pattern per sink and pattern caching

include/spdlog/common.h

@@ -49,7 +49,7 @@
 #define SPDLOG_DEPRECATED
 #endif
 
-#include "fmt/fmt.h"
+#include "spdlog/fmt/fmt.h"
 
 namespace spdlog {
 

include/spdlog/details/async_logger_impl.h

@@ -71,7 +71,6 @@ inline void spdlog::async_logger::backend_log_(details::log_msg &incoming_log_ms
 {
     try
     {
-        formatter_->format(incoming_log_msg);
         for (auto &s : sinks_)
         {
             if (s->should_log(incoming_log_msg.level))

include/spdlog/details/file_helper.h

@@ -80,10 +80,10 @@ public:
         }
     }
 
-    void write(const log_msg &msg)
+    void write(const fmt::memory_buffer &buf)
     {
-        size_t msg_size = msg.formatted.size();
-        auto data = msg.formatted.data();
+        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);

include/spdlog/details/fmt_helper.h

@@ -14,6 +14,12 @@ inline void append_str(const std::string &str, fmt::memory_buffer &dest)
     dest.append(str_ptr, str_ptr + str.size());
 }
 
+inline void append_c_str(const char *c_str, fmt::memory_buffer &dest)
+{
+    auto str_size = strlen(c_str);
+    dest.append(c_str, c_str + str_size);
+}
+
 inline void append_buf(const fmt::memory_buffer &buf, fmt::memory_buffer &dest)
 {
     const char *buf_ptr = buf.data();
@@ -74,7 +80,7 @@ inline void append_and_pad3(int n, fmt::memory_buffer &dest)
     append_int(n, dest);
 }
 
-void append_and_pad6(int n, fmt::memory_buffer &dest)
+inline void append_and_pad6(int n, fmt::memory_buffer &dest)
 {
     if (n > 99999)
     {

include/spdlog/details/log_msg.h

@@ -38,11 +38,10 @@ struct log_msg
     log_clock::time_point time;
     size_t thread_id;
     fmt::memory_buffer raw;
-    fmt::memory_buffer formatted;
     size_t msg_id{0};
     // info about wrapping the formatted text with color
-    size_t color_range_start{0};
-    size_t color_range_end{0};
+    mutable size_t color_range_start{0};
+    mutable size_t color_range_end{0};
 };
 } // namespace details
 } // namespace spdlog

include/spdlog/details/logger_impl.h

@@ -14,7 +14,6 @@ template<class It>
 inline spdlog::logger::logger(std::string logger_name, const It &begin, const It &end)
     : name_(std::move(logger_name))
     , sinks_(begin, end)
-    , formatter_(std::make_shared<pattern_formatter>("%+"))
     , level_(level::info)
     , flush_level_(level::off)
     , last_err_time_(0)
@@ -37,14 +36,19 @@ inline spdlog::logger::logger(const std::string &logger_name, spdlog::sink_ptr s
 
 inline spdlog::logger::~logger() = default;
 
-inline void spdlog::logger::set_formatter(spdlog::formatter_ptr msg_formatter)
+template<class FormatterT, typename... Args>
+inline void spdlog::logger::set_formatter(const Args &... args)
 {
-    formatter_ = std::move(msg_formatter);
+    for (auto &sink : sinks_)
+    {
+        std::unique_ptr<FormatterT> formatter(new FormatterT(args...));
+        sink->set_formatter(std::move(formatter));
+    }
 }
 
 inline void spdlog::logger::set_pattern(const std::string &pattern, pattern_time_type pattern_time)
 {
-    formatter_ = std::make_shared<pattern_formatter>(pattern, pattern_time);
+    set_formatter<spdlog::pattern_formatter>(pattern, pattern_time);
 }
 
 template<typename... Args>
@@ -288,7 +292,6 @@ inline void spdlog::logger::sink_it_(details::log_msg &msg)
 #if defined(SPDLOG_ENABLE_MESSAGE_COUNTER)
     incr_msg_counter_(msg);
 #endif
-    formatter_->format(msg);
     for (auto &sink : sinks_)
     {
         if (sink->should_log(msg.level))

include/spdlog/details/pattern_formatter_impl.h

@@ -28,7 +28,7 @@ class flag_formatter
 {
 public:
     virtual ~flag_formatter() = default;
-    virtual void format(details::log_msg &msg, const std::tm &tm_time) = 0;
+    virtual void format(const details::log_msg &msg, const std::tm &tm_time, fmt::memory_buffer &dest) = 0;
 };
 
 ///////////////////////////////////////////////////////////////////////
@@ -36,27 +36,27 @@ public:
 ///////////////////////////////////////////////////////////////////////
 class name_formatter : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_str(*msg.logger_name, msg.formatted);
+        fmt_helper::append_str(*msg.logger_name, dest);
     }
 };
 
 // log level appender
 class level_formatter : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_str(level::to_str(msg.level), msg.formatted);
+        fmt_helper::append_c_str(level::to_str(msg.level), dest);
     }
 };
 
 // short log level appender
 class short_level_formatter : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_str(level::to_short_str(msg.level), msg.formatted);
+        fmt_helper::append_c_str(level::to_short_str(msg.level), dest);
     }
 };
 
@@ -78,9 +78,9 @@ static int to12h(const tm &t)
 static const std::string days[]{"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
 class a_formatter : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_str(days[tm_time.tm_wday], msg.formatted);
+        fmt_helper::append_str(days[tm_time.tm_wday], dest);
     }
 };
 
@@ -88,9 +88,9 @@ class a_formatter : public flag_formatter
 static const std::string full_days[]{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};
 class A_formatter : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_str(full_days[tm_time.tm_wday], msg.formatted);
+        fmt_helper::append_str(full_days[tm_time.tm_wday], dest);
     }
 };
 
@@ -98,9 +98,9 @@ class A_formatter : public flag_formatter
 static const std::string months[]{"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sept", "Oct", "Nov", "Dec"};
 class b_formatter : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_str(months[tm_time.tm_mon], msg.formatted);
+        fmt_helper::append_str(months[tm_time.tm_mon], dest);
     }
 };
 
@@ -109,205 +109,203 @@ static const std::string full_months[]{
     "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};
 class B_formatter : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_str(full_months[tm_time.tm_mon], msg.formatted);
+        fmt_helper::append_str(full_months[tm_time.tm_mon], dest);
     }
 };
 
 // Date and time representation (Thu Aug 23 15:35:46 2014)
 class c_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        fmt::format_to(msg.formatted, "{} {} {} ", days[tm_time.tm_wday], months[tm_time.tm_mon], tm_time.tm_mday); //
-        fmt_helper::append_and_pad2(tm_time.tm_hour, msg.formatted);
-        msg.formatted.push_back(':');
-        fmt_helper::append_and_pad2(tm_time.tm_min, msg.formatted);
-        msg.formatted.push_back(':');
-        fmt_helper::append_and_pad2(tm_time.tm_sec, msg.formatted);
-        msg.formatted.push_back(' ');
-        fmt_helper::append_int(tm_time.tm_year + 1900, msg.formatted);
+        fmt::format_to(dest, "{} {} {} ", days[tm_time.tm_wday], months[tm_time.tm_mon], tm_time.tm_mday); //
+        fmt_helper::append_and_pad2(tm_time.tm_hour, dest);
+        dest.push_back(':');
+        fmt_helper::append_and_pad2(tm_time.tm_min, dest);
+        dest.push_back(':');
+        fmt_helper::append_and_pad2(tm_time.tm_sec, dest);
+        dest.push_back(' ');
+        fmt_helper::append_int(tm_time.tm_year + 1900, dest);
     }
 };
 
 // year - 2 digit
 class C_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_and_pad2(tm_time.tm_year % 100, msg.formatted);
+        fmt_helper::append_and_pad2(tm_time.tm_year % 100, dest);
     }
 };
 
 // Short MM/DD/YY date, equivalent to %m/%d/%y 08/23/01
 class D_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_and_pad2(tm_time.tm_mon + 1, msg.formatted);
-        msg.formatted.push_back('/');
-        fmt_helper::append_and_pad2(tm_time.tm_mday, msg.formatted);
-        msg.formatted.push_back('/');
-        fmt_helper::append_and_pad2(tm_time.tm_year % 100, msg.formatted);
+        fmt_helper::append_and_pad2(tm_time.tm_mon + 1, dest);
+        dest.push_back('/');
+        fmt_helper::append_and_pad2(tm_time.tm_mday, dest);
+        dest.push_back('/');
+        fmt_helper::append_and_pad2(tm_time.tm_year % 100, dest);
     }
 };
 
 // year - 4 digit
 class Y_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_int(tm_time.tm_year + 1900, msg.formatted);
+        fmt_helper::append_int(tm_time.tm_year + 1900, dest);
     }
 };
 
 // month 1-12
 class m_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_and_pad2(tm_time.tm_mon + 1, msg.formatted);
+        fmt_helper::append_and_pad2(tm_time.tm_mon + 1, dest);
     }
 };
 
 // day of month 1-31
 class d_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        // fmt::format_to(msg.formatted, "{:02}", tm_time.tm_mday);
-        fmt_helper::append_and_pad2(tm_time.tm_mday, msg.formatted);
+        // fmt::format_to(dest, "{:02}", tm_time.tm_mday);
+        fmt_helper::append_and_pad2(tm_time.tm_mday, dest);
     }
 };
 
 // hours in 24 format 0-23
 class H_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_and_pad2(tm_time.tm_hour, msg.formatted);
+        fmt_helper::append_and_pad2(tm_time.tm_hour, dest);
     }
 };
 
 // hours in 12 format 1-12
 class I_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_and_pad2(to12h(tm_time), msg.formatted);
+        fmt_helper::append_and_pad2(to12h(tm_time), dest);
     }
 };
 
 // minutes 0-59
 class M_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_and_pad2(tm_time.tm_min, msg.formatted);
+        fmt_helper::append_and_pad2(tm_time.tm_min, dest);
     }
 };
 
 // seconds 0-59
 class S_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_and_pad2(tm_time.tm_sec, msg.formatted);
+        fmt_helper::append_and_pad2(tm_time.tm_sec, dest);
     }
 };
 
 // milliseconds
 class e_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
         auto duration = msg.time.time_since_epoch();
         auto millis = std::chrono::duration_cast<std::chrono::milliseconds>(duration).count() % 1000;
-        fmt_helper::append_and_pad3(static_cast<int>(millis), msg.formatted);
+        fmt_helper::append_and_pad3(static_cast<int>(millis), dest);
     }
 };
 
 // microseconds
 class f_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
         auto duration = msg.time.time_since_epoch();
         auto micros = std::chrono::duration_cast<std::chrono::microseconds>(duration).count() % 1000000;
-        fmt_helper::append_and_pad6(static_cast<int>(micros), msg.formatted);
+        fmt_helper::append_and_pad6(static_cast<int>(micros), dest);
     }
 };
 
 // nanoseconds
 class F_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
         auto duration = msg.time.time_since_epoch();
         auto ns = std::chrono::duration_cast<std::chrono::nanoseconds>(duration).count() % 1000000000;
-        fmt::format_to(msg.formatted, "{:09}", static_cast<int>(ns));
+        fmt::format_to(dest, "{:09}", static_cast<int>(ns));
     }
 };
 
 class E_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
         auto duration = msg.time.time_since_epoch();
         auto seconds = std::chrono::duration_cast<std::chrono::seconds>(duration).count();
-        // fmt::format_to(msg.formatted, "{}", seconds);
-        fmt_helper::append_int(seconds, msg.formatted);
+        fmt_helper::append_int(seconds, dest);
     }
 };
 
 // AM/PM
 class p_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        fmt::format_to(msg.formatted, "{}", ampm(tm_time));
+        fmt::format_to(dest, "{}", ampm(tm_time));
     }
 };
 
 // 12 hour clock 02:55:02 pm
 class r_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        // fmt::format_to(msg.formatted, "{:02}:{:02}:{:02} {}", to12h(tm_time), tm_time.tm_min, tm_time.tm_sec, ampm(tm_time));
-        fmt_helper::append_and_pad2(to12h(tm_time), msg.formatted);
-        msg.formatted.push_back(':');
-        fmt_helper::append_and_pad2(tm_time.tm_min, msg.formatted);
-        msg.formatted.push_back(':');
-        fmt_helper::append_and_pad2(tm_time.tm_sec, msg.formatted);
-        fmt::format_to(msg.formatted, " {}", ampm(tm_time));
+        // fmt::format_to(dest, "{:02}:{:02}:{:02} {}", to12h(tm_time), tm_time.tm_min, tm_time.tm_sec, ampm(tm_time));
+        fmt_helper::append_and_pad2(to12h(tm_time), dest);
+        dest.push_back(':');
+        fmt_helper::append_and_pad2(tm_time.tm_min, dest);
+        dest.push_back(':');
+        fmt_helper::append_and_pad2(tm_time.tm_sec, dest);
+        fmt::format_to(dest, " {}", ampm(tm_time));
     }
 };
 
 // 24-hour HH:MM time, equivalent to %H:%M
 class R_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        // fmt::format_to(msg.formatted, "{:02}:{:02}", tm_time.tm_hour, tm_time.tm_min);
-        fmt_helper::append_and_pad2(tm_time.tm_hour, msg.formatted);
-        msg.formatted.push_back(':');
-        fmt_helper::append_and_pad2(tm_time.tm_min, msg.formatted);
+        fmt_helper::append_and_pad2(tm_time.tm_hour, dest);
+        dest.push_back(':');
+        fmt_helper::append_and_pad2(tm_time.tm_min, dest);
     }
 };
 
 // ISO 8601 time format (HH:MM:SS), equivalent to %H:%M:%S
 class T_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
-        // fmt::format_to(msg.formatted, "{:02}:{:02}:{:02}", tm_time.tm_hour, tm_time.tm_min, tm_time.tm_sec);
-        fmt_helper::append_and_pad2(tm_time.tm_hour, msg.formatted);
-        msg.formatted.push_back(':');
-        fmt_helper::append_and_pad2(tm_time.tm_min, msg.formatted);
-        msg.formatted.push_back(':');
-        fmt_helper::append_and_pad2(tm_time.tm_sec, msg.formatted);
+        // fmt::format_to(dest, "{:02}:{:02}:{:02}", tm_time.tm_hour, tm_time.tm_min, tm_time.tm_sec);
+        fmt_helper::append_and_pad2(tm_time.tm_hour, dest);
+        dest.push_back(':');
+        fmt_helper::append_and_pad2(tm_time.tm_min, dest);
+        dest.push_back(':');
+        fmt_helper::append_and_pad2(tm_time.tm_sec, dest);
     }
 };
 
@@ -321,13 +319,14 @@ public:
     z_formatter(const z_formatter &) = delete;
     z_formatter &operator=(const z_formatter &) = delete;
 
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &msg, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
 #ifdef _WIN32
         int total_minutes = get_cached_offset(msg, tm_time);
 #else
         // No need to chache under gcc,
         // it is very fast (already stored in tm.tm_gmtoff)
+        (void)(msg);
         int total_minutes = os::utc_minutes_offset(tm_time);
 #endif
         bool is_negative = total_minutes < 0;
@@ -344,21 +343,19 @@ public:
 
         int h = total_minutes / 60;
         int m = total_minutes % 60;
-        // fmt::format_to(msg.formatted, "{}{:02}:{:02}", sign, h, m);
-        msg.formatted.push_back(sign);
-        fmt_helper::append_and_pad2(h, msg.formatted);
-        msg.formatted.push_back(':');
-        fmt_helper::append_and_pad2(m, msg.formatted);
+        dest.push_back(sign);
+        fmt_helper::append_and_pad2(h, dest);
+        dest.push_back(':');
+        fmt_helper::append_and_pad2(m, dest);
     }
 
 private:
     log_clock::time_point last_update_{std::chrono::seconds(0)};
+#ifdef _WIN32
     int offset_minutes_{0};
-    std::mutex mutex_;
 
     int get_cached_offset(const log_msg &msg, const std::tm &tm_time)
     {
-        std::lock_guard<std::mutex> l(mutex_);
         if (msg.time - last_update_ >= cache_refresh)
         {
             offset_minutes_ = os::utc_minutes_offset(tm_time);
@@ -366,42 +363,42 @@ private:
         }
         return offset_minutes_;
     }
+#endif
 };
 
 // Thread id
 class t_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
-        // fmt::format_to(msg.formatted, "{}", msg.thread_id);
-        fmt_helper::append_size_t(msg.thread_id, msg.formatted);
+        // fmt::format_to(dest, "{}", msg.thread_id);
+        fmt_helper::append_size_t(msg.thread_id, dest);
     }
 };
 
 // Current pid
 class pid_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &, const std::tm &, fmt::memory_buffer &dest) override
     {
-        // fmt::format_to(msg.formatted, "{}", details::os::pid());
-        fmt_helper::append_int(details::os::pid(), msg.formatted);
+        fmt_helper::append_int(details::os::pid(), dest);
     }
 };
 
 // message counter formatter
 class i_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
-        fmt::format_to(msg.formatted, "{:06}", msg.msg_id);
+        fmt::format_to(dest, "{:06}", msg.msg_id);
     }
 };
 
 class v_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_buf(msg.raw, msg.formatted);
+        fmt_helper::append_buf(msg.raw, dest);
     }
 };
 
@@ -412,9 +409,9 @@ public:
         : ch_(ch)
     {
     }
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &, const std::tm &, fmt::memory_buffer &dest) override
     {
-        msg.formatted.push_back(ch_);
+        dest.push_back(ch_);
     }
 
 private:
@@ -431,9 +428,9 @@ public:
     {
         str_ += ch;
     }
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &, const std::tm &, fmt::memory_buffer &dest) override
     {
-        fmt_helper::append_str(str_, msg.formatted);
+        fmt_helper::append_str(str_, dest);
     }
 
 private:
@@ -443,16 +440,16 @@ private:
 // mark the color range. expect it to be in the form of "%^colored text%$"
 class color_start_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
-        msg.color_range_start = msg.formatted.size();
+        msg.color_range_start = dest.size();
     }
 };
 class color_stop_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &) override
+    void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
-        msg.color_range_end = msg.formatted.size();
+        msg.color_range_end = dest.size();
     }
 };
 
@@ -460,54 +457,80 @@ class color_stop_formatter SPDLOG_FINAL : public flag_formatter
 // pattern: [%Y-%m-%d %H:%M:%S.%e] [%n] [%l] %v
 class full_formatter SPDLOG_FINAL : public flag_formatter
 {
-    void format(details::log_msg &msg, const std::tm &tm_time) override
+    void format(const details::log_msg &msg, const std::tm &tm_time, fmt::memory_buffer &dest) override
     {
 #ifndef SPDLOG_NO_DATETIME
         auto duration = msg.time.time_since_epoch();
-        auto millis = std::chrono::duration_cast<std::chrono::milliseconds>(duration).count() % 1000;
 
-        msg.formatted.push_back('[');
-        fmt_helper::append_int(tm_time.tm_year + 1900, msg.formatted);
-        msg.formatted.push_back('-');
+        // each second cache the header
+        auto seconds = std::chrono::duration_cast<std::chrono::seconds>(duration).count();
+        if (cached_header_.size() == 0 || cached_seconds_ts_ != seconds)
+        {
+
+            cached_header_ = std::move(fmt::memory_buffer());
+            cached_header_.push_back('[');
+            fmt_helper::append_int(tm_time.tm_year + 1900, cached_header_);
+            cached_header_.push_back('-');
 
-        fmt_helper::append_and_pad2(tm_time.tm_mon + 1, msg.formatted);
-        msg.formatted.push_back('-');
+            fmt_helper::append_and_pad2(tm_time.tm_mon + 1, cached_header_);
+            cached_header_.push_back('-');
 
-        fmt_helper::append_and_pad2(tm_time.tm_mday, msg.formatted);
-        msg.formatted.push_back(' ');
+            fmt_helper::append_and_pad2(tm_time.tm_mday, cached_header_);
+            cached_header_.push_back(' ');
 
-        fmt_helper::append_and_pad2(tm_time.tm_hour, msg.formatted);
-        msg.formatted.push_back(':');
+            fmt_helper::append_and_pad2(tm_time.tm_hour, cached_header_);
+            cached_header_.push_back(':');
 
-        fmt_helper::append_and_pad2(tm_time.tm_min, msg.formatted);
-        msg.formatted.push_back(':');
+            fmt_helper::append_and_pad2(tm_time.tm_min, cached_header_);
+            cached_header_.push_back(':');
 
-        fmt_helper::append_and_pad2(tm_time.tm_sec, msg.formatted);
-        msg.formatted.push_back('.');
+            fmt_helper::append_and_pad2(tm_time.tm_sec, cached_header_);
+            cached_header_.push_back('.');
 
-        fmt_helper::append_and_pad3(static_cast<int>(millis), msg.formatted);
-        msg.formatted.push_back(']');
-        msg.formatted.push_back(' ');
+            cached_seconds_ts_ = seconds;
+        }
+        fmt_helper::append_buf(cached_header_, dest);
 
-        // no datetime needed
-#else
+        //
+        auto millis = std::chrono::duration_cast<std::chrono::milliseconds>(duration).count() % 1000;
+
+        if (cached_millis_.size() == 0 || millis != cached_millis_ts_)
+        {
+            cached_millis_ = std::move(fmt::memory_buffer());
+            fmt_helper::append_and_pad3(static_cast<int>(millis), cached_millis_);
+            cached_millis_.push_back(']');
+            cached_millis_.push_back(' ');
+            cached_millis_ts_ = millis;
+        }
+        fmt_helper::append_buf(cached_millis_, dest);
+
+#else // no datetime needed
         (void)tm_time;
 #endif
 
 #ifndef SPDLOG_NO_NAME
-        fmt_helper::append_str(*msg.logger_name, msg.formatted);
+        dest.push_back('[');
+        fmt_helper::append_str(*msg.logger_name, dest);
+        dest.push_back(']');
+        dest.push_back(' ');
 #endif
 
-        msg.formatted.push_back('[');
+        dest.push_back('[');
 
         // wrap the level name with color
-        msg.color_range_start = msg.formatted.size();
-        fmt_helper::append_str(level::to_str(msg.level), msg.formatted);
-        msg.color_range_end = msg.formatted.size();
-        msg.formatted.push_back(']');
-        msg.formatted.push_back(' ');
-        fmt_helper::append_buf(msg.raw, msg.formatted);
+        msg.color_range_start = dest.size();
+        fmt_helper::append_c_str(level::to_str(msg.level), dest);
+        msg.color_range_end = dest.size();
+        dest.push_back(']');
+        dest.push_back(' ');
+        fmt_helper::append_buf(msg.raw, dest);
     }
+
+private:
+    long cached_seconds_ts_{0};
+    long cached_millis_ts_{0};
+    fmt::memory_buffer cached_header_;
+    fmt::memory_buffer cached_millis_;
 };
 
 } // namespace details
@@ -704,7 +727,7 @@ inline void spdlog::pattern_formatter::handle_flag(char flag)
     }
 }
 
-inline std::tm spdlog::pattern_formatter::get_time(details::log_msg &msg)
+inline std::tm spdlog::pattern_formatter::get_time(const details::log_msg &msg)
 {
     if (pattern_time_ == pattern_time_type::local)
     {
@@ -713,7 +736,7 @@ inline std::tm spdlog::pattern_formatter::get_time(details::log_msg &msg)
     return details::os::gmtime(log_clock::to_time_t(msg.time));
 }
 
-inline void spdlog::pattern_formatter::format(details::log_msg &msg)
+inline void spdlog::pattern_formatter::format(const details::log_msg &msg, fmt::memory_buffer &dest)
 {
 
 #ifndef SPDLOG_NO_DATETIME
@@ -723,8 +746,8 @@ inline void spdlog::pattern_formatter::format(details::log_msg &msg)
 #endif
     for (auto &f : formatters_)
     {
-        f->format(msg, tm_time);
+        f->format(msg, tm_time, dest);
     }
     // write eol
-    details::fmt_helper::append_str(eol_, msg.formatted);
+    details::fmt_helper::append_str(eol_, dest);
 }

include/spdlog/details/registry.h

@@ -46,10 +46,9 @@ public:
         auto logger_name = new_logger->name();
         throw_if_exists(logger_name);
 
-        if (formatter_)
-        {
-            new_logger->set_formatter(formatter_);
-        }
+        // create default formatter if not exists
+
+        new_logger->set_pattern(formatter_pattern_);
 
         if (err_handler_)
         {
@@ -82,23 +81,13 @@ public:
         return tp_;
     }
 
-    void set_formatter(formatter_ptr f)
-    {
-        std::lock_guard<Mutex> lock(mutex_);
-        formatter_ = f;
-        for (auto &l : loggers_)
-        {
-            l.second->set_formatter(formatter_);
-        }
-    }
-
     void set_pattern(const std::string &pattern)
     {
         std::lock_guard<Mutex> lock(mutex_);
-        formatter_ = std::make_shared<pattern_formatter>(pattern);
+        formatter_pattern_ = pattern;
         for (auto &l : loggers_)
         {
-            l.second->set_formatter(formatter_);
+            l.second->set_pattern(pattern);
         }
     }
 
@@ -184,7 +173,7 @@ private:
     Mutex mutex_;
     Mutex tp_mutex_;
     std::unordered_map<std::string, std::shared_ptr<logger>> loggers_;
-    formatter_ptr formatter_;
+    std::string formatter_pattern_ = "%+";
     level::level_enum level_ = level::info;
     level::level_enum flush_level_ = level::off;
     log_err_handler err_handler_;

include/spdlog/formatter.h

@@ -5,6 +5,7 @@
 
 #pragma once
 
+#include "fmt/fmt.h"
 #include "spdlog/details/log_msg.h"
 
 #include <memory>
@@ -12,31 +13,32 @@
 #include <vector>
 
 namespace spdlog {
-namespace details {
-class flag_formatter;
-}
 
 class formatter
 {
 public:
     virtual ~formatter() = default;
-    virtual void format(details::log_msg &msg) = 0;
+    virtual void format(const details::log_msg &msg, fmt::memory_buffer &dest) = 0;
 };
 
+namespace details {
+class flag_formatter;
+}
+
 class pattern_formatter SPDLOG_FINAL : public formatter
 {
 public:
     explicit pattern_formatter(const std::string &pattern, pattern_time_type pattern_time = pattern_time_type::local,
         std::string eol = spdlog::details::os::default_eol);
-    pattern_formatter(const pattern_formatter &) = delete;
-    pattern_formatter &operator=(const pattern_formatter &) = delete;
-    void format(details::log_msg &msg) override;
+    pattern_formatter(const pattern_formatter &) = default;
+    pattern_formatter &operator=(const pattern_formatter &) = default;
+    void format(const details::log_msg &msg, fmt::memory_buffer &dest) override;
 
 private:
     const std::string eol_;
     const pattern_time_type pattern_time_;
     std::vector<std::unique_ptr<details::flag_formatter>> formatters_;
-    std::tm get_time(details::log_msg &msg);
+    std::tm get_time(const details::log_msg &msg);
     void handle_flag(char flag);
     void compile_pattern(const std::string &pattern);
 };

include/spdlog/logger.h

@@ -8,9 +8,12 @@
 // Thread safe logger (except for set_pattern(..), set_formatter(..) and 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
-// 2. Format the message using the formatter function
-// 3. Pass the formatted message to its sinks to performa the actual logging
+// 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 customize format per each sink.
 
 #include "spdlog/common.h"
 #include "spdlog/formatter.h"
@@ -111,8 +114,15 @@ public:
     void set_level(level::level_enum log_level);
     level::level_enum level() const;
     const std::string &name() const;
+
+    // create a pattern formatter all the sinks in this logger.
+    // each sink gets itw own private copy of a formatter object.
     void set_pattern(const std::string &pattern, pattern_time_type pattern_time = pattern_time_type::local);
-    void set_formatter(formatter_ptr msg_formatter);
+
+    // create a FormatterT formatter all the sinks in this logger.
+    // each sink gets itw own private copy of a formatter object.
+    template<class FormatterT, typename... Args>
+    void set_formatter(const Args &... args);
 
     void flush();
     void flush_on(level::level_enum log_level);
@@ -137,7 +147,6 @@ protected:
 
     const std::string name_;
     std::vector<sink_ptr> sinks_;
-    formatter_ptr formatter_;
     spdlog::level_t level_;
     spdlog::level_t flush_level_;
     log_err_handler err_handler_;

include/spdlog/sinks/android_sink.h

@@ -39,7 +39,17 @@ public:
     void log(const details::log_msg &msg) override
     {
         const android_LogPriority priority = convert_to_android(msg.level);
-        const char *msg_output = (use_raw_msg_ ? msg.raw.c_str() : msg.formatted.c_str());
+        fmt::memory_buffer formatted;
+        if (use_raw_msg_)
+        {
+            formatted.append(msg.raw.data(), msg.raw.data() + msg.raw.size());
+        }
+        else
+        {
+            formatter_->format(msg, formatted);
+        }
+        formatted.push_back('\0');
+        const char *msg_output = formatted.data();
 
         // See system/core/liblog/logger_write.c for explanation of return value
         int ret = __android_log_write(priority, tag_.c_str(), msg_output);

include/spdlog/sinks/ansicolor_sink.h

@@ -88,20 +88,23 @@ public:
         // 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_);
+
+        fmt::memory_buffer formatted;
+        formatter_->format(msg, formatted);
         if (should_do_colors_ && msg.color_range_end > msg.color_range_start)
         {
             // before color range
-            print_range_(msg, 0, msg.color_range_start);
+            print_range_(formatted, 0, msg.color_range_start);
             // in color range
             print_ccode_(colors_[msg.level]);
-            print_range_(msg, msg.color_range_start, msg.color_range_end);
+            print_range_(formatted, msg.color_range_start, msg.color_range_end);
             print_ccode_(reset);
             // after color range
-            print_range_(msg, msg.color_range_end, msg.formatted.size());
+            print_range_(formatted, msg.color_range_end, formatted.size());
         }
         else // no color
         {
-            print_range_(msg, 0, msg.formatted.size());
+            print_range_(formatted, 0, formatted.size());
         }
         fflush(target_file_);
     }
@@ -117,9 +120,9 @@ private:
     {
         fwrite(color_code.data(), sizeof(char), color_code.size(), target_file_);
     }
-    void print_range_(const details::log_msg &msg, size_t start, size_t end)
+    void print_range_(const fmt::memory_buffer &formatted, size_t start, size_t end)
     {
-        fwrite(msg.formatted.data() + start, sizeof(char), end - start, target_file_);
+        fwrite(formatted.data() + start, sizeof(char), end - start, target_file_);
     }
 
     FILE *target_file_;

include/spdlog/sinks/base_sink.h

@@ -21,7 +21,20 @@ template<class Mutex>
 class base_sink : public sink
 {
 public:
-    base_sink() = default;
+    base_sink()
+        : sink()
+    {
+    }
+
+    base_sink(const std::string &formatter_pattern)
+        : sink(formatter_pattern)
+    {
+    }
+
+    base_sink(std::unique_ptr<spdlog::formatter> sink_formatter)
+        : sink(std::move(sink_formatter))
+    {
+    }
 
     base_sink(const base_sink &) = delete;
     base_sink &operator=(const base_sink &) = delete;
@@ -29,7 +42,9 @@ public:
     void log(const details::log_msg &msg) SPDLOG_FINAL override
     {
         std::lock_guard<Mutex> lock(mutex_);
-        sink_it_(msg);
+        fmt::memory_buffer formatted;
+        formatter_->format(msg, formatted);
+        sink_it_(msg, formatted);
     }
 
     void flush() SPDLOG_FINAL override
@@ -39,7 +54,7 @@ public:
     }
 
 protected:
-    virtual void sink_it_(const details::log_msg &msg) = 0;
+    virtual void sink_it_(const details::log_msg &msg, const fmt::memory_buffer &formatted) = 0;
     virtual void flush_() = 0;
     Mutex mutex_;
 };

include/spdlog/sinks/daily_file_sink.h

@@ -76,14 +76,14 @@ public:
     }
 
 protected:
-    void sink_it_(const details::log_msg &msg) override
+    void sink_it_(const details::log_msg &, const fmt::memory_buffer &formatted) override
     {
         if (std::chrono::system_clock::now() >= rotation_tp_)
         {
             file_helper_.open(FileNameCalc::calc_filename(base_filename_));
             rotation_tp_ = next_rotation_tp_();
         }
-        file_helper_.write(msg);
+        file_helper_.write(formatted);
     }
 
     void flush_() override

include/spdlog/sinks/null_sink.h

@@ -17,12 +17,12 @@ template<class Mutex>
 class null_sink : public base_sink<Mutex>
 {
 protected:
-    void sink_it_(const details::log_msg &) override {}
+    void sink_it_(const details::log_msg &, const fmt::memory_buffer &) override {}
 
     void flush_() override {}
 };
 
-using null_sink_mt = null_sink<details::null_mutex>;
+using null_sink_mt = null_sink<std::mutex>;
 using null_sink_st = null_sink<details::null_mutex>;
 
 } // namespace sinks

include/spdlog/sinks/ostream_sink.h

@@ -26,9 +26,9 @@ public:
     ostream_sink &operator=(const ostream_sink &) = delete;
 
 protected:
-    void sink_it_(const details::log_msg &msg) override
+    void sink_it_(const details::log_msg &msg, const fmt::memory_buffer &formatted) override
     {
-        ostream_.write(msg.formatted.data(), msg.formatted.size());
+        ostream_.write(formatted.data(), formatted.size());
         if (force_flush_)
             ostream_.flush();
     }

include/spdlog/sinks/rotating_file_sink.h

@@ -55,15 +55,15 @@ public:
     }
 
 protected:
-    void sink_it_(const details::log_msg &msg) override
+    void sink_it_(const details::log_msg &, const fmt::memory_buffer &formatted) override
     {
-        current_size_ += msg.formatted.size();
+        current_size_ += formatted.size();
         if (current_size_ > max_size_)
         {
             rotate_();
-            current_size_ = msg.formatted.size();
+            current_size_ = formatted.size();
         }
-        file_helper_.write(msg);
+        file_helper_.write(formatted);
     }
 
     void flush_() override

include/spdlog/sinks/simple_file_sink.h

@@ -33,9 +33,9 @@ public:
     }
 
 protected:
-    void sink_it_(const details::log_msg &msg) override
+    void sink_it_(const details::log_msg &, const fmt::memory_buffer &formatted) override
     {
-        file_helper_.write(msg);
+        file_helper_.write(formatted);
         if (force_flush_)
         {
             file_helper_.flush();

include/spdlog/sinks/sink.h

@@ -6,39 +6,62 @@
 #pragma once
 
 #include "spdlog/details/log_msg.h"
+#include "spdlog/formatter.h"
 
 namespace spdlog {
 namespace sinks {
 class sink
 {
 public:
+    // default sink ctor with default pattern formatter
+    sink()
+        : formatter_(std::unique_ptr<spdlog::formatter>(new pattern_formatter("%+")))
+    {
+    }
+
+    explicit sink(const std::string &formatter_pattern)
+        : formatter_(std::unique_ptr<spdlog::formatter>(new pattern_formatter(formatter_pattern)))
+    {
+    }
+
+    // sink with custom formatter
+    explicit sink(std::unique_ptr<spdlog::formatter> sink_formatter)
+        : formatter_(std::move(sink_formatter))
+    {
+    }
+
     virtual ~sink() = default;
 
     virtual void log(const details::log_msg &msg) = 0;
     virtual void flush() = 0;
 
-    bool should_log(level::level_enum msg_level) const;
-    void set_level(level::level_enum log_level);
-    level::level_enum level() const;
+    bool should_log(level::level_enum msg_level) const
+    {
+        return msg_level >= level_.load(std::memory_order_relaxed);
+    }
+    void set_level(level::level_enum log_level)
+    {
+        level_.store(log_level);
+    }
+    level::level_enum level() const
+    {
+        return static_cast<spdlog::level::level_enum>(level_.load(std::memory_order_relaxed));
+    }
 
-private:
-    level_t level_{level::trace};
-};
+    void set_formatter(std::unique_ptr<spdlog::formatter> sink_formatter)
+    {
+        formatter_ = std::move(sink_formatter);
+    }
 
-inline bool sink::should_log(level::level_enum msg_level) const
-{
-    return msg_level >= level_.load(std::memory_order_relaxed);
-}
+    spdlog::formatter *formatter()
+    {
+        return formatter_.get();
+    }
 
-inline void sink::set_level(level::level_enum log_level)
-{
-    level_.store(log_level);
-}
-
-inline level::level_enum sink::level() const
-{
-    return static_cast<spdlog::level::level_enum>(level_.load(std::memory_order_relaxed));
-}
+protected:
+    level_t level_{level::trace};
+    std::unique_ptr<spdlog::formatter> formatter_;
+};
 
 } // namespace sinks
 } // namespace spdlog

include/spdlog/sinks/wincolor_sink.h

@@ -5,6 +5,7 @@
 
 #pragma once
 
+#include "../fmt/fmt.h"
 #include "spdlog/common.h"
 #include "spdlog/details/null_mutex.h"
 #include "spdlog/details/traits.h"
@@ -63,22 +64,23 @@ public:
     void log(const details::log_msg &msg) SPDLOG_FINAL override
     {
         std::lock_guard<mutex_t> lock(mutex_);
-
+        fmt::memory_buffer formatted;
+        formatter_->format(msg, formatted);
         if (msg.color_range_end > msg.color_range_start)
         {
             // before color range
-            print_range_(msg, 0, msg.color_range_start);
+            print_range_(formatted, 0, msg.color_range_start);
 
             // in color range
             auto orig_attribs = set_console_attribs(colors_[msg.level]);
-            print_range_(msg, msg.color_range_start, msg.color_range_end);
+            print_range_(formatted, msg.color_range_start, msg.color_range_end);
             ::SetConsoleTextAttribute(out_handle_, orig_attribs); // reset to orig colors
                                                                   // after color range
-            print_range_(msg, msg.color_range_end, msg.formatted.size());
+            print_range_(formatted, msg.color_range_end, formatted.size());
         }
         else // print without colors if color range is invalid
         {
-            print_range_(msg, 0, msg.formatted.size());
+            print_range_(formatted, 0, formatted.size());
         }
     }
 
@@ -103,10 +105,10 @@ private:
     }
 
     // print a range of formatted message to console
-    void print_range_(const details::log_msg &msg, size_t start, size_t end)
+    void print_range_(const fmt::memory_buffer formatted, size_t start, size_t end)
     {
         auto size = static_cast<DWORD>(end - start);
-        ::WriteConsoleA(out_handle_, msg.formatted.data() + start, size, nullptr, nullptr);
+        ::WriteConsoleA(out_handle_, formatted.data() + start, size, nullptr, nullptr);
     }
 
     HANDLE out_handle_;

include/spdlog/spdlog.h

@@ -62,11 +62,6 @@ inline void set_pattern(const std::string &format_string)
     details::registry::instance().set_pattern(format_string);
 }
 
-inline void set_formatter(formatter_ptr f)
-{
-    details::registry::instance().set_formatter(std::move(f));
-}
-
 //
 // Set global logging level
 //

tests/file_helper.cpp

@@ -11,9 +11,9 @@ static const std::string target_filename = "logs/file_helper_test.txt";
 static void write_with_helper(file_helper &helper, size_t howmany)
 {
     log_msg msg;
-
-    fmt::format_to(msg.formatted, "{}", std::string(howmany, '1'));
-    helper.write(msg);
+    fmt::memory_buffer formatted;
+    fmt::format_to(formatted, "{}", std::string(howmany, '1'));
+    helper.write(formatted);
     helper.flush();
 }
 

tests/test_pattern_formatter.cpp

 #include "includes.h"
 
 // log to str and return it
-static std::string log_to_str(const std::string &msg, const std::shared_ptr<spdlog::formatter> &formatter = nullptr)
+template<typename... Args>
+
+static std::string log_to_str(const std::string &msg, const Args &... args)
 {
     std::ostringstream oss;
     auto oss_sink = std::make_shared<spdlog::sinks::ostream_sink_mt>(oss);
     spdlog::logger oss_logger("pattern_tester", oss_sink);
     oss_logger.set_level(spdlog::level::info);
-    if (formatter)
-    {
-        oss_logger.set_formatter(formatter);
-    }
+    oss_logger.set_formatter<spdlog::pattern_formatter>(args...);
+
     oss_logger.info(msg);
     return oss.str();
 }
@@ -19,49 +19,44 @@ TEST_CASE("custom eol", "[pattern_formatter]")
 {
     std::string msg = "Hello custom eol test";
     std::string eol = ";)";
-    auto formatter = std::make_shared<spdlog::pattern_formatter>("%v", spdlog::pattern_time_type::local, ";)");
+    // auto formatter = std::make_shared<spdlog::pattern_formatter>("%v", spdlog::pattern_time_type::local, ";)");
+    std::unique_ptr<spdlog::formatter>(new spdlog::pattern_formatter("%v", spdlog::pattern_time_type::local, ";)"));
 
-    REQUIRE(log_to_str(msg, formatter) == msg + eol);
+    REQUIRE(log_to_str(msg, "%v", spdlog::pattern_time_type::local, ";)") == msg + eol);
 }
 
 TEST_CASE("empty format", "[pattern_formatter]")
 {
-    auto formatter = std::make_shared<spdlog::pattern_formatter>("", spdlog::pattern_time_type::local, "");
-    REQUIRE(log_to_str("Some message", formatter) == "");
+    REQUIRE(log_to_str("Some message", "", spdlog::pattern_time_type::local, "") == "");
 }
 
 TEST_CASE("empty format2", "[pattern_formatter]")
 {
-    auto formatter = std::make_shared<spdlog::pattern_formatter>("", spdlog::pattern_time_type::local, "\n");
-    REQUIRE(log_to_str("Some message", formatter) == "\n");
+    REQUIRE(log_to_str("Some message", "", spdlog::pattern_time_type::local, "\n") == "\n");
 }
 
 TEST_CASE("level", "[pattern_formatter]")
 {
-    auto formatter = std::make_shared<spdlog::pattern_formatter>("[%l] %v", spdlog::pattern_time_type::local, "\n");
-    REQUIRE(log_to_str("Some message", formatter) == "[info] Some message\n");
+    REQUIRE(log_to_str("Some message", "[%l] %v", spdlog::pattern_time_type::local, "\n") == "[info] Some message\n");
 }
 
 TEST_CASE("short level", "[pattern_formatter]")
 {
-    auto formatter = std::make_shared<spdlog::pattern_formatter>("[%L] %v", spdlog::pattern_time_type::local, "\n");
-    REQUIRE(log_to_str("Some message", formatter) == "[I] Some message\n");
+    REQUIRE(log_to_str("Some message", "[%L] %v", spdlog::pattern_time_type::local, "\n") == "[I] Some message\n");
 }
 
 TEST_CASE("name", "[pattern_formatter]")
 {
-    auto formatter = std::make_shared<spdlog::pattern_formatter>("[%n] %v", spdlog::pattern_time_type::local, "\n");
-    REQUIRE(log_to_str("Some message", formatter) == "[pattern_tester] Some message\n");
+    REQUIRE(log_to_str("Some message", "[%n] %v", spdlog::pattern_time_type::local, "\n") == "[pattern_tester] Some message\n");
 }
 
 TEST_CASE("date MM/DD/YY ", "[pattern_formatter]")
 {
-    auto formatter = std::make_shared<spdlog::pattern_formatter>("%D %v", spdlog::pattern_time_type::local, "\n");
     auto now_tm = spdlog::details::os::localtime();
     std::stringstream oss;
     oss << std::setfill('0') << std::setw(2) << now_tm.tm_mon + 1 << "/" << std::setw(2) << now_tm.tm_mday << "/" << std::setw(2)
         << (now_tm.tm_year + 1900) % 1000 << " Some message\n";
-    REQUIRE(log_to_str("Some message", formatter) == oss.str());
+    REQUIRE(log_to_str("Some message", "%D %v", spdlog::pattern_time_type::local, "\n") == oss.str());
 }
 
 TEST_CASE("color range test1", "[pattern_formatter]")
@@ -69,27 +64,30 @@ TEST_CASE("color range test1", "[pattern_formatter]")
     auto formatter = std::make_shared<spdlog::pattern_formatter>("%^%v%$", spdlog::pattern_time_type::local, "\n");
     spdlog::details::log_msg msg;
     fmt::format_to(msg.raw, "Hello");
-    formatter->format(msg);
+    fmt::memory_buffer formatted;
+    formatter->format(msg, formatted);
     REQUIRE(msg.color_range_start == 0);
     REQUIRE(msg.color_range_end == 5);
-    REQUIRE(log_to_str("hello", formatter) == "hello\n");
+    REQUIRE(log_to_str("hello", "%^%v%$", spdlog::pattern_time_type::local, "\n") == "hello\n");
 }
 
 TEST_CASE("color range test2", "[pattern_formatter]")
 {
     auto formatter = std::make_shared<spdlog::pattern_formatter>("%^%$", spdlog::pattern_time_type::local, "\n");
     spdlog::details::log_msg msg;
-    formatter->format(msg);
+    fmt::memory_buffer formatted;
+    formatter->format(msg, formatted);
     REQUIRE(msg.color_range_start == 0);
     REQUIRE(msg.color_range_end == 0);
-    REQUIRE(log_to_str("", formatter) == "\n");
+    REQUIRE(log_to_str("", "%^%$", spdlog::pattern_time_type::local, "\n") == "\n");
 }
 
 TEST_CASE("color range test3", "[pattern_formatter]")
 {
     auto formatter = std::make_shared<spdlog::pattern_formatter>("%^***%$");
     spdlog::details::log_msg msg;
-    formatter->format(msg);
+    fmt::memory_buffer formatted;
+    formatter->format(msg, formatted);
     REQUIRE(msg.color_range_start == 0);
     REQUIRE(msg.color_range_end == 3);
 }
@@ -99,17 +97,19 @@ TEST_CASE("color range test4", "[pattern_formatter]")
     auto formatter = std::make_shared<spdlog::pattern_formatter>("XX%^YYY%$", spdlog::pattern_time_type::local, "\n");
     spdlog::details::log_msg msg;
     fmt::format_to(msg.raw, "ignored");
-    formatter->format(msg);
+    fmt::memory_buffer formatted;
+    formatter->format(msg, formatted);
     REQUIRE(msg.color_range_start == 2);
     REQUIRE(msg.color_range_end == 5);
-    REQUIRE(log_to_str("ignored", formatter) == "XXYYY\n");
+    REQUIRE(log_to_str("ignored", "XX%^YYY%$", spdlog::pattern_time_type::local, "\n") == "XXYYY\n");
 }
 
 TEST_CASE("color range test5", "[pattern_formatter]")
 {
     auto formatter = std::make_shared<spdlog::pattern_formatter>("**%^");
     spdlog::details::log_msg msg;
-    formatter->format(msg);
+    fmt::memory_buffer formatted;
+    formatter->format(msg, formatted);
     REQUIRE(msg.color_range_start == 2);
     REQUIRE(msg.color_range_end == 0);
 }
@@ -118,7 +118,8 @@ TEST_CASE("color range test6", "[pattern_formatter]")
 {
     auto formatter = std::make_shared<spdlog::pattern_formatter>("**%$");
     spdlog::details::log_msg msg;
-    formatter->format(msg);
+    fmt::memory_buffer formatted;
+    formatter->format(msg, formatted);
     REQUIRE(msg.color_range_start == 0);
     REQUIRE(msg.color_range_end == 2);
 }

tests/test_sink.h

@@ -35,7 +35,7 @@ public:
     }
 
 protected:
-    void sink_it_(const details::log_msg &) override
+    void sink_it_(const details::log_msg &, const fmt::memory_buffer &) override
     {
         msg_counter_++;
         std::this_thread::sleep_for(delay_);