Efficiently check string for one of several hundred possible suffixes
- by Ghostrider
I need to write a C/C++ function that would quickly check if string ends with one of ~1000 predefined suffixes. Specifically the string is a hostname and I need to check if it belongs to one of several hundred predefined second-level domains.
This function will be called a lot so it needs to be written as efficiently as possible. Bitwise hacks etc anything goes as long as it turns out fast.
Set of suffixes is predetermined at compile-time and doesn't change.
I am thinking of either implementing a variation of Rabin-Karp or write a tool that would generate a function with nested ifs and switches that would be custom tailored to specific set of suffixes. Since the application in question is 64-bit to speed up comparisons I could store suffixes of up to 8 bytes in length as const sorted array and do binary search within it.
Are there any other reasonable options?
