feat: java glue (kind of)

Cargo.toml

@@ -26,3 +26,18 @@ tokio-stream = { version = "0.1" }
 serde = { version = "1.0.193", features = ["derive"] }
 dashmap = { version = "5.5.3" }
 postcard = { version = "1.0.8" }
+#java
+jni = { version = "0.21.1", features = ["invocation"], optional = true }
+jni-sys = { version = "0.3.0", optional = true }
+rifgen = { git = "https://github.com/Kofituo/rifgen.git", rev = "d27d9785b2febcf5527f1deb6a846be5d583f7d7", optional = true }
+lazy_static = {version = "1.4.0", optional = true }
+log = { version = "0.4.21", optional = true }
+
+[build-dependencies]
+# java
+flapigen = { version = "0.6.0", optional = true }
+rifgen = { git = "https://github.com/Kofituo/rifgen.git", rev = "d27d9785b2febcf5527f1deb6a846be5d583f7d7", optional = true }
+
+[features]
+default = ["java"]
+java = ["lazy_static", "jni", "jni-sys", "flapigen", "rifgen", "log"]

build.rs

@@ -0,0 +1,71 @@
+/// The main method of the buildscript, required by some glue modules.
+fn main() {
+	#[cfg(feature = "java")] {
+		let pkg = "com.codemp.jni".to_string();
+		let pkg_folder = pkg.replace('.', "/"); // java moment
+
+		let out_dir = std::env::var("OUT_DIR").expect("cargo did not provide OUT_DIR");
+		let out_dir = std::path::Path::new(&out_dir);
+		let generated_glue_file = out_dir.join("generated_glue.in");
+		let src_dir = std::path::Path::new("src")
+			.join("glue")
+			.join("java");
+		let typemap_file = src_dir.join("typemap.in");
+		rifgen::Generator::new(rifgen::TypeCases::CamelCase, rifgen::Language::Java, vec![src_dir])
+			.generate_interface(&generated_glue_file);
+
+		// build java source path
+		let target = out_dir.parent().unwrap().parent().unwrap().parent().unwrap().to_path_buf();
+		let mut java_target = target.clone();
+		java_target.push("java");
+		let mut pkg_path = java_target.clone(); 
+		pkg_path.push("src");
+		pkg_path.push(pkg_folder);
+
+		// delete folder if it exists, then create it
+		recreate_path(&pkg_path);
+
+		// generate java code
+		let java_cfg = flapigen::JavaConfig::new(pkg_path.clone(), pkg);
+		let java_gen = flapigen::Generator::new(flapigen::LanguageConfig::JavaConfig(java_cfg))
+			.rustfmt_bindings(true);
+		java_gen.expand_many(
+			"codemp-intellij",
+			&[&generated_glue_file, &typemap_file],
+			out_dir.join("glue.rs")
+		);
+
+		//TODO panic if no jdk
+
+		// compile java code
+		let mut java_compiled = java_target.clone();
+		java_compiled.push("classes");
+		recreate_path(&java_compiled);	
+
+		let mut javac_cmd = std::process::Command::new("javac");
+		javac_cmd.arg("-d").arg(java_compiled.as_os_str());
+		for java_file in pkg_path.read_dir().unwrap().filter_map(|e| e.ok()) {
+			javac_cmd.arg(java_file.path().as_os_str());
+		}
+
+		// jar it! FIXME
+		let mut jar_file = target.clone();
+		jar_file.push("codemp-java.jar");
+		let mut jar_cmd = std::process::Command::new("jar");
+		jar_cmd.arg("cf").arg(jar_file.as_os_str());
+		jar_cmd.arg("-C").arg(java_compiled.as_os_str());
+		for java_file in java_compiled.read_dir().unwrap().filter_map(|e| e.ok()) {
+			jar_cmd.arg(java_file.path().as_os_str());
+		}
+		jar_cmd.spawn().expect("failed to run jar!");
+
+		println!("cargo:rerun-if-changed={}", generated_glue_file.display());
+	}
+}
+
+fn recreate_path(path: &std::path::PathBuf) {
+	if path.exists() {
+		std::fs::remove_dir_all(path).expect("failed to delete old dir!");
+	}
+	std::fs::create_dir_all(path).expect("error while creating folder!");
+}

src/glue/java/mod.rs

@@ -0,0 +1,333 @@
+use api::Controller;
+use codemp_proto::{cursor::{RowCol, CursorPosition}, files::BufferNode};
+use rifgen::rifgen_attr::{generate_access_methods, generate_interface, generate_interface_doc};
+use std::sync::Arc;
+use std::time::Duration;
+use uuid::Uuid;
+
+use crate::{
+	Client,
+	Error,
+	Result,
+	api::TextChange,
+	buffer::{self, tools},
+	cursor,
+	workspace::Workspace
+};
+
+//rifgen generated code
+include!(concat!(env!("OUT_DIR"), "/glue.rs"));
+
+lazy_static::lazy_static! {
+	/// the tokio runtime, since we can't easily have Java and Rust async work together
+	static ref RT: tokio::runtime::Runtime = tokio::runtime::Runtime::new()
+		.expect("could not start tokio runtime");
+}
+
+#[generate_interface_doc]
+/// the handler class that represent an instance of a CodeMP client
+struct ClientHandler {
+	client: Client,
+	url: String,
+}
+
+impl ClientHandler {
+	#[generate_interface(constructor)]
+	/// construct a new [ClientHandler]
+	fn new(address: &str) -> ClientHandler {
+		ClientHandler {
+			client: RT.block_on(Client::new(address)).unwrap(),
+			url: address.to_string(),
+		}
+	}
+
+	#[generate_interface]
+	/// join a workspace by name
+	fn join_workspace(&mut self, workspace_id: &str) -> Result<WorkspaceHandler> {
+		RT.block_on(self.client.join_workspace(workspace_id))
+			.map(|workspace| {
+				Self::spawn_updater(workspace.clone());
+				WorkspaceHandler { workspace }
+			})
+	}
+
+	fn spawn_updater(workspace: Arc<Workspace>) {
+		tokio::spawn(async move {
+			loop {
+				tokio::time::sleep(Duration::from_secs(60)).await;
+				workspace.fetch_buffers().await.unwrap();
+				workspace.fetch_users().await.unwrap();
+			}
+		});
+	}
+
+	#[generate_interface]
+	/// get the url you are currently connected to
+	fn get_url(&self) -> String {
+		self.url.clone()
+	}
+}
+
+#[generate_interface_doc]
+/// wraps a [codemp::workspace::Workspace] to be handled by Java
+struct WorkspaceHandler {
+	workspace: Arc<Workspace>,
+}
+
+impl WorkspaceHandler { // TODO: workspace leave / buffer detach ?
+	#[generate_interface(constructor)]
+	/// constructor required by flapigen, DO NOT CALL THIS
+	fn new() -> WorkspaceHandler {
+		unimplemented!()
+	}
+
+	#[generate_interface]
+	/// create a new buffer in current workspace
+	fn create_buffer(&mut self, path: &str) -> Result<BufferHandler> {
+		RT.block_on(self.workspace.create(path))?;
+		Ok(self.get_buffer(path).unwrap())
+	}
+
+	#[generate_interface]
+	/// attach to a buffer and get a [crate::BufferHandler] for it
+	fn attach_to_buffer(&mut self, path: &str) -> Result<BufferHandler> {
+		RT.block_on(self.workspace.attach(path))
+			.map(|buffer| BufferHandler { buffer })
+	}
+
+	#[generate_interface]
+	/// updates the local list of the workspace's buffers
+	fn fetch_buffers(&mut self) -> Result<()> {
+		RT.block_on(self.workspace.fetch_buffers())
+	}
+
+	#[generate_interface]
+	/// updates the local list of the workspace's users
+	fn fetch_users(&mut self) -> Result<()> {
+		RT.block_on(self.workspace.fetch_users())
+	}
+
+	#[generate_interface]
+	/// gets a list of all users in a buffer
+	fn list_buffer_users(&mut self, path: &str) -> Result<StringVec> {
+		let mut res = StringVec::new();
+		RT.block_on(self.workspace.list_buffer_users(path))?
+			.iter()
+			.for_each(|u| res.push(Uuid::from(u.clone()).to_string()));
+		Ok(res)
+	}
+
+	#[generate_interface]
+	/// delete a buffer
+	fn delete_buffer(&mut self, path: &str) -> Result<()> {
+		RT.block_on(self.workspace.delete(path))
+	}
+
+	#[generate_interface]
+	/// get the workspace id
+	fn get_workspace_id(&self) -> String {
+		self.workspace.id().clone()
+	}
+
+	#[generate_interface]
+	/// get a [crate::CursorHandler] for the workspace's cursor
+	fn get_cursor(&self) -> CursorHandler {
+		CursorHandler {
+			cursor: self.workspace.cursor().clone(),
+		}
+	}
+
+	#[generate_interface]
+	/// get a [crate::BufferHandler] for one of the workspace's buffers
+	fn get_buffer(&self, path: &str) -> Option<BufferHandler> {
+		self.workspace
+			.buffer_by_name(path)
+			.map(|buffer| BufferHandler { buffer })
+	}
+
+	#[generate_interface]
+	/// get the names of all buffers available in the workspace
+	fn get_filetree(&self) -> StringVec {
+		StringVec {
+			v: self.workspace.filetree()
+		}
+	}
+
+	#[generate_interface]
+	/// polls a list of buffers, returning the first ready one
+	fn select_buffer(
+		&mut self,
+		mut buffer_ids: StringVec,
+		timeout: i64,
+	) -> Result<Option<BufferHandler>> {
+		let mut buffers = Vec::new();
+		for id in buffer_ids.v.iter_mut() {
+			match self.get_buffer(id.as_str()) {
+				Some(buf) => buffers.push(buf.buffer),
+				None => continue,
+			}
+		}
+
+		let result = RT.block_on(tools::select_buffer(
+			buffers.as_slice(),
+			Some(Duration::from_millis(timeout as u64)),
+		));
+
+		match result {
+			Err(e) => Err(e),
+			Ok(buffer) => Ok(buffer.map(|buffer| BufferHandler { buffer })),
+		}
+	}
+}
+
+#[generate_interface_doc]
+#[generate_access_methods]
+/// wraps a [codemp::proto::cursor::CursorEvent] to be handled by Java
+struct CursorEventWrapper {
+	user: String,
+	buffer: String,
+	start_row: i32,
+	start_col: i32,
+	end_row: i32,
+	end_col: i32,
+}
+
+#[generate_interface_doc]
+/// a handler providing Java access to [codemp::cursor::Controller] methods
+struct CursorHandler {
+	pub cursor: Arc<cursor::Controller>,
+}
+
+impl CursorHandler {
+	#[generate_interface(constructor)]
+	/// constructor required by flapigen, DO NOT CALL THIS
+	fn new() -> CursorHandler {
+		unimplemented!()
+	}
+
+	#[generate_interface]
+	/// get next cursor event from current workspace, or block until one is available
+	fn recv(&self) -> Result<CursorEventWrapper> {
+		match RT.block_on(self.cursor.recv()) {
+			Err(err) => Err(err),
+			Ok(event) => Ok(CursorEventWrapper {
+				user: Uuid::from(event.user).to_string(),
+				buffer: event.position.buffer.path.clone(),
+				start_row: event.position.start.row,
+				start_col: event.position.start.col,
+				end_row: event.position.end.row,
+				end_col: event.position.end.col,
+			}),
+		}
+	}
+
+	#[generate_interface]
+	/// broadcast a cursor event
+	/// will automatically fix start and end if they are accidentally inverted
+	fn send(
+		&self,
+		buffer: String,
+		start_row: i32,
+		start_col: i32,
+		end_row: i32,
+		end_col: i32,
+	) -> Result<()> {
+		self.cursor.send(CursorPosition {
+			buffer: BufferNode { path: buffer },
+			start: RowCol::from((start_row, start_col)),
+			end: RowCol::from((end_row, end_col)),
+		})
+	}
+}
+
+#[generate_interface_doc]
+#[generate_access_methods]
+/// wraps a [codemp::api::change::TextChange] to make it accessible from Java
+struct TextChangeWrapper {
+	start: usize,
+	end: usize, //not inclusive
+	content: String,
+}
+
+#[generate_interface_doc]
+/// a handler providing Java access to [codemp::buffer::Controller] methods
+struct BufferHandler {
+	pub buffer: Arc<buffer::Controller>,
+}
+
+impl BufferHandler {
+	#[generate_interface(constructor)]
+	/// constructor required by flapigen, DO NOT CALL THIS
+	fn new() -> BufferHandler {
+		unimplemented!()
+	}
+
+	#[generate_interface]
+	/// get the name of the buffer
+	fn get_name(&self) -> String {
+		self.buffer.name().to_string()
+	}
+
+	#[generate_interface]
+	/// get the contents of the buffer
+	fn get_content(&self) -> String {
+		self.buffer.content()
+	}
+
+	#[generate_interface]
+	/// if a text change is available on the buffer, return it immediately
+	fn try_recv(&self) -> Result<Option<TextChangeWrapper>> {
+		match self.buffer.try_recv() {
+			Err(err) => Err(err),
+			Ok(None) => Ok(None),
+			Ok(Some(change)) => Ok(Some(TextChangeWrapper {
+				start: change.span.start,
+				end: change.span.end,
+				content: change.content.clone(),
+			})),
+		}
+	}
+
+	#[generate_interface]
+	/// broadcast a text change on the buffer
+	fn send(&self, start_offset: usize, end_offset: usize, content: String) -> Result<()> {
+		self.buffer.send(TextChange {
+			span: start_offset..end_offset,
+			content,
+		})
+	}
+}
+
+#[generate_interface_doc]
+/// a convenience struct allowing Java access to a Rust vector
+struct StringVec {
+	//jni moment
+	v: Vec<String>,
+}
+
+impl StringVec {
+	#[generate_interface(constructor)]
+	/// initialize an empty vector
+	fn new() -> StringVec {
+		Self { v: Vec::new() }
+	}
+
+	#[generate_interface]
+	/// push a new value onto the vector
+	fn push(&mut self, s: String) {
+		self.v.push(s);
+	}
+
+	#[generate_interface]
+	/// get the length of the underlying vector
+	fn length(&self) -> i64 {
+		self.v.len() as i64
+	}
+
+	#[generate_interface]
+	/// access the element at a given index
+	fn get(&self, idx: i64) -> Option<String> {
+		let elem: Option<&String> = self.v.get(idx as usize);
+		elem.map(|s| s.clone())
+	}
+}

src/glue/java/typemap.in

@@ -0,0 +1,39 @@
+foreign_typemap!( //thanks @tasn on GitHub for the idea
+	($p:r_type) <T> Result<T> => swig_i_type!(T) {
+		$out = match $p {
+			Ok(x) => {
+				swig_from_rust_to_i_type!(T, x, ret)
+				ret
+			}
+			Err(err) => {
+				let (msg, exception_class) = match err {
+					Error::Filler { message } => (
+						message,
+						swig_jni_find_class!(CODEMP_EXCEPTION, "com/codemp/intellij/exceptions/CodeMPException")
+					),
+					Error::Transport { status, message } => (
+						format!("Status {}: {}", status, message),
+						swig_jni_find_class!(TRANSPORT_EXCEPTION, "com/codemp/intellij/exceptions/lib/TransportException")
+					),
+					Error::InvalidState { msg } => (
+						msg, swig_jni_find_class!(INVALID_STATE_EXCEPTION, "com/codemp/intellij/exceptions/lib/InvalidStateException")
+					),
+					Error::Deadlocked => (
+						"WOOT deadlocked (safe to retry)!".to_string(),
+						swig_jni_find_class!(DEADLOCKED_EXCEPTION, "com/codemp/intellij/exceptions/lib/DeadlockedException")
+					),
+					Error::Channel { send } => {
+						let verb = if send { "sending" } else { "reading" };
+						(
+							format!("Error while {} message on channel: the channel was closed!", verb),
+							swig_jni_find_class!(CHANNEL_EXCEPTION, "com/codemp/intellij/exceptions/lib/ChannelException")
+						)
+					}
+				};
+				jni_throw(env, exception_class, &msg);
+				return <swig_i_type!(T)>::jni_invalid_value();
+			}
+		};
+	};
+	($p:f_type, unique_prefix="/*err*/") => "/*err*/swig_f_type!(T)" "swig_foreign_from_i_type!(T, $p)";
+);

src/glue/mod.rs

@@ -0,0 +1,2 @@
+#[cfg(feature = "java")]
+pub mod java;

src/lib.rs

@@ -137,6 +137,9 @@ pub mod workspace;
 /// all-in-one imports : `use codemp::prelude::*;`
 pub mod prelude;
 
+/// language-specific ffi "glue"
+pub mod glue;
+
 /// underlying OperationalTransform library used, re-exported
 pub use woot;
 

src/prelude.rs

@@ -7,7 +7,7 @@ pub use crate::{
 	Result as CodempResult,
 };
 
-pub use	crate::woot::crdt::Op as CodempOp;
+pub use crate::woot::crdt::Op as CodempOp;
 
 pub use crate::api::{
 	Controller as CodempController,