annotate rust/hg-core/src/dirstate_tree/dispatch.rs @ 47521:abed645b8e96

dirstate: move the handling of special case within the dirstatemap

The dirstatemap is as well, if not better, suited to decided how to encode the
various case. So we move the associated code in the dirstatemap `addfile`
method.

This means the dirstate no longer need to know about the various magic value
used in the dirstate V1 format.

The pain of the messy API start to be quite palpable in Rust, we should clean
this up once the current large refactoring is dealt with.

Differential Revision: https://phab.mercurial-scm.org/D10963

use std::path::PathBuf;

use crate::dirstate::parsers::Timestamp;
use crate::dirstate_tree::on_disk::DirstateV2ParseError;
use crate::matchers::Matcher;
use crate::utils::hg_path::{HgPath, HgPathBuf};
use crate::CopyMapIter;
use crate::DirstateEntry;
use crate::DirstateError;
use crate::DirstateMap;
use crate::DirstateParents;
use crate::DirstateStatus;
use crate::EntryState;
use crate::PatternFileWarning;
use crate::StateMapIter;
use crate::StatusError;
use crate::StatusOptions;

/// `rust/hg-cpython/src/dirstate/dirstate_map.rs` implements in Rust a
/// `DirstateMap` Python class that wraps `Box<dyn DirstateMapMethods + Send>`,
/// a trait object of this trait. Except for constructors, this trait defines
/// all APIs that the class needs to interact with its inner dirstate map.
///
/// A trait object is used to support two different concrete types:
///
/// * `rust/hg-core/src/dirstate/dirstate_map.rs` defines the "flat dirstate
///   map" which is based on a few large `HgPath`-keyed `HashMap` and `HashSet`
///   fields.
/// * `rust/hg-core/src/dirstate_tree/dirstate_map.rs` defines the "tree
///   dirstate map" based on a tree data struture with nodes for directories
///   containing child nodes for their files and sub-directories. This tree
///   enables a more efficient algorithm for `hg status`, but its details are
///   abstracted in this trait.
///
/// The dirstate map associates paths of files in the working directory to
/// various information about the state of those files.
pub trait DirstateMapMethods {
    /// Remove information about all files in this map
    fn clear(&mut self);

    /// Add or change the information associated to a given file.
    ///
    /// `old_state` is the state in the entry that `get` would have returned
    /// before this call, or `EntryState::Unknown` if there was no such entry.
    ///
    /// `entry.state` should never be `EntryState::Unknown`.
    fn add_file(
        &mut self,
        filename: &HgPath,
        old_state: EntryState,
        entry: DirstateEntry,
        from_p2: bool,
        possibly_dirty: bool,
    ) -> Result<(), DirstateError>;

    /// Mark a file as "removed" (as in `hg rm`).
    ///
    /// `old_state` is the state in the entry that `get` would have returned
    /// before this call, or `EntryState::Unknown` if there was no such entry.
    ///
    /// `size` is not actually a size but the 0 or -1 or -2 value that would be
    /// put in the size field in the dirstate-v1 format.
    fn remove_file(
        &mut self,
        filename: &HgPath,
        in_merge: bool,
    ) -> Result<(), DirstateError>;

    /// Drop information about this file from the map if any, and return
    /// whether there was any.
    ///
    /// `get` will now return `None` for this filename.
    ///
    /// `old_state` is the state in the entry that `get` would have returned
    /// before this call, or `EntryState::Unknown` if there was no such entry.
    fn drop_file(
        &mut self,
        filename: &HgPath,
        old_state: EntryState,
    ) -> Result<bool, DirstateError>;

    /// Among given files, mark the stored `mtime` as ambiguous if there is one
    /// (if `state == EntryState::Normal`) equal to the given current Unix
    /// timestamp.
    fn clear_ambiguous_times(
        &mut self,
        filenames: Vec<HgPathBuf>,
        now: i32,
    ) -> Result<(), DirstateV2ParseError>;

    /// Return whether the map has an "non-normal" entry for the given
    /// filename. That is, any entry with a `state` other than
    /// `EntryState::Normal` or with an ambiguous `mtime`.
    fn non_normal_entries_contains(
        &mut self,
        key: &HgPath,
    ) -> Result<bool, DirstateV2ParseError>;

    /// Mark the given path as "normal" file. This is only relevant in the flat
    /// dirstate map where there is a separate `HashSet` that needs to be kept
    /// up to date.
    fn non_normal_entries_remove(&mut self, key: &HgPath);

    /// Return an iterator of paths whose respective entry are either
    /// "non-normal" (see `non_normal_entries_contains`) or "from other
    /// parent".
    ///
    /// If that information is cached, create the cache as needed.
    ///
    /// "From other parent" is defined as `state == Normal && size == -2`.
    ///
    /// Because parse errors can happen during iteration, the iterated items
    /// are `Result`s.
    fn non_normal_or_other_parent_paths(
        &mut self,
    ) -> Box<dyn Iterator<Item = Result<&HgPath, DirstateV2ParseError>> + '_>;

    /// Create the cache for `non_normal_or_other_parent_paths` if needed.
    ///
    /// If `force` is true, the cache is re-created even if it already exists.
    fn set_non_normal_other_parent_entries(&mut self, force: bool);

    /// Return an iterator of paths whose respective entry are "non-normal"
    /// (see `non_normal_entries_contains`).
    ///
    /// If that information is cached, create the cache as needed.
    ///
    /// Because parse errors can happen during iteration, the iterated items
    /// are `Result`s.
    fn iter_non_normal_paths(
        &mut self,
    ) -> Box<
        dyn Iterator<Item = Result<&HgPath, DirstateV2ParseError>> + Send + '_,
    >;

    /// Same as `iter_non_normal_paths`, but takes `&self` instead of `&mut
    /// self`.
    ///
    /// Panics if a cache is necessary but does not exist yet.
    fn iter_non_normal_paths_panic(
        &self,
    ) -> Box<
        dyn Iterator<Item = Result<&HgPath, DirstateV2ParseError>> + Send + '_,
    >;

    /// Return an iterator of paths whose respective entry are "from other
    /// parent".
    ///
    /// If that information is cached, create the cache as needed.
    ///
    /// "From other parent" is defined as `state == Normal && size == -2`.
    ///
    /// Because parse errors can happen during iteration, the iterated items
    /// are `Result`s.
    fn iter_other_parent_paths(
        &mut self,
    ) -> Box<
        dyn Iterator<Item = Result<&HgPath, DirstateV2ParseError>> + Send + '_,
    >;

    /// Returns whether the sub-tree rooted at the given directory contains any
    /// tracked file.
    ///
    /// A file is tracked if it has a `state` other than `EntryState::Removed`.
    fn has_tracked_dir(
        &mut self,
        directory: &HgPath,
    ) -> Result<bool, DirstateError>;

    /// Returns whether the sub-tree rooted at the given directory contains any
    /// file with a dirstate entry.
    fn has_dir(&mut self, directory: &HgPath) -> Result<bool, DirstateError>;

    /// Clear mtimes that are ambigous with `now` (similar to
    /// `clear_ambiguous_times` but for all files in the dirstate map), and
    /// serialize bytes to write the `.hg/dirstate` file to disk in dirstate-v1
    /// format.
    fn pack_v1(
        &mut self,
        parents: DirstateParents,
        now: Timestamp,
    ) -> Result<Vec<u8>, DirstateError>;

    /// Clear mtimes that are ambigous with `now` (similar to
    /// `clear_ambiguous_times` but for all files in the dirstate map), and
    /// serialize bytes to write the `.hg/dirstate` file to disk in dirstate-v2
    /// format.
    ///
    /// Note: this is only supported by the tree dirstate map.
    fn pack_v2(
        &mut self,
        parents: DirstateParents,
        now: Timestamp,
    ) -> Result<Vec<u8>, DirstateError>;

    /// Run the status algorithm.
    ///
    /// This is not sematically a method of the dirstate map, but a different
    /// algorithm is used for the flat v.s. tree dirstate map so having it in
    /// this trait enables the same dynamic dispatch as with other methods.
    fn status<'a>(
        &'a mut self,
        matcher: &'a (dyn Matcher + Sync),
        root_dir: PathBuf,
        ignore_files: Vec<PathBuf>,
        options: StatusOptions,
    ) -> Result<(DirstateStatus<'a>, Vec<PatternFileWarning>), StatusError>;

    /// Returns how many files in the dirstate map have a recorded copy source.
    fn copy_map_len(&self) -> usize;

    /// Returns an iterator of `(path, copy_source)` for all files that have a
    /// copy source.
    fn copy_map_iter(&self) -> CopyMapIter<'_>;

    /// Returns whether the givef file has a copy source.
    fn copy_map_contains_key(
        &self,
        key: &HgPath,
    ) -> Result<bool, DirstateV2ParseError>;

    /// Returns the copy source for the given file.
    fn copy_map_get(
        &self,
        key: &HgPath,
    ) -> Result<Option<&HgPath>, DirstateV2ParseError>;

    /// Removes the recorded copy source if any for the given file, and returns
    /// it.
    fn copy_map_remove(
        &mut self,
        key: &HgPath,
    ) -> Result<Option<HgPathBuf>, DirstateV2ParseError>;

    /// Set the given `value` copy source for the given `key` file.
    fn copy_map_insert(
        &mut self,
        key: HgPathBuf,
        value: HgPathBuf,
    ) -> Result<Option<HgPathBuf>, DirstateV2ParseError>;

    /// Returns the number of files that have an entry.
    fn len(&self) -> usize;

    /// Returns whether the given file has an entry.
    fn contains_key(&self, key: &HgPath)
        -> Result<bool, DirstateV2ParseError>;

    /// Returns the entry, if any, for the given file.
    fn get(
        &self,
        key: &HgPath,
    ) -> Result<Option<DirstateEntry>, DirstateV2ParseError>;

    /// Returns a `(path, entry)` iterator of files that have an entry.
    ///
    /// Because parse errors can happen during iteration, the iterated items
    /// are `Result`s.
    fn iter(&self) -> StateMapIter<'_>;

    /// In the tree dirstate, return an iterator of "directory" (entry-less)
    /// nodes with the data stored for them. This is for `hg debugdirstate
    /// --dirs`.
    ///
    /// In the flat dirstate, returns an empty iterator.
    ///
    /// Because parse errors can happen during iteration, the iterated items
    /// are `Result`s.
    fn iter_directories(
        &self,
    ) -> Box<
        dyn Iterator<
                Item = Result<
                    (&HgPath, Option<Timestamp>),
                    DirstateV2ParseError,
                >,
            > + Send
            + '_,
    >;
}

impl DirstateMapMethods for DirstateMap {
    fn clear(&mut self) {
        self.clear()
    }

    fn add_file(
        &mut self,
        filename: &HgPath,
        old_state: EntryState,
        entry: DirstateEntry,
        from_p2: bool,
        possibly_dirty: bool,
    ) -> Result<(), DirstateError> {
        self.add_file(filename, old_state, entry, from_p2, possibly_dirty)
    }

    fn remove_file(
        &mut self,
        filename: &HgPath,
        in_merge: bool,
    ) -> Result<(), DirstateError> {
        self.remove_file(filename, in_merge)
    }

    fn drop_file(
        &mut self,
        filename: &HgPath,
        old_state: EntryState,
    ) -> Result<bool, DirstateError> {
        self.drop_file(filename, old_state)
    }

    fn clear_ambiguous_times(
        &mut self,
        filenames: Vec<HgPathBuf>,
        now: i32,
    ) -> Result<(), DirstateV2ParseError> {
        Ok(self.clear_ambiguous_times(filenames, now))
    }

    fn non_normal_entries_contains(
        &mut self,
        key: &HgPath,
    ) -> Result<bool, DirstateV2ParseError> {
        let (non_normal, _other_parent) =
            self.get_non_normal_other_parent_entries();
        Ok(non_normal.contains(key))
    }

    fn non_normal_entries_remove(&mut self, key: &HgPath) {
        self.non_normal_entries_remove(key)
    }

    fn non_normal_or_other_parent_paths(
        &mut self,
    ) -> Box<dyn Iterator<Item = Result<&HgPath, DirstateV2ParseError>> + '_>
    {
        let (non_normal, other_parent) =
            self.get_non_normal_other_parent_entries();
        Box::new(non_normal.union(other_parent).map(|p| Ok(&**p)))
    }

    fn set_non_normal_other_parent_entries(&mut self, force: bool) {
        self.set_non_normal_other_parent_entries(force)
    }

    fn iter_non_normal_paths(
        &mut self,
    ) -> Box<
        dyn Iterator<Item = Result<&HgPath, DirstateV2ParseError>> + Send + '_,
    > {
        let (non_normal, _other_parent) =
            self.get_non_normal_other_parent_entries();
        Box::new(non_normal.iter().map(|p| Ok(&**p)))
    }

    fn iter_non_normal_paths_panic(
        &self,
    ) -> Box<
        dyn Iterator<Item = Result<&HgPath, DirstateV2ParseError>> + Send + '_,
    > {
        let (non_normal, _other_parent) =
            self.get_non_normal_other_parent_entries_panic();
        Box::new(non_normal.iter().map(|p| Ok(&**p)))
    }

    fn iter_other_parent_paths(
        &mut self,
    ) -> Box<
        dyn Iterator<Item = Result<&HgPath, DirstateV2ParseError>> + Send + '_,
    > {
        let (_non_normal, other_parent) =
            self.get_non_normal_other_parent_entries();
        Box::new(other_parent.iter().map(|p| Ok(&**p)))
    }

    fn has_tracked_dir(
        &mut self,
        directory: &HgPath,
    ) -> Result<bool, DirstateError> {
        self.has_tracked_dir(directory)
    }

    fn has_dir(&mut self, directory: &HgPath) -> Result<bool, DirstateError> {
        self.has_dir(directory)
    }

    fn pack_v1(
        &mut self,
        parents: DirstateParents,
        now: Timestamp,
    ) -> Result<Vec<u8>, DirstateError> {
        self.pack(parents, now)
    }

    fn pack_v2(
        &mut self,
        _parents: DirstateParents,
        _now: Timestamp,
    ) -> Result<Vec<u8>, DirstateError> {
        panic!(
            "should have used dirstate_tree::DirstateMap to use the v2 format"
        )
    }

    fn status<'a>(
        &'a mut self,
        matcher: &'a (dyn Matcher + Sync),
        root_dir: PathBuf,
        ignore_files: Vec<PathBuf>,
        options: StatusOptions,
    ) -> Result<(DirstateStatus<'a>, Vec<PatternFileWarning>), StatusError>
    {
        crate::status(self, matcher, root_dir, ignore_files, options)
    }

    fn copy_map_len(&self) -> usize {
        self.copy_map.len()
    }

    fn copy_map_iter(&self) -> CopyMapIter<'_> {
        Box::new(
            self.copy_map
                .iter()
                .map(|(key, value)| Ok((&**key, &**value))),
        )
    }

    fn copy_map_contains_key(
        &self,
        key: &HgPath,
    ) -> Result<bool, DirstateV2ParseError> {
        Ok(self.copy_map.contains_key(key))
    }

    fn copy_map_get(
        &self,
        key: &HgPath,
    ) -> Result<Option<&HgPath>, DirstateV2ParseError> {
        Ok(self.copy_map.get(key).map(|p| &**p))
    }

    fn copy_map_remove(
        &mut self,
        key: &HgPath,
    ) -> Result<Option<HgPathBuf>, DirstateV2ParseError> {
        Ok(self.copy_map.remove(key))
    }

    fn copy_map_insert(
        &mut self,
        key: HgPathBuf,
        value: HgPathBuf,
    ) -> Result<Option<HgPathBuf>, DirstateV2ParseError> {
        Ok(self.copy_map.insert(key, value))
    }

    fn len(&self) -> usize {
        (&**self).len()
    }

    fn contains_key(
        &self,
        key: &HgPath,
    ) -> Result<bool, DirstateV2ParseError> {
        Ok((&**self).contains_key(key))
    }

    fn get(
        &self,
        key: &HgPath,
    ) -> Result<Option<DirstateEntry>, DirstateV2ParseError> {
        Ok((&**self).get(key).cloned())
    }

    fn iter(&self) -> StateMapIter<'_> {
        Box::new((&**self).iter().map(|(key, value)| Ok((&**key, *value))))
    }

    fn iter_directories(
        &self,
    ) -> Box<
        dyn Iterator<
                Item = Result<
                    (&HgPath, Option<Timestamp>),
                    DirstateV2ParseError,
                >,
            > + Send
            + '_,
    > {
        Box::new(std::iter::empty())
    }
}