How to detect when a Protocol Buffer message is fully received?

Question

This is kind of a branch off of my other question. Read it if you like, but it\'s not necessary.

Basically, I realized that in order to effectively use C#\'s BeginRe

Answer 1

You need to include the size or end marker in your protocol. Nothing is built into stream based sockets (TCP/IP) other than supporting an indefinite stream of octets arbitrarily broken up into separate packets (and packets can be spilt in transit as well).

A simple approach would be for each "message" to have a fixed size header, include both a protocol version and a payload size and any other fixed data. Then the message content (payload).

Optionally a message footer (fixed size) could be added with a checksum or even a cryptographic signature (depending on your reliability/security requirements).

Knowing the payload size allows you to keep reading a number of bytes that will be enough for the rest of the message (and if a read completes with less, doing another read for the remaining bytes until the whole message has been received).

Having a end message indicator also works, but you need to define how to handle your message containing that same octet sequence...