D10922: dirstate-tree: Keep a counter of descendant nodes that have an entry
SimonSapin
phabricator at mercurial-scm.org
Fri Jul 2 12:36:47 UTC 2021
SimonSapin created this revision.
Herald added a reviewer: hg-reviewers.
Herald added a subscriber: mercurial-patches.
REVISION SUMMARY
⦠and change the `DirstateMap::has_dir` method to be based on this counter
being non-zero instead of the mere presence of a node.
A node with zero descendent with an entry currently should be removed from
the tree, but soon weâll make the dirstate track additional nodes.
(Specifically, for non-ignored directories in order to keep track of their
mtime and optimize status by doing fewer `read_dir` calls.)
REPOSITORY
rHG Mercurial
BRANCH
default
REVISION DETAIL
https://phab.mercurial-scm.org/D10922
AFFECTED FILES
rust/hg-core/src/dirstate_tree/dirstate_map.rs
rust/hg-core/src/dirstate_tree/on_disk.rs
CHANGE DETAILS
diff --git a/rust/hg-core/src/dirstate_tree/on_disk.rs b/rust/hg-core/src/dirstate_tree/on_disk.rs
--- a/rust/hg-core/src/dirstate_tree/on_disk.rs
+++ b/rust/hg-core/src/dirstate_tree/on_disk.rs
@@ -76,6 +76,7 @@
copy_source: OptPathSlice,
children: ChildNodes,
+ pub(super) descendants_with_entry_count: Size,
pub(super) tracked_descendants_count: Size,
/// Dependending on the value of `state`:
@@ -172,7 +173,7 @@
/// Make sure that size-affecting changes are made knowingly
fn _static_assert_size_of() {
let _ = std::mem::transmute::<Header, [u8; 88]>;
- let _ = std::mem::transmute::<Node, [u8; 45]>;
+ let _ = std::mem::transmute::<Node, [u8; 49]>;
}
/// Unexpected file format found in `.hg/dirstate` with the "v2" format.
@@ -360,6 +361,9 @@
),
copy_source: self.copy_source(on_disk)?.map(Cow::Borrowed),
data: self.node_data()?,
+ descendants_with_entry_count: self
+ .descendants_with_entry_count
+ .get(),
tracked_descendants_count: self.tracked_descendants_count.get(),
})
}
@@ -565,6 +569,9 @@
// Could only panic for paths over 4 GiB
.expect("dirstate-v2 offset overflow")
.into(),
+ descendants_with_entry_count: node
+ .descendants_with_entry_count
+ .into(),
tracked_descendants_count: node
.tracked_descendants_count
.into(),
diff --git a/rust/hg-core/src/dirstate_tree/dirstate_map.rs b/rust/hg-core/src/dirstate_tree/dirstate_map.rs
--- a/rust/hg-core/src/dirstate_tree/dirstate_map.rs
+++ b/rust/hg-core/src/dirstate_tree/dirstate_map.rs
@@ -332,6 +332,15 @@
}
}
+ pub(super) fn descendants_with_entry_count(&self) -> u32 {
+ match self {
+ NodeRef::InMemory(_path, node) => {
+ node.descendants_with_entry_count
+ }
+ NodeRef::OnDisk(node) => node.descendants_with_entry_count.get(),
+ }
+ }
+
pub(super) fn tracked_descendants_count(&self) -> u32 {
match self {
NodeRef::InMemory(_path, node) => node.tracked_descendants_count,
@@ -349,7 +358,11 @@
pub(super) children: ChildNodes<'on_disk>,
- /// How many (non-inclusive) descendants of this node are tracked files
+ /// How many (non-inclusive) descendants of this node have an entry.
+ pub(super) descendants_with_entry_count: u32,
+
+ /// How many (non-inclusive) descendants of this node have an entry whose
+ /// state is "tracked".
pub(super) tracked_descendants_count: u32,
}
@@ -421,6 +434,7 @@
if tracked {
ancestor.tracked_descendants_count += 1
}
+ ancestor.descendants_with_entry_count += 1
},
)?;
assert!(
@@ -547,6 +561,7 @@
old_state: EntryState,
new_entry: DirstateEntry,
) -> Result<(), DirstateV2ParseError> {
+ let had_entry = old_state != EntryState::Unknown;
let tracked_count_increment =
match (old_state.is_tracked(), new_entry.state.is_tracked()) {
(false, true) => 1,
@@ -560,6 +575,10 @@
path,
WithBasename::to_cow_owned,
|ancestor| {
+ if !had_entry {
+ ancestor.descendants_with_entry_count += 1;
+ }
+
// We canât use `+= increment` because the counter is unsigned,
// and we want debug builds to detect accidental underflow
// through zero
@@ -570,7 +589,7 @@
}
},
)?;
- if !node.data.has_entry() {
+ if !had_entry {
self.nodes_with_entry_count += 1
}
node.data = NodeData::Entry(new_entry);
@@ -755,6 +774,9 @@
recur(on_disk, &mut node.children, rest)?
{
dropped = d;
+ if dropped.had_entry {
+ node.descendants_with_entry_count -= 1;
+ }
if dropped.was_tracked {
node.tracked_descendants_count -= 1;
}
@@ -899,7 +921,8 @@
if let Some(node) = self.get_node(directory)? {
// A node without a `DirstateEntry` was created to hold child
// nodes, and is therefore a directory.
- Ok(node.state()?.is_none())
+ let state = node.state()?;
+ Ok(state.is_none() && node.descendants_with_entry_count() > 0)
} else {
Ok(false)
}
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