code refactoring and optimisation

README.md

@@ -168,7 +168,8 @@ For ESP8266 device user, you should read the [Memory Options for ESP8266](#memor
 
 Please make sure that the `Arduino IDE's Board Manager URL` is up to date before you update your device's `platform Core SDK`. Any issue due to using out dated `platform Core SDK` is your own risk and does not support by library.
 
-In case the library compile status showed here is passing and your code compilation is error, you should check your libary installation, `platform Core SDK` installation and the library usage. You cannot install library in the cloud storage virtual folder or sandbox e.g. `Microsoft's OneDrive`.
+> [!NOTE]  
+> In the case that the library compilation status shows here is passing and your code compilation is error, you should check your libary installation, `platform Core SDK` installation and the library usage. You cannot install library in the cloud storage virtual folder or sandbox e.g. `Microsoft's OneDrive`.
 
 If you are using `Arduino® MKR 1000 WIFI`, please make sure you have already done the following steps.
 - Add the `Realtime Database host root certificate` to the board firmware. 
@@ -1061,7 +1062,7 @@ ServiceAuth::ServiceAuth(<timestamp>, <file_config_data>, <expire>)
 
 The auth token need to be re-created instead of refreshing.
 
-The `CustomAuth` and `ServiceAuth` classes required the JWT token processor which is done via the function `firebase::JWTClass::loop(<auth_data_t*>)` which accepts the pointer to the `auth_data_t` from the `FirebaseApp::getAuth()`. 
+The `CustomAuth` and `ServiceAuth` classes required the JWT token processor which is done via the function `firebase_ns::JWTClass::loop(<auth_data_t*>)` which accepts the pointer to the `auth_data_t` from the `FirebaseApp::getAuth()`. 
 
 The examples in this library, the static object of `JWTClass` called `JWT` will be used to save the stack memory usage and it is not thread safe when using in multi-threaded operations (`multi-FirebaseApp`) because of sharing internal `jwt_token_data_t`.
 

src/core/AsyncClient/RequestHandler.h

@@ -100,9 +100,9 @@ struct req_handler
     }
 
     void addNewLine() { val[reqns::header] += "\r\n"; }
-    void addHostHeader(const String &host) { sut.printTo(val[reqns::header], 100, "Host: %s\r\n", host.c_str()); }
+    void addHostHeader(const String &host) { sut.printTo(val[reqns::header], host.length(), "Host: %s\r\n", host.c_str()); }
     void addConnectionHeader(bool keepAlive) { sut.printTo(val[reqns::header], 50, "Connection: %s\r\n", keepAlive ? "keep-alive" : "close"); }
-    void addContentType(const String &type) { sut.printTo(val[reqns::header], 100, "Content-Type: %s\r\n", type.c_str()); }
+    void addContentType(const String &type) { sut.printTo(val[reqns::header], type.length(), "Content-Type: %s\r\n", type.c_str()); }
     void setContentLengthFinal(size_t len) { sut.printTo(val[reqns::header], 30, "Content-Length: %d\r\n\r\n", (int)len); }
     void addRequestHeader(reqns::http_request_method method, const String &path, const String &extras)
     {

src/core/FirebaseApp.h

@@ -220,21 +220,6 @@ namespace firebase_ns
             }
         }
 
-        void addGAPIsHost(String &str, PGM_P sub)
-        {
-            str += sub;
-            if (str[str.length() - 1] != '.')
-                str += ".";
-            str += FPSTR("googleapis.com");
-        }
-
-        void addContentTypeHeader(String &header, PGM_P v)
-        {
-            header += FPSTR("Content-Type: ");
-            header += v;
-            header += FPSTR("\r\n");
-        }
-
         void createSlot(AsyncClientClass *aClient, slot_options_t &soption)
         {
             if (aClient)
@@ -269,10 +254,10 @@ namespace firebase_ns
 
             if (sData)
             {
-                addGAPIsHost(host, subdomain.c_str());
+                sut.printTo(host, subdomain.length(), "%s.googleapis.com", subdomain.c_str());
                 newRequestBase(aClient, sData, host, extras, "", reqns::http_post, soption, uid);
 
-                addContentTypeHeader(sData->request.val[reqns::header], "application/json");
+                sData->request.addContentType("application/json");
                 sData->request.setContentLengthFinal(sData->request.val[reqns::payload].length());
                 req_timer.feed(FIREBASE_TCP_READ_TIMEOUT_SEC);
                 slot = slotCountBase(aClient) - 1;