// Copyright 2023 The Jujutsu Authors//// Licensed under the Apache License, Version 2.0 (the "License");// you may not use this file except in compliance with the License.// You may obtain a copy of the License at//// https://www.apache.org/licenses/LICENSE-2.0//// Unless required by applicable law or agreed to in writing, software// distributed under the License is distributed on an "AS IS" BASIS,// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.// See the License for the specific language governing permissions and// limitations under the License. #![allow(missing_docs)] use std::any::Any;use std::cmp::max;use std::collections::BTreeMap;use std::collections::HashMap;use std::io;use std::io::Write as _;use std::ops::Bound;use std::path::Path;use std::sync::Arc; use blake2::Blake2b512;use digest::Digest as _;use itertools::Itertools as _;use smallvec::smallvec;use smallvec::SmallVec;use tempfile::NamedTempFile; use super::composite::AsCompositeIndex;use super::composite::ChangeIdIndexImpl;use super::composite::CompositeIndex;use super::composite::DynIndexSegment;use super::composite::IndexSegment;use super::entry::IndexPosition;use super::entry::LocalPosition;use super::entry::SmallIndexPositionsVec;use super::entry::SmallLocalPositionsVec;use super::readonly::DefaultReadonlyIndex;use super::readonly::FieldLengths;use super::readonly::ReadonlyIndexSegment;use super::readonly::INDEX_SEGMENT_FILE_FORMAT_VERSION;use super::readonly::OVERFLOW_FLAG;use crate::backend::ChangeId;use crate::backend::CommitId;use crate::commit::Commit;use crate::file_util::persist_content_addressed_temp_file;use crate::hex_util;use crate::index::AllHeadsForGcUnsupported;use crate::index::ChangeIdIndex;use crate::index::Index;use crate::index::IndexError;use crate::index::MutableIndex;use crate::index::ReadonlyIndex;use crate::object_id::HexPrefix;use crate::object_id::ObjectId;use crate::object_id::PrefixResolution;use crate::revset::ResolvedExpression;use crate::revset::Revset;use crate::revset::RevsetEvaluationError;use crate::store::Store; #[derive(Debug)]struct MutableGraphEntry { commit_id: CommitId, change_id: ChangeId, generation_number: u32, parent_positions: SmallIndexPositionsVec,} pub(super) struct MutableIndexSegment { parent_file: Option<Arc<ReadonlyIndexSegment>>, num_parent_commits: u32, field_lengths: FieldLengths, graph: Vec<MutableGraphEntry>, commit_lookup: BTreeMap<CommitId, LocalPosition>, change_lookup: BTreeMap<ChangeId, SmallLocalPositionsVec>,} impl MutableIndexSegment { pub(super) fn full(field_lengths: FieldLengths) -> Self { Self { parent_file: None, num_parent_commits: 0, field_lengths, graph: vec![], commit_lookup: BTreeMap::new(), change_lookup: BTreeMap::new(), } } pub(super) fn incremental(parent_file: Arc<ReadonlyIndexSegment>) -> Self { let num_parent_commits = parent_file.as_composite().num_commits(); let field_lengths = parent_file.field_lengths(); Self { parent_file: Some(parent_file), num_parent_commits, field_lengths, graph: vec![], commit_lookup: BTreeMap::new(), change_lookup: BTreeMap::new(), } } pub(super) fn as_composite(&self) -> &CompositeIndex { CompositeIndex::new(self) } pub(super) fn add_commit(&mut self, commit: &Commit) { self.add_commit_data( commit.id().clone(), commit.change_id().clone(), commit.parent_ids(), ); } pub(super) fn add_commit_data( &mut self, commit_id: CommitId, change_id: ChangeId, parent_ids: &[CommitId], ) { if self.as_composite().has_id(&commit_id) { return; } let mut entry = MutableGraphEntry { commit_id, change_id, generation_number: 0, parent_positions: SmallVec::new(), }; for parent_id in parent_ids { let parent_entry = self .as_composite() .entry_by_id(parent_id) .expect("parent commit is not indexed"); entry.generation_number = max( entry.generation_number, parent_entry.generation_number() + 1, ); entry.parent_positions.push(parent_entry.position()); } let local_pos = LocalPosition(u32::try_from(self.graph.len()).unwrap()); self.commit_lookup .insert(entry.commit_id.clone(), local_pos); self.change_lookup .entry(entry.change_id.clone()) // positions are inherently sorted .and_modify(|positions| positions.push(local_pos)) .or_insert(smallvec![local_pos]); self.graph.push(entry); } pub(super) fn add_commits_from(&mut self, other_segment: &DynIndexSegment) { let other = CompositeIndex::new(other_segment); for pos in other_segment.num_parent_commits()..other.num_commits() { let entry = other.entry_by_pos(IndexPosition(pos)); let parent_ids = entry.parents().map(|entry| entry.commit_id()).collect_vec(); self.add_commit_data(entry.commit_id(), entry.change_id(), &parent_ids); } } pub(super) fn merge_in(&mut self, other: Arc<ReadonlyIndexSegment>) { let mut maybe_own_ancestor = self.parent_file.clone(); let mut maybe_other_ancestor = Some(other); let mut files_to_add = vec![]; loop { if maybe_other_ancestor.is_none() { break; } let other_ancestor = maybe_other_ancestor.as_ref().unwrap(); if maybe_own_ancestor.is_none() { files_to_add.push(other_ancestor.clone()); maybe_other_ancestor = other_ancestor.parent_file().cloned(); continue; } let own_ancestor = maybe_own_ancestor.as_ref().unwrap(); if own_ancestor.name() == other_ancestor.name() { break; } if own_ancestor.as_composite().num_commits() < other_ancestor.as_composite().num_commits() { files_to_add.push(other_ancestor.clone()); maybe_other_ancestor = other_ancestor.parent_file().cloned(); } else { maybe_own_ancestor = own_ancestor.parent_file().cloned(); } } for file in files_to_add.iter().rev() { self.add_commits_from(file.as_ref()); } } fn serialize_parent_filename(&self, buf: &mut Vec<u8>) { if let Some(parent_file) = &self.parent_file { buf.extend( u32::try_from(parent_file.name().len()) .unwrap() .to_le_bytes(), ); buf.extend_from_slice(parent_file.name().as_bytes()); } else { buf.extend(0_u32.to_le_bytes()); } } fn serialize_local_entries(&self, buf: &mut Vec<u8>) { assert_eq!(self.graph.len(), self.commit_lookup.len()); debug_assert_eq!( self.graph.len(), self.change_lookup.values().flatten().count() ); let num_commits = u32::try_from(self.graph.len()).unwrap(); buf.extend(num_commits.to_le_bytes()); let num_change_ids = u32::try_from(self.change_lookup.len()).unwrap(); buf.extend(num_change_ids.to_le_bytes()); // We'll write the actual values later let parent_overflow_offset = buf.len(); buf.extend(0_u32.to_le_bytes()); let change_overflow_offset = buf.len(); buf.extend(0_u32.to_le_bytes()); // Positions of change ids in the sorted table let change_id_pos_map: HashMap<&ChangeId, u32> = self .change_lookup .keys() .enumerate() .map(|(i, change_id)| (change_id, u32::try_from(i).unwrap())) .collect(); let mut parent_overflow = vec![]; for entry in &self.graph { buf.extend(entry.generation_number.to_le_bytes()); match entry.parent_positions.as_slice() { [] => { buf.extend((!0_u32).to_le_bytes()); buf.extend((!0_u32).to_le_bytes()); } [IndexPosition(pos1)] => { assert!(*pos1 < OVERFLOW_FLAG); buf.extend(pos1.to_le_bytes()); buf.extend((!0_u32).to_le_bytes()); } [IndexPosition(pos1), IndexPosition(pos2)] => { assert!(*pos1 < OVERFLOW_FLAG); assert!(*pos2 < OVERFLOW_FLAG); buf.extend(pos1.to_le_bytes()); buf.extend(pos2.to_le_bytes()); } positions => { let overflow_pos = u32::try_from(parent_overflow.len()).unwrap(); let num_parents = u32::try_from(positions.len()).unwrap(); assert!(overflow_pos < OVERFLOW_FLAG); assert!(num_parents < OVERFLOW_FLAG); buf.extend((!overflow_pos).to_le_bytes()); buf.extend((!num_parents).to_le_bytes()); parent_overflow.extend_from_slice(positions); } } buf.extend(change_id_pos_map[&entry.change_id].to_le_bytes()); assert_eq!( entry.commit_id.as_bytes().len(), self.field_lengths.commit_id ); buf.extend_from_slice(entry.commit_id.as_bytes()); } for LocalPosition(pos) in self.commit_lookup.values() { buf.extend(pos.to_le_bytes()); } for change_id in self.change_lookup.keys() { assert_eq!(change_id.as_bytes().len(), self.field_lengths.change_id); buf.extend_from_slice(change_id.as_bytes()); } let mut change_overflow = vec![]; for positions in self.change_lookup.values() { match positions.as_slice() { [] => panic!("change id lookup entry must not be empty"), // Optimize for imported commits [LocalPosition(pos1)] => { assert!(*pos1 < OVERFLOW_FLAG); buf.extend(pos1.to_le_bytes()); } positions => { let overflow_pos = u32::try_from(change_overflow.len()).unwrap(); assert!(overflow_pos < OVERFLOW_FLAG); buf.extend((!overflow_pos).to_le_bytes()); change_overflow.extend_from_slice(positions); } } } let num_parent_overflow = u32::try_from(parent_overflow.len()).unwrap(); buf[parent_overflow_offset..][..4].copy_from_slice(&num_parent_overflow.to_le_bytes()); for IndexPosition(pos) in parent_overflow { buf.extend(pos.to_le_bytes()); } let num_change_overflow = u32::try_from(change_overflow.len()).unwrap(); buf[change_overflow_offset..][..4].copy_from_slice(&num_change_overflow.to_le_bytes()); for LocalPosition(pos) in change_overflow { buf.extend(pos.to_le_bytes()); } } /// If the MutableIndex has more than half the commits of its parent /// ReadonlyIndex, return MutableIndex with the commits from both. This /// is done recursively, so the stack of index files has O(log n) files. fn maybe_squash_with_ancestors(self) -> MutableIndexSegment { let mut num_new_commits = self.num_local_commits(); let mut files_to_squash = vec![]; let mut base_parent_file = None; for parent_file in self.as_composite().ancestor_files_without_local() { // TODO: We should probably also squash if the parent file has less than N // commits, regardless of how many (few) are in `self`. if 2 * num_new_commits < parent_file.num_local_commits() { base_parent_file = Some(parent_file.clone()); break; } num_new_commits += parent_file.num_local_commits(); files_to_squash.push(parent_file.clone()); } if files_to_squash.is_empty() { return self; } let mut squashed = if let Some(parent_file) = base_parent_file { MutableIndexSegment::incremental(parent_file) } else { MutableIndexSegment::full(self.field_lengths) }; for parent_file in files_to_squash.iter().rev() { squashed.add_commits_from(parent_file.as_ref()); } squashed.add_commits_from(&self); squashed } pub(super) fn save_in(self, dir: &Path) -> io::Result<Arc<ReadonlyIndexSegment>> { if self.num_local_commits() == 0 && self.parent_file.is_some() { return Ok(self.parent_file.unwrap()); } let mut buf = Vec::new(); buf.extend(INDEX_SEGMENT_FILE_FORMAT_VERSION.to_le_bytes()); self.serialize_parent_filename(&mut buf); let local_entries_offset = buf.len(); self.serialize_local_entries(&mut buf); let mut hasher = Blake2b512::new(); hasher.update(&buf); let index_file_id_hex = hex_util::encode_hex(&hasher.finalize()); let index_file_path = dir.join(&index_file_id_hex); let mut temp_file = NamedTempFile::new_in(dir)?; let file = temp_file.as_file_mut(); file.write_all(&buf)?; persist_content_addressed_temp_file(temp_file, index_file_path)?; Ok(ReadonlyIndexSegment::load_with_parent_file( &mut &buf[local_entries_offset..], index_file_id_hex, self.parent_file, self.field_lengths, ) .expect("in-memory index data should be valid and readable")) }} impl IndexSegment for MutableIndexSegment { fn num_parent_commits(&self) -> u32 { self.num_parent_commits } fn num_local_commits(&self) -> u32 { self.graph.len().try_into().unwrap() } fn parent_file(&self) -> Option<&Arc<ReadonlyIndexSegment>> { self.parent_file.as_ref() } fn name(&self) -> Option<String> { None } fn commit_id_to_pos(&self, commit_id: &CommitId) -> Option<LocalPosition> { self.commit_lookup.get(commit_id).copied() } fn resolve_neighbor_commit_ids( &self, commit_id: &CommitId, ) -> (Option<CommitId>, Option<CommitId>) { let (prev_id, next_id) = resolve_neighbor_ids(&self.commit_lookup, commit_id); (prev_id.cloned(), next_id.cloned()) } fn resolve_commit_id_prefix(&self, prefix: &HexPrefix) -> PrefixResolution<CommitId> { let min_bytes_prefix = CommitId::from_bytes(prefix.min_prefix_bytes()); resolve_id_prefix(&self.commit_lookup, prefix, &min_bytes_prefix).map(|(id, _)| id.clone()) } fn resolve_neighbor_change_ids( &self, change_id: &ChangeId, ) -> (Option<ChangeId>, Option<ChangeId>) { let (prev_id, next_id) = resolve_neighbor_ids(&self.change_lookup, change_id); (prev_id.cloned(), next_id.cloned()) } fn resolve_change_id_prefix( &self, prefix: &HexPrefix, ) -> PrefixResolution<(ChangeId, SmallLocalPositionsVec)> { let min_bytes_prefix = ChangeId::from_bytes(prefix.min_prefix_bytes()); resolve_id_prefix(&self.change_lookup, prefix, &min_bytes_prefix) .map(|(id, positions)| (id.clone(), positions.clone())) } fn generation_number(&self, local_pos: LocalPosition) -> u32 { self.graph[local_pos.0 as usize].generation_number } fn commit_id(&self, local_pos: LocalPosition) -> CommitId { self.graph[local_pos.0 as usize].commit_id.clone() } fn change_id(&self, local_pos: LocalPosition) -> ChangeId { self.graph[local_pos.0 as usize].change_id.clone() } fn num_parents(&self, local_pos: LocalPosition) -> u32 { self.graph[local_pos.0 as usize] .parent_positions .len() .try_into() .unwrap() } fn parent_positions(&self, local_pos: LocalPosition) -> SmallIndexPositionsVec { self.graph[local_pos.0 as usize].parent_positions.clone() }} /// In-memory mutable records for the on-disk commit index backend.pub struct DefaultMutableIndex(MutableIndexSegment); impl DefaultMutableIndex { pub(super) fn full(lengths: FieldLengths) -> Self { let mutable_segment = MutableIndexSegment::full(lengths); DefaultMutableIndex(mutable_segment) } pub(super) fn incremental(parent_file: Arc<ReadonlyIndexSegment>) -> Self { let mutable_segment = MutableIndexSegment::incremental(parent_file); DefaultMutableIndex(mutable_segment) } #[cfg(test)] pub(super) fn add_commit_data( &mut self, commit_id: CommitId, change_id: ChangeId, parent_ids: &[CommitId], ) { self.0.add_commit_data(commit_id, change_id, parent_ids); } pub(super) fn squash_and_save_in(self, dir: &Path) -> io::Result<Arc<ReadonlyIndexSegment>> { self.0.maybe_squash_with_ancestors().save_in(dir) }} impl AsCompositeIndex for DefaultMutableIndex { fn as_composite(&self) -> &CompositeIndex { self.0.as_composite() }} impl Index for DefaultMutableIndex { fn shortest_unique_commit_id_prefix_len(&self, commit_id: &CommitId) -> usize { self.as_composite() .shortest_unique_commit_id_prefix_len(commit_id) } fn resolve_commit_id_prefix(&self, prefix: &HexPrefix) -> PrefixResolution<CommitId> { self.as_composite().resolve_commit_id_prefix(prefix)Lines 1–500 of 599. 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// Copyright 2023 The Jujutsu Authors // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // https://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. #![allow(missing_docs)] use std::any::Any; use std::cmp::max; use std::collections::BTreeMap; use std::collections::HashMap; use std::io; use std::io::Write as _; use std::ops::Bound; use std::path::Path; use std::sync::Arc; use blake2::Blake2b512; use digest::Digest as _; use itertools::Itertools as _; use smallvec::smallvec; use smallvec::SmallVec; use tempfile::NamedTempFile; use super::composite::AsCompositeIndex; use super::composite::ChangeIdIndexImpl; use super::composite::CompositeIndex; use super::composite::DynIndexSegment; use super::composite::IndexSegment; use super::entry::IndexPosition; use super::entry::LocalPosition; use super::entry::SmallIndexPositionsVec; use super::entry::SmallLocalPositionsVec; use super::readonly::DefaultReadonlyIndex; use super::readonly::FieldLengths; use super::readonly::ReadonlyIndexSegment; use super::readonly::INDEX_SEGMENT_FILE_FORMAT_VERSION; use super::readonly::OVERFLOW_FLAG; use crate::backend::ChangeId; use crate::backend::CommitId; use crate::commit::Commit; use crate::file_util::persist_content_addressed_temp_file; use crate::hex_util; use crate::index::AllHeadsForGcUnsupported; use crate::index::ChangeIdIndex; use crate::index::Index; use crate::index::IndexError; use crate::index::MutableIndex; use crate::index::ReadonlyIndex; use crate::object_id::HexPrefix; use crate::object_id::ObjectId; use crate::object_id::PrefixResolution; use crate::revset::ResolvedExpression; use crate::revset::Revset; use crate::revset::RevsetEvaluationError; use crate::store::Store; #[derive(Debug)] struct MutableGraphEntry { commit_id: CommitId, change_id: ChangeId, generation_number: u32, parent_positions: SmallIndexPositionsVec, } pub(super) struct MutableIndexSegment { parent_file: Option<Arc<ReadonlyIndexSegment>>, num_parent_commits: u32, field_lengths: FieldLengths, graph: Vec<MutableGraphEntry>, commit_lookup: BTreeMap<CommitId, LocalPosition>, change_lookup: BTreeMap<ChangeId, SmallLocalPositionsVec>, } impl MutableIndexSegment { pub(super) fn full(field_lengths: FieldLengths) -> Self { Self { parent_file: None, num_parent_commits: 0, field_lengths, graph: vec![], commit_lookup: BTreeMap::new(), change_lookup: BTreeMap::new(), } } pub(super) fn incremental(parent_file: Arc<ReadonlyIndexSegment>) -> Self { let num_parent_commits = parent_file.as_composite().num_commits(); let field_lengths = parent_file.field_lengths(); Self { parent_file: Some(parent_file), num_parent_commits, field_lengths, graph: vec![], commit_lookup: BTreeMap::new(), change_lookup: BTreeMap::new(), } } pub(super) fn as_composite(&self) -> &CompositeIndex { CompositeIndex::new(self) } pub(super) fn add_commit(&mut self, commit: &Commit) { self.add_commit_data( commit.id().clone(), commit.change_id().clone(), commit.parent_ids(), ); } pub(super) fn add_commit_data( &mut self, commit_id: CommitId, change_id: ChangeId, parent_ids: &[CommitId], ) { if self.as_composite().has_id(&commit_id) { return; } let mut entry = MutableGraphEntry { commit_id, change_id, generation_number: 0, parent_positions: SmallVec::new(), }; for parent_id in parent_ids { let parent_entry = self .as_composite() .entry_by_id(parent_id) .expect("parent commit is not indexed"); entry.generation_number = max( entry.generation_number, parent_entry.generation_number() + 1, ); entry.parent_positions.push(parent_entry.position()); } let local_pos = LocalPosition(u32::try_from(self.graph.len()).unwrap()); self.commit_lookup .insert(entry.commit_id.clone(), local_pos); self.change_lookup .entry(entry.change_id.clone()) // positions are inherently sorted .and_modify(|positions| positions.push(local_pos)) .or_insert(smallvec![local_pos]); self.graph.push(entry); } pub(super) fn add_commits_from(&mut self, other_segment: &DynIndexSegment) { let other = CompositeIndex::new(other_segment); for pos in other_segment.num_parent_commits()..other.num_commits() { let entry = other.entry_by_pos(IndexPosition(pos)); let parent_ids = entry.parents().map(|entry| entry.commit_id()).collect_vec(); self.add_commit_data(entry.commit_id(), entry.change_id(), &parent_ids); } } pub(super) fn merge_in(&mut self, other: Arc<ReadonlyIndexSegment>) { let mut maybe_own_ancestor = self.parent_file.clone(); let mut maybe_other_ancestor = Some(other); let mut files_to_add = vec![]; loop { if maybe_other_ancestor.is_none() { break; } let other_ancestor = maybe_other_ancestor.as_ref().unwrap(); if maybe_own_ancestor.is_none() { files_to_add.push(other_ancestor.clone()); maybe_other_ancestor = other_ancestor.parent_file().cloned(); continue; } let own_ancestor = maybe_own_ancestor.as_ref().unwrap(); if own_ancestor.name() == other_ancestor.name() { break; } if own_ancestor.as_composite().num_commits() < other_ancestor.as_composite().num_commits() { files_to_add.push(other_ancestor.clone()); maybe_other_ancestor = other_ancestor.parent_file().cloned(); } else { maybe_own_ancestor = own_ancestor.parent_file().cloned(); } } for file in files_to_add.iter().rev() { self.add_commits_from(file.as_ref()); } } fn serialize_parent_filename(&self, buf: &mut Vec<u8>) { if let Some(parent_file) = &self.parent_file { buf.extend( u32::try_from(parent_file.name().len()) .unwrap() .to_le_bytes(), ); buf.extend_from_slice(parent_file.name().as_bytes()); } else { buf.extend(0_u32.to_le_bytes()); } } fn serialize_local_entries(&self, buf: &mut Vec<u8>) { assert_eq!(self.graph.len(), self.commit_lookup.len()); debug_assert_eq!( self.graph.len(), self.change_lookup.values().flatten().count() ); let num_commits = u32::try_from(self.graph.len()).unwrap(); buf.extend(num_commits.to_le_bytes()); let num_change_ids = u32::try_from(self.change_lookup.len()).unwrap(); buf.extend(num_change_ids.to_le_bytes()); // We'll write the actual values later let parent_overflow_offset = buf.len(); buf.extend(0_u32.to_le_bytes()); let change_overflow_offset = buf.len(); buf.extend(0_u32.to_le_bytes()); // Positions of change ids in the sorted table let change_id_pos_map: HashMap<&ChangeId, u32> = self .change_lookup .keys() .enumerate() .map(|(i, change_id)| (change_id, u32::try_from(i).unwrap())) .collect(); let mut parent_overflow = vec![]; for entry in &self.graph { buf.extend(entry.generation_number.to_le_bytes()); match entry.parent_positions.as_slice() { [] => { buf.extend((!0_u32).to_le_bytes()); buf.extend((!0_u32).to_le_bytes()); } [IndexPosition(pos1)] => { assert!(*pos1 < OVERFLOW_FLAG); buf.extend(pos1.to_le_bytes()); buf.extend((!0_u32).to_le_bytes()); } [IndexPosition(pos1), IndexPosition(pos2)] => { assert!(*pos1 < OVERFLOW_FLAG); assert!(*pos2 < OVERFLOW_FLAG); buf.extend(pos1.to_le_bytes()); buf.extend(pos2.to_le_bytes()); } positions => { let overflow_pos = u32::try_from(parent_overflow.len()).unwrap(); let num_parents = u32::try_from(positions.len()).unwrap(); assert!(overflow_pos < OVERFLOW_FLAG); assert!(num_parents < OVERFLOW_FLAG); buf.extend((!overflow_pos).to_le_bytes()); buf.extend((!num_parents).to_le_bytes()); parent_overflow.extend_from_slice(positions); } } buf.extend(change_id_pos_map[&entry.change_id].to_le_bytes()); assert_eq!( entry.commit_id.as_bytes().len(), self.field_lengths.commit_id ); buf.extend_from_slice(entry.commit_id.as_bytes()); } for LocalPosition(pos) in self.commit_lookup.values() { buf.extend(pos.to_le_bytes()); } for change_id in self.change_lookup.keys() { assert_eq!(change_id.as_bytes().len(), self.field_lengths.change_id); buf.extend_from_slice(change_id.as_bytes()); } let mut change_overflow = vec![]; for positions in self.change_lookup.values() { match positions.as_slice() { [] => panic!("change id lookup entry must not be empty"), // Optimize for imported commits [LocalPosition(pos1)] => { assert!(*pos1 < OVERFLOW_FLAG); buf.extend(pos1.to_le_bytes()); } positions => { let overflow_pos = u32::try_from(change_overflow.len()).unwrap(); assert!(overflow_pos < OVERFLOW_FLAG); buf.extend((!overflow_pos).to_le_bytes()); change_overflow.extend_from_slice(positions); } } } let num_parent_overflow = u32::try_from(parent_overflow.len()).unwrap(); buf[parent_overflow_offset..][..4].copy_from_slice(&num_parent_overflow.to_le_bytes()); for IndexPosition(pos) in parent_overflow { buf.extend(pos.to_le_bytes()); } let num_change_overflow = u32::try_from(change_overflow.len()).unwrap(); buf[change_overflow_offset..][..4].copy_from_slice(&num_change_overflow.to_le_bytes()); for LocalPosition(pos) in change_overflow { buf.extend(pos.to_le_bytes()); } } /// If the MutableIndex has more than half the commits of its parent /// ReadonlyIndex, return MutableIndex with the commits from both. This /// is done recursively, so the stack of index files has O(log n) files. fn maybe_squash_with_ancestors(self) -> MutableIndexSegment { let mut num_new_commits = self.num_local_commits(); let mut files_to_squash = vec![]; let mut base_parent_file = None; for parent_file in self.as_composite().ancestor_files_without_local() { // TODO: We should probably also squash if the parent file has less than N // commits, regardless of how many (few) are in `self`. if 2 * num_new_commits < parent_file.num_local_commits() { base_parent_file = Some(parent_file.clone()); break; } num_new_commits += parent_file.num_local_commits(); files_to_squash.push(parent_file.clone()); } if files_to_squash.is_empty() { return self; } let mut squashed = if let Some(parent_file) = base_parent_file { MutableIndexSegment::incremental(parent_file) } else { MutableIndexSegment::full(self.field_lengths) }; for parent_file in files_to_squash.iter().rev() { squashed.add_commits_from(parent_file.as_ref()); } squashed.add_commits_from(&self); squashed } pub(super) fn save_in(self, dir: &Path) -> io::Result<Arc<ReadonlyIndexSegment>> { if self.num_local_commits() == 0 && self.parent_file.is_some() { return Ok(self.parent_file.unwrap()); } let mut buf = Vec::new(); buf.extend(INDEX_SEGMENT_FILE_FORMAT_VERSION.to_le_bytes()); self.serialize_parent_filename(&mut buf); let local_entries_offset = buf.len(); self.serialize_local_entries(&mut buf); let mut hasher = Blake2b512::new(); hasher.update(&buf); let index_file_id_hex = hex_util::encode_hex(&hasher.finalize()); let index_file_path = dir.join(&index_file_id_hex); let mut temp_file = NamedTempFile::new_in(dir)?; let file = temp_file.as_file_mut(); file.write_all(&buf)?; persist_content_addressed_temp_file(temp_file, index_file_path)?; Ok(ReadonlyIndexSegment::load_with_parent_file( &mut &buf[local_entries_offset..], index_file_id_hex, self.parent_file, self.field_lengths, ) .expect("in-memory index data should be valid and readable")) } } impl IndexSegment for MutableIndexSegment { fn num_parent_commits(&self) -> u32 { self.num_parent_commits } fn num_local_commits(&self) -> u32 { self.graph.len().try_into().unwrap() } fn parent_file(&self) -> Option<&Arc<ReadonlyIndexSegment>> { self.parent_file.as_ref() } fn name(&self) -> Option<String> { None } fn commit_id_to_pos(&self, commit_id: &CommitId) -> Option<LocalPosition> { self.commit_lookup.get(commit_id).copied() } fn resolve_neighbor_commit_ids( &self, commit_id: &CommitId, ) -> (Option<CommitId>, Option<CommitId>) { let (prev_id, next_id) = resolve_neighbor_ids(&self.commit_lookup, commit_id); (prev_id.cloned(), next_id.cloned()) } fn resolve_commit_id_prefix(&self, prefix: &HexPrefix) -> PrefixResolution<CommitId> { let min_bytes_prefix = CommitId::from_bytes(prefix.min_prefix_bytes()); resolve_id_prefix(&self.commit_lookup, prefix, &min_bytes_prefix).map(|(id, _)| id.clone()) } fn resolve_neighbor_change_ids( &self, change_id: &ChangeId, ) -> (Option<ChangeId>, Option<ChangeId>) { let (prev_id, next_id) = resolve_neighbor_ids(&self.change_lookup, change_id); (prev_id.cloned(), next_id.cloned()) } fn resolve_change_id_prefix( &self, prefix: &HexPrefix, ) -> PrefixResolution<(ChangeId, SmallLocalPositionsVec)> { let min_bytes_prefix = ChangeId::from_bytes(prefix.min_prefix_bytes()); resolve_id_prefix(&self.change_lookup, prefix, &min_bytes_prefix) .map(|(id, positions)| (id.clone(), positions.clone())) } fn generation_number(&self, local_pos: LocalPosition) -> u32 { self.graph[local_pos.0 as usize].generation_number } fn commit_id(&self, local_pos: LocalPosition) -> CommitId { self.graph[local_pos.0 as usize].commit_id.clone() } fn change_id(&self, local_pos: LocalPosition) -> ChangeId { self.graph[local_pos.0 as usize].change_id.clone() } fn num_parents(&self, local_pos: LocalPosition) -> u32 { self.graph[local_pos.0 as usize] .parent_positions .len() .try_into() .unwrap() } fn parent_positions(&self, local_pos: LocalPosition) -> SmallIndexPositionsVec { self.graph[local_pos.0 as usize].parent_positions.clone() } } /// In-memory mutable records for the on-disk commit index backend. pub struct DefaultMutableIndex(MutableIndexSegment); impl DefaultMutableIndex { pub(super) fn full(lengths: FieldLengths) -> Self { let mutable_segment = MutableIndexSegment::full(lengths); DefaultMutableIndex(mutable_segment) } pub(super) fn incremental(parent_file: Arc<ReadonlyIndexSegment>) -> Self { let mutable_segment = MutableIndexSegment::incremental(parent_file); DefaultMutableIndex(mutable_segment) } #[cfg(test)] pub(super) fn add_commit_data( &mut self, commit_id: CommitId, change_id: ChangeId, parent_ids: &[CommitId], ) { self.0.add_commit_data(commit_id, change_id, parent_ids); } pub(super) fn squash_and_save_in(self, dir: &Path) -> io::Result<Arc<ReadonlyIndexSegment>> { self.0.maybe_squash_with_ancestors().save_in(dir) } } impl AsCompositeIndex for DefaultMutableIndex { fn as_composite(&self) -> &CompositeIndex { self.0.as_composite() } } impl Index for DefaultMutableIndex { fn shortest_unique_commit_id_prefix_len(&self, commit_id: &CommitId) -> usize { self.as_composite() .shortest_unique_commit_id_prefix_len(commit_id) } fn resolve_commit_id_prefix(&self, prefix: &HexPrefix) -> PrefixResolution<CommitId> { self.as_composite().resolve_commit_id_prefix(prefix)