rust/hg-cpython/src/dirstate/dispatch.rs

dirstate-v2: Move fixed-size tree metadata into the docket file

Before this changeset, the dirstate-v2 data file contained not only nodes
and paths that may be reused when appending to an existing file,
but also some fixed-size metadata that applies to the entire tree
and was added at the end of the data file for every append.

This moves that metadata into the docket file, so that repeated "append"
operations without meaningful changes don’t actually need to grow any file.

Differential Revision: https://phab.mercurial-scm.org/D11098

use crate::dirstate::owning::OwningDirstateMap;
use hg::dirstate::parsers::Timestamp;
use hg::dirstate_tree::dispatch::DirstateMapMethods;
use hg::dirstate_tree::on_disk::DirstateV2ParseError;
use hg::matchers::Matcher;
use hg::utils::hg_path::{HgPath, HgPathBuf};
use hg::CopyMapIter;
use hg::DirstateEntry;
use hg::DirstateError;
use hg::DirstateParents;
use hg::DirstateStatus;
use hg::PatternFileWarning;
use hg::StateMapIter;
use hg::StatusError;
use hg::StatusOptions;
use std::path::PathBuf;

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

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

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

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

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

    fn non_normal_entries_contains(
        &mut self,
        key: &HgPath,
    ) -> Result<bool, DirstateV2ParseError> {
        self.get_mut().non_normal_entries_contains(key)
    }

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

    fn non_normal_or_other_parent_paths(
        &mut self,
    ) -> Box<dyn Iterator<Item = Result<&HgPath, DirstateV2ParseError>> + '_>
    {
        self.get_mut().non_normal_or_other_parent_paths()
    }

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

    fn iter_non_normal_paths(
        &mut self,
    ) -> Box<
        dyn Iterator<Item = Result<&HgPath, DirstateV2ParseError>> + Send + '_,
    > {
        self.get_mut().iter_non_normal_paths()
    }

    fn iter_non_normal_paths_panic(
        &self,
    ) -> Box<
        dyn Iterator<Item = Result<&HgPath, DirstateV2ParseError>> + Send + '_,
    > {
        self.get().iter_non_normal_paths_panic()
    }

    fn iter_other_parent_paths(
        &mut self,
    ) -> Box<
        dyn Iterator<Item = Result<&HgPath, DirstateV2ParseError>> + Send + '_,
    > {
        self.get_mut().iter_other_parent_paths()
    }

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

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

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

    fn pack_v2(
        &mut self,
        now: Timestamp,
        can_append: bool,
    ) -> Result<(Vec<u8>, Vec<u8>, bool), DirstateError> {
        self.get_mut().pack_v2(now, can_append)
    }

    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>
    {
        self.get_mut()
            .status(matcher, root_dir, ignore_files, options)
    }

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

    fn copy_map_iter(&self) -> CopyMapIter<'_> {
        self.get().copy_map_iter()
    }

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

    fn copy_map_get(
        &self,
        key: &HgPath,
    ) -> Result<Option<&HgPath>, DirstateV2ParseError> {
        self.get().copy_map_get(key)
    }

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

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

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

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

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

    fn iter(&self) -> StateMapIter<'_> {
        self.get().iter()
    }

    fn iter_directories(
        &self,
    ) -> Box<
        dyn Iterator<
                Item = Result<
                    (&HgPath, Option<Timestamp>),
                    DirstateV2ParseError,
                >,
            > + Send
            + '_,
    > {
        self.get().iter_directories()
    }
}