feat: async try_recv, delta_request

Co-authored-by: alemi <me@alemi.dev>

Cargo.toml

@@ -12,17 +12,15 @@ crate-type = ["cdylib"]
 tracing = "0.1"
 thiserror = "1.0"
 async-trait = "0.1"
-# woot
+# crdt
-codemp-woot = { git = "ssh://git@github.com/hexedtech/woot.git", features = ["serde"], tag = "v0.1.2" }
+diamond-types = "1.0"
-diamond-types="1.0"
 # proto
 codemp-proto = { git = "ssh://git@github.com/hexedtech/codemp-proto.git", tag = "v0.6.1" }
 uuid = { version = "1.7", features = ["v4"] }
 tonic = { version = "0.11", features = ["tls", "tls-roots"] }
-postcard = "1.0"
 # api
-similar = { version = "2.2", features = ["inline"] }
 tokio = { version = "1.0", features = ["macros", "rt-multi-thread", "sync"] }
+xxhash-rust = { version = "0.8", features = ["xxh3"] }
 # client
 tokio-stream = "0.1"
 dashmap = "5.5"

src/api/change.rs

@@ -3,13 +3,6 @@
 //! an editor-friendly representation of a text change in a buffer
 //! to easily interface with codemp from various editors
 
-/// an atomic and orderable operation
-///
-/// this under the hood thinly wraps our CRDT operation
-#[derive(Debug, Clone)]
-pub struct Op(pub(crate) diamond_types::list::operation::Operation);
-// Do we need this in the api? why not just have a TextChange, which already covers as operation.
-
 /// an editor-friendly representation of a text change in a buffer
 ///
 /// this represent a range in the previous state of the string and a new content which should be
@@ -25,7 +18,6 @@ pub struct Op(pub(crate) diamond_types::list::operation::Operation);
 /// to delete a the fourth character we should send a
 ///     `TextChange { span: 3..4, content: "".into() }`
 ///
-
 #[derive(Clone, Debug, Default)]
 #[cfg_attr(feature = "js", napi_derive::napi(object))]
 #[cfg_attr(feature = "python", pyo3::pyclass)]
@@ -37,6 +29,8 @@ pub struct TextChange {
 	pub end: u32,
 	/// new content of text inside span
 	pub content: String,
+	/// optional content hash after applying this change
+	pub hash: Option<i64>,
 }
 
 impl TextChange {
@@ -58,92 +52,6 @@ impl TextChange {
 	pub fn is_empty(&self) -> bool {
 		!self.is_delete() && !self.is_insert()
 	}
-}
-
-/*
-impl TextChange {
-	/// create a new TextChange from the difference of given strings
-	pub fn from_diff(before: &str, after: &str) -> TextChange {
-		let diff = similar::TextDiff::from_chars(before, after);
-		let mut start = 0;
-		let mut end = 0;
-		let mut from_beginning = true;
-		for op in diff.ops() {
-			match op {
-				similar::DiffOp::Equal { len, .. } => {
-					if from_beginning {
-						start += len
-					} else {
-						end += len
-					}
-				}
-				_ => {
-					end = 0;
-					from_beginning = false;
-				}
-			}
-		}
-		let end_before = before.len() - end;
-		let end_after = after.len() - end;
-
-		TextChange {
-			start: start as u32,
-			end: end_before as u32,
-			content: after[start..end_after].to_string(),
-		}
-	}
-
-	pub fn span(&self) -> std::ops::Range<usize> {
-		self.start as usize..self.end as usize
-	}
-
-	/// consume the [TextChange], transforming it into a Vec of [Op]
-	pub fn transform(&self, woot: &Woot) -> WootResult<Vec<Op>> {
-		let mut out = Vec::new();
-		if self.is_empty() {
-			return Ok(out);
-		} // no-op
-		let view = woot.view();
-		let Some(span) = view.get(self.span()) else {
-			return Err(crate::woot::WootError::OutOfBounds);
-		};
-		let diff = similar::TextDiff::from_chars(span, &self.content);
-		for (i, diff) in diff.iter_all_changes().enumerate() {
-			match diff.tag() {
-				similar::ChangeTag::Equal => {}
-				similar::ChangeTag::Delete => match woot.delete_one(self.span().start + i) {
-					Err(e) => tracing::error!("could not create deletion: {}", e),
-					Ok(op) => out.push(Op(op)),
-				},
-				similar::ChangeTag::Insert => {
-					match woot.insert(self.span().start + i, diff.value()) {
-						Ok(ops) => {
-							for op in ops {
-								out.push(Op(op))
-							}
-						}
-						Err(e) => tracing::error!("could not create insertion: {}", e),
-					}
-				}
-			}
-		}
-		Ok(out)
-	}
-
-	/// returns true if this TextChange deletes existing text
-	pub fn is_deletion(&self) -> bool {
-		!self.span().is_empty()
-	}
-
-	/// returns true if this TextChange adds new text
-	pub fn is_addition(&self) -> bool {
-		!self.content.is_empty()
-	}
-
-	/// returns true if this TextChange is effectively as no-op
-	pub fn is_empty(&self) -> bool {
-		!self.is_deletion() && !self.is_addition()
-	}
 	
 	/// applies this text change to given text, returning a new string
 	pub fn apply(&self, txt: &str) -> String {
@@ -152,55 +60,17 @@ impl TextChange {
 		let post = txt.get(self.span().end..).unwrap_or("").to_string();
 		format!("{}{}{}", pre, self.content, post)
 	}
-
-	/// convert from byte index to row and column
-	/// txt must be the whole content of the buffer, in order to count lines
-	pub fn index_to_rowcol(txt: &str, index: usize) -> codemp_proto::cursor::RowCol {
-		// FIXME might panic, use .get()
-		let row = txt[..index].matches('\n').count() as i32;
-		let col = txt[..index].split('\n').last().unwrap_or("").len() as i32;
-		codemp_proto::cursor::RowCol { row, col }
-	}
 }
 
 #[cfg(test)]
 mod tests {
-	#[test]
-	fn textchange_diff_works_for_deletions() {
-		let change = super::TextChange::from_diff(
-			"sphinx of black quartz, judge my vow",
-			"sphinx of quartz, judge my vow",
-		);
-		assert_eq!(change.span(), 10..16);
-		assert_eq!(change.content, "");
-	}
-
-	#[test]
-	fn textchange_diff_works_for_insertions() {
-		let change = super::TextChange::from_diff(
-			"sphinx of quartz, judge my vow",
-			"sphinx of black quartz, judge my vow",
-		);
-		assert_eq!(change.span(), 10..10);
-		assert_eq!(change.content, "black ");
-	}
-
-	#[test]
-	fn textchange_diff_works_for_changes() {
-		let change = super::TextChange::from_diff(
-			"sphinx of black quartz, judge my vow",
-			"sphinx who watches the desert, judge my vow",
-		);
-		assert_eq!(change.span(), 7..22);
-		assert_eq!(change.content, "who watches the desert");
-	}
-
 	#[test]
 	fn textchange_apply_works_for_insertions() {
 		let change = super::TextChange {
 			start: 5,
 			end: 5,
 			content: " cruel".to_string(),
+			hash: None
 		};
 		let result = change.apply("hello world!");
 		assert_eq!(result, "hello cruel world!");
@@ -212,6 +82,7 @@ mod tests {
 			start: 5,
 			end: 11,
 			content: "".to_string(),
+			hash: None
 		};
 		let result = change.apply("hello cruel world!");
 		assert_eq!(result, "hello world!");
@@ -223,6 +94,7 @@ mod tests {
 			start: 5,
 			end: 11,
 			content: " not very pleasant".to_string(),
+			hash: None
 		};
 		let result = change.apply("hello cruel world!");
 		assert_eq!(result, "hello not very pleasant world!");
@@ -234,6 +106,7 @@ mod tests {
 			start: 100,
 			end: 110,
 			content: "a very long string \n which totally matters".to_string(),
+			hash: None
 		};
 		let result = change.apply("a short text");
 		assert_eq!(
@@ -242,31 +115,15 @@ mod tests {
 		);
 	}
 
-	#[test]
-	fn empty_diff_produces_empty_textchange() {
-		let change = super::TextChange::from_diff("same \n\n text", "same \n\n text");
-		assert!(change.is_empty());
-	}
-
 	#[test]
 	fn empty_textchange_doesnt_alter_buffer() {
 		let change = super::TextChange {
 			start: 42,
 			end: 42,
 			content: "".to_string(),
+			hash: None
 		};
 		let result = change.apply("some important text");
 		assert_eq!(result, "some important text");
 	}
-}*/
-
-// TODO: properly implement this for diamond types directly
-impl From<Op> for TextChange {
-	fn from(value: Op) -> Self {
-		Self {
-			start: value.0.start() as u32,
-			end: value.0.end() as u32,
-			content: value.0.content_as_str().unwrap_or_default().to_string(),
-		}
-	}
 }

src/api/controller.rs

@@ -37,12 +37,12 @@ pub trait Controller<T : Sized + Send + Sync> : Sized + Send + Sync {
 	///
 	/// `async fn recv(&self) -> codemp::Result<T>;`
 	async fn recv(&self) -> Result<T> {
-		if let Some(x) = self.try_recv()? {
+		loop {
-			return Ok(x); // short circuit if already available
+			self.poll().await?;
+			if let Some(x) = self.try_recv().await? {
+				break Ok(x);
+			}
 		}
-
-		self.poll().await?;
-		Ok(self.try_recv()?.expect("no message available after polling"))
 	}
 
 	/// block until next value is available without consuming it
@@ -53,7 +53,7 @@ pub trait Controller<T : Sized + Send + Sync> : Sized + Send + Sync {
 	async fn poll(&self) -> Result<()>;
 
 	/// attempt to receive a value without blocking, return None if nothing is available
-	fn try_recv(&self) -> Result<Option<T>>;
+	async fn try_recv(&self) -> Result<Option<T>>;
 
 	/// stop underlying worker
 	///

src/api/mod.rs

@@ -21,7 +21,6 @@ pub mod user;
 
 pub use controller::Controller;
 pub use change::TextChange;
-pub use change::Op;
 pub use cursor::Cursor;
 pub use event::Event;
 pub use user::User;

src/buffer/controller.rs

@@ -5,16 +5,13 @@
 use std::sync::Arc;
 
 use diamond_types::LocalVersion;
-use tokio::sync::{oneshot, Mutex};
+use tokio::sync::{oneshot, mpsc, watch};
-use tokio::sync::{mpsc, watch};
 use tonic::async_trait;
 
 use crate::api::Controller;
 
 use crate::api::TextChange;
 
-use crate::api::Op;
-
 use crate::ext::InternallyMutable;
 
 /// the buffer controller implementation
@@ -45,39 +42,14 @@ impl BufferController {
 
 #[derive(Debug)]
 pub(crate) struct BufferControllerInner {
-	name: String,
+	pub(crate) name: String,
-	latest_version: watch::Receiver<diamond_types::LocalVersion>,
+	pub(crate) latest_version: watch::Receiver<diamond_types::LocalVersion>,
-	last_update: InternallyMutable<diamond_types::LocalVersion>,
+	pub(crate) last_update: InternallyMutable<diamond_types::LocalVersion>,
-	ops_in: mpsc::UnboundedSender<TextChange>,
+	pub(crate) ops_in: mpsc::UnboundedSender<TextChange>,
-	ops_out: Mutex<mpsc::UnboundedReceiver<(LocalVersion, Option<Op>)>>,
+	pub(crate) poller: mpsc::UnboundedSender<oneshot::Sender<()>>,
-	poller: mpsc::UnboundedSender<oneshot::Sender<()>>,
+	pub(crate) stopper: mpsc::UnboundedSender<()>, // just exist
-	stopper: mpsc::UnboundedSender<()>, // just exist
+	pub(crate) content_request: mpsc::Sender<oneshot::Sender<String>>,
-	content_request: mpsc::Sender<oneshot::Sender<String>>,
+	pub(crate) delta_request: mpsc::Sender<(LocalVersion, oneshot::Sender<(LocalVersion, TextChange)>)>,
-}
-
-impl BufferControllerInner {
-	pub(crate) fn new(
-		name: String,
-		latest_version: watch::Receiver<diamond_types::LocalVersion>,
-		ops_in: mpsc::UnboundedSender<TextChange>,
-		ops_out: mpsc::UnboundedReceiver<(LocalVersion, Option<Op>)>,
-		poller: mpsc::UnboundedSender<oneshot::Sender<()>>,
-		stopper: mpsc::UnboundedSender<()>,
-		content_request: mpsc::Sender<oneshot::Sender<String>>,
-		// TODO we're getting too much stuff via constructor, maybe make everything pub(crate)
-		// instead?? or maybe builder, or maybe defaults
-	) -> Self {
-		Self {
-			name,
-			latest_version,
-			last_update: InternallyMutable::new(diamond_types::LocalVersion::default()),
-			ops_in,
-			ops_out: Mutex::new(ops_out),
-			poller,
-			stopper,
-			content_request,
-		}
-	}
 }
 
 #[async_trait]
@@ -85,9 +57,6 @@ impl Controller<TextChange> for BufferController {
 	/// block until a text change is available
 	/// this returns immediately if one is already available
 	async fn poll(&self) -> crate::Result<()> {
-		// TODO there might be some extra logic we can play with using `seen` and `not seen` yet
-		// mechanics, not just the comparison. nevermind, the `has_changed` etc stuff needs mut self, yuk.
-
 		if self.0.last_update.get() != *self.0.latest_version.borrow() {
 			return Ok(());
 		}
@@ -100,7 +69,7 @@ impl Controller<TextChange> for BufferController {
 	}
 
 	/// if a text change is available, return it immediately
-	fn try_recv(&self) -> crate::Result<Option<TextChange>> {
+	async fn try_recv(&self) -> crate::Result<Option<TextChange>> {
 		let last_update = self.0.last_update.get();
 		let latest_version = self.0.latest_version.borrow().clone();
 
@@ -108,29 +77,11 @@ impl Controller<TextChange> for BufferController {
 			return Ok(None);
 		}
 
-		match self.0.ops_out.try_lock() {
+		let (tx, rx) = oneshot::channel();
-			Err(_) => Ok(None),
+		self.0.delta_request.send((last_update, tx)).await?;
-			Ok(mut ops) => match ops.try_recv() {
+		let (v, change) = rx.await?;
-				Ok((lv, Some(op))) => {
+		self.0.last_update.set(v);
-					self.0.last_update.set(lv);
+		Ok(Some(change))
-					Ok(Some(TextChange::from(op)))
-				},
-				Ok((_lv, None)) => Ok(None), // TODO what is going on here?
-				Err(mpsc::error::TryRecvError::Empty) => Ok(None),
-				Err(mpsc::error::TryRecvError::Disconnected) =>
-					Err(crate::Error::Channel { send: false }),
-			},
-		}
-	}
-
-	/// block until a new text change is available, and return it
-	async fn recv(&self) -> crate::Result<TextChange> {
-		if let Some((lv, Some(op))) = self.0.ops_out.lock().await.recv().await {
-			self.0.last_update.set(lv);
-			Ok(TextChange::from(op))
-		} else {
-			Err(crate::Error::Channel { send: false })
-		}
 	}
 
 	/// enqueue a text change for processing

src/buffer/worker.rs

@@ -6,10 +6,10 @@ use tonic::{async_trait, Streaming};
 use uuid::Uuid;
 
 use crate::api::controller::ControllerWorker;
-use crate::api::Op;
 use crate::api::TextChange;
 
 use crate::errors::IgnorableError;
+use crate::ext::InternallyMutable;
 use codemp_proto::buffer::{BufferEvent, Operation};
 
 use super::controller::{BufferController, BufferControllerInner};
@@ -18,10 +18,10 @@ pub(crate) struct BufferWorker {
 	user_id: Uuid,
 	latest_version: watch::Sender<diamond_types::LocalVersion>,
 	ops_in: mpsc::UnboundedReceiver<TextChange>,
-	ops_out: mpsc::UnboundedSender<(LocalVersion, Option<Op>)>,
 	poller: mpsc::UnboundedReceiver<oneshot::Sender<()>>,
 	pollers: Vec<oneshot::Sender<()>>,
 	content_checkout: mpsc::Receiver<oneshot::Sender<String>>,
+	delta_req: mpsc::Receiver<(LocalVersion, oneshot::Sender<(LocalVersion, TextChange)>)>,
 	stop: mpsc::UnboundedReceiver<()>,
 	controller: BufferController,
 }
@@ -32,34 +32,35 @@ impl BufferWorker {
 
 		let (latest_version_tx, latest_version_rx) = watch::channel(init.clone());
 		let (opin_tx, opin_rx) = mpsc::unbounded_channel();
-		let (opout_tx, opout_rx) = mpsc::unbounded_channel();
 
 		let (req_tx, req_rx) = mpsc::channel(1);
+		let (recv_tx, recv_rx) = mpsc::channel(1);
 
 		let (poller_tx, poller_rx) = mpsc::unbounded_channel();
 
 		let (end_tx, end_rx) = mpsc::unbounded_channel();
 
-		let controller = BufferControllerInner::new(
+		let controller = BufferControllerInner {
-			path.to_string(),
+			name: path.to_string(),
-			latest_version_rx,
+			latest_version: latest_version_rx,
-			opin_tx,
+			last_update: InternallyMutable::new(diamond_types::LocalVersion::default()),
-			opout_rx,
+			ops_in: opin_tx,
-			poller_tx,
+			poller: poller_tx,
-			end_tx,
+			stopper: end_tx,
-			req_tx,
+			content_request: req_tx,
-		);
+			delta_request: recv_tx,
+		};
 
 		BufferWorker {
 			user_id,
 			latest_version: latest_version_tx,
 			ops_in: opin_rx,
-			ops_out: opout_tx,
 			poller: poller_rx,
 			pollers: Vec::new(),
 			stop: end_rx,
 			controller: BufferController(Arc::new(controller)),
 			content_checkout: req_rx,
+			delta_req: recv_rx,
 		}
 	}
 }
@@ -77,6 +78,7 @@ impl ControllerWorker<TextChange> for BufferWorker {
 	async fn work(mut self, tx: Self::Tx, mut rx: Self::Rx) {
 		let mut branch = diamond_types::list::Branch::new();
 		let mut oplog = diamond_types::list::OpLog::new();
+		let mut timer = Timer::new(10); // TODO configurable!!
 		loop {
 			// block until one of these is ready
 			tokio::select! {
@@ -112,31 +114,15 @@ impl ControllerWorker<TextChange> for BufferWorker {
 					},
 				},
 
-				// received a message from server
+				// received a message from server: add to oplog and update latest version (+unlock pollers)
 				res = rx.message() => match res {
 					Err(_e) => break,
 					Ok(None) => break,
 					Ok(Some(change)) => {
-						let last_ver = oplog.local_version();
 						match oplog.decode_and_add(&change.op.data) {
 							Ok(local_version) => {
-								// give all the changes needed to the controller in a channel.
-								for (lv, dtop) in oplog.iter_xf_operations_from(&last_ver, &local_version) {
-									if let Some(dtop) = dtop {
-										// x.0.start should always be after lastver!
-										// this step_ver will be the version after we apply the operation
-										// we give it to the controller so that he knows where it's at.
-										let step_ver = oplog.version_union(&[lv.start], &last_ver);
-										let opout = (step_ver, Some(Op(dtop)));
-
-										self.ops_out.send(opout).unwrap_or_warn("could not update ops channel -- is controller dead?");
-									}
-								}
-
-								// finally we send the 
 								self.latest_version.send(local_version)
 									.unwrap_or_warn("failed to update latest version!");
-
 								for tx in self.pollers.drain(..) {
 									tx.send(()).unwrap_or_warn("could not wake up poller");
 								}
@@ -146,8 +132,35 @@ impl ControllerWorker<TextChange> for BufferWorker {
 					},
 				},
 
+				// controller is ready to apply change and recv(), calculate it and send it back
+				res = self.delta_req.recv() => match res {
+					None => break tracing::error!("no more active controllers: can't send changes"),
+					Some((last_ver, tx)) => {
+						if let Some((lv, Some(dtop))) = oplog.iter_xf_operations_from(&last_ver, oplog.local_version_ref()).next() {
+							// x.0.start should always be after lastver!
+							// this step_ver will be the version after we apply the operation
+							// we give it to the controller so that he knows where it's at.
+							let step_ver = oplog.version_union(&[lv.start], &last_ver);
+							
+							branch.merge(&oplog, oplog.local_version_ref());
+							let hash = if timer.step() {
+								let hash = xxhash_rust::xxh3::xxh3_64(branch.content().to_string().as_bytes());
+								Some(i64::from_ne_bytes(hash.to_ne_bytes()))
+							} else { None };
+							let tc = crate::api::change::TextChange {
+								start: dtop.start() as u32,
+								end: dtop.end() as u32,
+								content: dtop.content_as_str().unwrap_or_default().to_string(),
+								hash
+							};
+							tx.send((step_ver, tc)).unwrap_or_warn("could not update ops channel -- is controller dead?");
+						}
+					},
+				},
+
+				// received a request for full CRDT content
 				res = self.content_checkout.recv() => match res {
-					None => break tracing::error!("no more active controllers"),
+					None => break tracing::error!("no more active controllers: can't update content"),
 					Some(tx) => {
 						branch.merge(&oplog, oplog.local_version_ref());
 						let content = branch.content().to_string();
@@ -158,3 +171,17 @@ impl ControllerWorker<TextChange> for BufferWorker {
 		}
 	}
 }
+
+struct Timer(u32, u32);
+impl Timer {
+	fn new(period: u32) -> Self { Timer(0, period) }
+	fn step(&mut self) -> bool {
+		self.0 += 1;
+		if self.0 >= self.1 {
+			self.0 = 0;
+			true
+		} else {
+			false
+		}
+	}
+}

src/cursor/controller.rs

@@ -3,13 +3,7 @@
 //! a controller implementation for cursor actions
 use std::sync::Arc;
 
-use tokio::sync::{
+use tokio::sync::{broadcast::{self, error::TryRecvError}, mpsc, watch, Mutex};
-	broadcast::{
-		self,
-		error::{RecvError, TryRecvError},
-	},
-	mpsc, watch, Mutex,
-};
 use tonic::async_trait;
 
 use crate::api::{Controller, Cursor};
@@ -66,36 +60,15 @@ impl Controller<Cursor> for CursorController {
 	}
 
 	/// try to receive without blocking, but will still block on stream mutex
-	fn try_recv(&self) -> crate::Result<Option<Cursor>> {
+	async fn try_recv(&self) -> crate::Result<Option<Cursor>> {
-		match self.0.stream.try_lock() {
-			Err(_) => Ok(None),
-			Ok(mut stream) => match stream.try_recv() {
-				Ok(x) => Ok(Some(x.into())),
-				Err(TryRecvError::Empty) => Ok(None),
-				Err(TryRecvError::Closed) => Err(crate::Error::Channel { send: false }),
-				Err(TryRecvError::Lagged(n)) => {
-					tracing::warn!("cursor channel lagged, skipping {} events", n);
-					Ok(stream.try_recv().map(|x| x.into()).ok())
-				}
-			}
-		}
-	}
-
-	// TODO is this cancelable? so it can be used in tokio::select!
-	// TODO is the result type overkill? should be an option?
-	/// get next cursor event from current workspace, or block until one is available
-	async fn recv(&self) -> crate::Result<Cursor> {
 		let mut stream = self.0.stream.lock().await;
-		match stream.recv().await {
+		match stream.try_recv() {
-			Ok(x) => Ok(x.into()),
+			Ok(x) => Ok(Some(x.into())),
-			Err(RecvError::Closed) => Err(crate::Error::Channel { send: false }),
+			Err(TryRecvError::Empty) => Ok(None),
-			Err(RecvError::Lagged(n)) => {
+			Err(TryRecvError::Closed) => Err(crate::Error::Channel { send: false }),
-				tracing::error!("cursor channel lagged behind, skipping {} events", n);
+			Err(TryRecvError::Lagged(n)) => {
-				Ok(stream
+				tracing::warn!("cursor channel lagged, skipping {} events", n);
-					.recv()
+				Ok(stream.try_recv().map(|x| x.into()).ok())
-					.await
-					.expect("could not receive after lagging")
-					.into())
 			}
 		}
 	}

src/ffi/js/mod.rs

@@ -1,5 +1,3 @@
-#![deny(clippy::all)]
-
 pub mod client;
 pub mod workspace;
 pub mod cursor;

src/lib.rs

@@ -143,9 +143,6 @@ pub mod ffi;
 /// common utils used in this library and re-exposed
 pub mod ext;
 
-/// underlying OperationalTransform library used, re-exported
-pub use woot;
-
 pub use errors::Error;
 pub use errors::Result;
 

src/prelude.rs

@@ -11,7 +11,6 @@ pub use crate::api::{
 	Controller as CodempController,
 	TextChange as CodempTextChange,
 	Cursor as CodempCursor,
-	Op as CodempOp,
 	User as CodempUser,
 	Event as CodempEvent,
 };