D6632: rust-dirstate: rust implementation of dirstatemap
Alphare (Raphaël Gomès)
phabricator at mercurial-scm.org
Wed Jul 10 14:34:49 UTC 2019
Alphare created this revision.
Herald added subscribers: mercurial-devel, kevincox, durin42.
Herald added a reviewer: hg-reviewers.
REVISION SUMMARY
The `dirstatemap` is one of the last building blocks needed to get to a
`dirstate.walk` Rust implementation.
Disclaimer: This change is part of a big (10) series of patches, all of which
started as one big changeset that took a long time to write.
This `dirstatemap` implementation is a compromise in terms of complexity both
for me and for the reviewers. I chose to submit this patch right now because
while it is not perfect, it works and is simple enough (IMHO) to be reviewed.
The Python implementation uses a lot of lazy propertycaches, breaks
encapsulation and is used as an iterator in a lot of places, all of which
dictated the somewhat unidiomatic patterns in this change.
Like written in the comments, rewriting this struct to use the typestate
pattern might be a good idea, but this is a good first step.
REPOSITORY
rHG Mercurial
REVISION DETAIL
https://phab.mercurial-scm.org/D6632
AFFECTED FILES
rust/hg-core/src/dirstate/dirstate_map.rs
rust/hg-core/src/dirstate/mod.rs
rust/hg-core/src/lib.rs
CHANGE DETAILS
diff --git a/rust/hg-core/src/lib.rs b/rust/hg-core/src/lib.rs
--- a/rust/hg-core/src/lib.rs
+++ b/rust/hg-core/src/lib.rs
@@ -18,6 +18,7 @@
pub mod testing; // unconditionally built, for use from integration tests
pub use dirstate::{
dirs_multiset::DirsMultiset,
+ dirstate_map::DirstateMap,
parsers::{pack_dirstate, parse_dirstate},
CopyMap, DirsIterable, DirstateEntry, DirstateParents, EntryState,
StateMap,
diff --git a/rust/hg-core/src/dirstate/mod.rs b/rust/hg-core/src/dirstate/mod.rs
--- a/rust/hg-core/src/dirstate/mod.rs
+++ b/rust/hg-core/src/dirstate/mod.rs
@@ -10,6 +10,7 @@
use DirstateParseError;
pub mod dirs_multiset;
+pub mod dirstate_map;
pub mod parsers;
#[derive(Debug, PartialEq, Clone)]
diff --git a/rust/hg-core/src/dirstate/dirstate_map.rs b/rust/hg-core/src/dirstate/dirstate_map.rs
new file mode 100644
--- /dev/null
+++ b/rust/hg-core/src/dirstate/dirstate_map.rs
@@ -0,0 +1,431 @@
+// dirstate_map.rs
+//
+// Copyright 2019 Raphaël Gomès <rgomes at octobus.net>
+//
+// This software may be used and distributed according to the terms of the
+// GNU General Public License version 2 or any later version.
+
+use core::borrow::Borrow;
+use dirstate::parsers::PARENT_SIZE;
+use dirstate::EntryState;
+use std::collections::{HashMap, HashSet};
+use std::iter::FromIterator;
+use std::ops::Deref;
+use std::time::Duration;
+use {
+ pack_dirstate, parse_dirstate, CopyMap, DirsIterable, DirsMultiset,
+ DirstateEntry, DirstateError, DirstateMapError, DirstateParents,
+ DirstateParseError, StateMap,
+};
+
+pub type FileFoldMap = HashMap<Vec<u8>, Vec<u8>>;
+
+const NULL_REVISION: &[u8] = b"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
+const MTIME_UNSET: i32 = -1;
+const SIZE_DIRTY: i32 = -2;
+
+#[derive(Default)]
+pub struct DirstateMap {
+ state_map: StateMap,
+ pub copy_map: CopyMap,
+ file_fold_map: Option<FileFoldMap>,
+ pub dirs: Option<DirsMultiset>,
+ pub all_dirs: Option<DirsMultiset>,
+ non_normal_set: HashSet<Vec<u8>>,
+ other_parent_set: HashSet<Vec<u8>>,
+ parents: Option<DirstateParents>,
+ dirty_parents: bool,
+}
+
+/// Should only really be used in python interface code, for clarity
+impl Deref for DirstateMap {
+ type Target = StateMap;
+
+ fn deref(&self) -> &Self::Target {
+ &self.state_map
+ }
+}
+
+impl FromIterator<(Vec<u8>, DirstateEntry)> for DirstateMap {
+ fn from_iter<I: IntoIterator<Item = (Vec<u8>, DirstateEntry)>>(
+ iter: I,
+ ) -> Self {
+ Self {
+ state_map: iter.into_iter().collect(),
+ ..Self::default()
+ }
+ }
+}
+
+impl DirstateMap {
+ pub fn new() -> Self {
+ Self::default()
+ }
+
+ pub fn clear(&mut self) {
+ self.state_map.clear();
+ self.copy_map.clear();
+ self.file_fold_map = None;
+ self.non_normal_set.clear();
+ self.other_parent_set.clear();
+ self.set_parents(DirstateParents {
+ p1: NULL_REVISION.to_vec(),
+ p2: NULL_REVISION.to_vec(),
+ })
+ }
+
+ /// Add a tracked file to the dirstate
+ pub fn add_file(
+ &mut self,
+ filename: &[u8],
+ old_state: EntryState,
+ entry: DirstateEntry,
+ ) {
+ if old_state == EntryState::Unknown || old_state == EntryState::Removed
+ {
+ if let Some(ref mut dirs) = self.dirs {
+ dirs.add_path(filename)
+ }
+ }
+ if old_state == EntryState::Unknown {
+ if let Some(ref mut all_dirs) = self.all_dirs {
+ all_dirs.add_path(filename)
+ }
+ }
+ self.state_map.insert(filename.to_owned(), entry.to_owned());
+
+ if entry.state != EntryState::Normal || entry.mtime == MTIME_UNSET {
+ self.non_normal_set.insert(filename.to_owned());
+ }
+
+ if entry.size == SIZE_DIRTY {
+ self.other_parent_set.insert(filename.to_owned());
+ }
+ }
+
+ /// Mark a file as removed in the dirstate.
+ ///
+ /// The `size` parameter is used to store sentinel values that indicate
+ /// the file's previous state. In the future, we should refactor this
+ /// to be more explicit about what that state is.
+ pub fn remove_file(
+ &mut self,
+ filename: &[u8],
+ old_state: EntryState,
+ size: i32,
+ ) -> Result<(), DirstateMapError> {
+ if old_state != EntryState::Unknown && old_state != EntryState::Removed
+ {
+ if let Some(ref mut dirs) = self.dirs {
+ dirs.delete_path(filename)?;
+ }
+ }
+ if old_state == EntryState::Unknown {
+ if let Some(ref mut all_dirs) = self.all_dirs {
+ all_dirs.add_path(filename);
+ }
+ }
+
+ if let Some(ref mut file_fold_map) = self.file_fold_map {
+ file_fold_map
+ .remove::<Vec<u8>>(filename.to_ascii_uppercase().as_ref());
+ }
+ self.state_map.insert(
+ filename.to_owned(),
+ DirstateEntry {
+ state: EntryState::Removed,
+ mode: 0,
+ size,
+ mtime: 0,
+ },
+ );
+ self.non_normal_set.insert(filename.to_owned());
+ Ok(())
+ }
+
+ /// Remove a file from the dirstate.
+ /// Returns `true` if the file was previously recorded.
+ pub fn drop_file(
+ &mut self,
+ filename: &[u8],
+ old_state: EntryState,
+ ) -> Result<bool, DirstateMapError> {
+ let exists = self
+ .state_map
+ .remove::<Vec<u8>>(filename.to_owned().as_ref())
+ .is_some();
+
+ if exists {
+ if old_state != EntryState::Removed {
+ if let Some(ref mut dirs) = self.dirs {
+ dirs.delete_path(filename)?;
+ }
+ }
+ if let Some(ref mut all_dirs) = self.all_dirs {
+ all_dirs.delete_path(filename)?;
+ }
+ }
+ if let Some(ref mut file_fold_map) = self.file_fold_map {
+ file_fold_map
+ .remove::<Vec<u8>>(filename.to_ascii_uppercase().as_ref());
+ }
+ self.non_normal_set
+ .remove::<Vec<u8>>(filename.to_owned().as_ref());
+
+ Ok(exists)
+ }
+
+ pub fn clear_ambiguous_times(
+ &mut self,
+ filenames: Vec<Vec<u8>>,
+ now: i32,
+ ) {
+ for filename in filenames {
+ let mut changed = false;
+ self.state_map
+ .entry(filename.to_owned())
+ .and_modify(|entry| {
+ if entry.state == EntryState::Normal && entry.mtime == now
+ {
+ changed = true;
+ *entry = DirstateEntry {
+ mtime: MTIME_UNSET,
+ ..*entry
+ };
+ }
+ });
+ if changed {
+ self.non_normal_set.insert(filename.to_owned());
+ }
+ }
+ }
+
+ pub fn non_normal_other_parent_entries(
+ &self,
+ ) -> (HashSet<Vec<u8>>, HashSet<Vec<u8>>) {
+ let mut non_normal = HashSet::new();
+ let mut other_parent = HashSet::new();
+
+ for (
+ filename,
+ DirstateEntry {
+ state, size, mtime, ..
+ },
+ ) in self.state_map.iter()
+ {
+ if *state != EntryState::Normal || *mtime == MTIME_UNSET {
+ non_normal.insert(filename.to_owned());
+ }
+ if *state == EntryState::Normal && *size == SIZE_DIRTY {
+ other_parent.insert(filename.to_owned());
+ }
+ }
+
+ (non_normal, other_parent)
+ }
+ /// Both of these setters and their uses appear to be the simplest way to
+ /// emulate a Python lazy property, but it is ugly and unidiomatic.
+ /// TODO One day, rewriting this struct using the typestate might be a
+ /// good idea.
+ pub fn set_all_dirs(&mut self) {
+ if self.all_dirs.is_none() {
+ self.all_dirs = Some(DirsMultiset::new(
+ DirsIterable::Dirstate(&self.state_map),
+ None,
+ ));
+ }
+ }
+
+ pub fn set_dirs(&mut self) {
+ if self.dirs.is_none() {
+ self.dirs = Some(DirsMultiset::new(
+ DirsIterable::Dirstate(&self.state_map),
+ Some(EntryState::Removed),
+ ));
+ }
+ }
+
+ pub fn has_tracked_dir(&mut self, directory: &[u8]) -> bool {
+ self.set_dirs();
+ self.dirs.as_ref().unwrap().contains_key(directory.as_ref())
+ }
+
+ pub fn has_dir(&mut self, directory: &[u8]) -> bool {
+ self.set_all_dirs();
+ self.all_dirs
+ .as_ref()
+ .unwrap()
+ .contains_key(directory.as_ref())
+ }
+
+ pub fn parents(
+ &mut self,
+ file_contents: &[u8],
+ ) -> Result<DirstateParents, DirstateError> {
+ if let Some(ref parents) = self.parents {
+ return Ok(parents.clone());
+ }
+ let parents;
+ if file_contents.len() == 40 {
+ parents = DirstateParents {
+ p1: file_contents[..PARENT_SIZE].to_owned(),
+ p2: file_contents[PARENT_SIZE..PARENT_SIZE * 2].to_owned(),
+ };
+ } else if file_contents.is_empty() {
+ parents = DirstateParents {
+ p1: NULL_REVISION.to_owned(),
+ p2: NULL_REVISION.to_owned(),
+ };
+ } else {
+ return Err(DirstateError::Parse(DirstateParseError::Damaged));
+ }
+
+ self.parents = Some(parents.to_owned());
+ Ok(parents.clone())
+ }
+
+ pub fn set_parents(&mut self, parents: DirstateParents) {
+ self.parents = Some(parents.clone());
+ self.dirty_parents = true;
+ }
+
+ pub fn read(
+ &mut self,
+ file_contents: &[u8],
+ ) -> Result<Option<DirstateParents>, DirstateError> {
+ if file_contents.is_empty() {
+ return Ok(None);
+ }
+
+ let parents = parse_dirstate(
+ &mut self.state_map,
+ &mut self.copy_map,
+ file_contents,
+ )?;
+
+ if !self.dirty_parents {
+ self.set_parents(parents.to_owned());
+ }
+
+ Ok(Some(parents))
+ }
+
+ pub fn pack(
+ &mut self,
+ parents: DirstateParents,
+ now: Duration,
+ ) -> Result<Vec<u8>, DirstateError> {
+ let packed =
+ pack_dirstate(&mut self.state_map, &self.copy_map, parents, now)?;
+
+ self.dirty_parents = false;
+
+ let result = self.non_normal_other_parent_entries();
+ self.non_normal_set = result.0;
+ self.other_parent_set = result.1;
+ Ok(packed)
+ }
+ pub fn build_file_fold_map(&mut self) -> FileFoldMap {
+ if let Some(ref file_fold_map) = self.file_fold_map {
+ return file_fold_map.to_owned();
+ }
+ let mut new_file_fold_map = FileFoldMap::new();
+ for (filename, DirstateEntry { state, .. }) in self.state_map.borrow()
+ {
+ if *state == EntryState::Removed {
+ new_file_fold_map.insert(
+ filename.to_ascii_uppercase().to_owned(),
+ filename.to_owned(),
+ );
+ }
+ }
+ self.file_fold_map = Some(new_file_fold_map);
+ self.file_fold_map.to_owned().unwrap()
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+
+ #[test]
+ fn test_dirs_multiset() {
+ let mut map = DirstateMap::new();
+ assert!(map.dirs.is_none());
+ assert!(map.all_dirs.is_none());
+
+ assert_eq!(false, map.has_dir(b"nope"));
+ assert!(map.all_dirs.is_some());
+ assert!(map.dirs.is_none());
+
+ assert_eq!(false, map.has_tracked_dir(b"nope"));
+ assert!(map.dirs.is_some());
+ }
+
+ #[test]
+ fn test_add_file() {
+ let mut map = DirstateMap::new();
+
+ assert_eq!(0, map.len());
+
+ map.add_file(
+ b"meh",
+ EntryState::Normal,
+ DirstateEntry {
+ state: EntryState::Normal,
+ mode: 1337,
+ mtime: 1337,
+ size: 1337,
+ },
+ );
+
+ assert_eq!(1, map.len());
+ assert_eq!(0, map.non_normal_set.len());
+ assert_eq!(0, map.other_parent_set.len());
+ }
+
+ #[test]
+ fn test_non_normal_other_parent_entries() {
+ let map: DirstateMap = [
+ (b"f1", (EntryState::Removed, 1337, 1337, 1337)),
+ (b"f2", (EntryState::Normal, 1337, 1337, -1)),
+ (b"f3", (EntryState::Normal, 1337, 1337, 1337)),
+ (b"f4", (EntryState::Normal, 1337, -2, 1337)),
+ (b"f5", (EntryState::Added, 1337, 1337, 1337)),
+ (b"f6", (EntryState::Added, 1337, 1337, -1)),
+ (b"f7", (EntryState::Merged, 1337, 1337, -1)),
+ (b"f8", (EntryState::Merged, 1337, 1337, 1337)),
+ (b"f9", (EntryState::Merged, 1337, -2, 1337)),
+ (b"fa", (EntryState::Added, 1337, -2, 1337)),
+ (b"fb", (EntryState::Removed, 1337, -2, 1337)),
+ ]
+ .iter()
+ .map(|(fname, (state, mode, size, mtime))| {
+ (
+ fname.to_vec(),
+ DirstateEntry {
+ state: *state,
+ mode: *mode,
+ size: *size,
+ mtime: *mtime,
+ },
+ )
+ })
+ .collect();
+
+ let non_normal = [
+ b"f1", b"f2", b"f5", b"f6", b"f7", b"f8", b"f9", b"fa", b"fb",
+ ]
+ .iter()
+ .map(|x| x.to_vec())
+ .collect();
+
+ let mut other_parent = HashSet::new();
+ other_parent.insert(b"f4".to_vec());
+
+ assert_eq!(
+ (non_normal, other_parent),
+ map.non_normal_other_parent_entries()
+ );
+ }
+}
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