// 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. //! Defines the interface for the working copy. See `LocalWorkingCopy` for the//! default local-disk implementation. use std::any::Any;use std::ffi::OsString;use std::path::{Path, PathBuf};use std::sync::Arc; use thiserror::Error; use crate::backend::{BackendError, MergedTreeId};use crate::commit::Commit;use crate::fsmonitor::FsmonitorKind;use crate::gitignore::{GitIgnoreError, GitIgnoreFile};use crate::op_store::{OperationId, WorkspaceId};use crate::repo_path::{RepoPath, RepoPathBuf};use crate::settings::HumanByteSize;use crate::store::Store; /// The trait all working-copy implementations must implement.pub trait WorkingCopy: Send {    /// Should return `self`. For down-casting purposes.    fn as_any(&self) -> &dyn Any;     /// The name/id of the implementation. Used for choosing the right    /// implementation when loading a working copy.    fn name(&self) -> &str;     /// The working copy's root directory.    fn path(&self) -> &Path;     /// The working copy's workspace ID.    fn workspace_id(&self) -> &WorkspaceId;     /// The operation this working copy was most recently updated to.    fn operation_id(&self) -> &OperationId;     /// The ID of the tree this working copy was most recently updated to.    fn tree_id(&self) -> Result<&MergedTreeId, WorkingCopyStateError>;     /// Patterns that decide which paths from the current tree should be checked    /// out in the working copy. An empty list means that no paths should be    /// checked out in the working copy. A single `RepoPath::root()` entry means    /// that all files should be checked out.    fn sparse_patterns(&self) -> Result<&[RepoPathBuf], WorkingCopyStateError>;     /// Locks the working copy and returns an instance with methods for updating    /// the working copy files and state.    fn start_mutation(&self) -> Result<Box<dyn LockedWorkingCopy>, WorkingCopyStateError>;} /// The factory which creates and loads a specific type of working copy.pub trait WorkingCopyFactory {    /// Create a new working copy from scratch.    fn init_working_copy(        &self,        store: Arc<Store>,        working_copy_path: PathBuf,        state_path: PathBuf,        operation_id: OperationId,        workspace_id: WorkspaceId,    ) -> Result<Box<dyn WorkingCopy>, WorkingCopyStateError>;     /// Load an existing working copy.    fn load_working_copy(        &self,        store: Arc<Store>,        working_copy_path: PathBuf,        state_path: PathBuf,    ) -> Box<dyn WorkingCopy>;} /// A working copy that's being modified.pub trait LockedWorkingCopy {    /// Should return `self`. For down-casting purposes.    fn as_any(&self) -> &dyn Any;     /// Should return `self`. For down-casting purposes.    fn as_any_mut(&mut self) -> &mut dyn Any;     /// The operation at the time the lock was taken    fn old_operation_id(&self) -> &OperationId;     /// The tree at the time the lock was taken    fn old_tree_id(&self) -> &MergedTreeId;     /// Snapshot the working copy and return the tree id.    fn snapshot(&mut self, options: SnapshotOptions) -> Result<MergedTreeId, SnapshotError>;     /// Check out the specified commit in the working copy.    fn check_out(&mut self, commit: &Commit) -> Result<CheckoutStats, CheckoutError>;     /// Update to another commit without touching the files in the working copy.    fn reset(&mut self, commit: &Commit) -> Result<(), ResetError>;     /// Update to the empty tree without touching the files in the working copy.    fn reset_to_empty(&mut self) -> Result<(), ResetError>;     /// See `WorkingCopy::sparse_patterns()`    fn sparse_patterns(&self) -> Result<&[RepoPathBuf], WorkingCopyStateError>;     /// Updates the patterns that decide which paths from the current tree    /// should be checked out in the working copy.    // TODO: Use a different error type here so we can include a    // `SparseNotSupported` variants for working copies that don't support sparse    // checkouts (e.g. because they use a virtual file system so there's no reason    // to use sparse).    fn set_sparse_patterns(        &mut self,        new_sparse_patterns: Vec<RepoPathBuf>,    ) -> Result<CheckoutStats, CheckoutError>;     /// Finish the modifications to the working copy by writing the updated    /// states to disk. Returns the new (unlocked) working copy.    fn finish(        self: Box<Self>,        operation_id: OperationId,    ) -> Result<Box<dyn WorkingCopy>, WorkingCopyStateError>;} /// An error while snapshotting the working copy.#[derive(Debug, Error)]pub enum SnapshotError {    /// A path in the working copy was not valid UTF-8.    #[error("Working copy path {} is not valid UTF-8", path.to_string_lossy())]    InvalidUtf8Path {        /// The path with invalid UTF-8.        path: OsString,    },    /// A symlink target in the working copy was not valid UTF-8.    #[error("Symlink {path} target is not valid UTF-8")]    InvalidUtf8SymlinkTarget {        /// The path of the symlink that has a target that's not valid UTF-8.        /// This path itself is valid UTF-8.        path: PathBuf,    },    /// Reading or writing from the commit backend failed.    #[error("Internal backend error")]    InternalBackendError(#[from] BackendError),    /// A file was larger than the specified maximum file size for new    /// (previously untracked) files.    #[error("New file {path} of size ~{size} exceeds snapshot.max-new-file-size ({max_size})")]    NewFileTooLarge {        /// The path of the large file.        path: PathBuf,        /// The size of the large file.        size: HumanByteSize,        /// The maximum allowed size.        max_size: HumanByteSize,    },    /// Checking path with ignore patterns failed.    #[error(transparent)]    GitIgnoreError(#[from] GitIgnoreError),    /// Some other error happened while snapshotting the working copy.    #[error("{message}")]    Other {        /// Error message.        message: String,        /// The underlying error.        #[source]        err: Box<dyn std::error::Error + Send + Sync>,    },} /// Options used when snapshotting the working copy. Some of them may be ignored/// by some `WorkingCopy` implementations.pub struct SnapshotOptions<'a> {    /// The `.gitignore`s to use while snapshotting. The typically come from the    /// user's configured patterns combined with per-repo patterns.    // The base_ignores are passed in here rather than being set on the TreeState    // because the TreeState may be long-lived if the library is used in a    // long-lived process.    pub base_ignores: Arc<GitIgnoreFile>,    /// The fsmonitor (e.g. Watchman) to use, if any.    // TODO: Should we make this a field on `LocalWorkingCopy` instead since it's quite specific to    // that implementation?    pub fsmonitor_kind: FsmonitorKind,    /// A callback for the UI to display progress.    pub progress: Option<&'a SnapshotProgress<'a>>,    /// The size of the largest file that should be allowed to become tracked    /// (already tracked files are always snapshotted). If there are larger    /// files in the working copy, then `LockedWorkingCopy::snapshot()` may    /// (depending on implementation)    /// return `SnapshotError::NewFileTooLarge`.    pub max_new_file_size: u64,} impl SnapshotOptions<'_> {    /// Create an instance for use in tests.    pub fn empty_for_test() -> Self {        SnapshotOptions {            base_ignores: GitIgnoreFile::empty(),            fsmonitor_kind: FsmonitorKind::None,            progress: None,            max_new_file_size: u64::MAX,        }    }} /// A callback for getting progress updates.pub type SnapshotProgress<'a> = dyn Fn(&RepoPath) + 'a + Sync; /// Stats about a checkout operation on a working copy. All "files" mentioned/// below may also be symlinks or materialized conflicts.#[derive(Debug, PartialEq, Eq, Clone)]pub struct CheckoutStats {    /// The number of files that were updated in the working copy.    /// These files existed before and after the checkout.    pub updated_files: u32,    /// The number of files added in the working copy.    pub added_files: u32,    /// The number of files removed in the working copy.    pub removed_files: u32,    /// The number of files that were supposed to be updated or added in the    /// working copy but were skipped because there was an untracked (probably    /// ignored) file in its place.    pub skipped_files: u32,} /// The working-copy checkout failed.#[derive(Debug, Error)]pub enum CheckoutError {    /// The current working-copy commit was deleted, maybe by an overly    /// aggressive GC that happened while the current process was running.    #[error("Current working-copy commit not found")]    SourceNotFound {        /// The underlying error.        source: Box<dyn std::error::Error + Send + Sync>,    },    /// Another process checked out a commit while the current process was    /// running (after the working copy was read by the current process).    #[error("Concurrent checkout")]    ConcurrentCheckout,    /// Reading or writing from the commit backend failed.    #[error("Internal backend error")]    InternalBackendError(#[from] BackendError),    /// Some other error happened while checking out the working copy.    #[error("{message}")]    Other {        /// Error message.        message: String,        /// The underlying error.        #[source]        err: Box<dyn std::error::Error + Send + Sync>,    },} /// An error while resetting the working copy.#[derive(Debug, Error)]pub enum ResetError {    /// The current working-copy commit was deleted, maybe by an overly    /// aggressive GC that happened while the current process was running.    #[error("Current working-copy commit not found")]    SourceNotFound {        /// The underlying error.        source: Box<dyn std::error::Error + Send + Sync>,    },    /// Reading or writing from the commit backend failed.    #[error("Internal error")]    InternalBackendError(#[from] BackendError),    /// Some other error happened while checking out the working copy.    #[error("{message}")]    Other {        /// Error message.        message: String,        /// The underlying error.        #[source]        err: Box<dyn std::error::Error + Send + Sync>,    },} /// An error while reading the working copy state.#[derive(Debug, Error)]#[error("{message}")]pub struct WorkingCopyStateError {    /// Error message.    pub message: String,    /// The underlying error.    #[source]    pub err: Box<dyn std::error::Error + Send + Sync>,}