rust/hg-core/src/dirstate_tree/dirstate_map.rs
52–53	Maybe point out in the commentthat this is an estimate, not an exact value ?
131	We should document this, (and point out this is an estimate)
488	We should put this ratio in some constant (at least) to make its value clearer and easier to configure.
rust/hg-core/src/dirstate_tree/on_disk.rs
76	same feedback about being clear this is an estimate.

Diff	ID	Description	Created	Lint	Unit
Base		Base
Diff 1	29248		Jul 15 2021, 11:28 AM	★	★
Diff 2	29292		Jul 15 2021, 1:11 PM	★	★
Diff 3	29322		Jul 16 2021, 5:38 AM	★	★
Diff 4	29337		Jul 16 2021, 8:37 AM	★	★
Diff 5	29347		Jul 16 2021, 11:17 AM	★	★
Diff 6	29354		Jul 16 2021, 5:45 PM	★	★
Diff 7	29613		Jul 20 2021, 3:41 PM	★	★
Diff 8	29624	rHGd94118365ec58d02aa6c3a6f905cd1789dca1a98	Jul 8 2021, 1:23 PM	★	★

Status	Author	Revision
Closed	SimonSapin	D11101 dirstate-v2: Reserve a few bytes of space for future extensions
Closed	SimonSapin	D11099 dirstate-v2: Separate iterators for dirfoldmap and debugdirstate
Closed	SimonSapin	D11098 dirstate-v2: Move fixed-size tree metadata into the docket file
Closed	SimonSapin	D11097 dirstate-v2: Add heuristic for when to create a new data file
Closed	SimonSapin	D11096 dirstate-v2: Reuse existing paths when appending to a data file
Closed	SimonSapin	D11095 dirstate-v2: Reuse existing nodes when appending to a data file
Closed	SimonSapin	D11094 dirstate-v2: Support appending to the same data file
Closed	SimonSapin	D11091 dirstate-v2: shrink on-disk path lengths to 16-bits
Closed	SimonSapin	D11090 dirstate-v2: Rename Header to Root, move it to the end of the data file
Closed	SimonSapin	D11089 dirstate-v2: Enforce data size read from the docket file
Closed	SimonSapin	D11088 dirstate-v2: Introduce a docket file

Diff 29624

rust/hg-core/src/dirstate_tree/dirstate_map.rs

	use crate::DirstateStatus;			use crate::DirstateStatus;
	use crate::EntryState;			use crate::EntryState;
	use crate::FastHashMap;			use crate::FastHashMap;
	use crate::PatternFileWarning;			use crate::PatternFileWarning;
	use crate::StateMapIter;			use crate::StateMapIter;
	use crate::StatusError;			use crate::StatusError;
	use crate::StatusOptions;			use crate::StatusOptions;

				/// Append to an existing data file if the amount of unreachable data (not used
				/// anymore) is less than this fraction of the total amount of existing data.
				const ACCEPTABLE_UNREACHABLE_BYTES_RATIO: f32 = 0.5;

	pub struct DirstateMap<'on_disk> {			pub struct DirstateMap<'on_disk> {
	/// Contents of the `.hg/dirstate` file			/// Contents of the `.hg/dirstate` file
	pub(super) on_disk: &'on_disk [u8],			pub(super) on_disk: &'on_disk [u8],

	pub(super) root: ChildNodes<'on_disk>,			pub(super) root: ChildNodes<'on_disk>,

	/// Number of nodes anywhere in the tree that have `.entry.is_some()`.			/// Number of nodes anywhere in the tree that have `.entry.is_some()`.
	pub(super) nodes_with_entry_count: u32,			pub(super) nodes_with_entry_count: u32,

	/// Number of nodes anywhere in the tree that have			/// Number of nodes anywhere in the tree that have
	/// `.copy_source.is_some()`.			/// `.copy_source.is_some()`.
	pub(super) nodes_with_copy_source_count: u32,			pub(super) nodes_with_copy_source_count: u32,

	/// See on_disk::Header			/// See on_disk::Header
	pub(super) ignore_patterns_hash: on_disk::IgnorePatternsHash,			pub(super) ignore_patterns_hash: on_disk::IgnorePatternsHash,

				/// How many bytes of `on_disk` are not used anymore
				pub(super) unreachable_bytes: u32,
				marmouteUnsubmitted Not Done Maybe point out in the commentthat this is an estimate, not an exact value ? marmoute: Maybe point out in the commentthat this is an estimate, not an exact value ?
	}			}

	/// Using a plain `HgPathBuf` of the full path from the repository root as a			/// 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			/// 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			/// path, so comparing full paths gives the same result as comparing base
	/// names. However `HashMap` would waste time always re-hashing the same			/// names. However `HashMap` would waste time always re-hashing the same
	/// string prefix.			/// string prefix.
	pub(super) type NodeKey<'on_disk> = WithBasename<Cow<'on_disk, HgPath>>;			pub(super) type NodeKey<'on_disk> = WithBasename<Cow<'on_disk, HgPath>>;

	pub(super) fn is_empty(&self) -> bool {			pub(super) fn is_empty(&self) -> bool {
	match self {			match self {
	ChildNodes::InMemory(nodes) => nodes.is_empty(),			ChildNodes::InMemory(nodes) => nodes.is_empty(),
	ChildNodes::OnDisk(nodes) => nodes.is_empty(),			ChildNodes::OnDisk(nodes) => nodes.is_empty(),
	}			}
	}			}

	pub(super) fn make_mut(			fn make_mut(
	&mut self,			&mut self,
	on_disk: &'on_disk [u8],			on_disk: &'on_disk [u8],
				unreachable_bytes: &mut u32,
				marmouteUnsubmitted Not Done We should document this, (and point out this is an estimate) marmoute: We should document this, (and point out this is an estimate)
	) -> Result<			) -> Result<
	&mut FastHashMap<NodeKey<'on_disk>, Node<'on_disk>>,			&mut FastHashMap<NodeKey<'on_disk>, Node<'on_disk>>,
	DirstateV2ParseError,			DirstateV2ParseError,
	> {			> {
	match self {			match self {
	ChildNodes::InMemory(nodes) => Ok(nodes),			ChildNodes::InMemory(nodes) => Ok(nodes),
	ChildNodes::OnDisk(nodes) => {			ChildNodes::OnDisk(nodes) => {
				*unreachable_bytes +=
				std::mem::size_of_val::<[on_disk::Node]>(nodes) as u32;
	let nodes = nodes			let nodes = nodes
	.iter()			.iter()
	.map(\|node\| {			.map(\|node\| {
	Ok((			Ok((
	node.path(on_disk)?,			node.path(on_disk)?,
	node.to_in_memory_node(on_disk)?,			node.to_in_memory_node(on_disk)?,
	))			))
	})			})
	impl<'on_disk> DirstateMap<'on_disk> {			impl<'on_disk> DirstateMap<'on_disk> {
	pub(super) fn empty(on_disk: &'on_disk [u8]) -> Self {			pub(super) fn empty(on_disk: &'on_disk [u8]) -> Self {
	Self {			Self {
	on_disk,			on_disk,
	root: ChildNodes::default(),			root: ChildNodes::default(),
	nodes_with_entry_count: 0,			nodes_with_entry_count: 0,
	nodes_with_copy_source_count: 0,			nodes_with_copy_source_count: 0,
	ignore_patterns_hash: [0; on_disk::IGNORE_PATTERNS_HASH_LEN],			ignore_patterns_hash: [0; on_disk::IGNORE_PATTERNS_HASH_LEN],
				unreachable_bytes: 0,
	}			}
	}			}

	#[timed]			#[timed]
	pub fn new_v2(			pub fn new_v2(
	on_disk: &'on_disk [u8],			on_disk: &'on_disk [u8],
	data_size: usize,			data_size: usize,
	) -> Result<Self, DirstateError> {			) -> Result<Self, DirstateError> {
	}			}

	let parents = parse_dirstate_entries(			let parents = parse_dirstate_entries(
	map.on_disk,			map.on_disk,
	\|path, entry, copy_source\| {			\|path, entry, copy_source\| {
	let tracked = entry.state.is_tracked();			let tracked = entry.state.is_tracked();
	let node = Self::get_or_insert_node(			let node = Self::get_or_insert_node(
	map.on_disk,			map.on_disk,
				&mut map.unreachable_bytes,
	&mut map.root,			&mut map.root,
	path,			path,
	WithBasename::to_cow_borrowed,			WithBasename::to_cow_borrowed,
	\|ancestor\| {			\|ancestor\| {
	if tracked {			if tracked {
	ancestor.tracked_descendants_count += 1			ancestor.tracked_descendants_count += 1
	}			}
	ancestor.descendants_with_entry_count += 1			ancestor.descendants_with_entry_count += 1

	Ok((map, parents))			Ok((map, parents))
	}			}

	/// Assuming dirstate-v2 format, returns whether the next write should			/// Assuming dirstate-v2 format, returns whether the next write should
	/// append to the existing data file that contains `self.on_disk` (true),			/// append to the existing data file that contains `self.on_disk` (true),
	/// or create a new data file from scratch (false).			/// or create a new data file from scratch (false).
	pub(super) fn write_should_append(&self) -> bool {			pub(super) fn write_should_append(&self) -> bool {
	// Soon this will be a heuristic based on the amount of unreachable			let ratio = self.unreachable_bytes as f32 / self.on_disk.len() as f32;
	// data. For now it’s pseudo-random in order to make tests exercise			ratio < ACCEPTABLE_UNREACHABLE_BYTES_RATIO
				marmouteUnsubmitted Not Done We should put this ratio in some constant (at least) to make its value clearer and easier to configure. marmoute: We should put this ratio in some constant (at least) to make its value clearer and easier to…
	// both code paths.

	fn bad_rng() -> u32 {
	std::time::SystemTime::now()
	.duration_since(std::time::UNIX_EPOCH)
	.unwrap()
	.subsec_millis()
	}

	bad_rng() % 2 == 0
	}			}

	fn get_node<'tree>(			fn get_node<'tree>(
	&'tree self,			&'tree self,
	path: &HgPath,			path: &HgPath,
	) -> Result<Option<NodeRef<'tree, 'on_disk>>, DirstateV2ParseError> {			) -> Result<Option<NodeRef<'tree, 'on_disk>>, DirstateV2ParseError> {
	let mut children = self.root.as_ref();			let mut children = self.root.as_ref();
	let mut components = path.components();			let mut components = path.components();
	}			}

	/// Returns a mutable reference to the node at `path` if it exists			/// Returns a mutable reference to the node at `path` if it exists
	///			///
	/// This takes `root` instead of `&mut self` so that callers can mutate			/// This takes `root` instead of `&mut self` so that callers can mutate
	/// other fields while the returned borrow is still valid			/// other fields while the returned borrow is still valid
	fn get_node_mut<'tree>(			fn get_node_mut<'tree>(
	on_disk: &'on_disk [u8],			on_disk: &'on_disk [u8],
				unreachable_bytes: &mut u32,
	root: &'tree mut ChildNodes<'on_disk>,			root: &'tree mut ChildNodes<'on_disk>,
	path: &HgPath,			path: &HgPath,
	) -> Result<Option<&'tree mut Node<'on_disk>>, DirstateV2ParseError> {			) -> Result<Option<&'tree mut Node<'on_disk>>, DirstateV2ParseError> {
	let mut children = root;			let mut children = root;
	let mut components = path.components();			let mut components = path.components();
	let mut component =			let mut component =
	components.next().expect("expected at least one components");			components.next().expect("expected at least one components");
	loop {			loop {
	if let Some(child) = children.make_mut(on_disk)?.get_mut(component)			if let Some(child) = children
				.make_mut(on_disk, unreachable_bytes)?
				.get_mut(component)
	{			{
	if let Some(next_component) = components.next() {			if let Some(next_component) = components.next() {
	component = next_component;			component = next_component;
	children = &mut child.children;			children = &mut child.children;
	} else {			} else {
	return Ok(Some(child));			return Ok(Some(child));
	}			}
	} else {			} else {
	return Ok(None);			return Ok(None);
	}			}
	}			}
	}			}

	pub(super) fn get_or_insert<'tree, 'path>(			pub(super) fn get_or_insert<'tree, 'path>(
	&'tree mut self,			&'tree mut self,
	path: &HgPath,			path: &HgPath,
	) -> Result<&'tree mut Node<'on_disk>, DirstateV2ParseError> {			) -> Result<&'tree mut Node<'on_disk>, DirstateV2ParseError> {
	Self::get_or_insert_node(			Self::get_or_insert_node(
	self.on_disk,			self.on_disk,
				&mut self.unreachable_bytes,
	&mut self.root,			&mut self.root,
	path,			path,
	WithBasename::to_cow_owned,			WithBasename::to_cow_owned,
	\|_\| {},			\|_\| {},
	)			)
	}			}

	pub(super) fn get_or_insert_node<'tree, 'path>(			fn get_or_insert_node<'tree, 'path>(
	on_disk: &'on_disk [u8],			on_disk: &'on_disk [u8],
				unreachable_bytes: &mut u32,
	root: &'tree mut ChildNodes<'on_disk>,			root: &'tree mut ChildNodes<'on_disk>,
	path: &'path HgPath,			path: &'path HgPath,
	to_cow: impl Fn(			to_cow: impl Fn(
	WithBasename<&'path HgPath>,			WithBasename<&'path HgPath>,
	) -> WithBasename<Cow<'on_disk, HgPath>>,			) -> WithBasename<Cow<'on_disk, HgPath>>,
	mut each_ancestor: impl FnMut(&mut Node),			mut each_ancestor: impl FnMut(&mut Node),
	) -> Result<&'tree mut Node<'on_disk>, DirstateV2ParseError> {			) -> Result<&'tree mut Node<'on_disk>, DirstateV2ParseError> {
	let mut child_nodes = root;			let mut child_nodes = root;
	let mut inclusive_ancestor_paths =			let mut inclusive_ancestor_paths =
	WithBasename::inclusive_ancestors_of(path);			WithBasename::inclusive_ancestors_of(path);
	let mut ancestor_path = inclusive_ancestor_paths			let mut ancestor_path = inclusive_ancestor_paths
	.next()			.next()
	.expect("expected at least one inclusive ancestor");			.expect("expected at least one inclusive ancestor");
	loop {			loop {
	// TODO: can we avoid allocating an owned key in cases where the			// TODO: can we avoid allocating an owned key in cases where the
	// map already contains that key, without introducing double			// map already contains that key, without introducing double
	// lookup?			// lookup?
	let child_node = child_nodes			let child_node = child_nodes
	.make_mut(on_disk)?			.make_mut(on_disk, unreachable_bytes)?
	.entry(to_cow(ancestor_path))			.entry(to_cow(ancestor_path))
	.or_default();			.or_default();
	if let Some(next) = inclusive_ancestor_paths.next() {			if let Some(next) = inclusive_ancestor_paths.next() {
	each_ancestor(child_node);			each_ancestor(child_node);
	ancestor_path = next;			ancestor_path = next;
	child_nodes = &mut child_node.children;			child_nodes = &mut child_node.children;
	} else {			} else {
	return Ok(child_node);			return Ok(child_node);
	match (old_state.is_tracked(), new_entry.state.is_tracked()) {			match (old_state.is_tracked(), new_entry.state.is_tracked()) {
	(false, true) => 1,			(false, true) => 1,
	(true, false) => -1,			(true, false) => -1,
	_ => 0,			_ => 0,
	};			};

	let node = Self::get_or_insert_node(			let node = Self::get_or_insert_node(
	self.on_disk,			self.on_disk,
				&mut self.unreachable_bytes,
	&mut self.root,			&mut self.root,
	path,			path,
	WithBasename::to_cow_owned,			WithBasename::to_cow_owned,
	\|ancestor\| {			\|ancestor\| {
	if !had_entry {			if !had_entry {
	ancestor.descendants_with_entry_count += 1;			ancestor.descendants_with_entry_count += 1;
	}			}


	fn clear_known_ambiguous_mtimes(			fn clear_known_ambiguous_mtimes(
	&mut self,			&mut self,
	paths: &[impl AsRef<HgPath>],			paths: &[impl AsRef<HgPath>],
	) -> Result<(), DirstateV2ParseError> {			) -> Result<(), DirstateV2ParseError> {
	for path in paths {			for path in paths {
	if let Some(node) = Self::get_node_mut(			if let Some(node) = Self::get_node_mut(
	self.on_disk,			self.on_disk,
				&mut self.unreachable_bytes,
	&mut self.root,			&mut self.root,
	path.as_ref(),			path.as_ref(),
	)? {			)? {
	if let NodeData::Entry(entry) = &mut node.data {			if let NodeData::Entry(entry) = &mut node.data {
	entry.clear_mtime();			entry.clear_mtime();
	}			}
	}			}
	}			}
	if let Some(entry) = node.entry()? {			if let Some(entry) = node.entry()? {
	if predicate(&entry) {			if predicate(&entry) {
	return Ok(Some(node.full_path(self.on_disk)?));			return Ok(Some(node.full_path(self.on_disk)?));
	}			}
	}			}
	Ok(None)			Ok(None)
	})			})
	}			}

				fn count_dropped_path(unreachable_bytes: &mut u32, path: &Cow<HgPath>) {
				if let Cow::Borrowed(path) = path {
				*unreachable_bytes += path.len() as u32
				}
				}
	}			}

	/// Like `Iterator::filter_map`, but over a fallible iterator of `Result`s.			/// Like `Iterator::filter_map`, but over a fallible iterator of `Result`s.
	///			///
	/// The callback is only called for incoming `Ok` values. Errors are passed			/// The callback is only called for incoming `Ok` values. Errors are passed
	/// through as-is. In order to let it use the `?` operator the callback is			/// through as-is. In order to let it use the `?` operator the callback is
	/// expected to return a `Result` of `Option`, instead of an `Option` of			/// expected to return a `Result` of `Option`, instead of an `Option` of
	/// `Result`.			/// `Result`.

	/// If this returns `Ok(Some((dropped, removed)))`, then			/// If this returns `Ok(Some((dropped, removed)))`, then
	///			///
	/// * `dropped` is about the leaf node that was at `filename`			/// * `dropped` is about the leaf node that was at `filename`
	/// * `removed` is whether this particular level of recursion just			/// * `removed` is whether this particular level of recursion just
	/// removed a node in `nodes`.			/// removed a node in `nodes`.
	fn recur<'on_disk>(			fn recur<'on_disk>(
	on_disk: &'on_disk [u8],			on_disk: &'on_disk [u8],
				unreachable_bytes: &mut u32,
	nodes: &mut ChildNodes<'on_disk>,			nodes: &mut ChildNodes<'on_disk>,
	path: &HgPath,			path: &HgPath,
	) -> Result<Option<(Dropped, bool)>, DirstateV2ParseError> {			) -> Result<Option<(Dropped, bool)>, DirstateV2ParseError> {
	let (first_path_component, rest_of_path) =			let (first_path_component, rest_of_path) =
	path.split_first_component();			path.split_first_component();
	let node = if let Some(node) =			let nodes = nodes.make_mut(on_disk, unreachable_bytes)?;
	nodes.make_mut(on_disk)?.get_mut(first_path_component)			let node = if let Some(node) = nodes.get_mut(first_path_component)
	{			{
	node			node
	} else {			} else {
	return Ok(None);			return Ok(None);
	};			};
	let dropped;			let dropped;
	if let Some(rest) = rest_of_path {			if let Some(rest) = rest_of_path {
	if let Some((d, removed)) =			if let Some((d, removed)) = recur(
	recur(on_disk, &mut node.children, rest)?			on_disk,
	{			unreachable_bytes,
				&mut node.children,
				rest,
				)? {
	dropped = d;			dropped = d;
	if dropped.had_entry {			if dropped.had_entry {
	node.descendants_with_entry_count -= 1;			node.descendants_with_entry_count -= 1;
	}			}
	if dropped.was_tracked {			if dropped.was_tracked {
	node.tracked_descendants_count -= 1;			node.tracked_descendants_count -= 1;
	}			}

	// Directory caches must be invalidated when removing a			// Directory caches must be invalidated when removing a
	// child node			// child node
	if removed {			if removed {
	if let NodeData::CachedDirectory { .. } = &node.data {			if let NodeData::CachedDirectory { .. } = &node.data {
	node.data = NodeData::None			node.data = NodeData::None
	}			}
	}			}
	} else {			} else {
	return Ok(None);			return Ok(None);
	}			}
	} else {			} else {
	let had_entry = node.data.has_entry();			let had_entry = node.data.has_entry();
	if had_entry {			if had_entry {
	node.data = NodeData::None			node.data = NodeData::None
	}			}
				if let Some(source) = &node.copy_source {
				DirstateMap::count_dropped_path(unreachable_bytes, source)
				}
	dropped = Dropped {			dropped = Dropped {
	was_tracked: node			was_tracked: node
	.data			.data
	.as_entry()			.as_entry()
	.map_or(false, \|entry\| entry.state.is_tracked()),			.map_or(false, \|entry\| entry.state.is_tracked()),
	had_entry,			had_entry,
	had_copy_source: node.copy_source.take().is_some(),			had_copy_source: node.copy_source.take().is_some(),
	};			};
	}			}
	// After recursion, for both leaf (rest_of_path is None) nodes and			// After recursion, for both leaf (rest_of_path is None) nodes and
	// parent nodes, remove a node if it just became empty.			// parent nodes, remove a node if it just became empty.
	let remove = !node.data.has_entry()			let remove = !node.data.has_entry()
	&& node.copy_source.is_none()			&& node.copy_source.is_none()
	&& node.children.is_empty();			&& node.children.is_empty();
	if remove {			if remove {
	nodes.make_mut(on_disk)?.remove(first_path_component);			let (key, _) =
				nodes.remove_entry(first_path_component).unwrap();
				DirstateMap::count_dropped_path(
				unreachable_bytes,
				key.full_path(),
				)
	}			}
	Ok(Some((dropped, remove)))			Ok(Some((dropped, remove)))
	}			}

	if let Some((dropped, _removed)) =			if let Some((dropped, _removed)) = recur(
	recur(self.on_disk, &mut self.root, filename)?			self.on_disk,
	{			&mut self.unreachable_bytes,
				&mut self.root,
				filename,
				)? {
	if dropped.had_entry {			if dropped.had_entry {
	self.nodes_with_entry_count -= 1			self.nodes_with_entry_count -= 1
	}			}
	if dropped.had_copy_source {			if dropped.had_copy_source {
	self.nodes_with_copy_source_count -= 1			self.nodes_with_copy_source_count -= 1
	}			}
	Ok(dropped.had_entry)			Ok(dropped.had_entry)
	} else {			} else {
	debug_assert!(!old_state.is_tracked());			debug_assert!(!old_state.is_tracked());
	Ok(false)			Ok(false)
	}			}
	}			}

	fn clear_ambiguous_times(			fn clear_ambiguous_times(
	&mut self,			&mut self,
	filenames: Vec<HgPathBuf>,			filenames: Vec<HgPathBuf>,
	now: i32,			now: i32,
	) -> Result<(), DirstateV2ParseError> {			) -> Result<(), DirstateV2ParseError> {
	for filename in filenames {			for filename in filenames {
	if let Some(node) =			if let Some(node) = Self::get_node_mut(
	Self::get_node_mut(self.on_disk, &mut self.root, &filename)?			self.on_disk,
	{			&mut self.unreachable_bytes,
				&mut self.root,
				&filename,
				)? {
	if let NodeData::Entry(entry) = &mut node.data {			if let NodeData::Entry(entry) = &mut node.data {
	entry.clear_ambiguous_mtime(now);			entry.clear_ambiguous_mtime(now);
	}			}
	}			}
	}			}
	Ok(())			Ok(())
	}			}

	Ok(None)			Ok(None)
	}			}

	fn copy_map_remove(			fn copy_map_remove(
	&mut self,			&mut self,
	key: &HgPath,			key: &HgPath,
	) -> Result<Option<HgPathBuf>, DirstateV2ParseError> {			) -> Result<Option<HgPathBuf>, DirstateV2ParseError> {
	let count = &mut self.nodes_with_copy_source_count;			let count = &mut self.nodes_with_copy_source_count;
	Ok(			let unreachable_bytes = &mut self.unreachable_bytes;
	Self::get_node_mut(self.on_disk, &mut self.root, key)?.and_then(			Ok(Self::get_node_mut(
	\|node\| {			self.on_disk,
	if node.copy_source.is_some() {			unreachable_bytes,
	*count -= 1			&mut self.root,
				key,
				)?
				.and_then(\|node\| {
				if let Some(source) = &node.copy_source {
				*count -= 1;
				Self::count_dropped_path(unreachable_bytes, source);
	}			}
	node.copy_source.take().map(Cow::into_owned)			node.copy_source.take().map(Cow::into_owned)
	},			}))
	),
	)
	}			}

	fn copy_map_insert(			fn copy_map_insert(
	&mut self,			&mut self,
	key: HgPathBuf,			key: HgPathBuf,
	value: HgPathBuf,			value: HgPathBuf,
	) -> Result<Option<HgPathBuf>, DirstateV2ParseError> {			) -> Result<Option<HgPathBuf>, DirstateV2ParseError> {
	let node = Self::get_or_insert_node(			let node = Self::get_or_insert_node(
	self.on_disk,			self.on_disk,
				&mut self.unreachable_bytes,
	&mut self.root,			&mut self.root,
	&key,			&key,
	WithBasename::to_cow_owned,			WithBasename::to_cow_owned,
	\|_ancestor\| {},			\|_ancestor\| {},
	)?;			)?;
	if node.copy_source.is_none() {			if node.copy_source.is_none() {
	self.nodes_with_copy_source_count += 1			self.nodes_with_copy_source_count += 1
	}			}

rust/hg-core/src/dirstate_tree/on_disk.rs


	#[derive(BytesCast)]			#[derive(BytesCast)]
	#[repr(C)]			#[repr(C)]
	struct Root {			struct Root {
	root_nodes: ChildNodes,			root_nodes: ChildNodes,
	nodes_with_entry_count: Size,			nodes_with_entry_count: Size,
	nodes_with_copy_source_count: Size,			nodes_with_copy_source_count: Size,

				/// How many bytes of this data file are not used anymore
				marmouteUnsubmitted Not Done same feedback about being clear this is an estimate. marmoute: same feedback about being clear this is an estimate.
				unreachable_bytes: Size,

	/// If non-zero, a hash of ignore files that were used for some previous			/// If non-zero, a hash of ignore files that were used for some previous
	/// run of the `status` algorithm.			/// run of the `status` algorithm.
	///			///
	/// We define:			/// We define:
	///			///
	/// * "Root" ignore files are `.hgignore` at the root of the repository if			/// * "Root" ignore files are `.hgignore` at the root of the repository if
	/// it exists, and files from `ui.ignore.*` config. This set of files is			/// it exists, and files from `ui.ignore.*` config. This set of files is
	/// then sorted by the string representation of their path.			/// then sorted by the string representation of their path.
	}			}

	/// Either nothing if `start == 0`, or a `HgPath` of `len` bytes			/// Either nothing if `start == 0`, or a `HgPath` of `len` bytes
	type OptPathSlice = PathSlice;			type OptPathSlice = PathSlice;

	/// Make sure that size-affecting changes are made knowingly			/// Make sure that size-affecting changes are made knowingly
	fn _static_assert_size_of() {			fn _static_assert_size_of() {
	let _ = std::mem::transmute::<DocketHeader, [u8; 81]>;			let _ = std::mem::transmute::<DocketHeader, [u8; 81]>;
	let _ = std::mem::transmute::<Root, [u8; 36]>;			let _ = std::mem::transmute::<Root, [u8; 40]>;
	let _ = std::mem::transmute::<Node, [u8; 43]>;			let _ = std::mem::transmute::<Node, [u8; 43]>;
	}			}

	/// Unexpected file format found in `.hg/dirstate` with the "v2" format.			/// Unexpected file format found in `.hg/dirstate` with the "v2" format.
	///			///
	/// This should only happen if Mercurial is buggy or a repository is corrupted.			/// This should only happen if Mercurial is buggy or a repository is corrupted.
	#[derive(Debug)]			#[derive(Debug)]
	pub struct DirstateV2ParseError;			pub struct DirstateV2ParseError;

	pub(super) fn read<'on_disk>(			pub(super) fn read<'on_disk>(
	on_disk: &'on_disk [u8],			on_disk: &'on_disk [u8],
	) -> Result<DirstateMap<'on_disk>, DirstateV2ParseError> {			) -> Result<DirstateMap<'on_disk>, DirstateV2ParseError> {
	if on_disk.is_empty() {			if on_disk.is_empty() {
	return Ok(DirstateMap::empty(on_disk));			return Ok(DirstateMap::empty(on_disk));
	}			}
	let root = read_root(on_disk)?;			let root = read_root(on_disk)?;
				let mut unreachable_bytes = root.unreachable_bytes.get();
				// Each append writes a new `Root`, so it’s never reused
				unreachable_bytes += std::mem::size_of::<Root>() as u32;
	let dirstate_map = DirstateMap {			let dirstate_map = DirstateMap {
	on_disk,			on_disk,
	root: dirstate_map::ChildNodes::OnDisk(read_nodes(			root: dirstate_map::ChildNodes::OnDisk(read_nodes(
	on_disk,			on_disk,
	root.root_nodes,			root.root_nodes,
	)?),			)?),
	nodes_with_entry_count: root.nodes_with_entry_count.get(),			nodes_with_entry_count: root.nodes_with_entry_count.get(),
	nodes_with_copy_source_count: root.nodes_with_copy_source_count.get(),			nodes_with_copy_source_count: root.nodes_with_copy_source_count.get(),
	ignore_patterns_hash: root.ignore_patterns_hash,			ignore_patterns_hash: root.ignore_patterns_hash,
				unreachable_bytes,
	};			};
	Ok(dirstate_map)			Ok(dirstate_map)
	}			}

	impl Node {			impl Node {
	pub(super) fn full_path<'on_disk>(			pub(super) fn full_path<'on_disk>(
	&self,			&self,
	on_disk: &'on_disk [u8],			on_disk: &'on_disk [u8],
	let root_nodes = writer.write_nodes(dirstate_map.root.as_ref())?;			let root_nodes = writer.write_nodes(dirstate_map.root.as_ref())?;

	let root = Root {			let root = Root {
	root_nodes,			root_nodes,
	nodes_with_entry_count: dirstate_map.nodes_with_entry_count.into(),			nodes_with_entry_count: dirstate_map.nodes_with_entry_count.into(),
	nodes_with_copy_source_count: dirstate_map			nodes_with_copy_source_count: dirstate_map
	.nodes_with_copy_source_count			.nodes_with_copy_source_count
	.into(),			.into(),
				unreachable_bytes: dirstate_map.unreachable_bytes.into(),
	ignore_patterns_hash: dirstate_map.ignore_patterns_hash,			ignore_patterns_hash: dirstate_map.ignore_patterns_hash,
	};			};
	writer.out.extend(root.as_bytes());			writer.out.extend(root.as_bytes());
	Ok((writer.out, append))			Ok((writer.out, append))
	}			}

	struct Writer<'dmap, 'on_disk> {			struct Writer<'dmap, 'on_disk> {
	dirstate_map: &'dmap DirstateMap<'on_disk>,			dirstate_map: &'dmap DirstateMap<'on_disk>,

			Path	Packages
M			rust/hg-core/src/dirstate_tree/dirstate_map.rs (114 lines)
M			rust/hg-core/src/dirstate_tree/on_disk.rs (10 lines)

This is an archive of the discontinued Mercurial Phabricator instance.

dirstate-v2: Add heuristic for when to create a new data file
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Diff 29624

rust/hg-core/src/dirstate_tree/dirstate_map.rs

rust/hg-core/src/dirstate_tree/on_disk.rs

This is an archive of the discontinued Mercurial Phabricator instance.

dirstate-v2: Add heuristic for when to create a new data fileClosedPublic

Details

Diff Detail

Event Timeline

Revision ContentsChangeset List

Diff 29624

rust/hg-core/src/dirstate_tree/dirstate_map.rs

rust/hg-core/src/dirstate_tree/on_disk.rs

dirstate-v2: Add heuristic for when to create a new data file
ClosedPublic

Revision Contents
Changeset List