add doc for TelegramHeader and TelegramFrame structures

Author: w0lek

vpr/src/server/telegramframe.h

@@ -8,6 +8,15 @@
 
 namespace comm {
 
+
+/**
+* @brief Structure representing a TelegramFrame.
+*
+* A TelegramFrame consists of a TelegramHeader followed by data.
+*
+* @var header The TelegramHeader containing metadata about the telegram message. @see TelegramHeader
+* @var data The actual data of the telegram message.
+*/
 struct TelegramFrame {
     TelegramHeader header;
     ByteArray data;

vpr/src/server/telegramheader.h

@@ -8,6 +8,21 @@
 
 namespace comm {
 
+/**
+ * @brief The fixed size bytes sequence where the metadata of a telegram message is stored.
+ *
+ * This structure is used to describe the message frame sequence in order to successfully extract it.
+ * The TelegramHeader structure follows this format:
+ * ------------------------------------------------------
+ * [ 4 bytes ][  4 bytes  ][   4 bytes   ][    1 byte   ]
+ * [SIGNATURE][DATA_LENGTH][DATA_CHECKSUM][COMPRESSOR_ID]
+ * ------------------------------------------------------
+ *
+ * The SIGNATURE is a 4-byte constant sequence "I", "P", "A", "\0" which indicates the valid start of a TelegramHeader.
+ * The DATA_LENGTH is a 4-byte field where the data length is stored, allowing for proper identification of the start and end of the TelegramFrame sequence.
+ * The DATA_CHECKSUM is a 4-byte field where the data checksum is stored to validate the attached data.
+ * The COMPRESSOR_ID is a 1-byte field where the compressor id is stored. If it's NULL, it means the data is not compressed (in text/json format).
+ */
 class TelegramHeader {
 public:
     static constexpr const char SIGNATURE[] = "IPA";