use espMqttClient, qos2 fixed

lib/espMqttClient/src/Packets/Parser.h

@@ -0,0 +1,100 @@
+/*
+Copyright (c) 2022 Bert Melis. All rights reserved.
+
+This work is licensed under the terms of the MIT license.  
+For a copy, see <https://opensource.org/licenses/MIT> or
+the LICENSE file.
+*/
+
+#pragma once
+
+#include <stdint.h>
+#include <stddef.h>
+#include <algorithm>
+
+#include "../Config.h"
+#include "Constants.h"
+#include "../Logging.h"
+#include "RemainingLength.h"
+
+namespace espMqttClientInternals {
+
+struct IncomingPacket {
+  struct __attribute__((__packed__)) {
+    MQTTPacketType packetType;
+    union {
+      size_t remainingLength;
+      uint8_t remainingLengthRaw[4];
+    } remainingLength;
+  } fixedHeader;
+  struct __attribute__((__packed__)) {
+    uint16_t topicLength;
+    char topic[EMC_MAX_TOPIC_LENGTH + 1];  // + 1 for c-string delimiter
+    union {
+      struct {
+        uint8_t sessionPresent;
+        uint8_t returnCode;
+      } connackVarHeader;
+      uint16_t packetId;
+    } fixed;
+  } variableHeader;
+  struct {
+    const uint8_t* data;
+    size_t length;
+    size_t index;
+    size_t total;
+  } payload;
+
+  uint8_t qos() const;
+  bool retain() const;
+  bool dup() const;
+  void reset();
+};
+
+enum class ParserResult : uint8_t {
+  awaitData,
+  packet,
+  protocolError
+};
+
+class Parser;
+typedef ParserResult(*ParserFunc)(Parser*);
+
+class Parser {
+ public:
+  Parser();
+  ParserResult parse(const uint8_t* data, size_t len, size_t* bytesRead);
+  const IncomingPacket& getPacket() const;
+  void reset();
+
+ private:
+  // keep data variables in class to avoid copying on every iteration of the parser
+  const uint8_t* _data;
+  size_t _len;
+  size_t _bytesRead;
+  size_t _bytePos;
+  ParserFunc _parse;
+  IncomingPacket _packet;
+  uint8_t _payloadBuffer[EMC_PAYLOAD_BUFFER_SIZE];
+
+  static ParserResult _fixedHeader(Parser* p);
+  static ParserResult _remainingLengthFixed(Parser* p);
+  static ParserResult _remainingLengthNone(Parser* p);
+  static ParserResult _remainingLengthVariable(Parser* p);
+
+
+  static ParserResult _varHeaderConnack1(Parser* p);
+  static ParserResult _varHeaderConnack2(Parser* p);
+
+  static ParserResult _varHeaderPacketId1(Parser* p);
+  static ParserResult _varHeaderPacketId2(Parser* p);
+
+  static ParserResult _varHeaderTopicLength1(Parser* p);
+  static ParserResult _varHeaderTopicLength2(Parser* p);
+  static ParserResult _varHeaderTopic(Parser* p);
+
+  static ParserResult _payloadSuback(Parser* p);
+  static ParserResult _payloadPublish(Parser* p);
+};
+
+}  // end namespace espMqttClientInternals