Initial commit of Arduino libraries

AsyncMQTT_ESP32/src/AsyncMqttClient/Helpers.hpp

@@ -0,0 +1,66 @@
+/****************************************************************************************************************************
+  Helpers.hpp
+  
+  AsyncMQTT_ESP32 is a library for ESP32 boards using WiFi or LwIP W5500 / W6100 / ENC28J60 / LAN8720 Ethernet
+
+  Based on and modified from :
+
+  1) async-mqtt-client (https://github.com/marvinroger/async-mqtt-client)
+  2) AsyncMQTT_Generic (https://github.com/khoih-prog/AsyncMQTT_Generic)
+
+  Built by Khoi Hoang https://github.com/khoih-prog/AsyncMQTT_ESP32
+ *****************************************************************************************************************************/
+
+#pragma once
+
+#ifndef HELPERS_HPP
+#define HELPERS_HPP
+
+namespace AsyncMqttClientInternals
+{
+class Helpers
+{
+  public:
+    static uint32_t decodeRemainingLength(char* bytes)
+    {
+      uint32_t multiplier = 1;
+      uint32_t value = 0;
+      uint8_t currentByte = 0;
+      uint8_t encodedByte;
+
+      do
+      {
+        encodedByte = bytes[currentByte++];
+        value += (encodedByte & 127) * multiplier;
+        multiplier *= 128;
+      } while ((encodedByte & 128) != 0);
+
+      return value;
+    }
+
+    static uint8_t encodeRemainingLength(uint32_t remainingLength, char* destination)
+    {
+      uint8_t currentByte = 0;
+      uint8_t bytesNeeded = 0;
+
+      do
+      {
+        uint8_t encodedByte = remainingLength % 128;
+        remainingLength /= 128;
+
+        if (remainingLength > 0)
+        {
+          encodedByte = encodedByte | 128;
+        }
+
+        destination[currentByte++] = encodedByte;
+        bytesNeeded++;
+      } while (remainingLength > 0);
+
+      return bytesNeeded;
+    }
+};
+
+}  // namespace AsyncMqttClientInternals
+
+#endif    // HELPERS_HPP