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rust-node: handling binary Node prefix...
rust-node: handling binary Node prefix Parallel to the inner signatures of the nodetree functions in revlog.c, we'll have to handle prefixes of `Node` in binary form. Another motivation is that it allows to convert from full Node references to `NodePrefixRef` without copy. This is expected to be by far the most common case in practice. There's a slight complication due to the fact that we'll be sometimes interested in prefixes with an odd number of hexadecimal digits, which translates in binary form by a last byte in which only the highest weight 4 bits are considered. This is totally transparent for callers and could be revised once we have proper means to measure performance. The C implementation does the same, passing the length in nybbles as function arguments. Because Rust byte slices already have a length, we carry the even/odd informaton as a boolean, to avoid introducing logical redundancies and the related potential inconsistency bugs. There are a few candidates for inlining here, but we refrain from such premature optimizations, letting the compiler decide. Differential Revision: https://phab.mercurial-scm.org/D7790

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dirs_multiset.rs
346 lines | 10.9 KiB | application/rls-services+xml | RustLexer
// dirs_multiset.rs
//
// Copyright 2019 Raphaël Gomès <rgomes@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.
//! A multiset of directory names.
//!
//! Used to counts the references to directories in a manifest or dirstate.
use crate::utils::hg_path::{HgPath, HgPathBuf};
use crate::{
dirstate::EntryState, utils::files, DirstateEntry, DirstateMapError,
FastHashMap,
};
use std::collections::hash_map::{self, Entry};
// could be encapsulated if we care API stability more seriously
pub type DirsMultisetIter<'a> = hash_map::Keys<'a, HgPathBuf, u32>;
#[derive(PartialEq, Debug)]
pub struct DirsMultiset {
inner: FastHashMap<HgPathBuf, u32>,
}
impl DirsMultiset {
/// Initializes the multiset from a dirstate.
///
/// If `skip_state` is provided, skips dirstate entries with equal state.
pub fn from_dirstate(
dirstate: &FastHashMap<HgPathBuf, DirstateEntry>,
skip_state: Option<EntryState>,
) -> Result<Self, DirstateMapError> {
let mut multiset = DirsMultiset {
inner: FastHashMap::default(),
};
for (filename, DirstateEntry { state, .. }) in dirstate {
// This `if` is optimized out of the loop
if let Some(skip) = skip_state {
if skip != *state {
multiset.add_path(filename)?;
}
} else {
multiset.add_path(filename)?;
}
}
Ok(multiset)
}
/// Initializes the multiset from a manifest.
pub fn from_manifest(
manifest: &[impl AsRef<HgPath>],
) -> Result<Self, DirstateMapError> {
let mut multiset = DirsMultiset {
inner: FastHashMap::default(),
};
for filename in manifest {
multiset.add_path(filename.as_ref())?;
}
Ok(multiset)
}
/// Increases the count of deepest directory contained in the path.
///
/// If the directory is not yet in the map, adds its parents.
pub fn add_path(
&mut self,
path: impl AsRef<HgPath>,
) -> Result<(), DirstateMapError> {
for subpath in files::find_dirs(path.as_ref()) {
if subpath.as_bytes().last() == Some(&b'/') {
// TODO Remove this once PathAuditor is certified
// as the only entrypoint for path data
return Err(DirstateMapError::ConsecutiveSlashes);
}
if let Some(val) = self.inner.get_mut(subpath) {
*val += 1;
break;
}
self.inner.insert(subpath.to_owned(), 1);
}
Ok(())
}
/// Decreases the count of deepest directory contained in the path.
///
/// If it is the only reference, decreases all parents until one is
/// removed.
/// If the directory is not in the map, something horrible has happened.
pub fn delete_path(
&mut self,
path: impl AsRef<HgPath>,
) -> Result<(), DirstateMapError> {
for subpath in files::find_dirs(path.as_ref()) {
match self.inner.entry(subpath.to_owned()) {
Entry::Occupied(mut entry) => {
let val = entry.get().clone();
if val > 1 {
entry.insert(val - 1);
break;
}
entry.remove();
}
Entry::Vacant(_) => {
return Err(DirstateMapError::PathNotFound(
path.as_ref().to_owned(),
))
}
};
}
Ok(())
}
pub fn contains(&self, key: impl AsRef<HgPath>) -> bool {
self.inner.contains_key(key.as_ref())
}
pub fn iter(&self) -> DirsMultisetIter {
self.inner.keys()
}
pub fn len(&self) -> usize {
self.inner.len()
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_delete_path_path_not_found() {
let manifest: Vec<HgPathBuf> = vec![];
let mut map = DirsMultiset::from_manifest(&manifest).unwrap();
let path = HgPathBuf::from_bytes(b"doesnotexist/");
assert_eq!(
Err(DirstateMapError::PathNotFound(path.to_owned())),
map.delete_path(&path)
);
}
#[test]
fn test_delete_path_empty_path() {
let mut map =
DirsMultiset::from_manifest(&vec![HgPathBuf::new()]).unwrap();
let path = HgPath::new(b"");
assert_eq!(Ok(()), map.delete_path(path));
assert_eq!(
Err(DirstateMapError::PathNotFound(path.to_owned())),
map.delete_path(path)
);
}
#[test]
fn test_delete_path_successful() {
let mut map = DirsMultiset {
inner: [("", 5), ("a", 3), ("a/b", 2), ("a/c", 1)]
.iter()
.map(|(k, v)| (HgPathBuf::from_bytes(k.as_bytes()), *v))
.collect(),
};
assert_eq!(Ok(()), map.delete_path(HgPath::new(b"a/b/")));
eprintln!("{:?}", map);
assert_eq!(Ok(()), map.delete_path(HgPath::new(b"a/b/")));
eprintln!("{:?}", map);
assert_eq!(
Err(DirstateMapError::PathNotFound(HgPathBuf::from_bytes(
b"a/b/"
))),
map.delete_path(HgPath::new(b"a/b/"))
);
assert_eq!(2, *map.inner.get(HgPath::new(b"a")).unwrap());
assert_eq!(1, *map.inner.get(HgPath::new(b"a/c")).unwrap());
eprintln!("{:?}", map);
assert_eq!(Ok(()), map.delete_path(HgPath::new(b"a/")));
eprintln!("{:?}", map);
assert_eq!(Ok(()), map.delete_path(HgPath::new(b"a/c/")));
assert_eq!(
Err(DirstateMapError::PathNotFound(HgPathBuf::from_bytes(
b"a/c/"
))),
map.delete_path(HgPath::new(b"a/c/"))
);
}
#[test]
fn test_add_path_empty_path() {
let manifest: Vec<HgPathBuf> = vec![];
let mut map = DirsMultiset::from_manifest(&manifest).unwrap();
let path = HgPath::new(b"");
map.add_path(path).unwrap();
assert_eq!(1, map.len());
}
#[test]
fn test_add_path_successful() {
let manifest: Vec<HgPathBuf> = vec![];
let mut map = DirsMultiset::from_manifest(&manifest).unwrap();
map.add_path(HgPath::new(b"a/")).unwrap();
assert_eq!(1, *map.inner.get(HgPath::new(b"a")).unwrap());
assert_eq!(1, *map.inner.get(HgPath::new(b"")).unwrap());
assert_eq!(2, map.len());
// Non directory should be ignored
map.add_path(HgPath::new(b"a")).unwrap();
assert_eq!(1, *map.inner.get(HgPath::new(b"a")).unwrap());
assert_eq!(2, map.len());
// Non directory will still add its base
map.add_path(HgPath::new(b"a/b")).unwrap();
assert_eq!(2, *map.inner.get(HgPath::new(b"a")).unwrap());
assert_eq!(2, map.len());
// Duplicate path works
map.add_path(HgPath::new(b"a/")).unwrap();
assert_eq!(3, *map.inner.get(HgPath::new(b"a")).unwrap());
// Nested dir adds to its base
map.add_path(HgPath::new(b"a/b/")).unwrap();
assert_eq!(4, *map.inner.get(HgPath::new(b"a")).unwrap());
assert_eq!(1, *map.inner.get(HgPath::new(b"a/b")).unwrap());
// but not its base's base, because it already existed
map.add_path(HgPath::new(b"a/b/c/")).unwrap();
assert_eq!(4, *map.inner.get(HgPath::new(b"a")).unwrap());
assert_eq!(2, *map.inner.get(HgPath::new(b"a/b")).unwrap());
map.add_path(HgPath::new(b"a/c/")).unwrap();
assert_eq!(1, *map.inner.get(HgPath::new(b"a/c")).unwrap());
let expected = DirsMultiset {
inner: [("", 2), ("a", 5), ("a/b", 2), ("a/b/c", 1), ("a/c", 1)]
.iter()
.map(|(k, v)| (HgPathBuf::from_bytes(k.as_bytes()), *v))
.collect(),
};
assert_eq!(map, expected);
}
#[test]
fn test_dirsmultiset_new_empty() {
let manifest: Vec<HgPathBuf> = vec![];
let new = DirsMultiset::from_manifest(&manifest).unwrap();
let expected = DirsMultiset {
inner: FastHashMap::default(),
};
assert_eq!(expected, new);
let new = DirsMultiset::from_dirstate(&FastHashMap::default(), None)
.unwrap();
let expected = DirsMultiset {
inner: FastHashMap::default(),
};
assert_eq!(expected, new);
}
#[test]
fn test_dirsmultiset_new_no_skip() {
let input_vec: Vec<HgPathBuf> = ["a/", "b/", "a/c", "a/d/"]
.iter()
.map(|e| HgPathBuf::from_bytes(e.as_bytes()))
.collect();
let expected_inner = [("", 2), ("a", 3), ("b", 1), ("a/d", 1)]
.iter()
.map(|(k, v)| (HgPathBuf::from_bytes(k.as_bytes()), *v))
.collect();
let new = DirsMultiset::from_manifest(&input_vec).unwrap();
let expected = DirsMultiset {
inner: expected_inner,
};
assert_eq!(expected, new);
let input_map = ["a/", "b/", "a/c", "a/d/"]
.iter()
.map(|f| {
(
HgPathBuf::from_bytes(f.as_bytes()),
DirstateEntry {
state: EntryState::Normal,
mode: 0,
mtime: 0,
size: 0,
},
)
})
.collect();
let expected_inner = [("", 2), ("a", 3), ("b", 1), ("a/d", 1)]
.iter()
.map(|(k, v)| (HgPathBuf::from_bytes(k.as_bytes()), *v))
.collect();
let new = DirsMultiset::from_dirstate(&input_map, None).unwrap();
let expected = DirsMultiset {
inner: expected_inner,
};
assert_eq!(expected, new);
}
#[test]
fn test_dirsmultiset_new_skip() {
let input_map = [
("a/", EntryState::Normal),
("a/b/", EntryState::Normal),
("a/c", EntryState::Removed),
("a/d/", EntryState::Merged),
]
.iter()
.map(|(f, state)| {
(
HgPathBuf::from_bytes(f.as_bytes()),
DirstateEntry {
state: *state,
mode: 0,
mtime: 0,
size: 0,
},
)
})
.collect();
// "a" incremented with "a/c" and "a/d/"
let expected_inner = [("", 1), ("a", 2), ("a/d", 1)]
.iter()
.map(|(k, v)| (HgPathBuf::from_bytes(k.as_bytes()), *v))
.collect();
let new =
DirsMultiset::from_dirstate(&input_map, Some(EntryState::Normal))
.unwrap();
let expected = DirsMultiset {
inner: expected_inner,
};
assert_eq!(expected, new);
}
}