| 1 | use dashmap::{DashMap, Entry}; |
| 2 | use serde::de::DeserializeOwned; |
| 3 | use serde::{Deserialize, Serialize}; |
| 4 | use std::collections::HashMap; |
| 5 | use std::fmt::Formatter; |
| 6 | use std::sync::Arc; |
| 7 | use thiserror::Error; |
| 8 | |
| 9 | use crate::block::ClientID; |
| 10 | use crate::sync::{Clock, Timestamp}; |
| 11 | use crate::updates::decoder::{Decode, Decoder}; |
| 12 | use crate::updates::encoder::{Encode, Encoder}; |
| 13 | use crate::{Doc, Observer, Origin}; |
| 14 | |
| 15 | const NULL_STR: &str = "null"; |
| 16 | |
| 17 | #[cfg(feature = "sync")] |
| 18 | type AwarenessUpdateFn = Box<dyn Fn(&Awareness, &Event, Option<&Origin>) + Send + Sync + 'static>; |
| 19 | |
| 20 | #[cfg(not(feature = "sync"))] |
| 21 | type AwarenessUpdateFn = Box<dyn Fn(&Awareness, &Event, Option<&Origin>) + 'static>; |
| 22 | |
| 23 | /// The Awareness class implements a simple shared state protocol that can be used for non-persistent |
| 24 | /// data like awareness information (cursor, username, status, ..). Each client can update its own |
| 25 | /// local state and listen to state changes of remote clients. |
| 26 | /// |
| 27 | /// Each client is identified by a unique client id (something we borrow from `doc.clientID`). |
| 28 | /// A client can override its own state by propagating a message with an increasing timestamp |
| 29 | /// (`clock`). If such a message is received, it is applied if the known state of that client is |
| 30 | /// older than the new state (`clock < new_clock`). If a client thinks that a remote client is |
| 31 | /// offline, it may propagate a message with `{ clock, state: null, client }`. If such a message is |
| 32 | /// received, and the known clock of that client equals the received clock, it will clean the state. |
| 33 | /// |
| 34 | /// Before a client disconnects, it should propagate a `null` state with an updated clock. |
| 35 | pub struct Awareness { |
| 36 | doc: Doc, |
| 37 | states: DashMap<ClientID, ClientState>, |
| 38 | clock: Arc<dyn Clock>, |
| 39 | on_update: Observer<AwarenessUpdateFn>, |
| 40 | on_change: Observer<AwarenessUpdateFn>, |
| 41 | } |
| 42 | |
| 43 | impl Awareness { |
| 44 | /// Creates a new instance of [Awareness] struct, which operates over a given document. |
| 45 | /// Awareness instance has full ownership of that document. If necessary it can be accessed |
| 46 | /// using either [Awareness::doc] or [Awareness::doc_mut] methods. |
| 47 | #[cfg(not(target_family = "wasm"))] |
| 48 | pub fn new(doc: Doc) -> Self { |
| 49 | Self::with_clock(doc, crate::sync::time::SystemClock) |
| 50 | } |
| 51 | |
| 52 | /// Creates a new instance of [Awareness] struct, which operates over a given document. |
| 53 | /// Awareness instance has full ownership of that document. If necessary it can be accessed |
| 54 | /// using either [Awareness::doc] or [Awareness::doc_mut] methods. |
| 55 | pub fn with_clock<C>(doc: Doc, clock: C) -> Self |
| 56 | where |
| 57 | C: Clock + 'static, |
| 58 | { |
| 59 | Awareness { |
| 60 | doc, |
| 61 | states: DashMap::new(), |
| 62 | clock: Arc::new(clock), |
| 63 | on_update: Observer::new(), |
| 64 | on_change: Observer::new(), |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | /// Returns a channel receiver for an incoming awareness events. This channel can be cloned. |
| 69 | #[cfg(feature = "sync")] |
| 70 | pub fn on_update<F>(&self, f: F) -> crate::Subscription |
| 71 | where |
| 72 | F: Fn(&Awareness, &Event, Option<&Origin>) + Send + Sync + 'static, |
| 73 | { |
| 74 | self.on_update.subscribe(Box::new(f)) |
| 75 | } |
| 76 | |
| 77 | /// Returns a channel receiver for an incoming awareness events. This channel can be cloned. |
| 78 | #[cfg(not(feature = "sync"))] |
| 79 | pub fn on_update<F>(&self, f: F) -> crate::Subscription |
| 80 | where |
| 81 | F: Fn(&Awareness, &Event, Option<&Origin>) + 'static, |
| 82 | { |
| 83 | self.on_update.subscribe(Box::new(f)) |
| 84 | } |
| 85 | |
| 86 | /// Returns a channel receiver for an incoming awareness events. This channel can be cloned. |
| 87 | #[cfg(feature = "sync")] |
| 88 | pub fn on_update_with<K, F>(&self, key: K, f: F) |
| 89 | where |
| 90 | K: Into<Origin>, |
| 91 | F: Fn(&Awareness, &Event, Option<&Origin>) + Send + Sync + 'static, |
| 92 | { |
| 93 | self.on_update.subscribe_with(key.into(), Box::new(f)) |
| 94 | } |
| 95 | |
| 96 | /// Returns a channel receiver for an incoming awareness events. This channel can be cloned. |
| 97 | #[cfg(not(feature = "sync"))] |
| 98 | pub fn on_update_with<K, F>(&self, key: K, f: F) |
| 99 | where |
| 100 | K: Into<Origin>, |
| 101 | F: Fn(&Awareness, &Event, Option<&Origin>) + 'static, |
| 102 | { |
| 103 | self.on_update.subscribe_with(key.into(), Box::new(f)) |
| 104 | } |
| 105 | |
| 106 | /// Returns a channel receiver for an incoming awareness events. This channel can be cloned. |
| 107 | pub fn unobserve_update<K>(&self, key: K) -> bool |
| 108 | where |
| 109 | K: Into<Origin>, |
| 110 | { |
| 111 | self.on_update.unsubscribe(&key.into()) |
| 112 | } |
| 113 | |
| 114 | /// Returns a channel receiver for an incoming awareness events. This channel can be cloned. |
| 115 | #[cfg(feature = "sync")] |
| 116 | pub fn on_change<F>(&self, f: F) -> crate::Subscription |
| 117 | where |
| 118 | F: Fn(&Awareness, &Event, Option<&Origin>) + Send + Sync + 'static, |
| 119 | { |
| 120 | self.on_change.subscribe(Box::new(f)) |
| 121 | } |
| 122 | |
| 123 | /// Returns a channel receiver for an incoming awareness events. This channel can be cloned. |
| 124 | #[cfg(not(feature = "sync"))] |
| 125 | pub fn on_change<F>(&self, f: F) -> crate::Subscription |
| 126 | where |
| 127 | F: Fn(&Awareness, &Event, Option<&Origin>) + 'static, |
| 128 | { |
| 129 | self.on_change.subscribe(Box::new(f)) |
| 130 | } |
| 131 | |
| 132 | /// Returns a channel receiver for an incoming awareness events. This channel can be cloned. |
| 133 | #[cfg(feature = "sync")] |
| 134 | pub fn on_change_with<K, F>(&self, key: K, f: F) |
| 135 | where |
| 136 | K: Into<Origin>, |
| 137 | F: Fn(&Awareness, &Event, Option<&Origin>) + Send + Sync + 'static, |
| 138 | { |
| 139 | self.on_change.subscribe_with(key.into(), Box::new(f)) |
| 140 | } |
| 141 | |
| 142 | /// Returns a channel receiver for an incoming awareness events. This channel can be cloned. |
| 143 | #[cfg(not(feature = "sync"))] |
| 144 | pub fn on_change_with<K, F>(&self, key: K, f: F) |
| 145 | where |
| 146 | K: Into<Origin>, |
| 147 | F: Fn(&Awareness, &Event, Option<&Origin>) + 'static, |
| 148 | { |
| 149 | self.on_change.subscribe_with(key.into(), Box::new(f)) |
| 150 | } |
| 151 | |
| 152 | /// Returns a channel receiver for an incoming awareness events. This channel can be cloned. |
| 153 | pub fn unobserve_change<K>(&self, key: K) -> bool |
| 154 | where |
| 155 | K: Into<Origin>, |
| 156 | { |
| 157 | self.on_change.unsubscribe(&key.into()) |
| 158 | } |
| 159 | |
| 160 | /// Returns a read-only reference to an underlying [Doc]. |
| 161 | pub fn doc(&self) -> &Doc { |
| 162 | &self.doc |
| 163 | } |
| 164 | |
| 165 | /// Returns a read-write reference to an underlying [Doc]. |
| 166 | pub fn doc_mut(&mut self) -> &mut Doc { |
| 167 | &mut self.doc |
| 168 | } |
| 169 | |
| 170 | /// Returns a globally unique client ID of an underlying [Doc]. |
| 171 | pub fn client_id(&self) -> ClientID { |
| 172 | self.doc.client_id() |
| 173 | } |
| 174 | |
| 175 | /// Returns a state map of all the clients tracked by current [Awareness] instance. Those |
| 176 | /// states are identified by their corresponding [ClientID]s. The associated state is |
| 177 | /// represented and replicated to other clients as a JSON string. |
| 178 | pub fn iter(&self) -> AwarenessIter { |
| 179 | AwarenessIter(self.states.iter()) |
| 180 | } |
| 181 | |
| 182 | /// Returns a JSON string state representation of a current [Awareness] instance. |
| 183 | pub fn local_state<S: DeserializeOwned>(&self) -> Option<S> { |
| 184 | let json_str = self.local_state_raw()?; |
| 185 | serde_json::from_str(&json_str).ok() |
| 186 | } |
| 187 | |
| 188 | /// Returns a JSON string state representation of a current [Awareness] instance. |
| 189 | pub fn local_state_raw(&self) -> Option<Arc<str>> { |
| 190 | let e = self.states.get(&self.doc.client_id())?; |
| 191 | let json_str = e.value().clone().data?; |
| 192 | Some(json_str) |
| 193 | } |
| 194 | |
| 195 | /// Clears out a state of a given client, effectively marking it as disconnected. |
| 196 | pub fn remove_state(&self, client_id: ClientID) { |
| 197 | let is_removed = match self.states.entry(client_id) { |
| 198 | Entry::Occupied(mut e) => { |
| 199 | let state = e.get_mut(); |
| 200 | state.data = None; |
| 201 | state.clock += 1; |
| 202 | true |
| 203 | } |
| 204 | Entry::Vacant(e) => { |
| 205 | e.insert(ClientState::new(1, self.clock.now(), None)); |
| 206 | false |
| 207 | } |
| 208 | }; |
| 209 | if is_removed && self.on_update.has_subscribers() || self.on_change.has_subscribers() { |
| 210 | let e = Event::new(Vec::default(), Vec::default(), vec![client_id]); |
| 211 | self.on_change.trigger(|fun| fun(self, &e, None)); |
| 212 | self.on_update.trigger(|fun| fun(self, &e, None)); |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | /// Gets the state of a particular client. |
| 217 | pub fn state<D: DeserializeOwned>(&self, client_id: ClientID) -> Option<D> { |
| 218 | let state = self.states.get(&client_id)?; |
| 219 | let json = state.data.clone()?; |
| 220 | serde_json::from_str(&json).ok() |
| 221 | } |
| 222 | |
| 223 | /// Get the `(sequence number, last updated timestamp)` metadata associated with particular client. |
| 224 | pub fn meta(&self, client_id: ClientID) -> Option<(u32, Timestamp)> { |
| 225 | let state = self.states.get(&client_id)?; |
| 226 | Some((state.clock, state.last_updated)) |
| 227 | } |
| 228 | |
| 229 | /// Clears out a state of a current client (see: [Awareness::client_id]), |
| 230 | /// effectively marking it as disconnected. |
| 231 | pub fn clean_local_state(&self) { |
| 232 | let client_id = self.doc.client_id(); |
| 233 | self.remove_state(client_id); |
| 234 | } |
| 235 | |
| 236 | /// Sets a current [Awareness] instance state to a corresponding JSON string. This state will |
| 237 | /// be replicated to other clients as part of the [AwarenessUpdate] and it will trigger an event |
| 238 | /// to be emitted if current instance was created using [Awareness::with_observer] method. |
| 239 | pub fn set_local_state<S: Serialize>(&self, state: S) -> Result<(), Error> { |
| 240 | let json = serde_json::to_string(&state)?; |
| 241 | self.set_local_state_raw(json); |
| 242 | Ok(()) |
| 243 | } |
| 244 | |
| 245 | /// Sets a current [Awareness] instance state to a corresponding JSON string. This state will |
| 246 | /// be replicated to other clients as part of the [AwarenessUpdate] and it will trigger an event |
| 247 | /// to be emitted if current instance was created using [Awareness::with_observer] method. |
| 248 | pub fn set_local_state_raw<S: Into<Arc<str>>>(&self, json: S) { |
| 249 | let client_id = self.doc.client_id(); |
| 250 | let now = self.clock.now(); |
| 251 | let json = json.into(); |
| 252 | let prev = match self.states.entry(client_id) { |
| 253 | Entry::Occupied(mut e) => { |
| 254 | let state = e.get_mut(); |
| 255 | state.last_updated = now; |
| 256 | state.clock += 1; |
| 257 | state.data.replace(json.clone()) |
| 258 | } |
| 259 | Entry::Vacant(e) => { |
| 260 | e.insert(ClientState::new(1, now, Some(json.clone()))); |
| 261 | None |
| 262 | } |
| 263 | }; |
| 264 | self.notify_subscribers(client_id, prev, json); |
| 265 | } |
| 266 | |
| 267 | fn notify_subscribers( |
| 268 | &self, |
| 269 | client_id: ClientID, |
| 270 | prev_state: Option<Arc<str>>, |
| 271 | curr_state: Arc<str>, |
| 272 | ) { |
| 273 | if self.on_update.has_subscribers() || self.on_change.has_subscribers() { |
| 274 | let mut added = vec![]; |
| 275 | let mut updated = vec![]; |
| 276 | let mut changed = vec![]; |
| 277 | match prev_state { |
| 278 | None => added.push(client_id), |
| 279 | Some(prev) => { |
| 280 | updated.push(client_id); |
| 281 | if prev != curr_state { |
| 282 | changed.push(client_id); |
| 283 | } |
| 284 | } |
| 285 | } |
| 286 | let mut e = Event::new(added, changed, Vec::default()); |
| 287 | if !e.is_empty() { |
| 288 | self.on_change.trigger(|fun| fun(self, &e, None)); |
| 289 | } |
| 290 | e.summary.updated = updated; |
| 291 | if !e.is_empty() { |
| 292 | self.on_update.trigger(|fun| fun(self, &e, None)); |
| 293 | } |
| 294 | } |
| 295 | } |
| 296 | |
| 297 | /// Returns a serializable update object which is representation of a current Awareness state. |
| 298 | /// This doesn't include states that have been removed in the past. |
| 299 | pub fn update(&self) -> Result<AwarenessUpdate, Error> { |
| 300 | let clients: Vec<_> = self |
| 301 | .states |
| 302 | .iter() |
| 303 | .flat_map(|e| { |
| 304 | if e.data.is_none() { |
| 305 | None |
| 306 | } else { |
| 307 | Some(*e.key()) |
| 308 | } |
| 309 | }) |
| 310 | .collect(); |
| 311 | self.update_with_clients(clients) |
| 312 | } |
| 313 | |
| 314 | /// Returns a serializable update object which is representation of a current Awareness state. |
| 315 | /// Unlike [Awareness::update], this method variant allows to prepare update only for a subset |
| 316 | /// of known clients. These clients must all be known to a current [Awareness] instance, |
| 317 | /// otherwise a [Error::ClientNotFound] error will be returned. |
| 318 | pub fn update_with_clients<I: IntoIterator<Item = ClientID>>( |
| 319 | &self, |
| 320 | clients: I, |
| 321 | ) -> Result<AwarenessUpdate, Error> { |
| 322 | let mut res = HashMap::new(); |
| 323 | for client_id in clients { |
| 324 | let (clock, json) = if let Some(meta) = self.states.get(&client_id) { |
| 325 | let data = meta.data.clone().unwrap_or_else(|| NULL_STR.into()); |
| 326 | (meta.clock, data) |
| 327 | } else { |
| 328 | return Err(Error::ClientNotFound(client_id)); |
| 329 | }; |
| 330 | res.insert(client_id, AwarenessUpdateEntry { clock, json }); |
| 331 | } |
| 332 | Ok(AwarenessUpdate { clients: res }) |
| 333 | } |
| 334 | |
| 335 | /// Applies an update (incoming from remote channel or generated using [Awareness::update] / |
| 336 | /// [Awareness::update_with_clients] methods) and modifies a state of a current instance. |
| 337 | /// |
| 338 | /// If current instance has an observer channel (see: [Awareness::with_observer]), applied |
| 339 | /// changes will also be emitted as events. |
| 340 | pub fn apply_update(&self, update: AwarenessUpdate) -> Result<(), Error> { |
| 341 | let gen_summary = self.on_update.has_subscribers() || self.on_change.has_subscribers(); |
| 342 | self.apply_update_internal(update, None, gen_summary)?; |
| 343 | Ok(()) |
| 344 | } |
| 345 | |
| 346 | /// Applies an update (incoming from remote channel or generated using [Awareness::update] / |
| 347 | /// [Awareness::update_with_clients] methods) and modifies a state of a current instance. |
| 348 | /// |
| 349 | /// If current instance has an observer channel (see: [Awareness::with_observer]), applied |
| 350 | /// changes will also be emitted as events. |
| 351 | pub fn apply_update_with<O: Into<Origin>>( |
| 352 | &self, |
| 353 | update: AwarenessUpdate, |
| 354 | origin: O, |
| 355 | ) -> Result<(), Error> { |
| 356 | let gen_summary = self.on_update.has_subscribers() || self.on_change.has_subscribers(); |
| 357 | self.apply_update_internal(update, Some(origin.into()), gen_summary)?; |
| 358 | Ok(()) |
| 359 | } |
| 360 | |
| 361 | /// Applies an update (incoming from remote channel or generated using [Awareness::update] / |
| 362 | /// [Awareness::update_with_clients] methods) and modifies a state of a current instance. |
| 363 | /// Returns an [AwarenessUpdateSummary] object informing about the changes that were applied. |
| 364 | /// |
| 365 | /// If current instance has an observer channel (see: [Awareness::with_observer]), applied |
| 366 | /// changes will also be emitted as events. |
| 367 | pub fn apply_update_summary( |
| 368 | &self, |
| 369 | update: AwarenessUpdate, |
| 370 | ) -> Result<Option<AwarenessUpdateSummary>, Error> { |
| 371 | self.apply_update_internal(update, None, true) |
| 372 | } |
| 373 | |
| 374 | /// Applies an update (incoming from remote channel or generated using [Awareness::update] / |
| 375 | /// [Awareness::update_with_clients] methods) and modifies a state of a current instance. |
| 376 | /// Returns an [AwarenessUpdateSummary] object informing about the changes that were applied. |
| 377 | /// |
| 378 | /// If current instance has an observer channel (see: [Awareness::with_observer]), applied |
| 379 | /// changes will also be emitted as events. |
| 380 | pub fn apply_update_summary_with<O: Into<Origin>>( |
| 381 | &self, |
| 382 | update: AwarenessUpdate, |
| 383 | origin: O, |
| 384 | ) -> Result<Option<AwarenessUpdateSummary>, Error> { |
| 385 | self.apply_update_internal(update, Some(origin.into()), true) |
| 386 | } |
| 387 | |
| 388 | fn apply_update_internal( |
| 389 | &self, |
| 390 | update: AwarenessUpdate, |
| 391 | origin: Option<Origin>, |
| 392 | generate_summary: bool, |
| 393 | ) -> Result<Option<AwarenessUpdateSummary>, Error> { |
| 394 | let now = self.clock.now(); |
| 395 | |
| 396 | let mut added = Vec::new(); |
| 397 | let mut updated = Vec::new(); |
| 398 | let mut changed = Vec::new(); |
| 399 | let mut removed = Vec::new(); |
| 400 | |
| 401 | for (client_id, entry) in update.clients { |
| 402 | let mut clock = entry.clock; |
| 403 | let new: Option<_> = if entry.json.as_ref() == NULL_STR { |
| 404 | None |
| 405 | } else { |
| 406 | Some(entry.json) |
| 407 | }; |
| 408 | match self.states.entry(client_id) { |
| 409 | Entry::Occupied(mut e) => { |
| 410 | let state: &mut ClientState = e.get_mut(); |
| 411 | let is_removed = state.clock == clock && new.is_none() && state.data.is_some(); |
| 412 | if state.clock < clock || is_removed { |
| 413 | match new { |
| 414 | None => { |
| 415 | // never let a remote client remove this local state |
| 416 | if client_id == self.doc.client_id() && state.data.is_some() { |
| 417 | // remote client removed the local state. Do not remove state. Broadcast a message indicating |
| 418 | // that this client still exists by increasing the clock |
| 419 | clock += 1; |
| 420 | } else { |
| 421 | state.data = None; |
| 422 | if generate_summary { |
| 423 | removed.push(client_id); |
| 424 | } |
| 425 | } |
| 426 | } |
| 427 | new => { |
| 428 | if generate_summary { |
| 429 | updated.push(client_id); |
| 430 | if state.data.is_some() && state.data != new { |
| 431 | changed.push(client_id); |
| 432 | } |
| 433 | } |
| 434 | state.data = new; |
| 435 | } |
| 436 | } |
| 437 | state.clock = clock; |
| 438 | state.last_updated = now; |
| 439 | true |
| 440 | } else { |
| 441 | false |
| 442 | } |
| 443 | } |
| 444 | Entry::Vacant(e) => { |
| 445 | let has_data = new.is_some(); |
| 446 | e.insert(ClientState::new(clock, now, new)); |
| 447 | if has_data { |
| 448 | if generate_summary { |
| 449 | added.push(client_id); |
| 450 | } |
| 451 | true |
| 452 | } else { |
| 453 | false |
| 454 | } |
| 455 | } |
| 456 | }; |
| 457 | } |
| 458 | |
| 459 | if !added.is_empty() || !updated.is_empty() || !removed.is_empty() { |
| 460 | let summary = if self.on_update.has_subscribers() || self.on_change.has_subscribers() { |
| 461 | let mut e = Event::new(added, changed, removed); |
| 462 | if !e.is_empty() { |
| 463 | self.on_change.trigger(|fun| fun(self, &e, origin.as_ref())); |
| 464 | } |
| 465 | e.summary.updated = updated; |
| 466 | self.on_update.trigger(|fun| fun(self, &e, origin.as_ref())); |
| 467 | e.summary |
| 468 | } else { |
| 469 | AwarenessUpdateSummary { |
| 470 | added, |
| 471 | updated, |
| 472 | removed, |
| 473 | } |
| 474 | }; |
| 475 | Ok(Some(summary)) |
| 476 | } else { |
| 477 | Ok(None) |
| 478 | } |
| 479 | } |
| 480 | } |
| 481 | |
| 482 | #[cfg(not(target_family = "wasm"))] |
| 483 | impl Default for Awareness { |
| 484 | fn default() -> Self { |
| 485 | Awareness::new(Doc::new()) |
| 486 | } |
| 487 | } |
| 488 | |
| 489 | impl std::fmt::Debug for Awareness { |
| 490 | fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result { |
| 491 | let mut s = f.debug_struct("Awareness"); |
| 492 | s.field("doc", &self.doc); |
| 493 | s.field("states", &self.states); |
| 494 | s.finish() |
| 495 | } |
| 496 | } |
| 497 | |
| 498 | pub struct AwarenessIter<'a>(dashmap::iter::Iter<'a, ClientID, ClientState>); |
| 499 | |
| 500 | impl<'a> Iterator for AwarenessIter<'a> { |
| 501 | type Item = (ClientID, ClientState); |
| 502 | |
| 503 | fn next(&mut self) -> Option<Self::Item> { |
| 504 | let e = self.0.next()?; |
| 505 | Some((*e.key(), e.value().clone())) |
| 506 | } |
| 507 | } |
| 508 | |
| 509 | /// Summary of applying an [AwarenessUpdate] over [Awareness::apply_update_summary] method. |
| 510 | #[derive(Debug, Clone, Eq, PartialEq, Serialize, Deserialize)] |
| 511 | pub struct AwarenessUpdateSummary { |
| 512 | /// New clients added as part of the update. |
| 513 | pub added: Vec<ClientID>, |
| 514 | /// Existing clients that have been changed by the update. |
| 515 | pub updated: Vec<ClientID>, |
| 516 | /// Existing clients that have been removed by the update. |
| 517 | pub removed: Vec<ClientID>, |
| 518 | } |
| 519 | |
| 520 | impl AwarenessUpdateSummary { |
| 521 | /// Returns a collection of all clients that have been changed by the [AwarenessUpdate]. |
| 522 | pub fn all_changes(&self) -> Vec<ClientID> { |
| 523 | let mut res = |
| 524 | Vec::with_capacity(self.added.len() + self.updated.len() + self.removed.len()); |
| 525 | res.extend_from_slice(&self.added); |
| 526 | res.extend_from_slice(&self.updated); |
| 527 | res.extend_from_slice(&self.removed); |
| 528 | res |
| 529 | } |
| 530 | } |
| 531 | |
| 532 | /// A structure that represents an encodable state of an [Awareness] struct. |
| 533 | #[derive(Debug, Clone, Eq, PartialEq, Serialize, Deserialize)] |
| 534 | pub struct AwarenessUpdate { |
| 535 | /// Client updates. |
| 536 | pub clients: HashMap<ClientID, AwarenessUpdateEntry>, |
| 537 | } |
| 538 | |
| 539 | impl Encode for AwarenessUpdate { |
| 540 | fn encode<E: Encoder>(&self, encoder: &mut E) { |
| 541 | encoder.write_var(self.clients.len()); |
| 542 | for (&client_id, e) in self.clients.iter() { |
| 543 | encoder.write_var(client_id); |
| 544 | encoder.write_var(e.clock); |
| 545 | encoder.write_string(&e.json); |
| 546 | } |
| 547 | } |
| 548 | } |
| 549 | |
| 550 | impl Decode for AwarenessUpdate { |
| 551 | fn decode<D: Decoder>(decoder: &mut D) -> Result<Self, crate::encoding::read::Error> { |
| 552 | let len: usize = decoder.read_var()?; |
| 553 | let mut clients = HashMap::with_capacity(len); |
| 554 | for _ in 0..len { |
| 555 | let client_id: ClientID = decoder.read_var()?; |
| 556 | let clock: u32 = decoder.read_var()?; |
| 557 | let json: Arc<str> = decoder.read_string()?.into(); |
| 558 | clients.insert(client_id, AwarenessUpdateEntry { clock, json }); |
| 559 | } |
| 560 | |
| 561 | Ok(AwarenessUpdate { clients }) |
| 562 | } |
| 563 | } |
| 564 | |
| 565 | /// A single client entry of an [AwarenessUpdate]. It consists of logical clock and JSON client |
| 566 | /// state represented as a string. |
| 567 | #[derive(Debug, Clone, Eq, PartialEq, Serialize, Deserialize)] |
| 568 | pub struct AwarenessUpdateEntry { |
| 569 | /// Timestamp used to recognize which update is the latest one. |
| 570 | pub clock: u32, |
| 571 | /// String with JSON payload containing user data. |
| 572 | pub json: Arc<str>, |
| 573 | } |
| 574 | |
| 575 | /// Errors generated by an [Awareness] struct methods. |
| 576 | #[derive(Error, Debug)] |
| 577 | pub enum Error { |
| 578 | /// Client ID was not found in [Awareness] metadata. |
| 579 | #[error("client ID `{0}` not found")] |
| 580 | ClientNotFound(ClientID), |
| 581 | #[error("couldn't serialize awareness state: {0}")] |
| 582 | Serde(#[from] serde_json::Error), |
| 583 | } |
| 584 | |
| 585 | #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)] |
| 586 | pub struct ClientState { |
| 587 | pub clock: u32, |
| 588 | pub last_updated: Timestamp, |
| 589 | pub data: Option<Arc<str>>, |
| 590 | } |
| 591 | |
| 592 | impl ClientState { |
| 593 | fn new(clock: u32, last_updated: Timestamp, state: Option<Arc<str>>) -> Self { |
| 594 | ClientState { |
| 595 | clock, |
| 596 | last_updated, |
| 597 | data: state, |
| 598 | } |
| 599 | } |
| 600 | } |
| 601 | |
| 602 | /// Event type emitted by an [Awareness] struct. |
| 603 | #[derive(Debug, Clone, PartialEq)] |
| 604 | pub struct Event { |
| 605 | summary: AwarenessUpdateSummary, |
| 606 | } |
| 607 | |
| 608 | impl Event { |
| 609 | pub fn new(added: Vec<ClientID>, updated: Vec<ClientID>, removed: Vec<ClientID>) -> Self { |
| 610 | Event { |
| 611 | summary: AwarenessUpdateSummary { |
| 612 | added, |
| 613 | updated, |
| 614 | removed, |
| 615 | }, |
| 616 | } |
| 617 | } |
| 618 | |
| 619 | pub fn summary(&self) -> &AwarenessUpdateSummary { |
| 620 | &self.summary |
| 621 | } |
| 622 | |
| 623 | /// Collection of new clients that have been added to an [Awareness] struct, that was not known |
| 624 | /// before. Actual client state can be accessed via `awareness.clients().get(client_id)`. |
| 625 | pub fn added(&self) -> &[ClientID] { |
| 626 | &self.summary.added |
| 627 | } |
| 628 | |
| 629 | /// Collection of new clients that have been updated within an [Awareness] struct since the last |
| 630 | /// update. Actual client state can be accessed via `awareness.clients().get(client_id)`. |
| 631 | pub fn updated(&self) -> &[ClientID] { |
| 632 | &self.summary.updated |
| 633 | } |
| 634 | |
| 635 | /// Collection of new clients that have been removed from [Awareness] struct since the last |
| 636 | /// update. |
| 637 | pub fn removed(&self) -> &[ClientID] { |
| 638 | &self.summary.removed |
| 639 | } |
| 640 | |
| 641 | /// Returns all the changed client IDs (added, updated and removed) combined. |
| 642 | pub fn all_changes(&self) -> Vec<ClientID> { |
| 643 | self.summary.all_changes() |
| 644 | } |
| 645 | |
| 646 | fn is_empty(&self) -> bool { |
| 647 | self.summary.added.is_empty() |
| 648 | && self.summary.updated.is_empty() |
| 649 | && self.summary.removed.is_empty() |
| 650 | } |
| 651 | } |
| 652 | |
| 653 | #[cfg(test)] |
| 654 | mod test { |
| 655 | use arc_swap::ArcSwapOption; |
| 656 | use serde_json::{json, Value}; |
| 657 | use std::collections::HashMap; |
| 658 | use std::sync::Arc; |
| 659 | |
| 660 | use crate::sync::awareness::{AwarenessUpdateSummary, Event}; |
| 661 | use crate::sync::Awareness; |
| 662 | use crate::Doc; |
| 663 | |
| 664 | #[test] |
| 665 | fn awareness() { |
| 666 | fn exchange(recv: &ArcSwapOption<Event>, from: &Awareness, to: &mut Awareness) { |
| 667 | let e = recv.swap(None); |
| 668 | if let Some(e) = e.as_deref() { |
| 669 | let total = [e.added(), e.updated(), e.removed()].concat(); |
| 670 | let u = from.update_with_clients(total).unwrap(); |
| 671 | to.apply_update(u).unwrap(); |
| 672 | } |
| 673 | } |
| 674 | |
| 675 | let local = Awareness::new(Doc::with_client_id(1)); |
| 676 | let last_change_local = Arc::new(ArcSwapOption::default()); |
| 677 | let update = Arc::new(ArcSwapOption::default()); |
| 678 | let _sub_update = { |
| 679 | let update = update.clone(); |
| 680 | local.on_update(move |_, e, _| update.store(Some(Arc::new(e.clone())))) |
| 681 | }; |
| 682 | let _sub_local = { |
| 683 | let last_change_local = last_change_local.clone(); |
| 684 | local.on_change(move |_, e, _| last_change_local.store(Some(Arc::new(e.clone())))) |
| 685 | }; |
| 686 | |
| 687 | let mut remote = Awareness::new(Doc::with_client_id(2)); |
| 688 | let last_change_remote = Arc::new(ArcSwapOption::default()); |
| 689 | let _sub_remote = { |
| 690 | let last_change_remote = last_change_remote.clone(); |
| 691 | remote.on_change(move |_, e, _| last_change_remote.store(Some(Arc::new(e.clone())))) |
| 692 | }; |
| 693 | |
| 694 | assert!(local.on_change.has_subscribers(), "local has subscribers"); |
| 695 | assert!(remote.on_change.has_subscribers(), "remote has subscribers"); |
| 696 | local.set_local_state(json!({"x":3})).unwrap(); |
| 697 | exchange(&update, &local, &mut remote); |
| 698 | let _e_local = last_change_local.swap(None).unwrap(); |
| 699 | assert_eq!(remote.state::<Value>(1).unwrap(), json!({"x":3})); |
| 700 | assert_eq!(remote.states.get(&1).unwrap().clock, 1); |
| 701 | assert_eq!(last_change_remote.swap(None).unwrap().added(), &[1]); |
| 702 | |
| 703 | local.set_local_state(json!({"x":4})).unwrap(); |
| 704 | exchange(&update, &local, &mut remote); |
| 705 | let e_local = last_change_local.swap(None).unwrap(); |
| 706 | let e_remote = last_change_remote.swap(None).unwrap(); |
| 707 | assert_eq!(remote.state::<Value>(1).unwrap(), json!({"x":4})); |
| 708 | assert_eq!( |
| 709 | e_remote.summary, |
| 710 | AwarenessUpdateSummary { |
| 711 | added: vec![], |
| 712 | updated: vec![1], |
| 713 | removed: vec![] |
| 714 | } |
| 715 | ); |
| 716 | assert_eq!(e_remote.summary, e_local.summary); |
| 717 | |
| 718 | local.set_local_state(json!({"x":4})).unwrap(); |
| 719 | exchange(&update, &local, &mut remote); |
| 720 | let e_local = last_change_local.swap(None); |
| 721 | let e_remote = last_change_remote.swap(None); |
| 722 | assert_eq!(remote.state::<Value>(1).unwrap(), json!({"x":4})); |
| 723 | assert_eq!(remote.states.get(&1).unwrap().clock, 3); |
| 724 | assert_eq!(e_remote, e_local); |
| 725 | |
| 726 | local.clean_local_state(); |
| 727 | exchange(&update, &local, &mut remote); |
| 728 | let e_local = last_change_local.swap(None).unwrap(); |
| 729 | let e_remote = last_change_remote.swap(None).unwrap(); |
| 730 | assert_eq!(e_remote.removed().len(), 1); |
| 731 | assert!(local.state::<Value>(1).is_none()); |
| 732 | assert_eq!(e_remote.summary, e_local.summary); |
| 733 | assert_eq!(e_remote, e_local); |
| 734 | } |
| 735 | |
| 736 | #[test] |
| 737 | fn awareness_summary() -> Result<(), Box<dyn std::error::Error>> { |
| 738 | let local = Awareness::new(Doc::with_client_id(1)); |
| 739 | let remote = Awareness::new(Doc::with_client_id(2)); |
| 740 | |
| 741 | local.set_local_state(json!({"x":3})).unwrap(); |
| 742 | let update = local.update_with_clients([local.client_id()])?; |
| 743 | let summary = remote.apply_update_summary(update)?; |
| 744 | assert_eq!(remote.state::<Value>(1).unwrap(), json!({"x":3})); |
| 745 | assert_eq!(remote.states.get(&1).unwrap().clock, 1); |
| 746 | assert_eq!( |
| 747 | summary, |
| 748 | Some(AwarenessUpdateSummary { |
| 749 | added: vec![1], |
| 750 | updated: vec![], |
| 751 | removed: vec![] |
| 752 | }) |
| 753 | ); |
| 754 | |
| 755 | local.set_local_state(json!({"x":4})).unwrap(); |
| 756 | let update = local.update_with_clients([local.client_id()])?; |
| 757 | let summary = remote.apply_update_summary(update)?; |
| 758 | assert_eq!(remote.state::<Value>(1).unwrap(), json!({"x":4})); |
| 759 | assert_eq!( |
| 760 | summary, |
| 761 | Some(AwarenessUpdateSummary { |
| 762 | added: vec![], |
| 763 | updated: vec![1], |
| 764 | removed: vec![] |
| 765 | }) |
| 766 | ); |
| 767 | let local_states: HashMap<_, _> = local.iter().collect(); |
| 768 | let remote_states: HashMap<_, _> = remote.iter().collect(); |
| 769 | assert_eq!(local_states, remote_states); |
| 770 | |
| 771 | local.clean_local_state(); |
| 772 | let update = local.update_with_clients([local.client_id()])?; |
| 773 | let summary = remote.apply_update_summary(update)?; |
| 774 | assert_eq!( |
| 775 | summary, |
| 776 | Some(AwarenessUpdateSummary { |
| 777 | added: vec![], |
| 778 | updated: vec![], |
| 779 | removed: vec![1] |
| 780 | }) |
| 781 | ); |
| 782 | assert!(local.state::<Value>(1).is_none()); |
| 783 | let local_states: HashMap<_, _> = local.iter().collect(); |
| 784 | let remote_states: HashMap<_, _> = remote.iter().collect(); |
| 785 | assert_eq!(local_states, remote_states); |
| 786 | Ok(()) |
| 787 | } |
| 788 | } |
| 789 | |
amadan