rhg: more efficient `HgPath::join`
This commit makes `HgPath::join` slightly more efficient
by avoiding one copy.
It also avoids a particularly inefficient (quadratic) use of
`HgPath::join` by using a new mutating function `HgPathBuf::push` instead.
The name for `HgPathBuf::push` is chosen by analogy to `PathBuf::push`.
Differential Revision: https://phab.mercurial-scm.org/D11721
--- a/rust/hg-core/src/filepatterns.rs Tue Nov 09 15:25:38 2021 +0100
+++ b/rust/hg-core/src/filepatterns.rs Tue Oct 26 19:47:30 2021 +0100
@@ -536,7 +536,7 @@
Ok(Self {
prefix: path_to_hg_path_buf(prefix).and_then(|mut p| {
if !p.is_empty() {
- p.push(b'/');
+ p.push_byte(b'/');
}
Ok(p)
})?,
--- a/rust/hg-core/src/matchers.rs Tue Nov 09 15:25:38 2021 +0100
+++ b/rust/hg-core/src/matchers.rs Tue Oct 26 19:47:30 2021 +0100
@@ -391,8 +391,7 @@
} = ignore_pattern;
match syntax {
PatternSyntax::RootGlob | PatternSyntax::Glob => {
- let mut root = vec![];
-
+ let mut root = HgPathBuf::new();
for p in pattern.split(|c| *c == b'/') {
if p.iter().any(|c| match *c {
b'[' | b'{' | b'*' | b'?' => true,
@@ -400,11 +399,9 @@
}) {
break;
}
- root.push(HgPathBuf::from_bytes(p));
+ root.push(HgPathBuf::from_bytes(p).as_ref());
}
- let buf =
- root.iter().fold(HgPathBuf::new(), |acc, r| acc.join(r));
- roots.push(buf);
+ roots.push(root);
}
PatternSyntax::Path | PatternSyntax::RelPath => {
let pat = HgPath::new(if pattern == b"." {
--- a/rust/hg-core/src/utils/hg_path.rs Tue Nov 09 15:25:38 2021 +0100
+++ b/rust/hg-core/src/utils/hg_path.rs Tue Oct 26 19:47:30 2021 +0100
@@ -220,13 +220,11 @@
),
}
}
- pub fn join<T: ?Sized + AsRef<Self>>(&self, other: &T) -> HgPathBuf {
- let mut inner = self.inner.to_owned();
- if !inner.is_empty() && inner.last() != Some(&b'/') {
- inner.push(b'/');
- }
- inner.extend(other.as_ref().bytes());
- HgPathBuf::from_bytes(&inner)
+
+ pub fn join(&self, path: &HgPath) -> HgPathBuf {
+ let mut buf = self.to_owned();
+ buf.push(path);
+ buf
}
pub fn components(&self) -> impl Iterator<Item = &HgPath> {
@@ -405,7 +403,15 @@
pub fn new() -> Self {
Default::default()
}
- pub fn push(&mut self, byte: u8) {
+
+ pub fn push<T: ?Sized + AsRef<HgPath>>(&mut self, other: &T) -> () {
+ if !self.inner.is_empty() && self.inner.last() != Some(&b'/') {
+ self.inner.push(b'/');
+ }
+ self.inner.extend(other.as_ref().bytes())
+ }
+
+ pub fn push_byte(&mut self, byte: u8) {
self.inner.push(byte);
}
pub fn from_bytes(s: &[u8]) -> HgPathBuf {