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pulls/pr_01m47d15m3e54sn21z27rpy5n9

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pr_01m47d15m3e54sn21z27rpy5n9/services/repos/src/lib.rs

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1//! The repos service: repository metadata, contents, forks, landing, and
2//! git over HTTPS.
3//!
4//! Other services reach it over `POST /rpc/<method>`; see
5//! `g1t_contracts::repos` for the methods and their arguments. Any other
6//! request is treated as git's smart HTTP protocol.
7
8mod blame;
9mod diff;
10mod git_http;
11mod import;
12mod land;
13mod refs;
14mod registry;
15mod store;
16
17use g1t_contracts::events::{GitPush, NewEvent, Publish, RepoCreated, RepoForked};
18use g1t_contracts::repos::*;
19use g1t_contracts::time::rfc3339;
20use g1t_contracts::{FailureCode, Outcome, PrincipalKind, User, Viewer, is_valid_repo_name, new_id};
21use g1t_kit::{args, now_ms, reply, rpc_method};
22use std::collections::{HashMap, HashSet, VecDeque};
23
24use serde::Serialize;
25use worker::{Context, Env, Fetcher, Request, Response, Result, event};
26
27use registry::{Registry, can_read, can_write, store_key};
28use store::{ArtifactsStore, GitRepo, GitStore, Scope};
29
30/// Namespace that holds every pull request's fork: `pulls/<pull id>`.
31const PULLS_NAMESPACE: &str = "pulls";
32const MAX_TEXT_BYTES: usize = 512 * 1024;
33/// How far back a pull request may have forked and still be landed.
34const MAX_ANCESTRY: u32 = 1000;
35const MAX_DESCRIPTION_CHARS: usize = 200;
36const SOURCE: &str = "repos";
37const UNVERIFIED: &str = "Confirm your email address first. Check your inbox, or resend the link from the banner on g1t.sh.";
38
39fn not_found<T>() -> Outcome<T> {
40 Outcome::fail(FailureCode::NotFound, "Repository not found.")
41}
42
43/// Decoded text, or `None` when the file is too large or looks binary.
44/// Whether a ref is a full commit hash rather than a branch name.
45fn is_commit_hash(git_ref: &str) -> bool {
46 git_ref.len() == 40 && git_ref.bytes().all(|b| b.is_ascii_hexdigit())
47}
48
49fn text_of(bytes: Vec<u8>) -> Option<String> {
50 if bytes.len() > MAX_TEXT_BYTES || bytes.contains(&0) {
51 return None;
52 }
53 Some(String::from_utf8_lossy(&bytes).into_owned())
54}
55
56fn is_readme(name: &str) -> bool {
57 matches!(
58 name.to_lowercase().as_str(),
59 "readme" | "readme.md" | "readme.markdown" | "readme.txt"
60 )
61}
62
63/// Whether `ancestor` is reachable from the newest commit in `history`.
64///
65/// `history` is the first-parent chain, which is all the store lists; a fork
66/// that merged the target branch in has the target's head on a second
67/// parent, so the walk follows every parent.
68async fn descends_from<R: GitRepo>(repo: &R, history: &[Commit], ancestor: &str) -> Result<bool> {
69 let known: HashMap<&str, &[String]> = history
70 .iter()
71 .map(|commit| (commit.hash.as_str(), commit.parents.as_slice()))
72 .collect();
73 let mut seen = HashSet::new();
74 let mut queue: Vec<String> = history
75 .first()
76 .map(|c| c.hash.clone())
77 .into_iter()
78 .collect();
79 while let Some(hash) = queue.pop() {
80 if hash == ancestor {
81 return Ok(true);
82 }
83 if !seen.insert(hash.clone()) || seen.len() > MAX_ANCESTRY as usize {
84 continue;
85 }
86 match known.get(hash.as_str()) {
87 Some(parents) => queue.extend(parents.iter().cloned()),
88 None => queue.extend(repo.parents(&hash).await?.unwrap_or_default()),
89 }
90 }
91 Ok(false)
92}
93
94/// The commit closest to the newest in `history` that is also in `shared`:
95/// where a fork and the repository it came from last agreed.
96async fn nearest_ancestor_in<R: GitRepo>(
97 repo: &R,
98 history: &[Commit],
99 shared: &HashSet<String>,
100) -> Result<Option<String>> {
101 let known: HashMap<&str, &[String]> = history
102 .iter()
103 .map(|commit| (commit.hash.as_str(), commit.parents.as_slice()))
104 .collect();
105 let mut seen = HashSet::new();
106 let mut queue: VecDeque<String> = history
107 .first()
108 .map(|c| c.hash.clone())
109 .into_iter()
110 .collect();
111 while let Some(hash) = queue.pop_front() {
112 if shared.contains(&hash) {
113 return Ok(Some(hash));
114 }
115 if !seen.insert(hash.clone()) || seen.len() > MAX_ANCESTRY as usize {
116 continue;
117 }
118 match known.get(hash.as_str()) {
119 Some(parents) => queue.extend(parents.iter().cloned()),
120 None => queue.extend(repo.parents(&hash).await?.unwrap_or_default()),
121 }
122 }
123 Ok(None)
124}
125
126struct Repos<S: GitStore> {
127 registry: Registry,
128 store: S,
129 events: Fetcher,
130}
131
132impl<S: GitStore> Repos<S> {
133 async fn publish<T: Serialize>(&self, event: NewEvent<T>) -> Result<()> {
134 g1t_kit::call(
135 &self.events,
136 "publish",
137 &Publish {
138 events: vec![event],
139 },
140 )
141 .await
142 }
143
144 /// Whether the viewer may read `repo`. A pull request's fork of a
145 /// private repository can be read by everyone who can read that
146 /// repository, so its members can review and check out the change, as
147 /// well as by whoever opened the pull request.
148 async fn may_read(&self, repo: &Repo, viewer: &Viewer) -> Result<bool> {
149 if can_read(repo, viewer) {
150 return Ok(true);
151 }
152 let Some(source_id) = &repo.fork_of else {
153 return Ok(false);
154 };
155 Ok(self
156 .registry
157 .by_id(source_id)
158 .await?
159 .is_some_and(|source| can_read(&source, viewer)))
160 }
161
162 /// `repo`, if there is one and the viewer may read it.
163 async fn visible(&self, repo: Option<Repo>, viewer: &Viewer) -> Result<Option<Repo>> {
164 Ok(match repo {
165 Some(repo) if self.may_read(&repo, viewer).await? => Some(repo),
166 _ => None,
167 })
168 }
169
170 /// Resolves a repo the viewer may read; private repos look missing.
171 async fn readable(&self, path: &RepoPath, viewer: &Viewer) -> Result<Option<Repo>> {
172 self.visible(self.registry.by_path(path).await?, viewer)
173 .await
174 }
175
176 async fn get(&self, a: GetArgs) -> Result<Outcome<Repo>> {
177 Ok(self
178 .readable(&a.path, &a.viewer)
179 .await?
180 .map_or_else(not_found, Outcome::Ok))
181 }
182
183 async fn get_by_id(&self, a: GetByIdArgs) -> Result<Outcome<Repo>> {
184 Ok(self
185 .visible(self.registry.by_id(&a.id).await?, &a.viewer)
186 .await?
187 .map_or_else(not_found, Outcome::Ok))
188 }
189
190 async fn update(&self, a: UpdateArgs) -> Result<Outcome<Repo>> {
191 let viewer = Some(a.actor.clone());
192 let Some(repo) = self.readable(&a.path, &viewer).await? else {
193 return Ok(not_found());
194 };
195 if repo.fork_of.is_some() || !can_write(&repo, &viewer) {
196 return Ok(Outcome::fail(
197 FailureCode::Forbidden,
198 "Only members of the repository's workspace can change its settings.",
199 ));
200 }
201 if !a.actor.verified {
202 return Ok(Outcome::fail(FailureCode::Forbidden, UNVERIFIED));
203 }
204 let description = match a.description {
205 Some(text) => Some(
206 text.trim()
207 .chars()
208 .take(MAX_DESCRIPTION_CHARS)
209 .collect::<String>(),
210 )
211 .filter(|text| !text.is_empty()),
212 None => repo.description.clone(),
213 };
214 let is_private = a.is_private.unwrap_or(repo.is_private);
215 let protected = a.protected.unwrap_or(repo.protected);
216 self.registry
217 .update(&repo.id, description.as_deref(), is_private, protected)
218 .await?;
219 Ok(Outcome::Ok(Repo {
220 description,
221 is_private,
222 protected,
223 ..repo
224 }))
225 }
226
227 async fn create(&self, a: CreateArgs) -> Result<Outcome<Repo>> {
228 if !a.owner.verified {
229 return Ok(Outcome::fail(FailureCode::Forbidden, UNVERIFIED));
230 }
231 let name = a.name.trim().to_lowercase();
232 if !is_valid_repo_name(&name) {
233 return Ok(Outcome::fail(
234 FailureCode::Invalid,
235 "Use letters, digits, dots, hyphens and underscores only.",
236 ));
237 }
238 let namespace = a.namespace.trim().to_lowercase();
239 if namespace.is_empty() {
240 return Ok(Outcome::fail(
241 FailureCode::Invalid,
242 "Say which workspace to create the repository in.",
243 ));
244 }
245 if !a.owner.is_member(&namespace) {
246 return Ok(Outcome::fail(
247 FailureCode::Forbidden,
248 "You are not a member of that workspace.",
249 ));
250 }
251 let path = RepoPath { namespace, name };
252 if self.registry.by_path(&path).await?.is_some() {
253 return Ok(Outcome::fail(
254 FailureCode::Conflict,
255 "That workspace already has a repository with that name.",
256 ));
257 }
258 // An import is fetched before anything is created, so that an
259 // address that does not work leaves nothing behind.
260 let mut imported = None;
261 if let Some(url) = a
262 .import_url
263 .as_deref()
264 .map(str::trim)
265 .filter(|url| !url.is_empty())
266 {
267 let Some(url) = import::clean_url(url) else {
268 return Ok(Outcome::fail(
269 FailureCode::Invalid,
270 "Give the https address of a public repository, such as https://github.com/owner/repo.",
271 ));
272 };
273 let remote = match import::discover(&url).await? {
274 Ok(remote) => remote,
275 Err(reason) => return Ok(Outcome::fail(FailureCode::Invalid, reason)),
276 };
277 let pack = match import::fetch(&url, &remote.head).await? {
278 Ok(pack) => pack,
279 Err(reason) => return Ok(Outcome::fail(FailureCode::Invalid, reason)),
280 };
281 imported = Some((remote, pack));
282 }
283 let now = now_ms();
284 let repo = Repo {
285 id: new_id("rep", now),
286 namespace: path.namespace,
287 name: path.name,
288 description: a
289 .description
290 .map(|text| text.trim().to_owned())
291 .filter(|text| !text.is_empty()),
292 is_private: a.is_private,
293 owner_id: a.owner.id.clone(),
294 default_branch: imported
295 .as_ref()
296 .map_or_else(|| "main".to_owned(), |(remote, _)| remote.branch.clone()),
297 fork_of: None,
298 protected: false,
299 created_at: rfc3339(now),
300 };
301 self.store
302 .create(
303 &store_key(&repo),
304 repo.description.as_deref(),
305 &repo.default_branch,
306 )
307 .await?;
308 self.registry.insert(&repo).await?;
309 let mut pushed = None;
310 if let Some((remote, pack)) = imported {
311 let access = self
312 .store
313 .open(&store_key(&repo))
314 .await?
315 .access(Scope::Write)
316 .await?;
317 let stored =
318 land::push_pack(&access, &repo.default_branch, None, &remote.head, pack).await?;
319 if let Err(reason) = stored {
320 self.registry.remove(&repo.id).await?;
321 return Ok(Outcome::fail(
322 FailureCode::Invalid,
323 format!("The repository could not be stored: {reason}"),
324 ));
325 }
326 pushed = Some(remote.head);
327 }
328 self.publish(NewEvent {
329 kind: "repo.created",
330 source: SOURCE,
331 repo_id: Some(repo.id.clone()),
332 actor: Some(a.owner.id),
333 data: RepoCreated {
334 repo_id: repo.id.clone(),
335 namespace: repo.namespace.clone(),
336 name: repo.name.clone(),
337 is_private: repo.is_private,
338 },
339 })
340 .await?;
341 if let Some(head) = pushed {
342 self.publish_push(&repo, &repo.default_branch, &head, None)
343 .await?;
344 }
345 Ok(Outcome::Ok(repo))
346 }
347
348 async fn tree(&self, a: TreeArgs) -> Result<Outcome<TreeView>> {
349 let Some(repo) = self.readable(&a.path, &a.viewer).await? else {
350 return Ok(not_found());
351 };
352 let git = self.store.open(&store_key(&repo)).await?;
353 let git_ref = a
354 .git_ref
355 .clone()
356 .unwrap_or_else(|| repo.default_branch.clone());
357
358 let Some(head) = git.log(&git_ref, 1).await?.into_iter().next() else {
359 // An unknown ref is an error; a repo with no commits is just empty.
360 if a.git_ref.is_some() {
361 return Ok(Outcome::fail(
362 FailureCode::NotFound,
363 "No such branch, tag or commit.",
364 ));
365 }
366 return Ok(Outcome::Ok(TreeView {
367 repo,
368 git_ref,
369 path: a.tree_path,
370 head: None,
371 entries: Vec::new(),
372 readme: None,
373 }));
374 };
375
376 let no_directory = || Outcome::fail(FailureCode::NotFound, "No such directory.");
377 let mut entries = git.read_tree(&head.tree_hash).await?;
378 for segment in a.tree_path.split('/').filter(|segment| !segment.is_empty()) {
379 let next = entries.as_ref().and_then(|entries| {
380 entries
381 .iter()
382 .find(|entry| entry.name == segment && entry.kind == EntryKind::Tree)
383 });
384 let Some(next) = next else {
385 return Ok(no_directory());
386 };
387 entries = git.read_tree(&next.hash).await?;
388 }
389 let Some(mut entries) = entries else {
390 return Ok(no_directory());
391 };
392 // Directories first, then by name.
393 entries.sort_by(|a, b| {
394 (b.kind == EntryKind::Tree)
395 .cmp(&(a.kind == EntryKind::Tree))
396 .then_with(|| a.name.cmp(&b.name))
397 });
398
399 let readme_entry = entries
400 .iter()
401 .find(|entry| entry.kind == EntryKind::Blob && is_readme(&entry.name));
402 let readme = match readme_entry {
403 Some(entry) => git.read_blob(&entry.hash).await?.map(|bytes| Readme {
404 name: entry.name.clone(),
405 text: text_of(bytes),
406 }),
407 None => None,
408 };
409 Ok(Outcome::Ok(TreeView {
410 repo,
411 git_ref,
412 path: a.tree_path,
413 head: Some(head),
414 entries,
415 readme,
416 }))
417 }
418
419 async fn blob(&self, a: BlobArgs) -> Result<Outcome<BlobView>> {
420 let Some(repo) = self.readable(&a.path, &a.viewer).await? else {
421 return Ok(not_found());
422 };
423 let bytes = if a.file_path.is_empty() {
424 None
425 } else {
426 let git = self.store.open(&store_key(&repo)).await?;
427 git.read_file(&a.git_ref, &a.file_path).await?
428 };
429 let Some(bytes) = bytes else {
430 return Ok(Outcome::fail(FailureCode::NotFound, "No such file."));
431 };
432 Ok(Outcome::Ok(BlobView {
433 repo,
434 git_ref: a.git_ref,
435 path: a.file_path,
436 size: bytes.len() as u64,
437 text: text_of(bytes),
438 }))
439 }
440
441 async fn blame(&self, a: BlameArgs) -> Result<Outcome<Blame>> {
442 let Some(repo) = self.readable(&a.path, &a.viewer).await? else {
443 return Ok(not_found());
444 };
445 let git = self.store.open(&store_key(&repo)).await?;
446 let git_ref = a.git_ref.unwrap_or_else(|| repo.default_branch.clone());
447 Ok(match blame::blame(&git, &git_ref, &a.file_path).await? {
448 Some(blame) => Outcome::Ok(blame),
449 None => not_found(),
450 })
451 }
452
453 async fn log(&self, a: LogArgs) -> Result<Outcome<Vec<Commit>>> {
454 let Some(repo) = self.readable(&a.path, &a.viewer).await? else {
455 return Ok(not_found());
456 };
457 let git = self.store.open(&store_key(&repo)).await?;
458 let git_ref = a.git_ref.unwrap_or_else(|| repo.default_branch.clone());
459 Ok(Outcome::Ok(git.log(&git_ref, a.limit).await?))
460 }
461
462 /// The repository's branches, default branch first.
463 async fn branches(&self, a: BranchesArgs) -> Result<Outcome<Vec<Branch>>> {
464 let Some(repo) = self.readable(&a.path, &a.viewer).await? else {
465 return Ok(not_found());
466 };
467 let mut branches = self.store.open(&store_key(&repo)).await?.branches().await?;
468 branches.sort_by_key(|branch| branch.name != repo.default_branch);
469 Ok(Outcome::Ok(branches))
470 }
471
472 /// Whether a pull request's source lacks commits that the branch it
473 /// would merge into has.
474 async fn behind(&self, a: BehindArgs) -> Result<bool> {
475 let Some(source) = self.registry.by_id(&a.source_id).await? else {
476 return Ok(false);
477 };
478 let target = match &source.fork_of {
479 Some(id) => self.registry.by_id(id).await?,
480 None => Some(source.clone()),
481 };
482 let Some(target) = target else {
483 return Ok(false);
484 };
485 let branch = a.branch.unwrap_or_else(|| target.default_branch.clone());
486 let target_head = self
487 .store
488 .open(&store_key(&target))
489 .await?
490 .log(&target.default_branch, 1)
491 .await?
492 .into_iter()
493 .next()
494 .map(|commit| commit.hash);
495 let Some(target_head) = target_head else {
496 return Ok(false);
497 };
498 let source_git = self.store.open(&store_key(&source)).await?;
499 let history = source_git.log(&branch, MAX_ANCESTRY).await?;
500 if history.is_empty() {
501 return Ok(false);
502 }
503 Ok(!descends_from(&source_git, &history, &target_head).await?)
504 }
505
506 async fn head(&self, a: HeadArgs) -> Result<Option<String>> {
507 let Some(repo) = self.registry.by_id(&a.repo_id).await? else {
508 return Ok(None);
509 };
510 let git = self.store.open(&store_key(&repo)).await?;
511 Ok(git
512 .log(&a.branch, 1)
513 .await?
514 .into_iter()
515 .next()
516 .map(|commit| commit.hash))
517 }
518
519 async fn fork_for_pull(&self, a: ForkArgs) -> Result<Outcome<Repo>> {
520 let viewer = Some(a.actor.clone());
521 let Some(source) = self
522 .registry
523 .by_id(&a.source_id)
524 .await?
525 .filter(|repo| can_read(repo, &viewer))
526 else {
527 return Ok(not_found());
528 };
529 let now = now_ms();
530 let fork = Repo {
531 id: new_id("rep", now),
532 namespace: PULLS_NAMESPACE.to_owned(),
533 name: a.pull_id.clone(),
534 description: None,
535 // A fork is exactly as visible as the repo it came from.
536 is_private: source.is_private,
537 owner_id: a.actor.id.clone(),
538 default_branch: source.default_branch.clone(),
539 fork_of: Some(source.id.clone()),
540 protected: false,
541 created_at: rfc3339(now),
542 };
543 self.store
544 .open(&store_key(&source))
545 .await?
546 .fork(&store_key(&fork))
547 .await?;
548 self.registry.insert(&fork).await?;
549 self.publish(NewEvent {
550 kind: "repo.forked",
551 source: SOURCE,
552 repo_id: Some(source.id.clone()),
553 actor: Some(a.actor.id),
554 data: RepoForked {
555 repo_id: fork.id.clone(),
556 source_repo_id: source.id,
557 pull_id: a.pull_id,
558 },
559 })
560 .await?;
561 Ok(Outcome::Ok(fork))
562 }
563
564 async fn git_access(&self, a: GitAccessArgs) -> Result<Outcome<GitAccess>> {
565 let write = a.service == GitService::ReceivePack;
566 // Anonymous callers are asked to authenticate whether or not the repo
567 // exists, so private repos cannot be told apart from missing ones.
568 let denied = || match &a.viewer {
569 Some(_) => not_found(),
570 None => Outcome::fail(FailureCode::Unauthenticated, "Authentication required."),
571 };
572 // An agent's token works through the API only: its sandbox has its
573 // own way to push, to its own pull request.
574 if a.viewer.as_ref().is_some_and(|user| user.kind == PrincipalKind::Agent) {
575 return Ok(Outcome::fail(
576 FailureCode::Forbidden,
577 "A g1t agent's token cannot be used with git.",
578 ));
579 }
580 if let (true, Some(user)) = (write, &a.viewer)
581 && !user.verified
582 {
583 return Ok(Outcome::fail(FailureCode::Forbidden, UNVERIFIED));
584 }
585
586 let repo = match self.registry.by_path(&a.path).await? {
587 Some(repo) => {
588 let allowed = if write {
589 can_write(&repo, &a.viewer)
590 } else {
591 self.may_read(&repo, &a.viewer).await?
592 };
593 if !allowed {
594 return Ok(denied());
595 }
596 repo
597 }
598 None => {
599 // Push to create, in a workspace the pusher belongs to.
600 let owner = a
601 .viewer
602 .as_ref()
603 .filter(|user| write && user.is_member(&a.path.namespace.to_lowercase()));
604 let Some(owner) = owner else {
605 return Ok(denied());
606 };
607 let created = self
608 .create(CreateArgs {
609 owner: owner.clone(),
610 namespace: a.path.namespace.clone(),
611 name: a.path.name.clone(),
612 description: None,
613 is_private: false,
614 import_url: None,
615 })
616 .await?;
617 match created {
618 Outcome::Ok(repo) => repo,
619 Outcome::Fail(failure) => return Ok(Outcome::Fail(failure)),
620 }
621 }
622 };
623 let git = self.store.open(&store_key(&repo)).await?;
624 let scope = if write { Scope::Write } else { Scope::Read };
625 Ok(Outcome::Ok(git.access(scope).await?))
626 }
627
628 async fn land(&self, a: LandArgs) -> Result<Outcome<Landed>> {
629 let actor: Viewer = Some(a.actor.clone());
630 let Some(source) = self.registry.by_id(&a.source_id).await? else {
631 return Ok(not_found());
632 };
633 // A fork lands on the repository it came from; a branch on its own.
634 let target = match &source.fork_of {
635 Some(id) => self.registry.by_id(id).await?,
636 None => Some(source.clone()),
637 };
638 let Some(target) = target.filter(|repo| can_read(repo, &actor)) else {
639 return Ok(not_found());
640 };
641 if !can_write(&target, &actor) {
642 return Ok(Outcome::fail(
643 FailureCode::Forbidden,
644 "Only members of the repository's workspace can merge a pull request.",
645 ));
646 }
647 if !a.actor.verified {
648 return Ok(Outcome::fail(FailureCode::Forbidden, UNVERIFIED));
649 }
650
651 let branch = &target.default_branch;
652 let from_fork = source.id != target.id;
653 let source_branch = match a.branch {
654 Some(name) if !from_fork && name == *branch => {
655 return Ok(Outcome::fail(
656 FailureCode::Invalid,
657 format!("{branch} cannot be merged into itself."),
658 ));
659 }
660 Some(name) => name,
661 None if from_fork => branch.clone(),
662 None => {
663 return Ok(Outcome::fail(
664 FailureCode::Invalid,
665 "Say which branch to merge.",
666 ));
667 }
668 };
669
670 let source_git = self.store.open(&store_key(&source)).await?;
671 let target_git = self.store.open(&store_key(&target)).await?;
672 let history = source_git.log(&source_branch, MAX_ANCESTRY).await?;
673 let Some(new) = history.first().map(|commit| commit.hash.clone()) else {
674 return Ok(Outcome::fail(
675 FailureCode::Conflict,
676 "This pull request has no commits to merge.",
677 ));
678 };
679 let old = target_git
680 .log(branch, 1)
681 .await?
682 .into_iter()
683 .next()
684 .map(|commit| commit.hash);
685
686 if old.as_deref() == Some(new.as_str()) {
687 return Ok(Outcome::Ok(Landed {
688 commit: new,
689 previous: None,
690 }));
691 }
692 // Moving the branch to a commit that does not descend from its
693 // current head would discard whatever landed in between.
694 if let Some(old) = &old
695 && !descends_from(&source_git, &history, old).await?
696 {
697 let remedy = if from_fork {
698 format!("Pull {branch} into the pull request's fork, push, and merge again.")
699 } else {
700 format!("Merge {branch} into {source_branch}, push, and merge again.")
701 };
702 return Ok(Outcome::fail(
703 FailureCode::Conflict,
704 format!("{branch} has moved since this pull request was opened. {remedy}"),
705 ));
706 }
707
708 // For a branch the objects are already in the target; sending them
709 // again is harmless and keeps one way of moving a ref.
710 let source_access = source_git.access(Scope::Read).await?;
711 let target_access = target_git.access(Scope::Write).await?;
712 let pushed =
713 land::fast_forward(&source_access, &target_access, branch, old.as_deref(), &new)
714 .await?;
715 if let Err(reason) = pushed {
716 // Most often another pull request landed between the check and the push.
717 return Ok(Outcome::fail(
718 FailureCode::Conflict,
719 format!("{branch} could not be updated: {reason}"),
720 ));
721 }
722 self.publish_push(&target, branch, &new, Some(a.actor.id))
723 .await?;
724 Ok(Outcome::Ok(Landed {
725 commit: new,
726 previous: old,
727 }))
728 }
729
730 async fn compare(&self, a: CompareArgs) -> Result<Outcome<Comparison>> {
731 let Some(repo) = self
732 .visible(self.registry.by_id(&a.repo_id).await?, &a.viewer)
733 .await?
734 else {
735 return Ok(not_found());
736 };
737 let git = self.store.open(&store_key(&repo)).await?;
738 let head_ref = a.head.as_deref().unwrap_or(&repo.default_branch);
739 // The head's history is only searched when the base is worked out
740 // from another branch.
741 let depth = if a.base.is_some() || is_commit_hash(head_ref) { 1 } else { MAX_ANCESTRY };
742 let history = git.log(head_ref, depth).await?;
743 let Some(head) = history.first() else {
744 return Ok(Outcome::fail(
745 FailureCode::Conflict,
746 "There are no commits to compare.",
747 ));
748 };
749
750 // Where the head's history meets the default branch of `against`.
751 let shared_with = async |against: &Repo| -> Result<Option<String>> {
752 let against_git = self.store.open(&store_key(against)).await?;
753 let shared: HashSet<String> = against_git
754 .log(&against.default_branch, MAX_ANCESTRY)
755 .await?
756 .into_iter()
757 .map(|commit| commit.hash)
758 .collect();
759 nearest_ancestor_in(&git, &history, &shared).await
760 };
761 let base = match (a.base, &repo.fork_of) {
762 (Some(base), _) => Some(base),
763 // A fork is compared with the last commit it shares with the
764 // repository it came from.
765 (None, Some(target_id)) => match self.registry.by_id(target_id).await? {
766 Some(target) => shared_with(&target).await?,
767 None => None,
768 },
769 // A branch, with the point where it left the default branch.
770 // A single commit, with its first parent.
771 (None, None) if is_commit_hash(head_ref) => head.parents.first().cloned(),
772 (None, None) if head_ref != repo.default_branch => shared_with(&repo).await?,
773 (None, None) => head.parents.first().cloned(),
774 };
775 let base_tree = match &base {
776 Some(base) => git
777 .log(base, 1)
778 .await?
779 .into_iter()
780 .next()
781 .map(|commit| commit.tree_hash),
782 None => None,
783 };
784 let (files, truncated) =
785 diff::compare_trees(&git, base_tree.as_deref(), &head.tree_hash).await?;
786 Ok(Outcome::Ok(Comparison {
787 base,
788 head: head.hash.clone(),
789 files,
790 truncated,
791 }))
792 }
793
794 /// Reports that `branch` of `repo` now points to `after`.
795 async fn publish_push(
796 &self,
797 repo: &Repo,
798 branch: &str,
799 after: &str,
800 actor: Option<String>,
801 ) -> Result<()> {
802 self.publish(NewEvent {
803 kind: "git.push",
804 source: SOURCE,
805 repo_id: Some(repo.id.clone()),
806 actor,
807 data: GitPush {
808 repo_id: repo.id.clone(),
809 git_ref: format!("refs/heads/{branch}"),
810 after: after.to_owned(),
811 default_branch: branch == repo.default_branch,
812 },
813 })
814 .await
815 }
816
817 /// Git over HTTPS.
818 async fn git_http(&self, request: Request, env: &Env) -> Result<Response> {
819 let Some(git) = git_http::parse(&request.url()?) else {
820 return Response::error("Not found", 404);
821 };
822 let viewer = git_http::viewer(&request, &env.service("IDENTITY")?).await?;
823 let access = self
824 .git_access(GitAccessArgs {
825 path: git.path.clone(),
826 viewer: viewer.clone(),
827 service: git.service,
828 })
829 .await?;
830 let access = match access {
831 Outcome::Ok(access) => access,
832 refused => return git_http::refuse(refused),
833 };
834 // A protected default branch takes changes only from a merged pull
835 // request, which lands without going through here.
836 let protected = match self.registry.by_path(&git.path).await? {
837 Some(repo) if repo.protected && repo.fork_of.is_none() => Some(repo.default_branch),
838 _ => None,
839 };
840 let forwarded =
841 match git_http::forward(request, &git, &access, protected.as_deref()).await? {
842 git_http::Push::Forwarded(forwarded) => forwarded,
843 git_http::Push::Refused(response) => return Ok(response),
844 };
845
846 // Artifacts' own push notifications are per repository, which does
847 // not fit a repo per pull request, so the front end reports pushes
848 // itself: one event for each branch that moved.
849 let accepted = forwarded.response.status_code() == 200 && !forwarded.pushed.is_empty();
850 if accepted && let Some(repo) = self.registry.by_path(&git.path).await? {
851 let stored = self.store.open(&store_key(&repo)).await?;
852 let actor = viewer.map(|user: User| user.id);
853 for (branch, pushed) in &forwarded.pushed {
854 // The store can refuse one ref and accept another, so each
855 // is checked against where the branch actually is.
856 let head = stored.log(branch, 1).await?;
857 if head.first().is_some_and(|commit| commit.hash == *pushed) {
858 self.publish_push(&repo, branch, pushed, actor.clone())
859 .await?;
860 }
861 }
862 }
863 Ok(forwarded.response)
864 }
865}
866
867#[event(fetch)]
868async fn fetch(mut request: Request, env: Env, _ctx: Context) -> Result<Response> {
869 let repos = Repos {
870 registry: Registry { db: env.d1("DB")? },
871 store: ArtifactsStore::new(&env)?,
872 events: env.service("EVENTS")?,
873 };
874 let Some(method) = rpc_method(&request) else {
875 return repos.git_http(request, &env).await;
876 };
877 let body: serde_json::Value = request.json().await?;
878
879 match method.as_str() {
880 "get" => reply(&repos.get(args(body)?).await?),
881 "get_by_id" => reply(&repos.get_by_id(args(body)?).await?),
882 "list" => {
883 let a: ListArgs = args(body)?;
884 reply(
885 &repos
886 .registry
887 .list(
888 &a.viewer,
889 a.query.as_deref(),
890 a.namespace.as_deref(),
891 a.member_only,
892 )
893 .await?,
894 )
895 }
896 "create" => reply(&repos.create(args(body)?).await?),
897 "update" => reply(&repos.update(args(body)?).await?),
898 "tree" => reply(&repos.tree(args(body)?).await?),
899 "blob" => reply(&repos.blob(args(body)?).await?),
900 "log" => reply(&repos.log(args(body)?).await?),
901 "blame" => reply(&repos.blame(args(body)?).await?),
902 "fork_for_pull" => reply(&repos.fork_for_pull(args(body)?).await?),
903 "git_access" => reply(&repos.git_access(args(body)?).await?),
904 "branches" => reply(&repos.branches(args(body)?).await?),
905 "head" => reply(&repos.head(args(body)?).await?),
906 "behind" => reply(&repos.behind(args(body)?).await?),
907 "land" => reply(&repos.land(args(body)?).await?),
908 "compare" => reply(&repos.compare(args(body)?).await?),
909 _ => Response::error("Unknown method", 404),
910 }
911}