feat: C API

Cargo.toml

@@ -62,6 +62,8 @@ serde = { version = "1.0", features = ["derive"], optional = true }
 napi-build = { version = "2.1", optional = true }
 # glue (python)
 pyo3-build-config = { version = "0.22", optional = true }
+# glue (C)
+cbindgen = { version = "0.24", optional = true }
 
 [features]
 default = []
@@ -73,6 +75,7 @@ java = ["lazy_static", "jni", "tracing-subscriber", "jni-toolbox"]
 js = ["napi-build", "tracing-subscriber", "napi", "napi-derive"]
 py-noabi = ["pyo3", "tracing-subscriber", "pyo3-build-config"]
 py = ["py-noabi", "pyo3/abi3-py38"]
+c = ["cbindgen"]
 lua = ["mlua-codemp-patch", "tracing-subscriber", "lazy_static", "serialize"]
 lua54 =["lua", "mlua-codemp-patch/lua54"] 
 luajit = ["lua", "mlua-codemp-patch/luajit"]

build.rs

@@ -4,6 +4,9 @@ extern crate napi_build;
 #[cfg(any(feature = "py", feature = "py-noabi"))]
 extern crate pyo3_build_config;
 
+#[cfg(feature = "c")]
+extern crate cbindgen;
+
 /// The main method of the buildscript, required by some glue modules.
 fn main() {
 	#[cfg(feature = "js")]
@@ -20,7 +23,16 @@ fn main() {
 	{
 		if let Ok("macos") = std::env::var("CARGO_CFG_TARGET_OS").as_deref() {
 			println!("cargo:rustc-cdylib-link-arg=-undefined");
-  		println!("cargo:rustc-cdylib-link-arg=dynamic_lookup");
-  	}
+			println!("cargo:rustc-cdylib-link-arg=dynamic_lookup");
+		}
+	}
+
+	#[cfg(feature = "c")]
+	{
+		cbindgen::Builder::new()
+			.with_crate(std::env::var("CARGO_MANIFEST_DIR").unwrap())
+			.generate()
+			.expect("Unable to generate bindings")
+			.write_to_file("dist/c/codemp.h");
 	}
 }

dist/c/codemp.h

@@ -0,0 +1,28 @@
+#include <cstdarg>
+#include <cstdint>
+#include <cstdlib>
+#include <ostream>
+#include <new>
+
+/// A `codemp` client handle.
+///
+/// It generates a new UUID and stores user credentials upon connecting.
+///
+/// A new [`Client`] can be obtained with [`Client::connect`].
+struct Client;
+
+/// A currently active shared development environment
+///
+/// Workspaces encapsulate a working environment: cursor positions, filetree, user list
+/// and more. Each holds a [cursor::Controller] and a map of [buffer::Controller]s.
+/// Using a workspace handle, it's possible to receive events (user join/leave, filetree updates)
+/// and create/delete/attach to new buffers.
+struct Workspace;
+
+extern "C" {
+
+Client *Codemp_Client_connect();
+
+Workspace *Codemp_Client_join_workspace(Client *client, char *workspace);
+
+} // extern "C"

src/ffi/c/mod.rs

@@ -0,0 +1,45 @@
+use std::ffi::{c_char, CString};
+
+use crate::{api::Config, Client, Workspace};
+
+pub(crate) fn tokio() -> &'static tokio::runtime::Runtime {
+	use std::sync::OnceLock;
+	static RT: OnceLock<tokio::runtime::Runtime> = OnceLock::new();
+	RT.get_or_init(||
+		tokio::runtime::Builder::new_current_thread()
+			.enable_all()
+			.build()
+			.expect("could not create tokio runtime")
+	)
+}
+
+
+#[no_mangle] // TODO config
+pub extern "C" fn Codemp_Client_connect() -> *mut Client {
+	match tokio()
+		.block_on(Client::connect(Config::new("", "")))
+	{
+		Ok(c) => Box::into_raw(Box::new(c)),
+		Err(e) => {
+			tracing::error!("failed connecting to remote: {e}");
+			std::ptr::null_mut()
+		},
+	}
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn Codemp_Client_join_workspace(client: *mut Client, workspace: *mut c_char) -> *mut Workspace {
+	let client = unsafe { Box::leak(Box::from_raw(client)) };
+	let workspace = unsafe { CString::from_raw(workspace) }.to_string_lossy().to_string();
+
+	match tokio()
+		.block_on(client.join_workspace(workspace))
+	{
+		Ok(ws) => Box::into_raw(Box::new(ws)),
+		Err(e) => {
+			tracing::error!("failed joining workspace: {e}");
+			std::ptr::null_mut()
+		},
+	}
+
+}

src/ffi/mod.rs

@@ -58,3 +58,7 @@ pub mod js;
 /// python bindings, built with [pyo3]
 #[cfg(any(feature = "py", feature = "py-noabi"))]
 pub mod python;
+
+/// c bindings, generated with [cbindgen]
+#[cfg(feature = "c")]
+pub mod c;