Home/ Questions/Q 515631
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-13T07:38:53+00:00

I want to analyze a message’s type for best performance, the message is begin

  • 0

I want to analyze a message’s type for best performance, the message is begin with constant string and one space followed. The constant strings belongs to one known list of string array, like “CUT”, “GET”, “LOGIN” …

So I do not like to memcmp(data, “GET”, 3) thing repeatedly which is bad for performance. I wonder is there any better solution. Maybe I can compile this constant string arrays into a DFA for quick string match, but I do not know how to do it, and is there any other better solution?

Possible use lexer to do this?

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Take a look at Ragel. And at Mongrel for a real-world use. Though I found the mail parsing example that is enclosed with ragel to be a fun small one to experiment with, too.

    Though, depending on your protocol, just a check on the first byte might get you down to a single subsequent memcmp() just to verify that your verb is indeed the correct one. ‘C’, ‘L’, ‘G’ are all different values.

    • 0