WIP: Start on live_kit crate that uses a C-based bridge

crates/live_kit/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "live_kit"
+version = "0.1.0"
+edition = "2021"
+description = "Bindings to LiveKit Swift client SDK"
+
+[lib]
+path = "src/live_kit.rs"
+doctest = false
+
+[dependencies]
+
+[build-dependencies]
+serde = { version = "1.0", features = ["derive", "rc"] }
+serde_json = { version = "1.0", features = ["preserve_order"] }

crates/live_kit/LiveKitBridge/.gitignore

@@ -0,0 +1,9 @@
+.DS_Store
+/.build
+/Packages
+/*.xcodeproj
+xcuserdata/
+DerivedData/
+.swiftpm/config/registries.json
+.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
+.netrc

crates/live_kit/LiveKitBridge/Package.resolved

@@ -0,0 +1,50 @@
+{
+  "pins" : [
+    {
+      "identity" : "client-sdk-swift",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/livekit/client-sdk-swift.git",
+      "state" : {
+        "revision" : "7e7decf3a09de4a169dfc0445a14d9fd2d8db58d",
+        "version" : "1.0.4"
+      }
+    },
+    {
+      "identity" : "promises",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/google/promises.git",
+      "state" : {
+        "revision" : "3e4e743631e86c8c70dbc6efdc7beaa6e90fd3bb",
+        "version" : "2.1.1"
+      }
+    },
+    {
+      "identity" : "specs",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/webrtc-sdk/Specs.git",
+      "state" : {
+        "revision" : "5225f2de4b6d0098803b3a0e55b255a41f293dad",
+        "version" : "104.5112.2"
+      }
+    },
+    {
+      "identity" : "swift-log",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-log.git",
+      "state" : {
+        "revision" : "6fe203dc33195667ce1759bf0182975e4653ba1c",
+        "version" : "1.4.4"
+      }
+    },
+    {
+      "identity" : "swift-protobuf",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-protobuf.git",
+      "state" : {
+        "revision" : "b8230909dedc640294d7324d37f4c91ad3dcf177",
+        "version" : "1.20.1"
+      }
+    }
+  ],
+  "version" : 2
+}

crates/live_kit/LiveKitBridge/Package.swift

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+// swift-tools-version: 5.6
+
+import PackageDescription
+
+let package = Package(
+    name: "LiveKitBridge",
+    platforms: [
+        .macOS(.v10_15)
+    ],
+    products: [
+        // Products define the executables and libraries a package produces, and make them visible to other packages.
+        .library(
+            name: "LiveKitBridge",
+            type: .static,
+            targets: ["LiveKitBridge"]),
+    ],
+    dependencies: [
+        .package(url: "https://github.com/livekit/client-sdk-swift.git", from: "1.0.0"),
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+        // Targets can depend on other targets in this package, and on products in packages this package depends on.
+        .target(
+            name: "LiveKitBridge",
+            dependencies: [.product(name: "LiveKit", package: "client-sdk-swift")]),
+    ]
+)

crates/live_kit/LiveKitBridge/README.md

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+# LiveKitBridge
+
+A description of this package.

crates/live_kit/LiveKitBridge/Sources/LiveKitBridge/LiveKitBridge.swift

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+import Foundation
+import LiveKit
+
+@_cdecl("LKRoomCreate")
+public func LKRoomCreate() -> UnsafeMutableRawPointer  {
+    Unmanaged.passRetained(Room()).toOpaque()
+}
+
+@_cdecl("LKRoomDestroy")
+public func LKRoomDestroy(ptr: UnsafeRawPointer)  {
+    let _ = Unmanaged<Room>.fromOpaque(ptr).takeRetainedValue();
+}

crates/live_kit/build.rs

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+use serde::Deserialize;
+use std::{env, path::PathBuf, process::Command};
+
+#[derive(Debug, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SwiftTargetInfo {
+    pub triple: String,
+    pub unversioned_triple: String,
+    pub module_triple: String,
+    pub swift_runtime_compatibility_version: String,
+    #[serde(rename = "librariesRequireRPath")]
+    pub libraries_require_rpath: bool,
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SwiftPaths {
+    pub runtime_library_paths: Vec<String>,
+    pub runtime_library_import_paths: Vec<String>,
+    pub runtime_resource_path: String,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct SwiftTarget {
+    pub target: SwiftTargetInfo,
+    pub paths: SwiftPaths,
+}
+
+const MACOS_TARGET_VERSION: &str = "12";
+
+fn main() {
+    build_bridge();
+    link_swift_stdlib();
+}
+
+fn build_bridge() {
+    let profile = env::var("PROFILE").unwrap();
+    let package_name = "LiveKitBridge";
+    let package_root = env::current_dir().unwrap().join(package_name);
+    if !Command::new("swift")
+        .args(&["build", "-c", &profile])
+        .current_dir(&package_root)
+        .status()
+        .unwrap()
+        .success()
+    {
+        panic!(
+            "Failed to compile swift package in {}",
+            package_root.display()
+        );
+    }
+
+    let swift_target_info = get_swift_target();
+    let swift_out_dir_path = format!(
+        "{}/.build/{}/{}",
+        package_root.display(),
+        swift_target_info.target.unversioned_triple,
+        profile
+    );
+
+    println!("cargo:rustc-link-search=native={}", swift_out_dir_path);
+    println!(
+        "cargo:rustc-link-search=framework={}",
+        "/Users/nathan/src/zed/crates/live_kit/frameworks"
+    );
+    println!("cargo:rustc-link-lib=static={}", package_name);
+    println!("cargo:rustc-link-lib=framework=WebRTC");
+}
+
+fn link_swift_stdlib() {
+    let target = get_swift_target();
+    if target.target.libraries_require_rpath {
+        panic!("Libraries require RPath! Change minimum MacOS value to fix.")
+    }
+
+    target.paths.runtime_library_paths.iter().for_each(|path| {
+        println!("cargo:rustc-link-search=native={}", path);
+    });
+}
+
+fn get_swift_target() -> SwiftTarget {
+    let mut arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
+    if arch == "aarch64" {
+        arch = "arm64".into();
+    }
+    let target = format!("{}-apple-macosx{}", arch, MACOS_TARGET_VERSION);
+
+    let swift_target_info_str = Command::new("swift")
+        .args(&["-target", &target, "-print-target-info"])
+        .output()
+        .unwrap()
+        .stdout;
+
+    serde_json::from_slice(&swift_target_info_str).unwrap()
+}

crates/live_kit/src/live_kit.rs

@@ -0,0 +1,24 @@
+use std::ffi::c_void;
+
+extern "C" {
+    fn LKRoomCreate() -> *const c_void;
+    fn LKRoomDestroy(ptr: *const c_void);
+}
+
+pub struct Room {
+    native_room: *const c_void,
+}
+
+impl Room {
+    pub fn new() -> Self {
+        Self {
+            native_room: unsafe { LKRoomCreate() },
+        }
+    }
+}
+
+impl Drop for Room {
+    fn drop(&mut self) {
+        unsafe { LKRoomDestroy(self.native_room) }
+    }
+}