io_getcookie(3)

💖 io_getcookie(3) — the one where you get your cookie back 💖

Library Functions Manual · a libowfat moment ✨

✨ NAME ✨

io_getcookie — retrieve cookie 🍪

🌸 SYNTAX 🌸

#include <libowfat/io.h>

void* io_getcookie(int64 fd);

bestie it literally takes one arg and hands you a pointer, we love a low-effort queen 👑

🦋 DESCRIPTION 🦋

So io_getcookie retrieves a cookie — and by "cookie" we mean a pointer to some anonymous data structure you associated with this descriptor. It's giving secret lil treat for your fd, no cap 💅

Wanna set one? Use io_setcookie(3) to associate a cookie with a descriptor. That's the whole pipeline, you put the cookie in, you get the cookie out 🫶

And if you did not associate a cookie with this descriptor, io_getcookie returns NULL. Like, respectfully, there was no cookie. Empty plate. Tragic but valid 😭

Now here's the actual galaxy-brain part, because this is the slay 🔥 The idea is that you put the state associated with a TCP connection you serve in a common struct. Then you do not need to have your own data structure to retrieve the state for a connection — you can just use the data structure io_wait already maintains. The way that this means zero extra bookkeeping on your end, we're obsessed fr fr 🌈

And the lookup itself? It works in constant time and should not cause any cache misses. The performance is genuinely iconic, no notes ⭐

ngl this is the part where you stop writing your own lookup table and just let io_wait carry the whole thing, main character energy 💜

🌈 SEE ALSO 🌈

• io_wait(3)
• io_setcookie(3)

go read io_setcookie(3) next so you actually have a cookie to get, iykyk 🎀

okay that's the whole page bestie, ty for reading, mwah 💖 this was the io_getcookie(3) entry from the Library Functions Manual, brought to you by libowfat, and yes the footer is literally just io_getcookie(3) again because manpages are dramatic like that 💅✨