g1t/services/work/src/prefetch.rs

368 lines14,636 bytesCodeBlame
1//! Reading a page's worth of rows in one round trip.
2//!
3//! A pull request's page used to cost about twenty queries one after
4//! another: the repository, the pull request, its issue, then where it
5//! stands (its progress, latest review, settings, statuses, verdicts,
6//! queue entry, the confidence signals), its comments, checks and
7//! messages. Each is a round trip to the database, and from most places a
8//! round trip is 20 to 40 ms. Here they go as one D1 batch, keyed by the
9//! repository's id and the pull request's number, and the batch starts
10//! while the repos service is still deciding whether the viewer may see
11//! the repository ([`Work::repo_then`]).
12//!
13//! The helpers that answer those questions (`settings`, `statuses`,
14//! `review_pending`, `approvals_gap` and the rest) look here first, so the
15//! code that decides a pull request's lifecycle is the same code whether
16//! its rows were batched or read one at a time. Only reads are kept; a
17//! helper that writes and reads back (mergeability) reads the database.
18
19use std::cell::RefCell;
20use std::collections::HashMap;
21use std::future::Future;
22use std::rc::Rc;
23
24use g1t_contracts::repos::{Repo, RepoPath};
25use g1t_contracts::time::rfc3339;
26use g1t_contracts::{Outcome, Viewer};
27use g1t_kit::now_ms;
28use serde::de::DeserializeOwned;
29use worker::wasm_bindgen::JsValue;
30use worker::{D1PreparedStatement, D1Result, Result};
31
32use crate::reviews::AGENT_ID;
33use crate::rows::PULL_COLUMNS;
34use crate::{ISSUE_COLUMNS, Work};
35
36/// The pull request's id, from the batch's `?1` (repository) and `?2` (number).
37const PULL_ID: &str = "(SELECT id FROM pulls WHERE repo_id = ?1 AND number = ?2)";
38
39/// How long a review that never reported is waited for (reviews.rs).
40pub(crate) const REVIEW_PENDING_MS: u64 = 30 * 60 * 1000;
41
42/// Each statement of a pull request's batch, in order.
43#[derive(Clone, Copy)]
44pub(crate) enum Slot {
45 Pull,
46 Issue,
47 Comments,
48 Verdicts,
49 Runs,
50 RunHistory,
51 Review,
52 ReviewComments,
53 ReviewPending,
54 Statuses,
55 Settings,
56 Hold,
57 Messages,
58 Others,
59 Queued,
60 LatestRun,
61 Halted,
62 Denials,
63 Unanswered,
64 Planned,
65}
66
67/// How many runs `latest_checks` and `earlier_checks` show together.
68pub(crate) const RECENT_RUNS: u32 = 11;
69
70/// One pull request's rows, as read for this request.
71pub(crate) struct Prefetched {
72 pub(crate) pull_id: String,
73 pub(crate) repo_id: String,
74 /// Its head commit when read, which its statuses are for.
75 pub(crate) head: Option<String>,
76 results: Vec<D1Result>,
77}
78
79impl Prefetched {
80 /// A slot's rows, as the helper that reads them would have.
81 pub(crate) fn rows<T: DeserializeOwned>(&self, slot: Slot) -> Result<Vec<T>> {
82 match self.results.get(slot as usize) {
83 Some(result) => result.results::<T>(),
84 None => Ok(Vec::new()),
85 }
86 }
87
88 /// A slot's first row.
89 pub(crate) fn first<T: DeserializeOwned>(&self, slot: Slot) -> Result<Option<T>> {
90 Ok(self.rows::<T>(slot)?.into_iter().next())
91 }
92}
93
94#[derive(serde::Deserialize)]
95struct IdRow {
96 id: String,
97 head_commit: Option<String>,
98}
99
100thread_local! {
101 /// Repository ids by path, as the repos service last answered: a guess
102 /// that lets a page's batch start before the answer comes. Never
103 /// trusted: nothing read with a guess is used unless the repos service
104 /// then says the viewer may see that very repository.
105 static REPO_IDS: RefCell<HashMap<String, String>> = RefCell::new(HashMap::new());
106}
107
108/// Guesses kept at most; the map is emptied past this.
109const MAX_GUESSES: usize = 1024;
110
111fn path_key(path: &RepoPath) -> String {
112 format!("{}/{}", path.namespace.to_lowercase(), path.name.to_lowercase())
113}
114
115fn guess(path: &RepoPath) -> Option<String> {
116 REPO_IDS.with(|ids| ids.borrow().get(&path_key(path)).cloned())
117}
118
119fn learn(path: &RepoPath, id: Option<&str>) {
120 REPO_IDS.with(|ids| {
121 let mut ids = ids.borrow_mut();
122 match id {
123 Some(id) => {
124 if ids.len() >= MAX_GUESSES {
125 ids.clear();
126 }
127 ids.insert(path_key(path), id.to_owned());
128 }
129 None => {
130 ids.remove(&path_key(path));
131 }
132 }
133 });
134}
135
136impl Work {
137 /// The repository at `path` if `viewer` may see it, and what `load`
138 /// reads for it. When this isolate has seen the repository before,
139 /// `load` starts with its id at once, beside the access check, instead
140 /// of after it: one round trip instead of two. What it read is
141 /// discarded unless the check passes for that same repository.
142 pub(crate) async fn repo_then<T, F, Fut>(&self, path: &RepoPath, viewer: &Viewer, load: F) -> Result<Outcome<(Repo, T)>>
143 where
144 F: Fn(String) -> Fut,
145 Fut: Future<Output = Result<T>>,
146 {
147 let guessed = guess(path);
148 let (found, early) = match &guessed {
149 Some(id) => {
150 let (found, early) = futures_util::future::join(self.repo(path, viewer), load(id.clone())).await;
151 (found?, Some(early))
152 }
153 None => (self.repo(path, viewer).await?, None),
154 };
155 let repo = match found {
156 Outcome::Ok(repo) => repo,
157 Outcome::Fail(failure) => {
158 learn(path, None);
159 return Ok(Outcome::Fail(failure));
160 }
161 };
162 if let (Some(id), Some(Ok(value))) = (&guessed, early)
163 && *id == repo.id
164 {
165 return Ok(Outcome::Ok((repo, value)));
166 }
167 learn(path, Some(&repo.id));
168 let value = load(repo.id.clone()).await?;
169 Ok(Outcome::Ok((repo, value)))
170 }
171
172 fn statement(&self, sql: &str, binds: &[JsValue]) -> Result<D1PreparedStatement> {
173 self.db.prepare(sql).bind(binds)
174 }
175
176 /// Everything a pull request's page and its lifecycle read, in one
177 /// batch. `None` when there is no such pull request.
178 pub(crate) async fn prefetch_pull(&self, repo_id: String, number: u32) -> Result<Option<Prefetched>> {
179 let key = || -> [JsValue; 2] { [repo_id.as_str().into(), number.into()] };
180 let with = |extra: JsValue| -> [JsValue; 3] { [repo_id.as_str().into(), number.into(), extra] };
181 let repo_only = || -> [JsValue; 1] { [repo_id.as_str().into()] };
182 let statements = vec![
183 // Slot::Pull: the row, with everything the lifecycle tracks on it.
184 self.statement(&format!("SELECT {PULL_COLUMNS} FROM pulls WHERE repo_id = ?1 AND number = ?2"), &key())?,
185 // Slot::Issue
186 self.statement(
187 &format!(
188 "SELECT {ISSUE_COLUMNS} FROM issues
189 WHERE repo_id = ?1 AND number = (SELECT issue_number FROM pulls WHERE repo_id = ?1 AND number = ?2)"
190 ),
191 &key(),
192 )?,
193 // Slot::Comments (lib.rs `comments`)
194 self.statement("SELECT * FROM comments WHERE repo_id = ?1 AND number = ?2 ORDER BY id LIMIT 500", &key())?,
195 // Slot::Verdicts: every verdict, oldest first, for the approval
196 // rule, a person's request for changes and a person's approval.
197 self.statement(
198 "SELECT author_id, author_name, verdict, created_at FROM comments
199 WHERE repo_id = ?1 AND number = ?2 AND verdict IS NOT NULL ORDER BY id",
200 &key(),
201 )?,
202 // Slot::Runs: the latest and the ten before it (checks.rs).
203 self.statement(
204 &format!("SELECT * FROM check_runs WHERE pull_id = {PULL_ID} ORDER BY id DESC LIMIT ?3"),
205 &with(RECENT_RUNS.into()),
206 )?,
207 // Slot::RunHistory (confidence.rs `signals`)
208 self.statement(
209 &format!("SELECT head_commit, status FROM check_runs WHERE pull_id = {PULL_ID} ORDER BY id LIMIT 50"),
210 &key(),
211 )?,
212 // Slot::Review (lifecycle.rs `assess_now`)
213 self.statement(
214 &format!(
215 "SELECT finished_at, verdict FROM review_runs
216 WHERE pull_id = {PULL_ID} AND finished_at IS NOT NULL ORDER BY id DESC LIMIT 1"
217 ),
218 &key(),
219 )?,
220 // Slot::ReviewComments: lines that latest review commented on
221 // (confidence.rs `review_comments`).
222 self.statement(
223 &format!(
224 "SELECT count(*) AS n FROM comments
225 WHERE repo_id = ?1 AND number = ?2 AND author_id = ?3 AND path IS NOT NULL
226 AND created_at = (SELECT finished_at FROM review_runs
227 WHERE pull_id = {PULL_ID} AND finished_at IS NOT NULL ORDER BY id DESC LIMIT 1)"
228 ),
229 &with(AGENT_ID.into()),
230 )?,
231 // Slot::ReviewPending (reviews.rs `review_pending`)
232 self.statement(
233 &format!(
234 "SELECT id AS value FROM review_runs
235 WHERE pull_id = {PULL_ID} AND finished_at IS NULL AND created_at > ?3 LIMIT 1"
236 ),
237 &with(rfc3339(now_ms().saturating_sub(REVIEW_PENDING_MS)).into()),
238 )?,
239 // Slot::Statuses: on its head (statuses.rs `statuses`).
240 self.statement(
241 "SELECT context, state, description, target_url, updated_at FROM commit_statuses
242 WHERE repo_id = ?1 AND sha = (SELECT head_commit FROM pulls WHERE repo_id = ?1 AND number = ?2)
243 ORDER BY context",
244 &key(),
245 )?,
246 // Slot::Settings and Slot::Hold (settings.rs `settings`)
247 self.statement("SELECT * FROM repo_settings WHERE repo_id = ?1", &repo_only())?,
248 self.statement("SELECT hold_low AS n FROM confidence_rules WHERE repo_id = ?1", &repo_only())?,
249 // Slot::Messages (messages.rs `messages`)
250 self.statement(
251 &format!("SELECT * FROM agent_messages WHERE pull_id = {PULL_ID} ORDER BY created_at, id"),
252 &key(),
253 )?,
254 // Slot::Others (reviews.rs `overlaps`)
255 self.statement(
256 "SELECT number, title, issue_number, files FROM pulls
257 WHERE repo_id = ?1 AND number != ?2 AND status IN ('draft', 'open')
258 ORDER BY number LIMIT 200",
259 &key(),
260 )?,
261 // Slot::Queued (queue.rs `queued_entry`)
262 self.statement(
263 &format!(
264 "SELECT * FROM queue_entries
265 WHERE pull_id = {PULL_ID} AND state IN ('waiting', 'testing', 'passed') LIMIT 1"
266 ),
267 &key(),
268 )?,
269 // Slot::LatestRun, Halted, Denials, Unanswered, Planned
270 // (confidence.rs `signals`)
271 self.statement(
272 &format!(
273 "SELECT r.id, r.cost_usd, r.budget_usd, r.time_cap_minutes,
274 (julianday(COALESCE(r.finished_at, r.updated_at)) - julianday(COALESCE(r.started_at, r.created_at))) * 1440 AS minutes,
275 c.self_level, c.uncertain_about
276 FROM agent_runs r LEFT JOIN run_confidence c ON c.run_id = r.id
277 WHERE r.pull_id = {PULL_ID} AND r.kind IN ('implement', 'revise')
278 ORDER BY r.created_at DESC LIMIT 1"
279 ),
280 &key(),
281 )?,
282 self.statement(
283 &format!(
284 "SELECT halted FROM agent_runs WHERE pull_id = {PULL_ID} AND halted IS NOT NULL
285 ORDER BY created_at DESC LIMIT 1"
286 ),
287 &key(),
288 )?,
289 self.statement(
290 &format!(
291 "SELECT count(*) AS n FROM session_entries
292 WHERE pull_id = {PULL_ID} AND kind = 'note' AND text LIKE 'Denied:%'"
293 ),
294 &key(),
295 )?,
296 self.statement(
297 "SELECT count(*) AS n FROM agent_messages
298 WHERE repo_id = ?1 AND from_number = ?2 AND kind IN ('question', 'handoff')
299 AND answered_at IS NULL",
300 &key(),
301 )?,
302 self.statement(
303 "SELECT json_extract(planned.value, '$.files') AS files
304 FROM plans, json_each(plans.issues) AS planned
305 WHERE plans.repo_id = ?1 AND plans.status = 'applied'
306 AND json_extract(planned.value, '$.number') = (SELECT issue_number FROM pulls WHERE repo_id = ?1 AND number = ?2)
307 LIMIT 1",
308 &key(),
309 )?,
310 ];
311 let count = statements.len() as u32;
312 let results = self.timing.db(count, self.db.batch(statements)).await?;
313 let Some(row) = results
314 .first()
315 .map(|result| result.results::<IdRow>())
316 .transpose()?
317 .and_then(|rows| rows.into_iter().next())
318 else {
319 return Ok(None);
320 };
321 Ok(Some(Prefetched {
322 pull_id: row.id,
323 repo_id,
324 head: row.head_commit,
325 results,
326 }))
327 }
328
329 /// The rows read for pull request `pull_id` in this request, if any.
330 pub(crate) fn prefetched_pull(&self, pull_id: &str) -> Option<Rc<Prefetched>> {
331 self.prefetched
332 .borrow()
333 .as_ref()
334 .filter(|found| found.pull_id == pull_id)
335 .cloned()
336 }
337
338 /// The rows read in this request for a pull request of `repo_id`.
339 pub(crate) fn prefetched_repo(&self, repo_id: &str) -> Option<Rc<Prefetched>> {
340 self.prefetched
341 .borrow()
342 .as_ref()
343 .filter(|found| found.repo_id == repo_id)
344 .cloned()
345 }
346
347 /// Keeps `found` for the rest of this request.
348 pub(crate) fn keep_prefetched(&self, found: Option<Prefetched>) {
349 *self.prefetched.borrow_mut() = found.map(Rc::new);
350 }
351}
352
353#[cfg(test)]
354mod tests {
355 use super::*;
356
357 fn at(namespace: &str, name: &str) -> RepoPath {
358 RepoPath { namespace: namespace.to_owned(), name: name.to_owned() }
359 }
360
361 #[test]
362 fn guesses_ignore_case_and_are_forgotten_on_refusal() {
363 learn(&at("Flagon-IO", "G1T"), Some("repo_1"));
364 assert_eq!(guess(&at("flagon-io", "g1t")).as_deref(), Some("repo_1"));
365 learn(&at("flagon-io", "g1t"), None);
366 assert_eq!(guess(&at("flagon-io", "g1t")), None);
367 }
368}