From eab522e743b4f41caed1a7426cf37c77531d1382 Mon Sep 17 00:00:00 2001
From: doug1234 <doug_ayers@yahoo.com>
Date: Thu, 13 Jan 2022 20:57:14 -0500
Subject: [PATCH 1/5] Now only getting the date if formater needs to display
 date related information.

---
 include/spdlog/pattern_formatter-inl.h | 43 +++++++++++++++++++++++---
 include/spdlog/pattern_formatter.h     |  1 +
 2 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/include/spdlog/pattern_formatter-inl.h b/include/spdlog/pattern_formatter-inl.h
index ec727032b..caf7c62ca 100644
--- a/include/spdlog/pattern_formatter-inl.h
+++ b/include/spdlog/pattern_formatter-inl.h
@@ -1021,6 +1021,7 @@ SPDLOG_INLINE pattern_formatter::pattern_formatter(
     , pattern_time_type_(time_type)
     , last_log_secs_(0)
     , custom_handlers_(std::move(custom_user_flags))
+    , needs_time_(false)
 {
     std::memset(&cached_tm_, 0, sizeof(cached_tm_));
     compile_pattern_(pattern_);
@@ -1032,6 +1033,7 @@ SPDLOG_INLINE pattern_formatter::pattern_formatter(pattern_time_type time_type,
     , eol_(std::move(eol))
     , pattern_time_type_(time_type)
     , last_log_secs_(0)
+    , needs_time_(false)
 {
     std::memset(&cached_tm_, 0, sizeof(cached_tm_));
     formatters_.push_back(details::make_unique<details::full_formatter>(details::padding_info{}));
@@ -1049,11 +1051,13 @@ SPDLOG_INLINE std::unique_ptr<formatter> pattern_formatter::clone() const
 
 SPDLOG_INLINE void pattern_formatter::format(const details::log_msg &msg, memory_buf_t &dest)
 {
-    auto secs = std::chrono::duration_cast<std::chrono::seconds>(msg.time.time_since_epoch());
-    if (secs != last_log_secs_)
-    {
-        cached_tm_ = get_time_(msg);
-        last_log_secs_ = secs;
+    if (needs_time_) {
+        const auto secs = std::chrono::duration_cast<std::chrono::seconds>(msg.time.time_since_epoch());
+        if (secs != last_log_secs_)
+        {
+            cached_tm_ = get_time_(msg);
+            last_log_secs_ = secs;
+        }
     }
 
     for (auto &f : formatters_)
@@ -1097,6 +1101,7 @@ SPDLOG_INLINE void pattern_formatter::handle_flag_(char flag, details::padding_i
     {
     case ('+'): // default formatter
         formatters_.push_back(details::make_unique<details::full_formatter>(padding));
+        needs_time_ = true;
         break;
 
     case 'n': // logger name
@@ -1121,101 +1126,125 @@ SPDLOG_INLINE void pattern_formatter::handle_flag_(char flag, details::padding_i
 
     case ('a'): // weekday
         formatters_.push_back(details::make_unique<details::a_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('A'): // short weekday
         formatters_.push_back(details::make_unique<details::A_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('b'):
     case ('h'): // month
         formatters_.push_back(details::make_unique<details::b_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('B'): // short month
         formatters_.push_back(details::make_unique<details::B_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('c'): // datetime
         formatters_.push_back(details::make_unique<details::c_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('C'): // year 2 digits
         formatters_.push_back(details::make_unique<details::C_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('Y'): // year 4 digits
         formatters_.push_back(details::make_unique<details::Y_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('D'):
     case ('x'): // datetime MM/DD/YY
         formatters_.push_back(details::make_unique<details::D_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('m'): // month 1-12
         formatters_.push_back(details::make_unique<details::m_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('d'): // day of month 1-31
         formatters_.push_back(details::make_unique<details::d_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('H'): // hours 24
         formatters_.push_back(details::make_unique<details::H_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('I'): // hours 12
         formatters_.push_back(details::make_unique<details::I_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('M'): // minutes
         formatters_.push_back(details::make_unique<details::M_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('S'): // seconds
         formatters_.push_back(details::make_unique<details::S_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('e'): // milliseconds
         formatters_.push_back(details::make_unique<details::e_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('f'): // microseconds
         formatters_.push_back(details::make_unique<details::f_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('F'): // nanoseconds
         formatters_.push_back(details::make_unique<details::F_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('E'): // seconds since epoch
         formatters_.push_back(details::make_unique<details::E_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('p'): // am/pm
         formatters_.push_back(details::make_unique<details::p_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('r'): // 12 hour clock 02:55:02 pm
         formatters_.push_back(details::make_unique<details::r_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('R'): // 24-hour HH:MM time
         formatters_.push_back(details::make_unique<details::R_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('T'):
     case ('X'): // ISO 8601 time format (HH:MM:SS)
         formatters_.push_back(details::make_unique<details::T_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('z'): // timezone
         formatters_.push_back(details::make_unique<details::z_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('P'): // pid
         formatters_.push_back(details::make_unique<details::pid_formatter<Padder>>(padding));
+        needs_time_ = true;
         break;
 
     case ('^'): // color range start
@@ -1252,18 +1281,22 @@ SPDLOG_INLINE void pattern_formatter::handle_flag_(char flag, details::padding_i
 
     case ('u'): // elapsed time since last log message in nanos
         formatters_.push_back(details::make_unique<details::elapsed_formatter<Padder, std::chrono::nanoseconds>>(padding));
+        needs_time_ = true;
         break;
 
     case ('i'): // elapsed time since last log message in micros
         formatters_.push_back(details::make_unique<details::elapsed_formatter<Padder, std::chrono::microseconds>>(padding));
+        needs_time_ = true;
         break;
 
     case ('o'): // elapsed time since last log message in millis
         formatters_.push_back(details::make_unique<details::elapsed_formatter<Padder, std::chrono::milliseconds>>(padding));
+        needs_time_ = true;
         break;
 
     case ('O'): // elapsed time since last log message in seconds
         formatters_.push_back(details::make_unique<details::elapsed_formatter<Padder, std::chrono::seconds>>(padding));
+        needs_time_ = true;
         break;
 
     default: // Unknown flag appears as is
diff --git a/include/spdlog/pattern_formatter.h b/include/spdlog/pattern_formatter.h
index 6810f03b6..57156cb7f 100644
--- a/include/spdlog/pattern_formatter.h
+++ b/include/spdlog/pattern_formatter.h
@@ -103,6 +103,7 @@ class SPDLOG_API pattern_formatter final : public formatter
     std::string pattern_;
     std::string eol_;
     pattern_time_type pattern_time_type_;
+    bool needs_time_;
     std::tm cached_tm_;
     std::chrono::seconds last_log_secs_;
     std::vector<std::unique_ptr<details::flag_formatter>> formatters_;

From 5568b16ed5e3a7dffe3e67d30e0ca721da0a489f Mon Sep 17 00:00:00 2001
From: doug1234 <doug_ayers@yahoo.com>
Date: Thu, 13 Jan 2022 21:35:02 -0500
Subject: [PATCH 2/5] Resetting the needs time flag when setting a pattern.

---
 include/spdlog/pattern_formatter-inl.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/spdlog/pattern_formatter-inl.h b/include/spdlog/pattern_formatter-inl.h
index caf7c62ca..4342685d3 100644
--- a/include/spdlog/pattern_formatter-inl.h
+++ b/include/spdlog/pattern_formatter-inl.h
@@ -1071,6 +1071,7 @@ SPDLOG_INLINE void pattern_formatter::format(const details::log_msg &msg, memory
 SPDLOG_INLINE void pattern_formatter::set_pattern(std::string pattern)
 {
     pattern_ = std::move(pattern);
+    needs_time_ = false;
     compile_pattern_(pattern_);
 }
 

From d9ec02d40024984e074fd357f352f41f421aedb0 Mon Sep 17 00:00:00 2001
From: doug1234 <doug_ayers@yahoo.com>
Date: Fri, 14 Jan 2022 20:06:26 -0500
Subject: [PATCH 3/5] Fix mistake in previous checkin.

---
 include/spdlog/pattern_formatter-inl.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/spdlog/pattern_formatter-inl.h b/include/spdlog/pattern_formatter-inl.h
index 4342685d3..c98c9fb2d 100644
--- a/include/spdlog/pattern_formatter-inl.h
+++ b/include/spdlog/pattern_formatter-inl.h
@@ -1033,7 +1033,7 @@ SPDLOG_INLINE pattern_formatter::pattern_formatter(pattern_time_type time_type,
     , eol_(std::move(eol))
     , pattern_time_type_(time_type)
     , last_log_secs_(0)
-    , needs_time_(false)
+    , needs_time_(true)
 {
     std::memset(&cached_tm_, 0, sizeof(cached_tm_));
     formatters_.push_back(details::make_unique<details::full_formatter>(details::padding_info{}));

From 584d77237ea732e924cb5b1473667ce51321a371 Mon Sep 17 00:00:00 2001
From: doug1234 <doug_ayers@yahoo.com>
Date: Sat, 15 Jan 2022 13:35:27 -0500
Subject: [PATCH 4/5] Several minor improvements based on code review
 suggestions.

---
 include/spdlog/pattern_formatter-inl.h | 62 ++++++++++++--------------
 include/spdlog/pattern_formatter.h     |  2 +-
 2 files changed, 30 insertions(+), 34 deletions(-)

diff --git a/include/spdlog/pattern_formatter-inl.h b/include/spdlog/pattern_formatter-inl.h
index c98c9fb2d..587e50620 100644
--- a/include/spdlog/pattern_formatter-inl.h
+++ b/include/spdlog/pattern_formatter-inl.h
@@ -1021,7 +1021,7 @@ SPDLOG_INLINE pattern_formatter::pattern_formatter(
     , pattern_time_type_(time_type)
     , last_log_secs_(0)
     , custom_handlers_(std::move(custom_user_flags))
-    , needs_time_(false)
+    , need_localtime_(false)
 {
     std::memset(&cached_tm_, 0, sizeof(cached_tm_));
     compile_pattern_(pattern_);
@@ -1033,7 +1033,7 @@ SPDLOG_INLINE pattern_formatter::pattern_formatter(pattern_time_type time_type,
     , eol_(std::move(eol))
     , pattern_time_type_(time_type)
     , last_log_secs_(0)
-    , needs_time_(true)
+    , need_localtime_(true)
 {
     std::memset(&cached_tm_, 0, sizeof(cached_tm_));
     formatters_.push_back(details::make_unique<details::full_formatter>(details::padding_info{}));
@@ -1051,7 +1051,8 @@ SPDLOG_INLINE std::unique_ptr<formatter> pattern_formatter::clone() const
 
 SPDLOG_INLINE void pattern_formatter::format(const details::log_msg &msg, memory_buf_t &dest)
 {
-    if (needs_time_) {
+    if (need_localtime_) 
+    {
         const auto secs = std::chrono::duration_cast<std::chrono::seconds>(msg.time.time_since_epoch());
         if (secs != last_log_secs_)
         {
@@ -1071,7 +1072,7 @@ SPDLOG_INLINE void pattern_formatter::format(const details::log_msg &msg, memory
 SPDLOG_INLINE void pattern_formatter::set_pattern(std::string pattern)
 {
     pattern_ = std::move(pattern);
-    needs_time_ = false;
+    need_localtime_ = false;
     compile_pattern_(pattern_);
 }
 
@@ -1102,7 +1103,7 @@ SPDLOG_INLINE void pattern_formatter::handle_flag_(char flag, details::padding_i
     {
     case ('+'): // default formatter
         formatters_.push_back(details::make_unique<details::full_formatter>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case 'n': // logger name
@@ -1127,125 +1128,120 @@ SPDLOG_INLINE void pattern_formatter::handle_flag_(char flag, details::padding_i
 
     case ('a'): // weekday
         formatters_.push_back(details::make_unique<details::a_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('A'): // short weekday
         formatters_.push_back(details::make_unique<details::A_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('b'):
     case ('h'): // month
         formatters_.push_back(details::make_unique<details::b_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('B'): // short month
         formatters_.push_back(details::make_unique<details::B_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('c'): // datetime
         formatters_.push_back(details::make_unique<details::c_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('C'): // year 2 digits
         formatters_.push_back(details::make_unique<details::C_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('Y'): // year 4 digits
         formatters_.push_back(details::make_unique<details::Y_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('D'):
     case ('x'): // datetime MM/DD/YY
         formatters_.push_back(details::make_unique<details::D_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('m'): // month 1-12
         formatters_.push_back(details::make_unique<details::m_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('d'): // day of month 1-31
         formatters_.push_back(details::make_unique<details::d_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('H'): // hours 24
         formatters_.push_back(details::make_unique<details::H_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('I'): // hours 12
         formatters_.push_back(details::make_unique<details::I_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('M'): // minutes
         formatters_.push_back(details::make_unique<details::M_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('S'): // seconds
         formatters_.push_back(details::make_unique<details::S_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('e'): // milliseconds
         formatters_.push_back(details::make_unique<details::e_formatter<Padder>>(padding));
-        needs_time_ = true;
         break;
 
     case ('f'): // microseconds
         formatters_.push_back(details::make_unique<details::f_formatter<Padder>>(padding));
-        needs_time_ = true;
         break;
 
     case ('F'): // nanoseconds
         formatters_.push_back(details::make_unique<details::F_formatter<Padder>>(padding));
-        needs_time_ = true;
         break;
 
     case ('E'): // seconds since epoch
         formatters_.push_back(details::make_unique<details::E_formatter<Padder>>(padding));
-        needs_time_ = true;
         break;
 
     case ('p'): // am/pm
         formatters_.push_back(details::make_unique<details::p_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('r'): // 12 hour clock 02:55:02 pm
         formatters_.push_back(details::make_unique<details::r_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('R'): // 24-hour HH:MM time
         formatters_.push_back(details::make_unique<details::R_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('T'):
     case ('X'): // ISO 8601 time format (HH:MM:SS)
         formatters_.push_back(details::make_unique<details::T_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('z'): // timezone
         formatters_.push_back(details::make_unique<details::z_formatter<Padder>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('P'): // pid
         formatters_.push_back(details::make_unique<details::pid_formatter<Padder>>(padding));
-        needs_time_ = true;
         break;
 
     case ('^'): // color range start
@@ -1282,22 +1278,22 @@ SPDLOG_INLINE void pattern_formatter::handle_flag_(char flag, details::padding_i
 
     case ('u'): // elapsed time since last log message in nanos
         formatters_.push_back(details::make_unique<details::elapsed_formatter<Padder, std::chrono::nanoseconds>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('i'): // elapsed time since last log message in micros
         formatters_.push_back(details::make_unique<details::elapsed_formatter<Padder, std::chrono::microseconds>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('o'): // elapsed time since last log message in millis
         formatters_.push_back(details::make_unique<details::elapsed_formatter<Padder, std::chrono::milliseconds>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     case ('O'): // elapsed time since last log message in seconds
         formatters_.push_back(details::make_unique<details::elapsed_formatter<Padder, std::chrono::seconds>>(padding));
-        needs_time_ = true;
+        need_localtime_ = true;
         break;
 
     default: // Unknown flag appears as is
diff --git a/include/spdlog/pattern_formatter.h b/include/spdlog/pattern_formatter.h
index 57156cb7f..a1a64807f 100644
--- a/include/spdlog/pattern_formatter.h
+++ b/include/spdlog/pattern_formatter.h
@@ -103,7 +103,7 @@ class SPDLOG_API pattern_formatter final : public formatter
     std::string pattern_;
     std::string eol_;
     pattern_time_type pattern_time_type_;
-    bool needs_time_;
+    bool need_localtime_;
     std::tm cached_tm_;
     std::chrono::seconds last_log_secs_;
     std::vector<std::unique_ptr<details::flag_formatter>> formatters_;

From 28b9adf794ac9affe13402a54f7e9ea58ec4dfc6 Mon Sep 17 00:00:00 2001
From: doug1234 <doug_ayers@yahoo.com>
Date: Sat, 15 Jan 2022 16:41:06 -0500
Subject: [PATCH 5/5] Added the last few suggested changes.

---
 include/spdlog/pattern_formatter-inl.h | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/include/spdlog/pattern_formatter-inl.h b/include/spdlog/pattern_formatter-inl.h
index 587e50620..19d19e291 100644
--- a/include/spdlog/pattern_formatter-inl.h
+++ b/include/spdlog/pattern_formatter-inl.h
@@ -1278,22 +1278,18 @@ SPDLOG_INLINE void pattern_formatter::handle_flag_(char flag, details::padding_i
 
     case ('u'): // elapsed time since last log message in nanos
         formatters_.push_back(details::make_unique<details::elapsed_formatter<Padder, std::chrono::nanoseconds>>(padding));
-        need_localtime_ = true;
         break;
 
     case ('i'): // elapsed time since last log message in micros
         formatters_.push_back(details::make_unique<details::elapsed_formatter<Padder, std::chrono::microseconds>>(padding));
-        need_localtime_ = true;
         break;
 
     case ('o'): // elapsed time since last log message in millis
         formatters_.push_back(details::make_unique<details::elapsed_formatter<Padder, std::chrono::milliseconds>>(padding));
-        need_localtime_ = true;
         break;
 
     case ('O'): // elapsed time since last log message in seconds
         formatters_.push_back(details::make_unique<details::elapsed_formatter<Padder, std::chrono::seconds>>(padding));
-        need_localtime_ = true;
         break;
 
     default: // Unknown flag appears as is