blue = "\033[34m";
+    const string_view_t magenta = "\033[35m";
+    const string_view_t cyan = "\033[36m";
+    const string_view_t white = "\033[37m";
+
+    /// Background colors
+    const string_view_t on_black = "\033[40m";
+    const string_view_t on_red = "\033[41m";
+    const string_view_t on_green = "\033[42m";
+    const string_view_t on_yellow = "\033[43m";
+    const string_view_t on_blue = "\033[44m";
+    const string_view_t on_magenta = "\033[45m";
+    const string_view_t on_cyan = "\033[46m";
+    const string_view_t on_white = "\033[47m";
+
+    /// Bold colors
+    const string_view_t yellow_bold = "\033[33m\033[1m";
+    const string_view_t red_bold = "\033[31m\033[1m";
+    const string_view_t bold_on_red = "\033[1m\033[41m";
+
+private:
+    FILE *target_file_;
+    mutex_t &mutex_;
+    bool should_do_colors_;
+    std::unique_ptr<spdlog::formatter> formatter_;
+    std::array<std::string, level::n_levels> colors_;
+    void print_ccode_(const string_view_t &color_code);
+    void print_range_(const memory_buf_t &formatted, size_t start, size_t end);
+    static std::string to_string_(const string_view_t &sv);
+};
+
+template <typename ConsoleMutex>
+class ansicolor_stdout_sink : public ansicolor_sink<ConsoleMutex> {
+public:
+    explicit ansicolor_stdout_sink(color_mode mode = color_mode::automatic);
+};
+
+template <typename ConsoleMutex>
+class ansicolor_stderr_sink : public ansicolor_sink<ConsoleMutex> {
+public:
+    explicit ansicolor_stderr_sink(color_mode mode = color_mode::automatic);
+};
+
+using ansicolor_stdout_sink_mt = ansicolor_stdout_sink<details::console_mutex>;
+using ansicolor_stdout_sink_st = ansicolor_stdout_sink<details::console_nullmutex>;
+
+using ansicolor_stderr_sink_mt = ansicolor_stderr_sink<details::console_mutex>;
+using ansicolor_stderr_sink_st = ansicolor_stderr_sink<details::console_nullmutex>;
+
+}  // namespace sinks
+}  // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "ansicolor_sink-inl.h"
+#endif

third_party/spdlog_headers/spdlog/sinks/base_sink-inl.h

@@ -0,0 +1,59 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#ifndef SPDLOG_HEADER_ONLY
+    #include <spdlog/sinks/base_sink.h>
+#endif
+
+#include <spdlog/common.h>
+#include <spdlog/pattern_formatter.h>
+
+#include <memory>
+#include <mutex>
+
+template <typename Mutex>
+SPDLOG_INLINE spdlog::sinks::base_sink<Mutex>::base_sink()
+    : formatter_{details::make_unique<spdlog::pattern_formatter>()} {}
+
+template <typename Mutex>
+SPDLOG_INLINE spdlog::sinks::base_sink<Mutex>::base_sink(
+    std::unique_ptr<spdlog::formatter> formatter)
+    : formatter_{std::move(formatter)} {}
+
+template <typename Mutex>
+void SPDLOG_INLINE spdlog::sinks::base_sink<Mutex>::log(const details::log_msg &msg) {
+    std::lock_guard<Mutex> lock(mutex_);
+    sink_it_(msg);
+}
+
+template <typename Mutex>
+void SPDLOG_INLINE spdlog::sinks::base_sink<Mutex>::flush() {
+    std::lock_guard<Mutex> lock(mutex_);
+    flush_();
+}
+
+template <typename Mutex>
+void SPDLOG_INLINE spdlog::sinks::base_sink<Mutex>::set_pattern(const std::string &pattern) {
+    std::lock_guard<Mutex> lock(mutex_);
+    set_pattern_(pattern);
+}
+
+template <typename Mutex>
+void SPDLOG_INLINE
+spdlog::sinks::base_sink<Mutex>::set_formatter(std::unique_ptr<spdlog::formatter> sink_formatter) {
+    std::lock_guard<Mutex> lock(mutex_);
+    set_formatter_(std::move(sink_formatter));
+}
+
+template <typename Mutex>
+void SPDLOG_INLINE spdlog::sinks::base_sink<Mutex>::set_pattern_(const std::string &pattern) {
+    set_formatter_(details::make_unique<spdlog::pattern_formatter>(pattern));
+}
+
+template <typename Mutex>
+void SPDLOG_INLINE
+spdlog::sinks::base_sink<Mutex>::set_formatter_(std::unique_ptr<spdlog::formatter> sink_formatter) {
+    formatter_ = std::move(sink_formatter);
+}

third_party/spdlog_headers/spdlog/sinks/base_sink.h

@@ -0,0 +1,51 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+//
+// base sink templated over a mutex (either dummy or real)
+// concrete implementation should override the sink_it_() and flush_()  methods.
+// locking is taken care of in this class - no locking needed by the
+// implementers..
+//
+
+#include <spdlog/common.h>
+#include <spdlog/details/log_msg.h>
+#include <spdlog/sinks/sink.h>
+
+namespace spdlog {
+namespace sinks {
+template <typename Mutex>
+class SPDLOG_API base_sink : public sink {
+public:
+    base_sink();
+    explicit base_sink(std::unique_ptr<spdlog::formatter> formatter);
+    ~base_sink() override = default;
+
+    base_sink(const base_sink &) = delete;
+    base_sink(base_sink &&) = delete;
+
+    base_sink &operator=(const base_sink &) = delete;
+    base_sink &operator=(base_sink &&) = delete;
+
+    void log(const details::log_msg &msg) final;
+    void flush() final;
+    void set_pattern(const std::string &pattern) final;
+    void set_formatter(std::unique_ptr<spdlog::formatter> sink_formatter) final;
+
+protected:
+    // sink formatter
+    std::unique_ptr<spdlog::formatter> formatter_;
+    Mutex mutex_;
+
+    virtual void sink_it_(const details::log_msg &msg) = 0;
+    virtual void flush_() = 0;
+    virtual void set_pattern_(const std::string &pattern);
+    virtual void set_formatter_(std::unique_ptr<spdlog::formatter> sink_formatter);
+};
+}  // namespace sinks
+}  // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "base_sink-inl.h"
+#endif

third_party/spdlog_headers/spdlog/sinks/basic_file_sink-inl.h

@@ -0,0 +1,42 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#ifndef SPDLOG_HEADER_ONLY
+    #include <spdlog/sinks/basic_file_sink.h>
+#endif
+
+#include <spdlog/common.h>
+#include <spdlog/details/os.h>
+
+namespace spdlog {
+namespace sinks {
+
+template <typename Mutex>
+SPDLOG_INLINE basic_file_sink<Mutex>::basic_file_sink(const filename_t &filename,
+                                                      bool truncate,
+                                                      const file_event_handlers &event_handlers)
+    : file_helper_{event_handlers} {
+    file_helper_.open(filename, truncate);
+}
+
+template <typename Mutex>
+SPDLOG_INLINE const filename_t &basic_file_sink<Mutex>::filename() const {
+    return file_helper_.filename();
+}
+
+template <typename Mutex>
+SPDLOG_INLINE void basic_file_sink<Mutex>::sink_it_(const details::log_msg &msg) {
+    memory_buf_t formatted;
+    base_sink<Mutex>::formatter_->format(msg, formatted);
+    file_helper_.write(formatted);
+}
+
+template <typename Mutex>
+SPDLOG_INLINE void basic_file_sink<Mutex>::flush_() {
+    file_helper_.flush();
+}
+
+}  // namespace sinks
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/sinks/basic_file_sink.h

@@ -0,0 +1,65 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// 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/details/synchronous_factory.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,
+                             const file_event_handlers &event_handlers = {});
+    const filename_t &filename() const;
+
+protected:
+    void sink_it_(const details::log_msg &msg) override;
+    void flush_() override;
+
+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 = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> basic_logger_mt(const std::string &logger_name,
+                                               const filename_t &filename,
+                                               bool truncate = false,
+                                               const file_event_handlers &event_handlers = {}) {
+    return Factory::template create<sinks::basic_file_sink_mt>(logger_name, filename, truncate,
+                                                               event_handlers);
+}
+
+template <typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> basic_logger_st(const std::string &logger_name,
+                                               const filename_t &filename,
+                                               bool truncate = false,
+                                               const file_event_handlers &event_handlers = {}) {
+    return Factory::template create<sinks::basic_file_sink_st>(logger_name, filename, truncate,
+                                                               event_handlers);
+}
+
+}  // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "basic_file_sink-inl.h"
+#endif

third_party/spdlog_headers/spdlog/sinks/sink-inl.h

@@ -0,0 +1,22 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#ifndef SPDLOG_HEADER_ONLY
+    #include <spdlog/sinks/sink.h>
+#endif
+
+#include <spdlog/common.h>
+
+SPDLOG_INLINE bool spdlog::sinks::sink::should_log(spdlog::level::level_enum msg_level) const {
+    return msg_level >= level_.load(std::memory_order_relaxed);
+}
+
+SPDLOG_INLINE void spdlog::sinks::sink::set_level(level::level_enum log_level) {
+    level_.store(log_level, std::memory_order_relaxed);
+}
+
+SPDLOG_INLINE spdlog::level::level_enum spdlog::sinks::sink::level() const {
+    return static_cast<spdlog::level::level_enum>(level_.load(std::memory_order_relaxed));
+}

third_party/spdlog_headers/spdlog/sinks/sink.h

@@ -0,0 +1,34 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <spdlog/details/log_msg.h>
+#include <spdlog/formatter.h>
+
+namespace spdlog {
+
+namespace sinks {
+class SPDLOG_API sink {
+public:
+    virtual ~sink() = default;
+    virtual void log(const details::log_msg &msg) = 0;
+    virtual void flush() = 0;
+    virtual void set_pattern(const std::string &pattern) = 0;
+    virtual void set_formatter(std::unique_ptr<spdlog::formatter> sink_formatter) = 0;
+
+    void set_level(level::level_enum log_level);
+    level::level_enum level() const;
+    bool should_log(level::level_enum msg_level) const;
+
+protected:
+    // sink log level - default is all
+    level_t level_{level::trace};
+};
+
+}  // namespace sinks
+}  // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "sink-inl.h"
+#endif

third_party/spdlog_headers/spdlog/spdlog-inl.h

@@ -0,0 +1,102 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#ifndef SPDLOG_HEADER_ONLY
+    #include <spdlog/spdlog.h>
+#endif
+
+#include <spdlog/common.h>
+#include <spdlog/pattern_formatter.h>
+
+namespace spdlog {
+
+SPDLOG_INLINE void initialize_logger(std::shared_ptr<logger> logger) {
+    details::registry::instance().initialize_logger(std::move(logger));
+}
+
+SPDLOG_INLINE std::shared_ptr<logger> get(const std::string &name) {
+    return details::registry::instance().get(name);
+}
+
+#if __cplusplus >= 201703L  // C++17
+SPDLOG_INLINE std::shared_ptr<logger> get(std::string_view name) {
+    return details::registry::instance().get(name);
+}
+
+SPDLOG_INLINE std::shared_ptr<logger> get(const char *name) {
+    return details::registry::instance().get(name);
+}
+#endif
+
+SPDLOG_INLINE void set_formatter(std::unique_ptr<spdlog::formatter> formatter) {
+    details::registry::instance().set_formatter(std::move(formatter));
+}
+
+SPDLOG_INLINE void set_pattern(std::string pattern, pattern_time_type time_type) {
+    set_formatter(
+        std::unique_ptr<spdlog::formatter>(new pattern_formatter(std::move(pattern), time_type)));
+}
+
+SPDLOG_INLINE void enable_backtrace(size_t n_messages) {
+    details::registry::instance().enable_backtrace(n_messages);
+}
+
+SPDLOG_INLINE void disable_backtrace() { details::registry::instance().disable_backtrace(); }
+
+SPDLOG_INLINE void dump_backtrace() { default_logger_raw()->dump_backtrace(); }
+
+SPDLOG_INLINE level::level_enum get_level() { return default_logger_raw()->level(); }
+
+SPDLOG_INLINE bool should_log(level::level_enum log_level) {
+    return default_logger_raw()->should_log(log_level);
+}
+
+SPDLOG_INLINE void set_level(level::level_enum log_level) {
+    details::registry::instance().set_level(log_level);
+}
+
+SPDLOG_INLINE void flush_on(level::level_enum log_level) {
+    details::registry::instance().flush_on(log_level);
+}
+
+SPDLOG_INLINE void set_error_handler(void (*handler)(const std::string &msg)) {
+    details::registry::instance().set_error_handler(handler);
+}
+
+SPDLOG_INLINE void register_logger(std::shared_ptr<logger> logger) {
+    details::registry::instance().register_logger(std::move(logger));
+}
+
+SPDLOG_INLINE void apply_all(const std::function<void(std::shared_ptr<logger>)> &fun) {
+    details::registry::instance().apply_all(fun);
+}
+
+SPDLOG_INLINE void drop(const std::string &name) { details::registry::instance().drop(name); }
+
+SPDLOG_INLINE void drop_all() { details::registry::instance().drop_all(); }
+
+SPDLOG_INLINE void shutdown() { details::registry::instance().shutdown(); }
+
+SPDLOG_INLINE void set_automatic_registration(bool automatic_registration) {
+    details::registry::instance().set_automatic_registration(automatic_registration);
+}
+
+SPDLOG_INLINE std::shared_ptr<spdlog::logger> default_logger() {
+    return details::registry::instance().default_logger();
+}
+
+SPDLOG_INLINE spdlog::logger *default_logger_raw() {
+    return details::registry::instance().get_default_raw();
+}
+
+SPDLOG_INLINE void set_default_logger(std::shared_ptr<spdlog::logger> default_logger) {
+    details::registry::instance().set_default_logger(std::move(default_logger));
+}
+
+SPDLOG_INLINE void apply_logger_env_levels(std::shared_ptr<logger> logger) {
+    details::registry::instance().apply_logger_env_levels(std::move(logger));
+}
+
+}  // namespace spdlog

third_party/spdlog_headers/spdlog/spdlog.h

@@ -0,0 +1,360 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+// spdlog main header file.
+// see example.cpp for usage example
+
+#ifndef SPDLOG_H
+#define SPDLOG_H
+
+#pragma once
+
+#include <spdlog/common.h>
+#include <spdlog/details/registry.h>
+#include <spdlog/details/synchronous_factory.h>
+#include <spdlog/logger.h>
+#include <spdlog/version.h>
+
+#include <chrono>
+#include <functional>
+#include <memory>
+#include <string>
+
+#if __cplusplus >= 201703L  // C++17
+    #include <string_view>
+#endif
+
+namespace spdlog {
+
+using default_factory = synchronous_factory;
+
+// Create and register a logger with a templated sink type
+// The logger's level, formatter and flush level will be set according the
+// global settings.
+//
+// Example:
+//   spdlog::create<daily_file_sink_st>("logger_name", "dailylog_filename", 11, 59);
+template <typename Sink, typename... SinkArgs>
+inline std::shared_ptr<spdlog::logger> create(std::string logger_name, SinkArgs &&...sink_args) {
+    return default_factory::create<Sink>(std::move(logger_name),
+                                         std::forward<SinkArgs>(sink_args)...);
+}
+
+// Initialize and register a logger,
+// formatter and flush level will be set according the global settings.
+//
+// Useful for initializing manually created loggers with the global settings.
+//
+// Example:
+//   auto mylogger = std::make_shared<spdlog::logger>("mylogger", ...);
+//   spdlog::initialize_logger(mylogger);
+SPDLOG_API void initialize_logger(std::shared_ptr<logger> logger);
+
+// Return an existing logger or nullptr if a logger with such name doesn't
+// exist.
+// example: spdlog::get("my_logger")->info("hello {}", "world");
+SPDLOG_API std::shared_ptr<logger> get(const std::string &name);
+#if __cplusplus >= 201703L  // C++17
+SPDLOG_API std::shared_ptr<logger> get(std::string_view name);
+SPDLOG_API std::shared_ptr<logger> get(const char *name);
+#endif
+
+// Set global formatter. Each sink in each logger will get a clone of this object
+SPDLOG_API void set_formatter(std::unique_ptr<spdlog::formatter> formatter);
+
+// Set global format string.
+// example: spdlog::set_pattern("%Y-%m-%d %H:%M:%S.%e %l : %v");
+SPDLOG_API void set_pattern(std::string pattern,
+                            pattern_time_type time_type = pattern_time_type::local);
+
+// enable global backtrace support
+SPDLOG_API void enable_backtrace(size_t n_messages);
+
+// disable global backtrace support
+SPDLOG_API void disable_backtrace();
+
+// call dump backtrace on default logger
+SPDLOG_API void dump_backtrace();
+
+// Get global logging level
+SPDLOG_API level::level_enum get_level();
+
+// Set global logging level
+SPDLOG_API void set_level(level::level_enum log_level);
+
+// Determine whether the default logger should log messages with a certain level
+SPDLOG_API bool should_log(level::level_enum lvl);
+
+// Set global flush level
+SPDLOG_API void flush_on(level::level_enum log_level);
+
+// Start/Restart a periodic flusher thread
+// Warning: Use only if all your loggers are thread safe!
+template <typename Rep, typename Period>
+inline void flush_every(std::chrono::duration<Rep, Period> interval) {
+    details::registry::instance().flush_every(interval);
+}
+
+// Set global error handler
+SPDLOG_API void set_error_handler(void (*handler)(const std::string &msg));
+
+// Register the given logger with the given name
+SPDLOG_API void register_logger(std::shared_ptr<logger> logger);
+
+// Apply a user defined function on all registered loggers
+// Example:
+// spdlog::apply_all([&](std::shared_ptr<spdlog::logger> l) {l->flush();});
+SPDLOG_API void apply_all(const std::function<void(std::shared_ptr<logger>)> &fun);
+
+// Drop the reference to the given logger
+SPDLOG_API void drop(const std::string &name);
+
+// Drop all references from the registry
+SPDLOG_API void drop_all();
+
+// stop any running threads started by spdlog and clean registry loggers
+SPDLOG_API void shutdown();
+
+// Automatic registration of loggers when using spdlog::create() or spdlog::create_async
+SPDLOG_API void set_automatic_registration(bool automatic_registration);
+
+// API for using default logger (stdout_color_mt),
+// e.g: spdlog::info("Message {}", 1);
+//
+// The default logger object can be accessed using the spdlog::default_logger():
+// For example, to add another sink to it:
+// spdlog::default_logger()->sinks().push_back(some_sink);
+//
+// The default logger can replaced using spdlog::set_default_logger(new_logger).
+// For example, to replace it with a file logger.
+//
+// IMPORTANT:
+// The default API is thread safe (for _mt loggers), but:
+// set_default_logger() *should not* be used concurrently with the default API.
+// e.g do not call set_default_logger() from one thread while calling spdlog::info() from another.
+
+SPDLOG_API std::shared_ptr<spdlog::logger> default_logger();
+
+SPDLOG_API spdlog::logger *default_logger_raw();
+
+SPDLOG_API void set_default_logger(std::shared_ptr<spdlog::logger> default_logger);
+
+// Initialize logger level based on environment configs.
+//
+// Useful for applying SPDLOG_LEVEL to manually created loggers.
+//
+// Example:
+//   auto mylogger = std::make_shared<spdlog::logger>("mylogger", ...);
+//   spdlog::apply_logger_env_levels(mylogger);
+SPDLOG_API void apply_logger_env_levels(std::shared_ptr<logger> logger);
+
+template <typename... Args>
+inline void log(source_loc source,
+                level::level_enum lvl,
+                format_string_t<Args...> fmt,
+                Args &&...args) {
+    default_logger_raw()->log(source, lvl, fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline void log(level::level_enum lvl, format_string_t<Args...> fmt, Args &&...args) {
+    default_logger_raw()->log(source_loc{}, lvl, fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline void trace(format_string_t<Args...> fmt, Args &&...args) {
+    default_logger_raw()->trace(fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline void debug(format_string_t<Args...> fmt, Args &&...args) {
+    default_logger_raw()->debug(fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline void info(format_string_t<Args...> fmt, Args &&...args) {
+    default_logger_raw()->info(fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline void warn(format_string_t<Args...> fmt, Args &&...args) {
+    default_logger_raw()->warn(fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline void error(format_string_t<Args...> fmt, Args &&...args) {
+    default_logger_raw()->error(fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline void critical(format_string_t<Args...> fmt, Args &&...args) {
+    default_logger_raw()->critical(fmt, std::forward<Args>(args)...);
+}
+
+template <typename T>
+inline void log(source_loc source, level::level_enum lvl, const T &msg) {
+    default_logger_raw()->log(source, lvl, msg);
+}
+
+template <typename T>
+inline void log(level::level_enum lvl, const T &msg) {
+    default_logger_raw()->log(lvl, msg);
+}
+
+#ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
+template <typename... Args>
+inline void log(source_loc source,
+                level::level_enum lvl,
+                wformat_string_t<Args...> fmt,
+                Args &&...args) {
+    default_logger_raw()->log(source, lvl, fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline void log(level::level_enum lvl, wformat_string_t<Args...> fmt, Args &&...args) {
+    default_logger_raw()->log(source_loc{}, lvl, fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline void trace(wformat_string_t<Args...> fmt, Args &&...args) {
+    default_logger_raw()->trace(fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline void debug(wformat_string_t<Args...> fmt, Args &&...args) {
+    default_logger_raw()->debug(fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline void info(wformat_string_t<Args...> fmt, Args &&...args) {
+    default_logger_raw()->info(fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline void warn(wformat_string_t<Args...> fmt, Args &&...args) {
+    default_logger_raw()->warn(fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline void error(wformat_string_t<Args...> fmt, Args &&...args) {
+    default_logger_raw()->error(fmt, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline void critical(wformat_string_t<Args...> fmt, Args &&...args) {
+    default_logger_raw()->critical(fmt, std::forward<Args>(args)...);
+}
+#endif
+
+template <typename T>
+inline void trace(const T &msg) {
+    default_logger_raw()->trace(msg);
+}
+
+template <typename T>
+inline void debug(const T &msg) {
+    default_logger_raw()->debug(msg);
+}
+
+template <typename T>
+inline void info(const T &msg) {
+    default_logger_raw()->info(msg);
+}
+
+template <typename T>
+inline void warn(const T &msg) {
+    default_logger_raw()->warn(msg);
+}
+
+template <typename T>
+inline void error(const T &msg) {
+    default_logger_raw()->error(msg);
+}
+
+template <typename T>
+inline void critical(const T &msg) {
+    default_logger_raw()->critical(msg);
+}
+
+}  // namespace spdlog
+
+//
+// enable/disable log calls at compile time according to global level.
+//
+// define SPDLOG_ACTIVE_LEVEL to one of those (before including spdlog.h):
+// SPDLOG_LEVEL_TRACE,
+// SPDLOG_LEVEL_DEBUG,
+// SPDLOG_LEVEL_INFO,
+// SPDLOG_LEVEL_WARN,
+// SPDLOG_LEVEL_ERROR,
+// SPDLOG_LEVEL_CRITICAL,
+// SPDLOG_LEVEL_OFF
+//
+
+#ifndef SPDLOG_NO_SOURCE_LOC
+    #define SPDLOG_LOGGER_CALL(logger, level, ...) \
+        (logger)->log(spdlog::source_loc{__FILE__, __LINE__, SPDLOG_FUNCTION}, level, __VA_ARGS__)
+#else
+    #define SPDLOG_LOGGER_CALL(logger, level, ...) \
+        (logger)->log(spdlog::source_loc{}, level, __VA_ARGS__)
+#endif
+
+#if SPDLOG_ACTIVE_LEVEL <= SPDLOG_LEVEL_TRACE
+    #define SPDLOG_LOGGER_TRACE(logger, ...) \
+        SPDLOG_LOGGER_CALL(logger, spdlog::level::trace, __VA_ARGS__)
+    #define SPDLOG_TRACE(...) SPDLOG_LOGGER_TRACE(spdlog::default_logger_raw(), __VA_ARGS__)
+#else
+    #define SPDLOG_LOGGER_TRACE(logger, ...) (void)0
+    #define SPDLOG_TRACE(...) (void)0
+#endif
+
+#if SPDLOG_ACTIVE_LEVEL <= SPDLOG_LEVEL_DEBUG
+    #define SPDLOG_LOGGER_DEBUG(logger, ...) \
+        SPDLOG_LOGGER_CALL(logger, spdlog::level::debug, __VA_ARGS__)
+    #define SPDLOG_DEBUG(...) SPDLOG_LOGGER_DEBUG(spdlog::default_logger_raw(), __VA_ARGS__)
+#else
+    #define SPDLOG_LOGGER_DEBUG(logger, ...) (void)0
+    #define SPDLOG_DEBUG(...) (void)0
+#endif
+
+#if SPDLOG_ACTIVE_LEVEL <= SPDLOG_LEVEL_INFO
+    #define SPDLOG_LOGGER_INFO(logger, ...) \
+        SPDLOG_LOGGER_CALL(logger, spdlog::level::info, __VA_ARGS__)
+    #define SPDLOG_INFO(...) SPDLOG_LOGGER_INFO(spdlog::default_logger_raw(), __VA_ARGS__)
+#else
+    #define SPDLOG_LOGGER_INFO(logger, ...) (void)0
+    #define SPDLOG_INFO(...) (void)0
+#endif
+
+#if SPDLOG_ACTIVE_LEVEL <= SPDLOG_LEVEL_WARN
+    #define SPDLOG_LOGGER_WARN(logger, ...) \
+        SPDLOG_LOGGER_CALL(logger, spdlog::level::warn, __VA_ARGS__)
+    #define SPDLOG_WARN(...) SPDLOG_LOGGER_WARN(spdlog::default_logger_raw(), __VA_ARGS__)
+#else
+    #define SPDLOG_LOGGER_WARN(logger, ...) (void)0
+    #define SPDLOG_WARN(...) (void)0
+#endif
+
+#if SPDLOG_ACTIVE_LEVEL <= SPDLOG_LEVEL_ERROR
+    #define SPDLOG_LOGGER_ERROR(logger, ...) \
+        SPDLOG_LOGGER_CALL(logger, spdlog::level::err, __VA_ARGS__)
+    #define SPDLOG_ERROR(...) SPDLOG_LOGGER_ERROR(spdlog::default_logger_raw(), __VA_ARGS__)
+#else
+    #define SPDLOG_LOGGER_ERROR(logger, ...) (void)0
+    #define SPDLOG_ERROR(...) (void)0
+#endif
+
+#if SPDLOG_ACTIVE_LEVEL <= SPDLOG_LEVEL_CRITICAL
+    #define SPDLOG_LOGGER_CRITICAL(logger, ...) \
+        SPDLOG_LOGGER_CALL(logger, spdlog::level::critical, __VA_ARGS__)
+    #define SPDLOG_CRITICAL(...) SPDLOG_LOGGER_CRITICAL(spdlog::default_logger_raw(), __VA_ARGS__)
+#else
+    #define SPDLOG_LOGGER_CRITICAL(logger, ...) (void)0
+    #define SPDLOG_CRITICAL(...) (void)0
+#endif
+
+#ifdef SPDLOG_HEADER_ONLY
+    #include "spdlog-inl.h"
+#endif
+
+#endif  // SPDLOG_H

third_party/spdlog_headers/spdlog/tweakme.h

@@ -0,0 +1,141 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+///////////////////////////////////////////////////////////////////////////////
+//
+// Edit this file to squeeze more performance, and to customize supported
+// features
+//
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Under Linux, the much faster CLOCK_REALTIME_COARSE clock can be used.
+// This clock is less accurate - can be off by dozens of millis - depending on
+// the kernel HZ.
+// Uncomment to use it instead of the regular clock.
+//
+// #define SPDLOG_CLOCK_COARSE
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment if source location logging is not needed.
+// This will prevent spdlog from using __FILE__, __LINE__ and SPDLOG_FUNCTION
+//
+// #define SPDLOG_NO_SOURCE_LOC
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment if thread id logging is not needed (i.e. no %t in the log pattern).
+// This will prevent spdlog from querying the thread id on each log call.
+//
+// WARNING: If the log pattern contains thread id (i.e, %t) while this flag is
+// on, zero will be logged as thread id.
+//
+// #define SPDLOG_NO_THREAD_ID
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to prevent spdlog from using thread local storage.
+//
+// WARNING: if your program forks, UNCOMMENT this flag to prevent undefined
+// thread ids in the children logs.
+//
+// #define SPDLOG_NO_TLS
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to avoid spdlog's usage of atomic log levels
+// Use only if your code never modifies a logger's log levels concurrently by
+// different threads.
+//
+// #define SPDLOG_NO_ATOMIC_LEVELS
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to enable usage of wchar_t for file names on Windows.
+//
+// #define SPDLOG_WCHAR_FILENAMES
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to override default eol ("\n" or "\r\n" under Linux/Windows)
+//
+// #define SPDLOG_EOL ";-)\n"
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to override default folder separators ("/" or "\\/" under
+// Linux/Windows). Each character in the string is treated as a different
+// separator.
+//
+// #define SPDLOG_FOLDER_SEPS "\\"
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to use your own copy of the fmt library instead of spdlog's copy.
+// In this case spdlog will try to include <fmt/format.h> so set your -I flag
+// accordingly.
+//
+// #define SPDLOG_FMT_EXTERNAL
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to use C++20 std::format instead of fmt.
+//
+// #define SPDLOG_USE_STD_FORMAT
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to enable wchar_t support (convert to utf8)
+//
+// #define SPDLOG_WCHAR_TO_UTF8_SUPPORT
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to prevent child processes from inheriting log file descriptors
+//
+// #define SPDLOG_PREVENT_CHILD_FD
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to customize level names (e.g. "MY TRACE")
+//
+// #define SPDLOG_LEVEL_NAMES { "MY TRACE", "MY DEBUG", "MY INFO", "MY WARNING", "MY ERROR", "MY
+// CRITICAL", "OFF" }
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to customize short level names (e.g. "MT")
+// These can be longer than one character.
+//
+// #define SPDLOG_SHORT_LEVEL_NAMES { "T", "D", "I", "W", "E", "C", "O" }
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to disable default logger creation.
+// This might save some (very) small initialization time if no default logger is needed.
+//
+// #define SPDLOG_DISABLE_DEFAULT_LOGGER
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment and set to compile time level with zero cost (default is INFO).
+// Macros like SPDLOG_DEBUG(..), SPDLOG_INFO(..)  will expand to empty statements if not enabled
+//
+// #define SPDLOG_ACTIVE_LEVEL SPDLOG_LEVEL_INFO
+///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment (and change if desired) macro to use for function names.
+// This is compiler dependent.
+// __PRETTY_FUNCTION__ might be nicer in clang/gcc, and __FUNCTION__ in msvc.
+// Defaults to __FUNCTION__ (should work on all compilers) if not defined.
+//
+// #ifdef __PRETTY_FUNCTION__
+// # define SPDLOG_FUNCTION __PRETTY_FUNCTION__
+// #else
+// # define SPDLOG_FUNCTION __FUNCTION__
+// #endif
+///////////////////////////////////////////////////////////////////////////////

third_party/spdlog_headers/spdlog/version.h

@@ -0,0 +1,11 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#define SPDLOG_VER_MAJOR 1
+#define SPDLOG_VER_MINOR 13
+#define SPDLOG_VER_PATCH 0
+
+#define SPDLOG_TO_VERSION(major, minor, patch) (major * 10000 + minor * 100 + patch)
+#define SPDLOG_VERSION SPDLOG_TO_VERSION(SPDLOG_VER_MAJOR, SPDLOG_VER_MINOR, SPDLOG_VER_PATCH)