From 38936bde81b36cc3e81d49ea903d9130cdb079b5 Mon Sep 17 00:00:00 2001
From: antao <antao2002@gmail.com>
Date: Mon, 31 Dec 2018 19:59:57 +0800
Subject: [PATCH] Modify Date header strategy

---
 lib/inc/drogon/utils/Utilities.h |  2 +-
 lib/src/HttpResponseImpl.cc      | 20 ++++++++++----------
 lib/src/HttpResponseImpl.h       |  3 +++
 lib/src/Utilities.cc             |  6 +-----
 4 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/lib/inc/drogon/utils/Utilities.h b/lib/inc/drogon/utils/Utilities.h
index 959d6721..04c22da0 100755
--- a/lib/inc/drogon/utils/Utilities.h
+++ b/lib/inc/drogon/utils/Utilities.h
@@ -71,7 +71,7 @@ int gzipDecompress(const char *zdata, const size_t nzdata,
  * like this:Sun, 06 Nov 1994 08:49:37 GMT
  *           Wed, 12 Sep 2018 09:22:40 GMT
  */
-char *getHttpFullDate(const trantor::Date &date = trantor::Date::now(), bool *isChanged = nullptr);
+char *getHttpFullDate(const trantor::Date &date = trantor::Date::now());
 
 /// Get a formatted string
 std::string formattedString(const char *format, ...);
diff --git a/lib/src/HttpResponseImpl.cc b/lib/src/HttpResponseImpl.cc
index 34cd6339..94380489 100755
--- a/lib/src/HttpResponseImpl.cc
+++ b/lib/src/HttpResponseImpl.cc
@@ -366,18 +366,18 @@ std::shared_ptr<std::string> HttpResponseImpl::renderToString() const
     {
         if (_datePos != std::string::npos)
         {
-            bool isDateChanged = false;
-            auto newDate = getHttpFullDate(trantor::Date::now(), &isDateChanged);
+            std::lock_guard<std::mutex> lock(*_httpStringMutex);
+            auto now = trantor::Date::now();
+            bool isDateChanged = ((now.microSecondsSinceEpoch() / MICRO_SECONDS_PRE_SEC) != _httpStringDate);
+            assert(_httpString);
+            if (isDateChanged)
             {
-                std::lock_guard<std::mutex> lock(*_httpStringMutex);
-                assert(_httpString);
-                if (isDateChanged)
-                {
-                    _httpString = std::make_shared<std::string>(*_httpString);
-                    memcpy(_httpString->data() + _datePos, newDate, strlen(newDate));
-                }
-                return _httpString;
+                _httpStringDate = now.microSecondsSinceEpoch() / MICRO_SECONDS_PRE_SEC;
+                auto newDate = getHttpFullDate(now);
+                _httpString = std::make_shared<std::string>(*_httpString);
+                memcpy(_httpString->data() + _datePos, newDate, strlen(newDate));
             }
+            return _httpString;
         }
     }
     auto httpString = std::make_shared<std::string>();
diff --git a/lib/src/HttpResponseImpl.h b/lib/src/HttpResponseImpl.h
index 1036c1cb..d99b5812 100755
--- a/lib/src/HttpResponseImpl.h
+++ b/lib/src/HttpResponseImpl.h
@@ -325,9 +325,12 @@ class HttpResponseImpl : public HttpResponse
     mutable std::shared_ptr<Json::Value> _jsonPtr;
 
     std::shared_ptr<std::string> _fullHeaderString;
+
     mutable std::shared_ptr<std::string> _httpString;
     mutable std::shared_ptr<std::mutex> _httpStringMutex;
     mutable std::string::size_type _datePos = std::string::npos;
+    mutable uint64_t _httpStringDate = -1;
+
     //trantor::Date receiveTime_;
 
     void setContentType(const std::string &contentType)
diff --git a/lib/src/Utilities.cc b/lib/src/Utilities.cc
index f1a713cd..59d4a674 100755
--- a/lib/src/Utilities.cc
+++ b/lib/src/Utilities.cc
@@ -404,19 +404,15 @@ int gzipDecompress(const char *zdata, const size_t nzdata,
     *ndata = d_stream.total_out;
     return 0;
 }
-char *getHttpFullDate(const trantor::Date &date, bool *isChanged)
+char *getHttpFullDate(const trantor::Date &date)
 {
     static __thread int64_t lastSecond = 0;
     static __thread char lastTimeString[128] = {0};
     auto nowSecond = date.microSecondsSinceEpoch() / MICRO_SECONDS_PRE_SEC;
     if (nowSecond == lastSecond)
     {
-        if(isChanged)
-            *isChanged = false;
         return lastTimeString;
     }
-    if(isChanged)
-        *isChanged = true;
     lastSecond = nowSecond;
     date.toCustomedFormattedString("%a, %d %b %Y %T GMT", lastTimeString, sizeof(lastTimeString));
     return lastTimeString;