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jj/lib/src/repo.rs
Martin von Zweigbergk 48a9f9ef56 repo: use Transaction for creating repo-init operation 
Since the operation log has a root operation, we don't need to create
the repo-initialization operation in order to create a valid
`ReadonlyRepo` instance. I think it's conceptually simpler to create
the instance at the root operation id and then add the initial
operation using the usual `Transaction` API. That's what this patch
does.

Doing that also brought two issues to light:

 1. The empty view object doesn't have the root commit as head.
 2. The initialized `OpHeadsStore` doesn't have the root operation as
     head.

Both of those seem somewhat reasonable, but maybe we should change
them. For now, I just made the initial repo (before the initial
operation) have a single op head (to compensate for (2)). It might be
worth addressing both issues so the repo is in a better state before
we create the initial operation. Until we do, we probably shouldn't
drop the initial operation.
2024-02-11 21:19:30 -08:00

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// Copyright 2020 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::collections::{HashMap, HashSet};
use std::fmt::{Debug, Formatter};
use std::io::ErrorKind;
use std::ops::Deref;
use std::path::{Path, PathBuf};
use std::sync::Arc;
use std::{fs, slice};
use itertools::Itertools;
use once_cell::sync::OnceCell;
use thiserror::Error;
use tracing::instrument;
use self::dirty_cell::DirtyCell;
use crate::backend::{
Backend, BackendError, BackendInitError, BackendLoadError, BackendResult, ChangeId, CommitId,
MergedTreeId, SigningFn,
};
use crate::commit::{Commit, CommitByCommitterTimestamp};
use crate::commit_builder::CommitBuilder;
use crate::default_index::DefaultIndexStore;
use crate::default_submodule_store::DefaultSubmoduleStore;
use crate::file_util::{IoResultExt as _, PathError};
use crate::git_backend::GitBackend;
use crate::index::{ChangeIdIndex, Index, IndexStore, MutableIndex, ReadonlyIndex};
use crate::local_backend::LocalBackend;
use crate::object_id::{HexPrefix, ObjectId, PrefixResolution};
use crate::op_heads_store::{self, OpHeadResolutionError, OpHeadsStore};
use crate::op_store::{
OpStore, OpStoreError, OperationId, RefTarget, RemoteRef, RemoteRefState, WorkspaceId,
};
use crate::operation::Operation;
use crate::refs::{
diff_named_ref_targets, diff_named_remote_refs, merge_ref_targets, merge_remote_refs,
};
use crate::rewrite::{DescendantRebaser, RebaseOptions};
use crate::settings::{RepoSettings, UserSettings};
use crate::signing::{SignInitError, Signer};
use crate::simple_op_heads_store::SimpleOpHeadsStore;
use crate::simple_op_store::SimpleOpStore;
use crate::store::Store;
use crate::submodule_store::SubmoduleStore;
use crate::transaction::Transaction;
use crate::tree::TreeMergeError;
use crate::view::View;
use crate::{backend, dag_walk, op_store, revset};
pub trait Repo {
fn store(&self) -> &Arc<Store>;
fn op_store(&self) -> &Arc<dyn OpStore>;
fn index(&self) -> &dyn Index;
fn view(&self) -> &View;
fn submodule_store(&self) -> &Arc<dyn SubmoduleStore>;
fn resolve_change_id(&self, change_id: &ChangeId) -> Option<Vec<CommitId>> {
// Replace this if we added more efficient lookup method.
let prefix = HexPrefix::from_bytes(change_id.as_bytes());
match self.resolve_change_id_prefix(&prefix) {
PrefixResolution::NoMatch => None,
PrefixResolution::SingleMatch(entries) => Some(entries),
PrefixResolution::AmbiguousMatch => panic!("complete change_id should be unambiguous"),
}
}
fn resolve_change_id_prefix(&self, prefix: &HexPrefix) -> PrefixResolution<Vec<CommitId>>;
fn shortest_unique_change_id_prefix_len(&self, target_id_bytes: &ChangeId) -> usize;
}
pub struct ReadonlyRepo {
repo_path: PathBuf,
store: Arc<Store>,
op_store: Arc<dyn OpStore>,
op_heads_store: Arc<dyn OpHeadsStore>,
operation: Operation,
settings: RepoSettings,
index_store: Arc<dyn IndexStore>,
submodule_store: Arc<dyn SubmoduleStore>,
index: OnceCell<Box<dyn ReadonlyIndex>>,
change_id_index: OnceCell<Box<dyn ChangeIdIndex>>,
// TODO: This should eventually become part of the index and not be stored fully in memory.
view: View,
}
impl Debug for ReadonlyRepo {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), std::fmt::Error> {
f.debug_struct("Repo")
.field("repo_path", &self.repo_path)
.field("store", &self.store)
.finish()
}
}
#[derive(Error, Debug)]
pub enum RepoInitError {
#[error(transparent)]
Backend(#[from] BackendInitError),
#[error(transparent)]
Path(#[from] PathError),
}
impl ReadonlyRepo {
pub fn default_op_store_initializer() -> &'static OpStoreInitializer<'static> {
&|_settings, store_path| Box::new(SimpleOpStore::init(store_path))
}
pub fn default_op_heads_store_initializer() -> &'static OpHeadsStoreInitializer<'static> {
&|_settings, store_path| {
let store = SimpleOpHeadsStore::init(store_path);
Box::new(store)
}
}
pub fn default_index_store_initializer() -> &'static IndexStoreInitializer<'static> {
&|_settings, store_path| Ok(Box::new(DefaultIndexStore::init(store_path)?))
}
pub fn default_submodule_store_initializer() -> &'static SubmoduleStoreInitializer<'static> {
&|_settings, store_path| Box::new(DefaultSubmoduleStore::init(store_path))
}
#[allow(clippy::too_many_arguments)]
pub fn init(
user_settings: &UserSettings,
repo_path: &Path,
backend_initializer: &BackendInitializer,
signer: Signer,
op_store_initializer: &OpStoreInitializer,
op_heads_store_initializer: &OpHeadsStoreInitializer,
index_store_initializer: &IndexStoreInitializer,
submodule_store_initializer: &SubmoduleStoreInitializer,
) -> Result<Arc<ReadonlyRepo>, RepoInitError> {
let repo_path = repo_path.canonicalize().context(repo_path)?;
let store_path = repo_path.join("store");
fs::create_dir(&store_path).context(&store_path)?;
let backend = backend_initializer(user_settings, &store_path)?;
let backend_path = store_path.join("type");
fs::write(&backend_path, backend.name()).context(&backend_path)?;
let store = Store::new(backend, signer, user_settings.use_tree_conflict_format());
let repo_settings = user_settings.with_repo(&repo_path).unwrap();
let op_store_path = repo_path.join("op_store");
fs::create_dir(&op_store_path).context(&op_store_path)?;
let op_store = op_store_initializer(user_settings, &op_store_path);
let op_store_type_path = op_store_path.join("type");
fs::write(&op_store_type_path, op_store.name()).context(&op_store_type_path)?;
let op_store: Arc<dyn OpStore> = Arc::from(op_store);
let op_heads_path = repo_path.join("op_heads");
fs::create_dir(&op_heads_path).context(&op_heads_path)?;
let op_heads_store = op_heads_store_initializer(user_settings, &op_heads_path);
let op_heads_type_path = op_heads_path.join("type");
fs::write(&op_heads_type_path, op_heads_store.name()).context(&op_heads_type_path)?;
op_heads_store.update_op_heads(&[], op_store.root_operation_id());
let op_heads_store: Arc<dyn OpHeadsStore> = Arc::from(op_heads_store);
let index_path = repo_path.join("index");
fs::create_dir(&index_path).context(&index_path)?;
let index_store = index_store_initializer(user_settings, &index_path)?;
let index_type_path = index_path.join("type");
fs::write(&index_type_path, index_store.name()).context(&index_type_path)?;
let index_store = Arc::from(index_store);
let submodule_store_path = repo_path.join("submodule_store");
fs::create_dir(&submodule_store_path).context(&submodule_store_path)?;
let submodule_store = submodule_store_initializer(user_settings, &submodule_store_path);
let submodule_store_type_path = submodule_store_path.join("type");
fs::write(&submodule_store_type_path, submodule_store.name())
.context(&submodule_store_type_path)?;
let submodule_store = Arc::from(submodule_store);
let root_operation_data = op_store
.read_operation(op_store.root_operation_id())
.expect("failed to read root operation");
let root_operation = Operation::new(
op_store.clone(),
op_store.root_operation_id().clone(),
root_operation_data,
);
let root_view = root_operation.view().expect("failed to read root view");
let repo = Arc::new(ReadonlyRepo {
repo_path,
store,
op_store,
op_heads_store,
operation: root_operation,
settings: repo_settings,
index_store,
index: OnceCell::new(),
change_id_index: OnceCell::new(),
view: root_view,
submodule_store,
});
let mut tx = repo.start_transaction(user_settings);
tx.mut_repo()
.add_head(&repo.store().root_commit())
.expect("failed to add root commit as head");
Ok(tx.commit("initialize repo"))
}
pub fn loader(&self) -> RepoLoader {
RepoLoader {
repo_path: self.repo_path.clone(),
repo_settings: self.settings.clone(),
store: self.store.clone(),
op_store: self.op_store.clone(),
op_heads_store: self.op_heads_store.clone(),
index_store: self.index_store.clone(),
submodule_store: self.submodule_store.clone(),
}
}
pub fn repo_path(&self) -> &PathBuf {
&self.repo_path
}
pub fn op_id(&self) -> &OperationId {
self.operation.id()
}
pub fn operation(&self) -> &Operation {
&self.operation
}
pub fn view(&self) -> &View {
&self.view
}
pub fn readonly_index(&self) -> &dyn ReadonlyIndex {
self.index
.get_or_init(|| {
// TODO: somehow propagate error, but it's weird if all callers
// had Result<T, IndexReadError> signature.
self.index_store
.get_index_at_op(&self.operation, &self.store)
.unwrap()
})
.deref()
}
fn change_id_index(&self) -> &dyn ChangeIdIndex {
self.change_id_index
.get_or_init(|| {
self.readonly_index()
.change_id_index(&mut self.view().heads().iter())
})
.as_ref()
}
pub fn op_heads_store(&self) -> &Arc<dyn OpHeadsStore> {
&self.op_heads_store
}
pub fn index_store(&self) -> &Arc<dyn IndexStore> {
&self.index_store
}
pub fn settings(&self) -> &RepoSettings {
&self.settings
}
pub fn start_transaction(
self: &Arc<ReadonlyRepo>,
user_settings: &UserSettings,
) -> Transaction {
let mut_repo = MutableRepo::new(self.clone(), self.readonly_index(), &self.view);
Transaction::new(mut_repo, user_settings)
}
pub fn reload_at_head(
&self,
user_settings: &UserSettings,
) -> Result<Arc<ReadonlyRepo>, RepoLoaderError> {
self.loader().load_at_head(user_settings)
}
#[instrument]
pub fn reload_at(&self, operation: &Operation) -> Result<Arc<ReadonlyRepo>, RepoLoaderError> {
self.loader().load_at(operation)
}
}
impl Repo for ReadonlyRepo {
fn store(&self) -> &Arc<Store> {
&self.store
}
fn op_store(&self) -> &Arc<dyn OpStore> {
&self.op_store
}
fn index(&self) -> &dyn Index {
self.readonly_index().as_index()
}
fn view(&self) -> &View {
&self.view
}
fn submodule_store(&self) -> &Arc<dyn SubmoduleStore> {
&self.submodule_store
}
fn resolve_change_id_prefix(&self, prefix: &HexPrefix) -> PrefixResolution<Vec<CommitId>> {
self.change_id_index().resolve_prefix(prefix)
}
fn shortest_unique_change_id_prefix_len(&self, target_id: &ChangeId) -> usize {
self.change_id_index().shortest_unique_prefix_len(target_id)
}
}
pub type BackendInitializer<'a> =
dyn Fn(&UserSettings, &Path) -> Result<Box<dyn Backend>, BackendInitError> + 'a;
pub type OpStoreInitializer<'a> = dyn Fn(&UserSettings, &Path) -> Box<dyn OpStore> + 'a;
pub type OpHeadsStoreInitializer<'a> = dyn Fn(&UserSettings, &Path) -> Box<dyn OpHeadsStore> + 'a;
pub type IndexStoreInitializer<'a> =
dyn Fn(&UserSettings, &Path) -> Result<Box<dyn IndexStore>, BackendInitError> + 'a;
pub type SubmoduleStoreInitializer<'a> =
dyn Fn(&UserSettings, &Path) -> Box<dyn SubmoduleStore> + 'a;
type BackendFactory =
Box<dyn Fn(&UserSettings, &Path) -> Result<Box<dyn Backend>, BackendLoadError>>;
type OpStoreFactory = Box<dyn Fn(&UserSettings, &Path) -> Box<dyn OpStore>>;
type OpHeadsStoreFactory = Box<dyn Fn(&UserSettings, &Path) -> Box<dyn OpHeadsStore>>;
type IndexStoreFactory =
Box<dyn Fn(&UserSettings, &Path) -> Result<Box<dyn IndexStore>, BackendLoadError>>;
type SubmoduleStoreFactory = Box<dyn Fn(&UserSettings, &Path) -> Box<dyn SubmoduleStore>>;
pub struct StoreFactories {
backend_factories: HashMap<String, BackendFactory>,
op_store_factories: HashMap<String, OpStoreFactory>,
op_heads_store_factories: HashMap<String, OpHeadsStoreFactory>,
index_store_factories: HashMap<String, IndexStoreFactory>,
submodule_store_factories: HashMap<String, SubmoduleStoreFactory>,
}
impl Default for StoreFactories {
fn default() -> Self {
let mut factories = StoreFactories::empty();
// Backends
factories.add_backend(
LocalBackend::name(),
Box::new(|_settings, store_path| Ok(Box::new(LocalBackend::load(store_path)))),
);
factories.add_backend(
GitBackend::name(),
Box::new(|settings, store_path| Ok(Box::new(GitBackend::load(settings, store_path)?))),
);
// OpStores
factories.add_op_store(
SimpleOpStore::name(),
Box::new(|_settings, store_path| Box::new(SimpleOpStore::load(store_path))),
);
// OpHeadsStores
factories.add_op_heads_store(
SimpleOpHeadsStore::name(),
Box::new(|_settings, store_path| Box::new(SimpleOpHeadsStore::load(store_path))),
);
// Index
factories.add_index_store(
DefaultIndexStore::name(),
Box::new(|_settings, store_path| Ok(Box::new(DefaultIndexStore::load(store_path)))),
);
// SubmoduleStores
factories.add_submodule_store(
DefaultSubmoduleStore::name(),
Box::new(|_settings, store_path| Box::new(DefaultSubmoduleStore::load(store_path))),
);
factories
}
}
#[derive(Debug, Error)]
pub enum StoreLoadError {
#[error("Unsupported {store} backend type '{store_type}'")]
UnsupportedType {
store: &'static str,
store_type: String,
},
#[error("Failed to read {store} backend type")]
ReadError {
store: &'static str,
source: PathError,
},
#[error(transparent)]
Backend(#[from] BackendLoadError),
#[error(transparent)]
Signing(#[from] SignInitError),
}
impl StoreFactories {
pub fn empty() -> Self {
StoreFactories {
backend_factories: HashMap::new(),
op_store_factories: HashMap::new(),
op_heads_store_factories: HashMap::new(),
index_store_factories: HashMap::new(),
submodule_store_factories: HashMap::new(),
}
}
pub fn add_backend(&mut self, name: &str, factory: BackendFactory) {
self.backend_factories.insert(name.to_string(), factory);
}
pub fn load_backend(
&self,
settings: &UserSettings,
store_path: &Path,
) -> Result<Box<dyn Backend>, StoreLoadError> {
// For compatibility with existing repos. TODO: Delete in 0.8+.
if store_path.join("backend").is_file() {
fs::rename(store_path.join("backend"), store_path.join("type"))
.expect("Failed to rename 'backend' file to 'type'");
}
// For compatibility with existing repos. TODO: Delete default in 0.8+.
let backend_type = read_store_type_compat("commit", store_path.join("type"), || {
if store_path.join("git_target").is_file() {
GitBackend::name()
} else {
LocalBackend::name()
}
})?;
let backend_factory = self.backend_factories.get(&backend_type).ok_or_else(|| {
StoreLoadError::UnsupportedType {
store: "commit",
store_type: backend_type.to_string(),
}
})?;
Ok(backend_factory(settings, store_path)?)
}
pub fn add_op_store(&mut self, name: &str, factory: OpStoreFactory) {
self.op_store_factories.insert(name.to_string(), factory);
}
pub fn load_op_store(
&self,
settings: &UserSettings,
store_path: &Path,
) -> Result<Box<dyn OpStore>, StoreLoadError> {
// For compatibility with existing repos. TODO: Delete default in 0.8+.
let op_store_type =
read_store_type_compat("operation", store_path.join("type"), SimpleOpStore::name)?;
let op_store_factory = self.op_store_factories.get(&op_store_type).ok_or_else(|| {
StoreLoadError::UnsupportedType {
store: "operation",
store_type: op_store_type.to_string(),
}
})?;
Ok(op_store_factory(settings, store_path))
}
pub fn add_op_heads_store(&mut self, name: &str, factory: OpHeadsStoreFactory) {
self.op_heads_store_factories
.insert(name.to_string(), factory);
}
pub fn load_op_heads_store(
&self,
settings: &UserSettings,
store_path: &Path,
) -> Result<Box<dyn OpHeadsStore>, StoreLoadError> {
// For compatibility with existing repos. TODO: Delete default in 0.8+.
let op_heads_store_type = read_store_type_compat(
"operation heads",
store_path.join("type"),
SimpleOpHeadsStore::name,
)?;
let op_heads_store_factory = self
.op_heads_store_factories
.get(&op_heads_store_type)
.ok_or_else(|| StoreLoadError::UnsupportedType {
store: "operation heads",
store_type: op_heads_store_type.to_string(),
})?;
Ok(op_heads_store_factory(settings, store_path))
}
pub fn add_index_store(&mut self, name: &str, factory: IndexStoreFactory) {
self.index_store_factories.insert(name.to_string(), factory);
}
pub fn load_index_store(
&self,
settings: &UserSettings,
store_path: &Path,
) -> Result<Box<dyn IndexStore>, StoreLoadError> {
// For compatibility with existing repos. TODO: Delete default in 0.9+
let index_store_type =
read_store_type_compat("index", store_path.join("type"), DefaultIndexStore::name)?;
let index_store_factory = self
.index_store_factories
.get(&index_store_type)
.ok_or_else(|| StoreLoadError::UnsupportedType {
store: "index",
store_type: index_store_type.to_string(),
})?;
Ok(index_store_factory(settings, store_path)?)
}
pub fn add_submodule_store(&mut self, name: &str, factory: SubmoduleStoreFactory) {
self.submodule_store_factories
.insert(name.to_string(), factory);
}
pub fn load_submodule_store(
&self,
settings: &UserSettings,
store_path: &Path,
) -> Result<Box<dyn SubmoduleStore>, StoreLoadError> {
// For compatibility with repos without repo/submodule_store.
// TODO Delete default in TBD version
let submodule_store_type = read_store_type_compat(
"submodule_store",
store_path.join("type"),
DefaultSubmoduleStore::name,
)?;
let submodule_store_factory = self
.submodule_store_factories
.get(&submodule_store_type)
.ok_or_else(|| StoreLoadError::UnsupportedType {
store: "submodule_store",
store_type: submodule_store_type.to_string(),
})?;
Ok(submodule_store_factory(settings, store_path))
}
}
pub fn read_store_type_compat(
store: &'static str,
path: impl AsRef<Path>,
default: impl FnOnce() -> &'static str,
) -> Result<String, StoreLoadError> {
let path = path.as_ref();
let read_or_write_default = || match fs::read_to_string(path) {
Ok(content) => Ok(content),
Err(err) if err.kind() == ErrorKind::NotFound => {
let default_type = default();
fs::create_dir(path.parent().unwrap()).ok();
fs::write(path, default_type)?;
Ok(default_type.to_owned())
}
Err(err) => Err(err),
};
read_or_write_default()
.context(path)
.map_err(|source| StoreLoadError::ReadError { store, source })
}
#[derive(Debug, Error)]
pub enum RepoLoaderError {
#[error(transparent)]
TreeMerge(#[from] TreeMergeError),
#[error(transparent)]
OpHeadResolution(#[from] OpHeadResolutionError),
#[error(transparent)]
OpStore(#[from] OpStoreError),
}
#[derive(Clone)]
pub struct RepoLoader {
repo_path: PathBuf,
repo_settings: RepoSettings,
store: Arc<Store>,
op_store: Arc<dyn OpStore>,
op_heads_store: Arc<dyn OpHeadsStore>,
index_store: Arc<dyn IndexStore>,
submodule_store: Arc<dyn SubmoduleStore>,
}
impl RepoLoader {
pub fn init(
user_settings: &UserSettings,
repo_path: &Path,
store_factories: &StoreFactories,
) -> Result<Self, StoreLoadError> {
let store = Store::new(
store_factories.load_backend(user_settings, &repo_path.join("store"))?,
Signer::from_settings(user_settings)?,
user_settings.use_tree_conflict_format(),
);
let repo_settings = user_settings.with_repo(repo_path).unwrap();
let op_store =
Arc::from(store_factories.load_op_store(user_settings, &repo_path.join("op_store"))?);
let op_heads_store = Arc::from(
store_factories.load_op_heads_store(user_settings, &repo_path.join("op_heads"))?,
);
let index_store =
Arc::from(store_factories.load_index_store(user_settings, &repo_path.join("index"))?);
let submodule_store = Arc::from(
store_factories
.load_submodule_store(user_settings, &repo_path.join("submodule_store"))?,
);
Ok(Self {
repo_path: repo_path.to_path_buf(),
repo_settings,
store,
op_store,
op_heads_store,
index_store,
submodule_store,
})
}
pub fn repo_path(&self) -> &PathBuf {
&self.repo_path
}
pub fn store(&self) -> &Arc<Store> {
&self.store
}
pub fn index_store(&self) -> &Arc<dyn IndexStore> {
&self.index_store
}
pub fn op_store(&self) -> &Arc<dyn OpStore> {
&self.op_store
}
pub fn op_heads_store(&self) -> &Arc<dyn OpHeadsStore> {
&self.op_heads_store
}
pub fn load_at_head(
&self,
user_settings: &UserSettings,
) -> Result<Arc<ReadonlyRepo>, RepoLoaderError> {
let op = op_heads_store::resolve_op_heads(
self.op_heads_store.as_ref(),
&self.op_store,
|op_heads| self._resolve_op_heads(op_heads, user_settings),
)?;
let view = op.view()?;
Ok(self._finish_load(op, view))
}
#[instrument(skip(self))]
pub fn load_at(&self, op: &Operation) -> Result<Arc<ReadonlyRepo>, RepoLoaderError> {
let view = op.view()?;
Ok(self._finish_load(op.clone(), view))
}
pub fn create_from(
&self,
operation: Operation,
view: View,
index: Box<dyn ReadonlyIndex>,
) -> Arc<ReadonlyRepo> {
let repo = ReadonlyRepo {
repo_path: self.repo_path.clone(),
store: self.store.clone(),
op_store: self.op_store.clone(),
op_heads_store: self.op_heads_store.clone(),
operation,
settings: self.repo_settings.clone(),
index_store: self.index_store.clone(),
submodule_store: self.submodule_store.clone(),
index: OnceCell::with_value(index),
change_id_index: OnceCell::new(),
view,
};
Arc::new(repo)
}
fn _resolve_op_heads(
&self,
op_heads: Vec<Operation>,
user_settings: &UserSettings,
) -> Result<Operation, RepoLoaderError> {
let base_repo = self.load_at(&op_heads[0])?;
let mut tx = base_repo.start_transaction(user_settings);
for other_op_head in op_heads.into_iter().skip(1) {
tx.merge_operation(other_op_head)?;
tx.mut_repo().rebase_descendants(user_settings)?;
}
let merged_repo = tx
.write("resolve concurrent operations")
.leave_unpublished();
Ok(merged_repo.operation().clone())
}
fn _finish_load(&self, operation: Operation, view: View) -> Arc<ReadonlyRepo> {
let repo = ReadonlyRepo {
repo_path: self.repo_path.clone(),
store: self.store.clone(),
op_store: self.op_store.clone(),
op_heads_store: self.op_heads_store.clone(),
operation,
settings: self.repo_settings.clone(),
index_store: self.index_store.clone(),
submodule_store: self.submodule_store.clone(),
index: OnceCell::new(),
change_id_index: OnceCell::new(),
view,
};
Arc::new(repo)
}
}
pub struct MutableRepo {
base_repo: Arc<ReadonlyRepo>,
index: Box<dyn MutableIndex>,
view: DirtyCell<View>,
rewritten_commits: HashMap<CommitId, HashSet<CommitId>>,
abandoned_commits: HashSet<CommitId>,
}
impl MutableRepo {
pub fn new(
base_repo: Arc<ReadonlyRepo>,
index: &dyn ReadonlyIndex,
view: &View,
) -> MutableRepo {
let mut_view = view.clone();
let mut_index = index.start_modification();
MutableRepo {
base_repo,
index: mut_index,
view: DirtyCell::with_clean(mut_view),
rewritten_commits: Default::default(),
abandoned_commits: Default::default(),
}
}
pub fn base_repo(&self) -> &Arc<ReadonlyRepo> {
&self.base_repo
}
fn view_mut(&mut self) -> &mut View {
self.view.get_mut()
}
pub fn mutable_index(&self) -> &dyn MutableIndex {
self.index.as_ref()
}
pub fn has_changes(&self) -> bool {
!(self.abandoned_commits.is_empty()
&& self.rewritten_commits.is_empty()
&& self.view() == &self.base_repo.view)
}
pub fn consume(self) -> (Box<dyn MutableIndex>, View) {
self.view.ensure_clean(|v| self.enforce_view_invariants(v));
(self.index, self.view.into_inner())
}
pub fn new_commit(
&mut self,
settings: &UserSettings,
parents: Vec<CommitId>,
tree_id: MergedTreeId,
) -> CommitBuilder {
CommitBuilder::for_new_commit(self, settings, parents, tree_id)
}
pub fn rewrite_commit(
&mut self,
settings: &UserSettings,
predecessor: &Commit,
) -> CommitBuilder {
CommitBuilder::for_rewrite_from(self, settings, predecessor)
// CommitBuilder::write will record the rewrite in
// `self.rewritten_commits`
}
pub fn write_commit(
&mut self,
commit: backend::Commit,
sign_with: Option<&mut SigningFn>,
) -> BackendResult<Commit> {
let commit = self.store().write_commit(commit, sign_with)?;
self.add_head(&commit)?;
Ok(commit)
}
/// Record a commit as having been rewritten to one or more ids in this
/// transaction.
///
/// This record is used by `rebase_descendants` to know which commits have
/// children that need to be rebased, and where to rebase them to. See the
/// docstring for `record_rewritten_commit` for details.
// TODO(ilyagr): Make this API saner, e.g. make `self.rewritten_commits` public
// and make empty values correspond to abandoned commits.
pub fn set_rewritten_commit(
&mut self,
old_id: CommitId,
new_ids: impl IntoIterator<Item = CommitId>,
) {
assert_ne!(old_id, *self.store().root_commit_id());
self.rewritten_commits
.insert(old_id, new_ids.into_iter().collect());
}
/// Record a commit as having been rewritten in this transaction. If it was
/// already rewritten, mark it as divergent (unlike `set_rewritten_commit`)
///
/// This record is used by `rebase_descendants` to know which commits have
/// children that need to be rebased, and where to rebase the children (as
/// well as branches) to.
///
/// The `rebase_descendants` logic treats these records as follows:
///
/// - If a commit is recorded as rewritten to a single commit, its
/// descendants would be rebased to become descendants of `new_id`. Any
/// branches at `old_id` are also moved to `new_id`.
/// - If a commit is recorded as rewritten to more than one commit, it is
/// assumed to have become divergent. Its descendants are *not* rebased.
/// However, the *branches* that were at `old_id` are moved to each of the
/// new ids, and thus become conflicted.
///
/// In neither case would `rebase_descendants` modify the `old_id` commit
/// itself.
pub fn record_rewritten_commit(&mut self, old_id: CommitId, new_id: CommitId) {
assert_ne!(old_id, *self.store().root_commit_id());
self.rewritten_commits
.entry(old_id)
.or_default()
.insert(new_id);
}
/// Record a commit as having been abandoned in this transaction.
///
/// This record is used by `rebase_descendants` to know which commits have
/// children that need to be rebased, and where to rebase the children (as
/// well as branches) to.
///
/// The `rebase_descendants` logic will rebase the descendants of `old_id`
/// to become the descendants of parent(s) of `old_id`. Any branches at
/// `old_id` would be moved to the parent(s) of `old_id` as well.
pub fn record_abandoned_commit(&mut self, old_id: CommitId) {
assert_ne!(old_id, *self.store().root_commit_id());
self.abandoned_commits.insert(old_id);
}
fn clear_descendant_rebaser_plans(&mut self) {
self.rewritten_commits.clear();
self.abandoned_commits.clear();
}
pub fn has_rewrites(&self) -> bool {
!(self.rewritten_commits.is_empty() && self.abandoned_commits.is_empty())
}
/// After the rebaser returned by this function is dropped,
/// self.clear_descendant_rebaser_plans() needs to be called.
fn rebase_descendants_return_rebaser<'settings, 'repo>(
&'repo mut self,
settings: &'settings UserSettings,
options: RebaseOptions,
) -> Result<Option<DescendantRebaser<'settings, 'repo>>, TreeMergeError> {
if !self.has_rewrites() {
// Optimization
return Ok(None);
}
let mut rebaser = DescendantRebaser::new(
settings,
self,
self.rewritten_commits.clone(),
self.abandoned_commits.clone(),
);
*rebaser.mut_options() = options;
rebaser.rebase_all()?;
Ok(Some(rebaser))
}
// TODO(ilyagr): Either document that this also moves branches (rename the
// function and the related functions?) or change things so that this only
// rebases descendants.
pub fn rebase_descendants_with_options(
&mut self,
settings: &UserSettings,
options: RebaseOptions,
) -> Result<usize, TreeMergeError> {
let result = self
.rebase_descendants_return_rebaser(settings, options)?
.map_or(0, |rebaser| rebaser.into_map().len());
self.clear_descendant_rebaser_plans();
Ok(result)
}
/// This is similar to `rebase_descendants_return_map`, but the return value
/// needs more explaining.
///
/// If the `options.empty` is the default, this function will only
/// rebase commits, and the return value is what you'd expect it to be.
///
/// Otherwise, this function may rebase some commits and abandon others. The
/// behavior is such that only commits with a single parent will ever be
/// abandoned. In the returned map, an abandoned commit will look as a
/// key-value pair where the key is the abandoned commit and the value is
/// **its parent**. One can tell this case apart since the change ids of the
/// key and the value will not match. The parent will inherit the
/// descendants and the branches of the abandoned commit.
pub fn rebase_descendants_with_options_return_map(
&mut self,
settings: &UserSettings,
options: RebaseOptions,
) -> Result<HashMap<CommitId, CommitId>, TreeMergeError> {
let result = Ok(self
// We do not set RebaseOptions here, since this function does not currently return
// enough information to describe the results of a rebase if some commits got
// abandoned
.rebase_descendants_return_rebaser(settings, options)?
.map_or(HashMap::new(), |rebaser| rebaser.into_map()));
self.clear_descendant_rebaser_plans();
result
}
pub fn rebase_descendants(&mut self, settings: &UserSettings) -> Result<usize, TreeMergeError> {
self.rebase_descendants_with_options(settings, Default::default())
}
pub fn rebase_descendants_return_map(
&mut self,
settings: &UserSettings,
) -> Result<HashMap<CommitId, CommitId>, TreeMergeError> {
self.rebase_descendants_with_options_return_map(settings, Default::default())
}
pub fn set_wc_commit(
&mut self,
workspace_id: WorkspaceId,
commit_id: CommitId,
) -> Result<(), RewriteRootCommit> {
if &commit_id == self.store().root_commit_id() {
return Err(RewriteRootCommit);
}
self.view_mut().set_wc_commit(workspace_id, commit_id);
Ok(())
}
pub fn remove_wc_commit(&mut self, workspace_id: &WorkspaceId) {
self.view_mut().remove_wc_commit(workspace_id);
}
pub fn check_out(
&mut self,
workspace_id: WorkspaceId,
settings: &UserSettings,
commit: &Commit,
) -> Result<Commit, CheckOutCommitError> {
let wc_commit = self
.new_commit(
settings,
vec![commit.id().clone()],
commit.tree_id().clone(),
)
.write()?;
self.edit(workspace_id, &wc_commit)?;
Ok(wc_commit)
}
pub fn edit(
&mut self,
workspace_id: WorkspaceId,
commit: &Commit,
) -> Result<(), EditCommitError> {
fn local_branch_target_ids(view: &View) -> impl Iterator<Item = &CommitId> {
view.local_branches()
.flat_map(|(_, target)| target.added_ids())
}
let maybe_wc_commit_id = self
.view
.with_ref(|v| v.get_wc_commit_id(&workspace_id).cloned());
if let Some(wc_commit_id) = maybe_wc_commit_id {
let wc_commit = self
.store()
.get_commit(&wc_commit_id)
.map_err(EditCommitError::WorkingCopyCommitNotFound)?;
if wc_commit.is_discardable()
&& self
.view
.with_ref(|v| local_branch_target_ids(v).all(|id| id != wc_commit.id()))
&& self.view().heads().contains(wc_commit.id())
{
// Abandon the working-copy commit we're leaving if it's empty, not pointed by
// local branch, and a head commit.
self.record_abandoned_commit(wc_commit_id);
}
}
self.set_wc_commit(workspace_id, commit.id().clone())
.map_err(|RewriteRootCommit| EditCommitError::RewriteRootCommit)
}
fn enforce_view_invariants(&self, view: &mut View) {
let view = view.store_view_mut();
let root_commit_id = self.store().root_commit_id();
if view.head_ids.is_empty() {
view.head_ids.insert(root_commit_id.clone());
} else if view.head_ids.len() > 1 {
// An empty head_ids set is padded with the root_commit_id, but the
// root id is unwanted during the heads resolution.
view.head_ids.remove(root_commit_id);
view.head_ids = self
.index()
.heads(&mut view.head_ids.iter())
.into_iter()
.collect();
}
assert!(!view.head_ids.is_empty());
}
/// Ensures that the given `head` and ancestor commits are reachable from
/// the visible heads.
pub fn add_head(&mut self, head: &Commit) -> BackendResult<()> {
self.add_heads(slice::from_ref(head))
}
/// Ensures that the given `heads` and ancestor commits are reachable from
/// the visible heads.
///
/// The `heads` may contain redundant commits such as already visible ones
/// and ancestors of the other heads. The `heads` and ancestor commits
/// should exist in the store.
pub fn add_heads(&mut self, heads: &[Commit]) -> BackendResult<()> {
let current_heads = self.view.get_mut().heads();
// Use incremental update for common case of adding a single commit on top a
// current head. TODO: Also use incremental update when adding a single
// commit on top a non-head.
match heads {
[] => {}
[head]
if head
.parent_ids()
.iter()
.all(|parent_id| current_heads.contains(parent_id)) =>
{
self.index.add_commit(head);
self.view.get_mut().add_head(head.id());
for parent_id in head.parent_ids() {
self.view.get_mut().remove_head(parent_id);
}
}
_ => {
let missing_commits = dag_walk::topo_order_reverse_ord_ok(
heads
.iter()
.cloned()
.map(CommitByCommitterTimestamp)
.map(Ok),
|CommitByCommitterTimestamp(commit)| commit.id().clone(),
|CommitByCommitterTimestamp(commit)| {
commit
.parent_ids()
.iter()
.filter(|id| !self.index().has_id(id))
.map(|id| self.store().get_commit(id))
.map_ok(CommitByCommitterTimestamp)
.collect_vec()
},
)?;
for CommitByCommitterTimestamp(missing_commit) in missing_commits.iter().rev() {
self.index.add_commit(missing_commit);
}
for head in heads {
self.view.get_mut().add_head(head.id());
}
self.view.mark_dirty();
}
}
Ok(())
}
pub fn remove_head(&mut self, head: &CommitId) {
self.view_mut().remove_head(head);
self.view.mark_dirty();
}
/// Returns true if any local or remote branch of the given `name` exists.
#[must_use]
pub fn has_branch(&self, name: &str) -> bool {
self.view.with_ref(|v| v.has_branch(name))
}
pub fn remove_branch(&mut self, name: &str) {
self.view_mut().remove_branch(name);
}
pub fn get_local_branch(&self, name: &str) -> RefTarget {
self.view.with_ref(|v| v.get_local_branch(name).clone())
}
pub fn set_local_branch_target(&mut self, name: &str, target: RefTarget) {
self.view_mut().set_local_branch_target(name, target);
}
pub fn merge_local_branch(
&mut self,
name: &str,
base_target: &RefTarget,
other_target: &RefTarget,
) {
let view = self.view.get_mut();
let index = self.index.as_index();
let self_target = view.get_local_branch(name);
let new_target = merge_ref_targets(index, self_target, base_target, other_target);
view.set_local_branch_target(name, new_target);
}
pub fn get_remote_branch(&self, name: &str, remote_name: &str) -> RemoteRef {
self.view
.with_ref(|v| v.get_remote_branch(name, remote_name).clone())
}
pub fn set_remote_branch(&mut self, name: &str, remote_name: &str, remote_ref: RemoteRef) {
self.view_mut()
.set_remote_branch(name, remote_name, remote_ref);
}
fn merge_remote_branch(
&mut self,
name: &str,
remote_name: &str,
base_ref: &RemoteRef,
other_ref: &RemoteRef,
) {
let view = self.view.get_mut();
let index = self.index.as_index();
let self_ref = view.get_remote_branch(name, remote_name);
let new_ref = merge_remote_refs(index, self_ref, base_ref, other_ref);
view.set_remote_branch(name, remote_name, new_ref);
}
/// Merges the specified remote branch in to local branch, and starts
/// tracking it.
pub fn track_remote_branch(&mut self, name: &str, remote_name: &str) {
let mut remote_ref = self.get_remote_branch(name, remote_name);
let base_target = remote_ref.tracking_target();
self.merge_local_branch(name, base_target, &remote_ref.target);
remote_ref.state = RemoteRefState::Tracking;
self.set_remote_branch(name, remote_name, remote_ref);
}
/// Stops tracking the specified remote branch.
pub fn untrack_remote_branch(&mut self, name: &str, remote_name: &str) {
let mut remote_ref = self.get_remote_branch(name, remote_name);
remote_ref.state = RemoteRefState::New;
self.set_remote_branch(name, remote_name, remote_ref);
}
pub fn remove_remote(&mut self, remote_name: &str) {
self.view_mut().remove_remote(remote_name);
}
pub fn rename_remote(&mut self, old: &str, new: &str) {
self.view_mut().rename_remote(old, new);
}
pub fn get_tag(&self, name: &str) -> RefTarget {
self.view.with_ref(|v| v.get_tag(name).clone())
}
pub fn set_tag_target(&mut self, name: &str, target: RefTarget) {
self.view_mut().set_tag_target(name, target);
}
pub fn merge_tag(&mut self, name: &str, base_target: &RefTarget, other_target: &RefTarget) {
let view = self.view.get_mut();
let index = self.index.as_index();
let self_target = view.get_tag(name);
let new_target = merge_ref_targets(index, self_target, base_target, other_target);
view.set_tag_target(name, new_target);
}
pub fn get_git_ref(&self, name: &str) -> RefTarget {
self.view.with_ref(|v| v.get_git_ref(name).clone())
}
pub fn set_git_ref_target(&mut self, name: &str, target: RefTarget) {
self.view_mut().set_git_ref_target(name, target);
}
fn merge_git_ref(&mut self, name: &str, base_target: &RefTarget, other_target: &RefTarget) {
let view = self.view.get_mut();
let index = self.index.as_index();
let self_target = view.get_git_ref(name);
let new_target = merge_ref_targets(index, self_target, base_target, other_target);
view.set_git_ref_target(name, new_target);
}
pub fn git_head(&self) -> RefTarget {
self.view.with_ref(|v| v.git_head().clone())
}
pub fn set_git_head_target(&mut self, target: RefTarget) {
self.view_mut().set_git_head_target(target);
}
pub fn set_view(&mut self, data: op_store::View) {
self.view_mut().set_view(data);
self.view.mark_dirty();
}
pub fn merge(&mut self, base_repo: &ReadonlyRepo, other_repo: &ReadonlyRepo) {
// First, merge the index, so we can take advantage of a valid index when
// merging the view. Merging in base_repo's index isn't typically
// necessary, but it can be if base_repo is ahead of either self or other_repo
// (e.g. because we're undoing an operation that hasn't been published).
self.index.merge_in(base_repo.readonly_index());
self.index.merge_in(other_repo.readonly_index());
self.view.ensure_clean(|v| self.enforce_view_invariants(v));
self.merge_view(&base_repo.view, &other_repo.view);
self.view.mark_dirty();
}
fn merge_view(&mut self, base: &View, other: &View) {
// Merge working-copy commits. If there's a conflict, we keep the self side.
for (workspace_id, base_wc_commit) in base.wc_commit_ids() {
let self_wc_commit = self.view().get_wc_commit_id(workspace_id);
let other_wc_commit = other.get_wc_commit_id(workspace_id);
if other_wc_commit == Some(base_wc_commit) || other_wc_commit == self_wc_commit {
// The other side didn't change or both sides changed in the
// same way.
} else if let Some(other_wc_commit) = other_wc_commit {
if self_wc_commit == Some(base_wc_commit) {
self.view_mut()
.set_wc_commit(workspace_id.clone(), other_wc_commit.clone());
}
} else {
// The other side removed the workspace. We want to remove it even if the self
// side changed the working-copy commit.
self.view_mut().remove_wc_commit(workspace_id);
}
}
for (workspace_id, other_wc_commit) in other.wc_commit_ids() {
if self.view().get_wc_commit_id(workspace_id).is_none()
&& base.get_wc_commit_id(workspace_id).is_none()
{
// The other side added the workspace.
self.view_mut()
.set_wc_commit(workspace_id.clone(), other_wc_commit.clone());
}
}
let base_heads = base.heads().iter().cloned().collect_vec();
let own_heads = self.view().heads().iter().cloned().collect_vec();
let other_heads = other.heads().iter().cloned().collect_vec();
self.record_rewrites(&base_heads, &own_heads);
self.record_rewrites(&base_heads, &other_heads);
// No need to remove heads removed by `other` because we already marked them
// abandoned or rewritten.
for added_head in other.heads().difference(base.heads()) {
self.view_mut().add_head(added_head);
}
let changed_local_branches =
diff_named_ref_targets(base.local_branches(), other.local_branches());
for (name, (base_target, other_target)) in changed_local_branches {
self.merge_local_branch(name, base_target, other_target);
}
let changed_tags = diff_named_ref_targets(base.tags(), other.tags());
for (name, (base_target, other_target)) in changed_tags {
self.merge_tag(name, base_target, other_target);
}
let changed_git_refs = diff_named_ref_targets(base.git_refs(), other.git_refs());
for (name, (base_target, other_target)) in changed_git_refs {
self.merge_git_ref(name, base_target, other_target);
}
let changed_remote_branches =
diff_named_remote_refs(base.all_remote_branches(), other.all_remote_branches());
for ((name, remote_name), (base_ref, other_ref)) in changed_remote_branches {
self.merge_remote_branch(name, remote_name, base_ref, other_ref);
}
let new_git_head_target = merge_ref_targets(
self.index(),
self.view().git_head(),
base.git_head(),
other.git_head(),
);
self.set_git_head_target(new_git_head_target);
}
/// Finds and records commits that were rewritten or abandoned between
/// `old_heads` and `new_heads`.
fn record_rewrites(&mut self, old_heads: &[CommitId], new_heads: &[CommitId]) {
let mut removed_changes: HashMap<ChangeId, Vec<CommitId>> = HashMap::new();
for (commit_id, change_id) in revset::walk_revs(self, old_heads, new_heads)
.unwrap()
.commit_change_ids()
{
removed_changes
.entry(change_id)
.or_default()
.push(commit_id);
}
if removed_changes.is_empty() {
return;
}
let mut rewritten_changes = HashSet::new();
let mut rewritten_commits: HashMap<CommitId, Vec<CommitId>> = HashMap::new();
for (commit_id, change_id) in revset::walk_revs(self, new_heads, old_heads)
.unwrap()
.commit_change_ids()
{
if let Some(old_commits) = removed_changes.get(&change_id) {
for old_commit in old_commits {
rewritten_commits
.entry(old_commit.clone())
.or_default()
.push(commit_id.clone());
}
}
rewritten_changes.insert(change_id);
}
for (old_commit, new_commits) in rewritten_commits {
for new_commit in new_commits {
self.record_rewritten_commit(old_commit.clone(), new_commit);
}
}
for (change_id, removed_commit_ids) in &removed_changes {
if !rewritten_changes.contains(change_id) {
for removed_commit_id in removed_commit_ids {
self.record_abandoned_commit(removed_commit_id.clone());
}
}
}
}
}
impl Repo for MutableRepo {
fn store(&self) -> &Arc<Store> {
self.base_repo.store()
}
fn op_store(&self) -> &Arc<dyn OpStore> {
self.base_repo.op_store()
}
fn index(&self) -> &dyn Index {
self.index.as_index()
}
fn submodule_store(&self) -> &Arc<dyn SubmoduleStore> {
self.base_repo.submodule_store()
}
fn view(&self) -> &View {
self.view
.get_or_ensure_clean(|v| self.enforce_view_invariants(v))
}
fn resolve_change_id_prefix(&self, prefix: &HexPrefix) -> PrefixResolution<Vec<CommitId>> {
let change_id_index = self.index.change_id_index(&mut self.view().heads().iter());
change_id_index.resolve_prefix(prefix)
}
fn shortest_unique_change_id_prefix_len(&self, target_id: &ChangeId) -> usize {
let change_id_index = self.index.change_id_index(&mut self.view().heads().iter());
change_id_index.shortest_unique_prefix_len(target_id)
}
}
/// Error from attempts to check out the root commit for editing
#[derive(Debug, Error)]
#[error("Cannot rewrite the root commit")]
pub struct RewriteRootCommit;
/// Error from attempts to edit a commit
#[derive(Debug, Error)]
pub enum EditCommitError {
#[error("Current working-copy commit not found")]
WorkingCopyCommitNotFound(#[source] BackendError),
#[error("Cannot rewrite the root commit")]
RewriteRootCommit,
}
/// Error from attempts to check out a commit
#[derive(Debug, Error)]
pub enum CheckOutCommitError {
#[error("Failed to create new working-copy commit")]
CreateCommit(#[from] BackendError),
#[error("Failed to edit commit")]
EditCommit(#[from] EditCommitError),
}
mod dirty_cell {
use std::cell::{OnceCell, RefCell};
/// Cell that lazily updates the value after `mark_dirty()`.
///
/// A clean value can be immutably borrowed within the `self` lifetime.
#[derive(Clone, Debug)]
pub struct DirtyCell<T> {
// Either clean or dirty value is set. The value is boxed to reduce stack space
// and memcopy overhead.
clean: OnceCell<Box<T>>,
dirty: RefCell<Option<Box<T>>>,
}
impl<T> DirtyCell<T> {
pub fn with_clean(value: T) -> Self {
DirtyCell {
clean: OnceCell::from(Box::new(value)),
dirty: RefCell::new(None),
}
}
pub fn get_or_ensure_clean(&self, f: impl FnOnce(&mut T)) -> &T {
self.clean.get_or_init(|| {
// Panics if ensure_clean() is invoked from with_ref() callback for example.
let mut value = self.dirty.borrow_mut().take().unwrap();
f(&mut value);
value
})
}
pub fn ensure_clean(&self, f: impl FnOnce(&mut T)) {
self.get_or_ensure_clean(f);
}
pub fn into_inner(self) -> T {
*self
.clean
.into_inner()
.or_else(|| self.dirty.into_inner())
.unwrap()
}
pub fn with_ref<R>(&self, f: impl FnOnce(&T) -> R) -> R {
if let Some(value) = self.clean.get() {
f(value)
} else {
f(self.dirty.borrow().as_ref().unwrap())
}
}
pub fn get_mut(&mut self) -> &mut T {
self.clean
.get_mut()
.or_else(|| self.dirty.get_mut().as_mut())
.unwrap()
}
pub fn mark_dirty(&mut self) {
if let Some(value) = self.clean.take() {
*self.dirty.get_mut() = Some(value);
}
}
}
}
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