优化文件上传速度，增加请求头预校验功能

webcc/response_builder.h

@@ -17,7 +17,7 @@ public:
   // NOTE:
   // Currently, |request| is necessary only when Gzip is enabled and the client
   // does want to accept Gzip compressed response.
-  explicit ResponseBuilder(RequestPtr request) : request_(request) {
+  explicit ResponseBuilder(RequestPtr request) : request_(request), headers_() {
   }
 
   ResponseBuilder(const ResponseBuilder&) = delete;
@@ -103,6 +103,24 @@ public:
   // Add the `Date` header to the response.
   ResponseBuilder& Date();
 
+  //getter for information logger
+  int GetCode() const
+  {
+    return (int)code_;
+  }
+
+  size_t GetBodySize() const
+  {
+    if(body_ == nullptr)
+      return 0;
+    return body_->GetSize();
+  }
+
+  bool IsBodyEmpty() const
+  {
+    return ((body_ == nullptr) || body_->IsEmpty());
+  }
+
 #if WEBCC_ENABLE_GZIP
   ResponseBuilder& Gzip(bool gzip = true) {
     gzip_ = gzip;