use std::ops::Deref; use git_hash::oid; use super::find::Error;use crate::{ find::Header, store::{find::error::DeltaBaseRecursion, handle, load_index},}; impl<S> super::Handle<S>where S: Deref<Target = super::Store> + Clone,{ fn try_header_inner<'b>( &'b self, mut id: &'b git_hash::oid, snapshot: &mut load_index::Snapshot, recursion: Option<DeltaBaseRecursion<'_>>, ) -> Result<Option<Header>, Error> { if let Some(r) = recursion { if r.depth >= self.max_recursion_depth { return Err(Error::DeltaBaseRecursionLimit { max_depth: self.max_recursion_depth, id: r.original_id.to_owned(), }); } } else if !self.ignore_replacements { if let Ok(pos) = self .store .replacements .binary_search_by(|(map_this, _)| map_this.as_ref().cmp(id)) { id = self.store.replacements[pos].1.as_ref(); } } 'outer: loop { { let marker = snapshot.marker; for (idx, index) in snapshot.indices.iter_mut().enumerate() { if let Some(handle::index_lookup::Outcome { object_index: handle::IndexForObjectInPack { pack_id, pack_offset }, index_file, pack: possibly_pack, }) = index.lookup(id) { let pack = match possibly_pack { Some(pack) => pack, None => match self.store.load_pack(pack_id, marker)? { Some(pack) => { *possibly_pack = Some(pack); possibly_pack.as_deref().expect("just put it in") } None => { // The pack wasn't available anymore so we are supposed to try another round with a fresh index match self.store.load_one_index(self.refresh, snapshot.marker)? { Some(new_snapshot) => { *snapshot = new_snapshot; self.clear_cache(); continue 'outer; } None => { // nothing new in the index, kind of unexpected to not have a pack but to also // to have no new index yet. We set the new index before removing any slots, so // this should be observable. return Ok(None); } } } }, }; let entry = pack.entry(pack_offset); let res = match pack.decode_header(entry, |id| { index_file.pack_offset_by_id(id).map(|pack_offset| { git_pack::data::decode::header::ResolvedBase::InPack(pack.entry(pack_offset)) }) }) { Ok(header) => Ok(header.into()), Err(git_pack::data::decode::Error::DeltaBaseUnresolved(base_id)) => { // Only with multi-pack indices it's allowed to jump to refer to other packs within this // multi-pack. Otherwise this would constitute a thin pack which is only allowed in transit. // However, if we somehow end up with that, we will resolve it safely, even though we could // avoid handling this case and error instead. let hdr = self .try_header_inner( &base_id, snapshot, recursion .map(|r| r.inc_depth()) .or_else(|| DeltaBaseRecursion::new(id).into()), ) .map_err(|err| Error::DeltaBaseLookup { err: Box::new(err), base_id, id: id.to_owned(), })? .ok_or_else(|| Error::DeltaBaseMissing { base_id, id: id.to_owned(), })?; let handle::index_lookup::Outcome { object_index: handle::IndexForObjectInPack { pack_id: _, pack_offset, }, index_file, pack: possibly_pack, } = match snapshot.indices[idx].lookup(id) { Some(res) => res, None => { let mut out = None; for index in snapshot.indices.iter_mut() { out = index.lookup(id); if out.is_some() { break; } } out.unwrap_or_else(|| { panic!("could not find object {id} in any index after looking up one of its base objects {base_id}") }) } }; let pack = possibly_pack .as_ref() .expect("pack to still be available like just now"); let entry = pack.entry(pack_offset); pack.decode_header(entry, |id| { index_file .pack_offset_by_id(id) .map(|pack_offset| { git_pack::data::decode::header::ResolvedBase::InPack( pack.entry(pack_offset), ) }) .or_else(|| { (id == base_id).then(|| { git_pack::data::decode::header::ResolvedBase::OutOfPack { kind: hdr.kind(), num_deltas: hdr.num_deltas(), } }) }) }) .map(Into::into) } Err(err) => Err(err), }?; if idx != 0 { snapshot.indices.swap(0, idx); } return Ok(Some(res)); } } } for lodb in snapshot.loose_dbs.iter() { // TODO: remove this double-lookup once the borrow checker allows it. if lodb.contains(id) { return lodb.try_header(id).map(|opt| opt.map(Into::into)).map_err(Into::into); } } match self.store.load_one_index(self.refresh, snapshot.marker)? { Some(new_snapshot) => { *snapshot = new_snapshot; self.clear_cache(); } None => return Ok(None), } } }} impl<S> crate::Header for super::Handle<S>where S: Deref<Target = super::Store> + Clone,{ type Error = Error; fn try_header(&self, id: impl AsRef<oid>) -> Result<Option<Header>, Self::Error> { let id = id.as_ref(); let mut snapshot = self.snapshot.borrow_mut(); self.try_header_inner(id, &mut snapshot, None) }}