Mercurial > hg-stable
changeset 47111:e66ea29e2b1a
dirstate-tree: Implement DirstateMap::read
This reads the on-disk dirstate in its current format (a flat sequence of
entries) and creates a tree in memory.
Differential Revision: https://phab.mercurial-scm.org/D10367
author | Simon Sapin <simon.sapin@octobus.net> |
---|---|
date | Wed, 31 Mar 2021 18:59:49 +0200 |
parents | 3c11c24b82b6 |
children | d7631d55da3e |
files | rust/hg-core/src/dirstate/parsers.rs rust/hg-core/src/dirstate_tree/dirstate_map.rs |
diffstat | 2 files changed, 99 insertions(+), 13 deletions(-) [+] |
line wrap: on
line diff
--- a/rust/hg-core/src/dirstate/parsers.rs Thu Apr 08 20:12:24 2021 +0200 +++ b/rust/hg-core/src/dirstate/parsers.rs Wed Mar 31 18:59:49 2021 +0200 @@ -35,10 +35,23 @@ } #[timed] -pub fn parse_dirstate(mut contents: &[u8]) -> Result<ParseResult, HgError> { +pub fn parse_dirstate(contents: &[u8]) -> Result<ParseResult, HgError> { let mut copies = Vec::new(); let mut entries = Vec::new(); + let parents = + parse_dirstate_entries(contents, |path, entry, copy_source| { + if let Some(source) = copy_source { + copies.push((path, source)); + } + entries.push((path, *entry)); + })?; + Ok((parents, entries, copies)) +} +pub fn parse_dirstate_entries<'a>( + mut contents: &'a [u8], + mut each_entry: impl FnMut(&'a HgPath, &DirstateEntry, Option<&'a HgPath>), +) -> Result<&'a DirstateParents, HgError> { let (parents, rest) = DirstateParents::from_bytes(contents) .map_err(|_| HgError::corrupted("Too little data for dirstate."))?; contents = rest; @@ -62,14 +75,12 @@ let path = HgPath::new( iter.next().expect("splitn always yields at least one item"), ); - if let Some(copy_source) = iter.next() { - copies.push((path, HgPath::new(copy_source))); - } + let copy_source = iter.next().map(HgPath::new); + each_entry(path, &entry, copy_source); - entries.push((path, entry)); contents = rest; } - Ok((parents, entries, copies)) + Ok(parents) } /// `now` is the duration in seconds since the Unix epoch
--- a/rust/hg-core/src/dirstate_tree/dirstate_map.rs Thu Apr 08 20:12:24 2021 +0200 +++ b/rust/hg-core/src/dirstate_tree/dirstate_map.rs Wed Mar 31 18:59:49 2021 +0200 @@ -1,7 +1,12 @@ +use std::collections::BTreeMap; use std::path::PathBuf; use std::time::Duration; +use super::path_with_basename::WithBasename; + +use crate::dirstate::parsers::parse_dirstate_entries; use crate::matchers::Matcher; +use crate::revlog::node::NULL_NODE; use crate::utils::hg_path::{HgPath, HgPathBuf}; use crate::CopyMapIter; use crate::DirstateEntry; @@ -18,18 +23,70 @@ use crate::StatusOptions; pub struct DirstateMap { - // TODO + parents: Option<DirstateParents>, + dirty_parents: bool, + root: ChildNodes, +} + +/// Using a plain `HgPathBuf` of the full path from the repository root as a +/// map key would also work: all paths in a given map have the same parent +/// path, so comparing full paths gives the same result as comparing base +/// names. However `BTreeMap` would waste time always re-comparing the same +/// string prefix. +type ChildNodes = BTreeMap<WithBasename<HgPathBuf>, Node>; + +#[derive(Default)] +struct Node { + entry: Option<DirstateEntry>, + copy_source: Option<HgPathBuf>, + children: ChildNodes, } impl DirstateMap { pub fn new() -> Self { - todo!() + Self { + parents: None, + dirty_parents: false, + root: ChildNodes::new(), + } + } + + fn get_or_insert_node(&mut self, path: &HgPath) -> &mut Node { + let mut child_nodes = &mut self.root; + let mut inclusive_ancestor_paths = + WithBasename::inclusive_ancestors_of(path); + let mut ancestor_path = inclusive_ancestor_paths + .next() + .expect("expected at least one inclusive ancestor"); + loop { + // TODO: can we avoid double lookup in all cases without allocating + // an owned key in cases where the map already contains that key? + let child_node = + if child_nodes.contains_key(ancestor_path.base_name()) { + child_nodes.get_mut(ancestor_path.base_name()).unwrap() + } else { + // This is always a vacant entry, using `.entry()` lets us + // return a `&mut Node` of the newly-inserted node without + // yet another lookup. `BTreeMap::insert` doesn’t do this. + child_nodes.entry(ancestor_path.to_owned()).or_default() + }; + if let Some(next) = inclusive_ancestor_paths.next() { + ancestor_path = next; + child_nodes = &mut child_node.children; + } else { + return child_node; + } + } } } impl super::dispatch::DirstateMapMethods for DirstateMap { fn clear(&mut self) { - todo!() + self.set_parents(&DirstateParents { + p1: NULL_NODE, + p2: NULL_NODE, + }); + self.root.clear() } fn add_file( @@ -123,15 +180,33 @@ todo!() } - fn set_parents(&mut self, _parents: &DirstateParents) { - todo!() + fn set_parents(&mut self, parents: &DirstateParents) { + self.parents = Some(parents.clone()); + self.dirty_parents = true; } fn read<'a>( &mut self, - _file_contents: &'a [u8], + file_contents: &'a [u8], ) -> Result<Option<&'a DirstateParents>, DirstateError> { - todo!() + if file_contents.is_empty() { + return Ok(None); + } + + let parents = parse_dirstate_entries( + file_contents, + |path, entry, copy_source| { + let node = self.get_or_insert_node(path); + node.entry = Some(*entry); + node.copy_source = copy_source.map(HgPath::to_owned); + }, + )?; + + if !self.dirty_parents { + self.set_parents(parents); + } + + Ok(Some(parents)) } fn pack(