Vali, a C library for Varlink (opens in new tab)

(emersion.fr)

43 pointsGalaxySnail5mo ago15 comments

15 comments

Here's a C++/Qt one by KDE hacker David Edmundson: https://blog.davidedmundson.co.uk/blog/introducing-qtvarlink...

ongy5mo ago

Huh, that way of doing asynchronicity is quite interesting.

Though my Haskell and Rust primed brain really dislikes the way ownership of the memory allocation for the response struct works.

It gets allocated by the caller (library), handed over to the function fully owned, and then gets consumed by the response function?

andrewshadura5mo ago

I'm wondering why Varlink, while incredibly similar to JSON-RPC, is designed to be incompatible with it?

NewJazz5mo ago

Linux people don't want web folks messing with their plumbing is my take lol.

More realistically, adding HTTP where it is not needed adds unnecessary complexity.

blixtra5mo ago

If you want to know more about Varlink, Lennart Poettering gave a talk about it at All Systems Go! last year. https://media.ccc.de/v/all-systems-go-2024-276-varlink-now-/...

NewJazz5mo ago

What does varlink do that grpc or capnproto don't offer? Hell, it doesn't even seem much batter than openapi...

emersion5mo ago

The main use-case is different: gRPC and Cap'n'Proto are designed for networked servers, while D-Bus and Varlink are designed for local IPC. Varlink is a lot simpler than other alternatives.

sam_bristow5mo ago

I've only had a cursory look at Varlink, but it almost felt too simple. In particular the lack of unsigned or sized integers.

This might enf up being be fine, but it gave me pause when I looked at it previously.

2 more replies

NewJazz5mo ago

Simpler is pretty subjective. A lot of people have already ingrained the complexity of grpc and/or capnproto. And more importantly, there are a lot of well maintained libraries for those protocols.

At the end of the day, local or remote, it is all just pushing data over sockets, no?

burstmode5mo ago

So, there's another copy of CORBA. :-)

guerrilla5mo ago

That's intentional. That's where this began. GNOME started out by implementing CORBA in a library called ORBit. It was eventually replaced by D-Bus which got more widespread usage across desktop environments and components. Eventually that was adopted at the OS level because of systemd and now they're replacing that with this. So, literally yes.

malkia5mo ago

json, rpc, and that uint64_t bit integer

j / k navigate · click thread line to collapse

15 comments

sho_hn5mo ago

Here's a C++/Qt one by KDE hacker David Edmundson: https://blog.davidedmundson.co.uk/blog/introducing-qtvarlink...

ongy5mo ago

Huh, that way of doing asynchronicity is quite interesting.

Though my Haskell and Rust primed brain really dislikes the way ownership of the memory allocation for the response struct works.

It gets allocated by the caller (library), handed over to the function fully owned, and then gets consumed by the response function?

andrewshadura5mo ago

I'm wondering why Varlink, while incredibly similar to JSON-RPC, is designed to be incompatible with it?

NewJazz5mo ago

Linux people don't want web folks messing with their plumbing is my take lol.

More realistically, adding HTTP where it is not needed adds unnecessary complexity.

blixtra5mo ago

If you want to know more about Varlink, Lennart Poettering gave a talk about it at All Systems Go! last year. https://media.ccc.de/v/all-systems-go-2024-276-varlink-now-/...

NewJazz5mo ago

What does varlink do that grpc or capnproto don't offer? Hell, it doesn't even seem much batter than openapi...

emersion5mo ago

The main use-case is different: gRPC and Cap'n'Proto are designed for networked servers, while D-Bus and Varlink are designed for local IPC. Varlink is a lot simpler than other alternatives.

sam_bristow5mo ago

I've only had a cursory look at Varlink, but it almost felt too simple. In particular the lack of unsigned or sized integers.

This might enf up being be fine, but it gave me pause when I looked at it previously.

2 more replies

NewJazz5mo ago

Simpler is pretty subjective. A lot of people have already ingrained the complexity of grpc and/or capnproto. And more importantly, there are a lot of well maintained libraries for those protocols.

At the end of the day, local or remote, it is all just pushing data over sockets, no?

burstmode5mo ago

So, there's another copy of CORBA. :-)

guerrilla5mo ago

malkia5mo ago

json, rpc, and that uint64_t bit integer

j / k navigate · click thread line to collapse