uniffi-lab

A repo for trying the Mozilla UniFFI library with examples. A first read to the UniFFI user manual is encouraged.

Basic

An example with basic, primitive types and basic error handling. The target is to build a generated folder, which should contain the resultant execution chain:

graph LR;
caller.py-->basic.py;
basic.py-->libbasic.so;

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• caller.py file would represent the client code of the FFI. An application.
• basic.py the python bindings to our rust code.
• libbasic.so The shared library, which contains all the low level FFI extern blocks, and the Rust logic itself.

$ cd basic/generated
$ python caller.py
2 + 4 = 6

How do we get there ?

We will work in the basic folder from here and create the generated one.

$ cd basic
$ mkdir generated

First we place our caller, application code at generated/caller.py

import basic

if __name__ == "__main__":
    print("2 + 4 = {}".format(basic.add(2, 4)))

After defining the UDL file and our rust logic, its needed to generate the language specific bindings with:

## This works because we have a special crate in the current workspace 
## for building and run the uniffi-bindgen binary. See https://mozilla.github.io/uniffi-rs/tutorial/foreign_language_bindings.html
$ cargo run -p uniffi-bindgen generate ./src/basic.udl --language python
$ mv ./src/basic.py generated

Next, generate our shared library and move it to the generated folder:

$ cargo build --release
$ mv ../target/release/libbasic.so generated

Execute the result by:

$ cd basic/generated
$ python caller.py
2 + 4 = 6

Custom

An example managing:

• Custom types.
• Internal state.
• Borrowing by using [ByRef] .
• Passing shared ownership by using Arc.