add new method for litelib to check if server is online

lib/silentdragonlitelib.h

@@ -14,6 +14,7 @@ extern char * litelib_initialize_existing (bool dangerous,const char* server);
 extern char * litelib_execute             (const char* s, const char* args);
 extern void   litelib_rust_free_string    (char* s);
 extern char * blake3_PW                   (char* pw);
+extern bool litelib_check_server_online   (const char* server);
 
 #ifdef __cplusplus
 }

lib/src/lib.rs

@@ -245,6 +245,24 @@ pub extern fn litelib_execute(cmd: *const c_char, args: *const c_char) -> *mut c
     return c_str.into_raw();
 }
 
+// Check is Server Connection is fine
+#[no_mangle]
+pub extern "C" fn litelib_check_server_online(server: *const c_char) -> bool {
+    let server_str = unsafe {
+        assert!(!server.is_null());
+
+        CStr::from_ptr(server).to_string_lossy().into_owned()
+    };
+
+    let server = LightClientConfig::get_server_or_default(Some(server_str));
+    let result = LightClientConfig::create(server, false);
+
+    match result {
+        Ok(_) => true,
+        Err(_) => false,
+    }
+}
+
 /**
  * Callers that receive string return values from other functions should call this to return the string 
  * back to rust, so it can be freed. Failure to call this function will result in a memory leak

src/settings.cpp

@@ -37,16 +37,15 @@ Config Settings::getSettings() {
     if (server.trimmed().isEmpty()) {
         server = Settings::getRandomServer();
 
-        QString response = "";
+        bool isOnline = false;
         // make sure existing server in conf is alive, otherwise choose random one
         try {
-            char* resp = litelib_initialize_existing(false, server.toStdString().c_str());
-            response = litelib_process_response(resp);
+            bool isOnline = litelib_check_server_online(server.toStdString().c_str());
         } catch (const std::exception& e)  {
             qDebug() << __func__ << ": caught an exception, ignoring: " << e.what();
         }
 
-        if (response.toUpper().trimmed() != "OK") {
+        if (!isOnline) {
             qDebug() << "Lite server in conf " << server << " is down, getting a random one";
             server = Settings::getRandomServer();
             s.setValue("connection/server", server);
@@ -333,11 +332,10 @@ QString Settings::getRandomServer() {
     while (tries < servers.size() ) {
         qDebug() << "Checking if lite server " << server << " is a alive, try=" << tries;
 
-        QString response = "";
+        bool isOnline = "";
 
         try {
-            char* resp = litelib_initialize_existing(false, server.toStdString().c_str());
-            response = litelib_process_response(resp);
+             isOnline = litelib_check_server_online(server.toStdString().c_str());
         } catch (const std::exception& e)  {
             qDebug() << __func__ << ": caught an exception, ignoring: " << e.what();
         }
@@ -345,7 +343,7 @@ QString Settings::getRandomServer() {
         // if we see a valid connection, return this server. when the server is alive, 
         //it tries to read the wallet. This causes an error because it cannot find it (SDL only has a non-encrypted wallet.dat during storage processes)
         // We can use that. 
-        if (response.contains("Error: Cannot read wallet.")) {
+        if (isOnline) {
             qDebug() << "Choosing lite server " << server;
             return server;
         }