build.rs

#[cfg(feature = "protoc-rust")]
use protoc_rust::{Codegen, Customize};
#[cfg(feature = "protoc-rust")]
use std::{env, ffi::OsStr, fs, path::Path};

#[cfg(feature = "protoc-rust")]
fn proto_modules(proto_dir: &Path) -> Vec<String> {
    fs::read_dir(proto_dir)
        .expect("Could not read protobuf directory")
        .filter_map(|entry| {
            let path = entry.ok()?.path();
            if path.is_file() && path.extension() == Some(OsStr::new("proto")) {
                path.file_stem()
                    .and_then(|n| n.to_os_string().into_string().ok())
            } else {
                None
            }
        })
        .collect()
}

#[cfg(feature = "protoc-rust")]
fn main() {
    let in_dir = "./s2client-proto/s2clientprotocol";
    let out_dir = &env::var("OUT_DIR").unwrap();

    // Read list of all input protobuf files
    let input_mods = proto_modules(Path::new(in_dir));
    let input_files: Vec<String> = input_mods
        .iter()
        .map(|s| format!("{}/{}.proto", in_dir, s))
        .collect();

    // Compile protocol buffers
    if let Err(e) = Codegen::new()
        .out_dir(out_dir)
        .include("s2client-proto/")
        .inputs(input_files)
        .customize(Customize {
            expose_fields: Some(true),
            ..Default::default()
        })
        .run()
    {
        panic!("{:#?}", e);
    }
    println!("protobufs were generated successfully");

    // Generate the lib.rs source code
    fs::write(
        format!("{}/{}", out_dir, "lib.rs"),
        input_mods
            .iter()
            .map(|s| format!("pub mod {};", s))
            .collect::<Vec<_>>()
            .join("\n"),
    )
    .unwrap();
}

#[cfg(not(feature = "protoc-rust"))]
fn main() {
    println!("using pre-generated *.rs files in 'src/'");
}