| 1 | //! The events service: the bus every state change in g1t is published on, |
| 2 | //! and its durable log. |
| 3 | //! |
| 4 | //! Publishing puts events on a queue and returns. The queue consumer writes |
| 5 | //! them to the log and passes each batch on to every subscriber's own |
| 6 | //! queue, so a slow or failing subscriber holds up nobody else. |
| 7 | //! |
| 8 | //! It keeps two more things beside the log: the audit log (audit.rs) and |
| 9 | //! each person's inbox (inbox.rs), written as events arrive, with who |
| 10 | //! follows what (subscriptions.rs). |
| 11 | //! |
| 12 | //! Other services reach it over `POST /rpc/<method>`; see |
| 13 | //! `g1t_contracts::events`, `audit` and `inbox` for the methods and their |
| 14 | //! arguments. |
| 15 | |
| 16 | mod audit; |
| 17 | mod inbox; |
| 18 | mod subscriptions; |
| 19 | |
| 20 | use g1t_contracts::events::{Event, ListArgs, PublishArgs}; |
| 21 | use g1t_contracts::new_id; |
| 22 | use g1t_contracts::time::rfc3339; |
| 23 | use g1t_kit::{args, js, now_ms, reply, rpc_method}; |
| 24 | use serde::Deserialize; |
| 25 | use worker::js_sys::{Array, Object}; |
| 26 | use worker::wasm_bindgen::{JsCast, JsValue}; |
| 27 | use worker::{Context, D1Database, Env, MessageBatch, Request, Response, Result, event}; |
| 28 | |
| 29 | const DEFAULT_PAGE: u32 = 50; |
| 30 | const MAX_PAGE: u32 = 200; |
| 31 | /// Every binding whose name starts with this is a queue that receives all |
| 32 | /// events: one per subscribing service. |
| 33 | const SUBSCRIBER_PREFIX: &str = "SUBSCRIBER_"; |
| 34 | |
| 35 | #[derive(Deserialize)] |
| 36 | struct EventRow { |
| 37 | id: String, |
| 38 | #[serde(rename = "type")] |
| 39 | kind: String, |
| 40 | source: String, |
| 41 | time: String, |
| 42 | repo_id: Option<String>, |
| 43 | actor: Option<String>, |
| 44 | /// JSON. |
| 45 | data: String, |
| 46 | } |
| 47 | |
| 48 | impl From<EventRow> for Event { |
| 49 | fn from(row: EventRow) -> Self { |
| 50 | Event { |
| 51 | id: row.id, |
| 52 | kind: row.kind, |
| 53 | source: row.source, |
| 54 | time: row.time, |
| 55 | repo_id: row.repo_id, |
| 56 | actor: row.actor, |
| 57 | data: serde_json::from_str(&row.data).unwrap_or_default(), |
| 58 | } |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | fn optional(value: &Option<String>) -> JsValue { |
| 63 | value.as_deref().map_or(JsValue::NULL, JsValue::from) |
| 64 | } |
| 65 | |
| 66 | /// Sends `events` to a queue binding, one message each. |
| 67 | async fn send(queue: &JsValue, events: &[Event]) -> Result<()> { |
| 68 | let messages = Array::new(); |
| 69 | for event in events { |
| 70 | let message = Object::new(); |
| 71 | js::set(&message, "body", &js::to_js(event)?); |
| 72 | messages.push(&message); |
| 73 | } |
| 74 | js::call(queue, "sendBatch", &[messages.into()]).await?; |
| 75 | Ok(()) |
| 76 | } |
| 77 | |
| 78 | struct Events { |
| 79 | db: D1Database, |
| 80 | env: Env, |
| 81 | } |
| 82 | |
| 83 | impl Events { |
| 84 | /// Assigns each event its id and time and puts it on the bus. |
| 85 | async fn publish(&self, a: PublishArgs) -> Result<()> { |
| 86 | if a.events.is_empty() { |
| 87 | return Ok(()); |
| 88 | } |
| 89 | let now = now_ms(); |
| 90 | let events: Vec<Event> = a |
| 91 | .events |
| 92 | .into_iter() |
| 93 | .map(|event| Event { |
| 94 | id: new_id("evt", now), |
| 95 | kind: event.kind, |
| 96 | source: event.source, |
| 97 | time: rfc3339(now), |
| 98 | repo_id: event.repo_id, |
| 99 | actor: event.actor, |
| 100 | data: event.data, |
| 101 | }) |
| 102 | .collect(); |
| 103 | send(&js::binding(&self.env, "BUS")?, &events).await |
| 104 | } |
| 105 | |
| 106 | /// Newest first. Callers must have checked that the viewer may see the |
| 107 | /// repository asked about. |
| 108 | async fn list(&self, a: ListArgs) -> Result<Vec<Event>> { |
| 109 | let mut conditions = Vec::new(); |
| 110 | let mut values: Vec<JsValue> = Vec::new(); |
| 111 | if let Some(repo_id) = &a.repo_id { |
| 112 | conditions.push("repo_id = ?".to_owned()); |
| 113 | values.push(repo_id.as_str().into()); |
| 114 | } |
| 115 | if !a.types.is_empty() { |
| 116 | let marks = vec!["?"; a.types.len()].join(", "); |
| 117 | conditions.push(format!("type IN ({marks})")); |
| 118 | values.extend(a.types.iter().map(|kind| JsValue::from(kind.as_str()))); |
| 119 | } |
| 120 | if let Some(before) = &a.before { |
| 121 | conditions.push("id < ?".to_owned()); |
| 122 | values.push(before.as_str().into()); |
| 123 | } |
| 124 | let filter = if conditions.is_empty() { |
| 125 | String::new() |
| 126 | } else { |
| 127 | format!("WHERE {}", conditions.join(" AND ")) |
| 128 | }; |
| 129 | values.push(a.limit.unwrap_or(DEFAULT_PAGE).min(MAX_PAGE).into()); |
| 130 | let rows = self |
| 131 | .db |
| 132 | .prepare(format!( |
| 133 | "SELECT * FROM events {filter} ORDER BY id DESC LIMIT ?" |
| 134 | )) |
| 135 | .bind(&values)? |
| 136 | .all() |
| 137 | .await? |
| 138 | .results::<EventRow>()?; |
| 139 | Ok(rows.into_iter().map(Event::from).collect()) |
| 140 | } |
| 141 | |
| 142 | /// Writes a batch from the bus to the log, hands it to every |
| 143 | /// subscriber, then tells the people it concerns (inbox.rs). |
| 144 | async fn deliver(&self, events: &[Event]) -> Result<()> { |
| 145 | let mut statements = Vec::with_capacity(events.len()); |
| 146 | for event in events { |
| 147 | statements.push( |
| 148 | self.db |
| 149 | .prepare( |
| 150 | // Redelivered batches must not duplicate log rows. |
| 151 | "INSERT OR IGNORE INTO events (id, type, source, time, repo_id, actor, data) |
| 152 | VALUES (?, ?, ?, ?, ?, ?, ?)", |
| 153 | ) |
| 154 | .bind(&[ |
| 155 | event.id.as_str().into(), |
| 156 | event.kind.as_str().into(), |
| 157 | event.source.as_str().into(), |
| 158 | event.time.as_str().into(), |
| 159 | optional(&event.repo_id), |
| 160 | optional(&event.actor), |
| 161 | serde_json::to_string(&event.data)?.into(), |
| 162 | ])?, |
| 163 | ); |
| 164 | } |
| 165 | self.db.batch(statements).await?; |
| 166 | audit::follow_renames(&self.db, events).await?; |
| 167 | |
| 168 | let bindings: &JsValue = self.env.as_ref(); |
| 169 | for name in Object::keys(bindings.unchecked_ref::<Object>()).iter() { |
| 170 | let Some(name) = name |
| 171 | .as_string() |
| 172 | .filter(|name| name.starts_with(SUBSCRIBER_PREFIX)) |
| 173 | else { |
| 174 | continue; |
| 175 | }; |
| 176 | send(&js::binding(&self.env, &name)?, events).await?; |
| 177 | } |
| 178 | inbox::follow(&self.db, events).await?; |
| 179 | let (work, repos, identity) = ( |
| 180 | self.env.service("WORK")?, |
| 181 | self.env.service("REPOS")?, |
| 182 | self.env.service("IDENTITY")?, |
| 183 | ); |
| 184 | let sources = inbox::Sources { |
| 185 | work: &work, |
| 186 | repos: &repos, |
| 187 | identity: &identity, |
| 188 | }; |
| 189 | inbox::deliver(&self.db, &sources, events).await; |
| 190 | Ok(()) |
| 191 | } |
| 192 | } |
| 193 | |
| 194 | #[event(fetch)] |
| 195 | async fn fetch(mut request: Request, env: Env, _ctx: Context) -> Result<Response> { |
| 196 | let Some(method) = rpc_method(&request) else { |
| 197 | return Response::error("Not found", 404); |
| 198 | }; |
| 199 | let body: serde_json::Value = request.json().await?; |
| 200 | let events = Events { |
| 201 | db: env.d1("DB")?, |
| 202 | env, |
| 203 | }; |
| 204 | match method.as_str() { |
| 205 | "publish" => reply(&events.publish(args(body)?).await?), |
| 206 | "list" => reply(&events.list(args(body)?).await?), |
| 207 | "audit_record" => reply(&audit::record(&events.db, args(body)?).await?), |
| 208 | "audit_list" => reply(&audit::list(&events.db, args(body)?).await?), |
| 209 | "inbox_list" => { |
| 210 | let repos = events.env.service("REPOS")?; |
| 211 | reply(&inbox::list(&events.db, &repos, args(body)?).await?) |
| 212 | } |
| 213 | "inbox_counts" => reply(&inbox::counts(&events.db, args(body)?).await?), |
| 214 | "inbox_mark" => reply(&inbox::mark(&events.db, args(body)?).await?), |
| 215 | "inbox_thread" => { |
| 216 | let (repos, work) = (events.env.service("REPOS")?, events.env.service("WORK")?); |
| 217 | reply(&inbox::thread(&events.db, &repos, &work, args(body)?).await?) |
| 218 | } |
| 219 | "inbox_subscription" => { |
| 220 | let work = events.env.service("WORK")?; |
| 221 | reply(&subscriptions::subscription(&events.db, &work, args(body)?).await?) |
| 222 | } |
| 223 | "inbox_subscribe" => { |
| 224 | let work = events.env.service("WORK")?; |
| 225 | reply(&subscriptions::subscribe(&events.db, &work, args(body)?).await?) |
| 226 | } |
| 227 | "inbox_watching" => reply(&subscriptions::watching(&events.db, args(body)?).await?), |
| 228 | "inbox_watch" => reply(&subscriptions::watch(&events.db, args(body)?).await?), |
| 229 | "inbox_watchers" => reply(&subscriptions::watchers_count(&events.db, args(body)?).await?), |
| 230 | "inbox_watched" => reply(&subscriptions::watched(&events.db, args(body)?).await?), |
| 231 | "inbox_settings" => reply(&subscriptions::settings(&events.db, args(body)?).await?), |
| 232 | "inbox_update_settings" => reply(&subscriptions::update_settings(&events.db, args(body)?).await?), |
| 233 | _ => Response::error("Unknown method", 404), |
| 234 | } |
| 235 | } |
| 236 | |
| 237 | /// Events from the bus. A batch that fails is retried whole, which is safe |
| 238 | /// because both the log and subscribers ignore an event they have seen. |
| 239 | #[event(queue)] |
| 240 | async fn queue(batch: MessageBatch<Event>, env: Env, _ctx: Context) -> Result<()> { |
| 241 | let events = Events { |
| 242 | db: env.d1("DB")?, |
| 243 | env, |
| 244 | }; |
| 245 | let delivered: Vec<Event> = batch |
| 246 | .messages()? |
| 247 | .into_iter() |
| 248 | .map(|message| message.into_body()) |
| 249 | .collect(); |
| 250 | events.deliver(&delivered).await?; |
| 251 | batch.ack_all(); |
| 252 | Ok(()) |
| 253 | } |
| 254 | |
| 255 | /// Once a day, old audit entries are removed: first everything older than |
| 256 | /// any workspace keeps (`AUDIT_MAX_DAYS`, 400 days), then each workspace's |
| 257 | /// entries older than its own plan keeps, as billing says (7 days free, 90 |
| 258 | /// on the plan, or what staff set). Workspaces with nothing older than the |
| 259 | /// shortest (`AUDIT_MIN_DAYS`, 7) are left alone. |
| 260 | #[event(scheduled)] |
| 261 | async fn scheduled(_event: worker::ScheduledEvent, env: Env, _ctx: worker::ScheduleContext) { |
| 262 | let days = |name: &str, default: u32| { |
| 263 | env.var(name) |
| 264 | .ok() |
| 265 | .and_then(|v| v.to_string().trim().parse::<u32>().ok()) |
| 266 | .filter(|days| *days > 0) |
| 267 | .unwrap_or(default) |
| 268 | }; |
| 269 | let max_days = days("AUDIT_MAX_DAYS", audit::DEFAULT_MAX_DAYS); |
| 270 | let min_days = days("AUDIT_MIN_DAYS", audit::DEFAULT_MIN_DAYS).min(max_days); |
| 271 | let Ok(db) = env.d1("DB") else { return }; |
| 272 | let now = now_ms(); |
| 273 | match inbox::purge(&db, now).await { |
| 274 | Ok(removed) if removed > 0 => worker::console_log!("removed {removed} old inbox items"), |
| 275 | Ok(_) => {} |
| 276 | Err(error) => worker::console_error!("could not remove old inbox items: {error}"), |
| 277 | } |
| 278 | match audit::purge(&db, &audit::keep_from(now, max_days), 20).await { |
| 279 | Ok(removed) if removed > 0 => { |
| 280 | worker::console_log!("removed {removed} audit entries older than {max_days} days") |
| 281 | } |
| 282 | Ok(_) => {} |
| 283 | Err(error) => worker::console_error!("could not remove old audit entries: {error}"), |
| 284 | } |
| 285 | // Without billing nobody's plan is known, so nothing younger than the |
| 286 | // ceiling is removed. |
| 287 | let billing = match env.service("BILLING") { |
| 288 | Ok(billing) => billing, |
| 289 | Err(error) => { |
| 290 | worker::console_error!( |
| 291 | "audit entries kept past their plan's days: no billing: {error}" |
| 292 | ); |
| 293 | return; |
| 294 | } |
| 295 | }; |
| 296 | match audit::purge_by_plan(&db, &billing, now, min_days, max_days).await { |
| 297 | Ok(removed) if removed > 0 => { |
| 298 | worker::console_log!("removed {removed} audit entries older than their plan keeps") |
| 299 | } |
| 300 | Ok(_) => {} |
| 301 | Err(error) => worker::console_error!("audit entries kept past their plan's days: {error}"), |
| 302 | } |
| 303 | } |