-
-
Notifications
You must be signed in to change notification settings - Fork 259
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
2 changed files
with
194 additions
and
184 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
193 changes: 193 additions & 0 deletions
193
git-repository/src/remote/connection/fetch/receive_pack.rs
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,193 @@ | ||
| use crate::remote::connection::fetch::config; | ||
| use crate::remote::fetch::{negotiate, refs, Prepare, RefLogMessage}; | ||
| use crate::{ | ||
| remote, | ||
| remote::{ | ||
| fetch, | ||
| fetch::{Error, Outcome, Status}, | ||
| }, | ||
| Progress, | ||
| }; | ||
| use git_odb::FindExt; | ||
| use git_protocol::transport::client::Transport; | ||
| use std::sync::atomic::AtomicBool; | ||
|
|
||
| impl<'remote, 'repo, T, P> Prepare<'remote, 'repo, T, P> | ||
| where | ||
| T: Transport, | ||
| P: Progress, | ||
| P::SubProgress: 'static, | ||
| { | ||
| /// Receive the pack and perform the operation as configured by git via `git-config` or overridden by various builder methods. | ||
| /// Return `Ok(None)` if there was nothing to do because all remote refs are at the same state as they are locally, or `Ok(Some(outcome))` | ||
| /// to inform about all the changes that were made. | ||
| /// | ||
| /// ### Negotiation | ||
| /// | ||
| /// "fetch.negotiationAlgorithm" describes algorithms `git` uses currently, with the default being `consecutive` and `skipping` being | ||
| /// experimented with. We currently implement something we could call 'naive' which works for now. | ||
| /// | ||
| /// ### Pack `.keep` files | ||
| /// | ||
| /// That packs that are freshly written to the object database are vulnerable to garbage collection for the brief time that it takes between | ||
| /// them being placed and the respective references to be written to disk which binds their objects to the commit graph, making them reachable. | ||
| /// | ||
| /// To circumvent this issue, a `.keep` file is created before any pack related file (i.e. `.pack` or `.idx`) is written, which indicates the | ||
| /// garbage collector (like `git maintenance`, `git gc`) to leave the corresponding pack file alone. | ||
| /// | ||
| /// If there were any ref updates or the received pack was empty, the `.keep` file will be deleted automatically leaving in its place at | ||
| /// `write_pack_bundle.keep_path` a `None`. | ||
| /// However, if no ref-update happened the path will still be present in `write_pack_bundle.keep_path` and is expected to be handled by the caller. | ||
| /// A known application for this behaviour is in `remote-helper` implementations which should send this path via `lock <path>` to stdout | ||
| /// to inform git about the file that it will remove once it updated the refs accordingly. | ||
| /// | ||
| /// ### Deviation | ||
| /// | ||
| /// When **updating refs**, the `git-fetch` docs state that the following: | ||
| /// | ||
| /// > Unlike when pushing with git-push, any updates outside of refs/{tags,heads}/* will be accepted without + in the refspec (or --force), whether that’s swapping e.g. a tree object for a blob, or a commit for another commit that’s doesn’t have the previous commit as an ancestor etc. | ||
| /// | ||
| /// We explicitly don't special case those refs and expect the user to take control. Note that by its nature, | ||
| /// force only applies to refs pointing to commits and if they don't, they will be updated either way in our | ||
| /// implementation as well. | ||
| pub fn receive(mut self, should_interrupt: &AtomicBool) -> Result<Outcome, Error> { | ||
| let mut con = self.con.take().expect("receive() can only be called once"); | ||
|
|
||
| let handshake = &self.ref_map.handshake; | ||
| let protocol_version = handshake.server_protocol_version; | ||
|
|
||
| let fetch = git_protocol::fetch::Command::Fetch; | ||
| let fetch_features = fetch.default_features(protocol_version, &handshake.capabilities); | ||
|
|
||
| git_protocol::fetch::Response::check_required_features(protocol_version, &fetch_features)?; | ||
| let sideband_all = fetch_features.iter().any(|(n, _)| *n == "sideband-all"); | ||
| let mut arguments = git_protocol::fetch::Arguments::new(protocol_version, fetch_features); | ||
| let mut previous_response = None::<git_protocol::fetch::Response>; | ||
| let mut round = 1; | ||
| let progress = &mut con.progress; | ||
| let repo = con.remote.repo; | ||
|
|
||
| if self.ref_map.object_hash != repo.object_hash() { | ||
| return Err(Error::IncompatibleObjectHash { | ||
| local: repo.object_hash(), | ||
| remote: self.ref_map.object_hash, | ||
| }); | ||
| } | ||
|
|
||
| let reader = 'negotiation: loop { | ||
| progress.step(); | ||
| progress.set_name(format!("negotiate (round {})", round)); | ||
|
|
||
| let is_done = match negotiate::one_round( | ||
| negotiate::Algorithm::Naive, | ||
| round, | ||
| repo, | ||
| &self.ref_map, | ||
| &mut arguments, | ||
| previous_response.as_ref(), | ||
| ) { | ||
| Ok(_) if arguments.is_empty() => { | ||
| git_protocol::fetch::indicate_end_of_interaction(&mut con.transport).ok(); | ||
| return Ok(Outcome { | ||
| ref_map: std::mem::take(&mut self.ref_map), | ||
| status: Status::NoChange, | ||
| }); | ||
| } | ||
| Ok(is_done) => is_done, | ||
| Err(err) => { | ||
| git_protocol::fetch::indicate_end_of_interaction(&mut con.transport).ok(); | ||
| return Err(err.into()); | ||
| } | ||
| }; | ||
| round += 1; | ||
| let mut reader = arguments.send(&mut con.transport, is_done)?; | ||
| if sideband_all { | ||
| setup_remote_progress(progress, &mut reader); | ||
| } | ||
| let response = git_protocol::fetch::Response::from_line_reader(protocol_version, &mut reader)?; | ||
| if response.has_pack() { | ||
| progress.step(); | ||
| progress.set_name("receiving pack"); | ||
| if !sideband_all { | ||
| setup_remote_progress(progress, &mut reader); | ||
| } | ||
| break 'negotiation reader; | ||
| } else { | ||
| previous_response = Some(response); | ||
| } | ||
| }; | ||
|
|
||
| let options = git_pack::bundle::write::Options { | ||
| thread_limit: config::index_threads(repo)?, | ||
| index_version: config::pack_index_version(repo)?, | ||
| iteration_mode: git_pack::data::input::Mode::Verify, | ||
| object_hash: con.remote.repo.object_hash(), | ||
| }; | ||
|
|
||
| let mut write_pack_bundle = if matches!(self.dry_run, fetch::DryRun::No) { | ||
| Some(git_pack::Bundle::write_to_directory( | ||
| reader, | ||
| Some(repo.objects.store_ref().path().join("pack")), | ||
| con.progress, | ||
| should_interrupt, | ||
| Some(Box::new({ | ||
| let repo = repo.clone(); | ||
| move |oid, buf| repo.objects.find(oid, buf).ok() | ||
| })), | ||
| options, | ||
| )?) | ||
| } else { | ||
| drop(reader); | ||
| None | ||
| }; | ||
|
|
||
| if matches!(protocol_version, git_protocol::transport::Protocol::V2) { | ||
| git_protocol::fetch::indicate_end_of_interaction(&mut con.transport).ok(); | ||
| } | ||
|
|
||
| let update_refs = refs::update( | ||
| repo, | ||
| self.reflog_message | ||
| .take() | ||
| .unwrap_or_else(|| RefLogMessage::Prefixed { action: "fetch".into() }), | ||
| &self.ref_map.mappings, | ||
| con.remote.refspecs(remote::Direction::Fetch), | ||
| self.dry_run, | ||
| )?; | ||
|
|
||
| if let Some(bundle) = write_pack_bundle.as_mut() { | ||
| if !update_refs.edits.is_empty() || bundle.index.num_objects == 0 { | ||
| if let Some(path) = bundle.keep_path.take() { | ||
| std::fs::remove_file(&path).map_err(|err| Error::RemovePackKeepFile { path, source: err })?; | ||
| } | ||
| } | ||
| } | ||
|
|
||
| Ok(Outcome { | ||
| ref_map: std::mem::take(&mut self.ref_map), | ||
| status: match write_pack_bundle { | ||
| Some(write_pack_bundle) => Status::Change { | ||
| write_pack_bundle, | ||
| update_refs, | ||
| }, | ||
| None => Status::DryRun { update_refs }, | ||
| }, | ||
| }) | ||
| } | ||
| } | ||
|
|
||
| fn setup_remote_progress<P>( | ||
| progress: &mut P, | ||
| reader: &mut Box<dyn git_protocol::transport::client::ExtendedBufRead + Unpin + '_>, | ||
| ) where | ||
| P: Progress, | ||
| P::SubProgress: 'static, | ||
| { | ||
| use git_protocol::transport::client::ExtendedBufRead; | ||
| reader.set_progress_handler(Some(Box::new({ | ||
| let mut remote_progress = progress.add_child("remote"); | ||
| move |is_err: bool, data: &[u8]| { | ||
| git_protocol::RemoteProgress::translate_to_progress(is_err, data, &mut remote_progress) | ||
| } | ||
| }) as git_protocol::transport::client::HandleProgress)); | ||
| } |