dirstate-tree: Downgrade `&mut Node` to `&Node` in status and serialization
Mutable access is not used, and upcoming changes will make it more costly
(with copy-on-write nodes that can be read from disk representation)
Differential Revision: https://phab.mercurial-scm.org/D10745
use crate::dirstate::status::IgnoreFnType;
use crate::dirstate_tree::dirstate_map::ChildNodes;
use crate::dirstate_tree::dirstate_map::DirstateMap;
use crate::dirstate_tree::dirstate_map::Node;
use crate::matchers::get_ignore_function;
use crate::matchers::Matcher;
use crate::utils::files::get_bytes_from_os_string;
use crate::utils::hg_path::HgPath;
use crate::BadMatch;
use crate::DirstateStatus;
use crate::EntryState;
use crate::HgPathBuf;
use crate::PatternFileWarning;
use crate::StatusError;
use crate::StatusOptions;
use micro_timer::timed;
use rayon::prelude::*;
use std::borrow::Cow;
use std::io;
use std::path::Path;
use std::path::PathBuf;
use std::sync::Mutex;
/// Returns the status of the working directory compared to its parent
/// changeset.
///
/// This algorithm is based on traversing the filesystem tree (`fs` in function
/// and variable names) and dirstate tree at the same time. The core of this
/// traversal is the recursive `traverse_fs_directory_and_dirstate` function
/// and its use of `itertools::merge_join_by`. When reaching a path that only
/// exists in one of the two trees, depending on information requested by
/// `options` we may need to traverse the remaining subtree.
#[timed]
pub fn status<'tree>(
dmap: &'tree mut DirstateMap,
matcher: &(dyn Matcher + Sync),
root_dir: PathBuf,
ignore_files: Vec<PathBuf>,
options: StatusOptions,
) -> Result<(DirstateStatus<'tree>, Vec<PatternFileWarning>), StatusError> {
let (ignore_fn, warnings): (IgnoreFnType, _) =
if options.list_ignored || options.list_unknown {
get_ignore_function(ignore_files, &root_dir)?
} else {
(Box::new(|&_| true), vec![])
};
let common = StatusCommon {
options,
matcher,
ignore_fn,
outcome: Mutex::new(DirstateStatus::default()),
};
let is_at_repo_root = true;
let hg_path = HgPath::new("");
let has_ignored_ancestor = false;
common.traverse_fs_directory_and_dirstate(
has_ignored_ancestor,
&dmap.root,
hg_path,
&root_dir,
is_at_repo_root,
);
Ok((common.outcome.into_inner().unwrap(), warnings))
}
/// Bag of random things needed by various parts of the algorithm. Reduces the
/// number of parameters passed to functions.
struct StatusCommon<'tree, 'a> {
options: StatusOptions,
matcher: &'a (dyn Matcher + Sync),
ignore_fn: IgnoreFnType<'a>,
outcome: Mutex<DirstateStatus<'tree>>,
}
impl<'tree, 'a> StatusCommon<'tree, 'a> {
fn read_dir(
&self,
hg_path: &HgPath,
fs_path: &Path,
is_at_repo_root: bool,
) -> Result<Vec<DirEntry>, ()> {
DirEntry::read_dir(fs_path, is_at_repo_root).map_err(|error| {
let errno = error.raw_os_error().expect("expected real OS error");
self.outcome
.lock()
.unwrap()
.bad
.push((hg_path.to_owned().into(), BadMatch::OsError(errno)))
})
}
fn traverse_fs_directory_and_dirstate(
&self,
has_ignored_ancestor: bool,
dirstate_nodes: &'tree ChildNodes,
directory_hg_path: &'tree HgPath,
directory_fs_path: &Path,
is_at_repo_root: bool,
) {
let mut fs_entries = if let Ok(entries) = self.read_dir(
directory_hg_path,
directory_fs_path,
is_at_repo_root,
) {
entries
} else {
return;
};
// `merge_join_by` requires both its input iterators to be sorted:
let dirstate_nodes = Node::sorted(dirstate_nodes);
// `sort_unstable_by_key` doesn’t allow keys borrowing from the value:
// https://github.com/rust-lang/rust/issues/34162
fs_entries.sort_unstable_by(|e1, e2| e1.base_name.cmp(&e2.base_name));
itertools::merge_join_by(
dirstate_nodes,
&fs_entries,
|(full_path, _node), fs_entry| {
full_path.base_name().cmp(&fs_entry.base_name)
},
)
.par_bridge()
.for_each(|pair| {
use itertools::EitherOrBoth::*;
match pair {
Both((hg_path, dirstate_node), fs_entry) => {
self.traverse_fs_and_dirstate(
fs_entry,
hg_path.full_path(),
dirstate_node,
has_ignored_ancestor,
);
}
Left((hg_path, dirstate_node)) => self.traverse_dirstate_only(
hg_path.full_path(),
dirstate_node,
),
Right(fs_entry) => self.traverse_fs_only(
has_ignored_ancestor,
directory_hg_path,
fs_entry,
),
}
})
}
fn traverse_fs_and_dirstate(
&self,
fs_entry: &DirEntry,
hg_path: &'tree HgPath,
dirstate_node: &'tree Node,
has_ignored_ancestor: bool,
) {
let file_type = fs_entry.metadata.file_type();
let file_or_symlink = file_type.is_file() || file_type.is_symlink();
if !file_or_symlink {
// If we previously had a file here, it was removed (with
// `hg rm` or similar) or deleted before it could be
// replaced by a directory or something else.
self.mark_removed_or_deleted_if_file(
hg_path,
dirstate_node.state(),
);
}
if file_type.is_dir() {
if self.options.collect_traversed_dirs {
self.outcome.lock().unwrap().traversed.push(hg_path.into())
}
let is_ignored = has_ignored_ancestor || (self.ignore_fn)(hg_path);
let is_at_repo_root = false;
self.traverse_fs_directory_and_dirstate(
is_ignored,
&dirstate_node.children,
hg_path,
&fs_entry.full_path,
is_at_repo_root,
);
} else {
if file_or_symlink && self.matcher.matches(hg_path) {
let full_path = Cow::from(hg_path);
if let Some(entry) = &dirstate_node.entry {
match entry.state {
EntryState::Added => {
self.outcome.lock().unwrap().added.push(full_path)
}
EntryState::Removed => self
.outcome
.lock()
.unwrap()
.removed
.push(full_path),
EntryState::Merged => self
.outcome
.lock()
.unwrap()
.modified
.push(full_path),
EntryState::Normal => {
self.handle_normal_file(
full_path,
dirstate_node,
entry,
fs_entry,
);
}
// This variant is not used in DirstateMap
// nodes
EntryState::Unknown => unreachable!(),
}
} else {
// `node.entry.is_none()` indicates a "directory"
// node, but the filesystem has a file
self.mark_unknown_or_ignored(
has_ignored_ancestor,
full_path,
)
}
}
for (child_hg_path, child_node) in &dirstate_node.children {
self.traverse_dirstate_only(
child_hg_path.full_path(),
child_node,
)
}
}
}
/// A file with `EntryState::Normal` in the dirstate was found in the
/// filesystem
fn handle_normal_file(
&self,
full_path: Cow<'tree, HgPath>,
dirstate_node: &Node,
entry: &crate::DirstateEntry,
fs_entry: &DirEntry,
) {
// Keep the low 31 bits
fn truncate_u64(value: u64) -> i32 {
(value & 0x7FFF_FFFF) as i32
}
fn truncate_i64(value: i64) -> i32 {
(value & 0x7FFF_FFFF) as i32
}
let mode_changed = || {
self.options.check_exec && entry.mode_changed(&fs_entry.metadata)
};
let size_changed = entry.size != truncate_u64(fs_entry.metadata.len());
if entry.size >= 0
&& size_changed
&& fs_entry.metadata.file_type().is_symlink()
{
// issue6456: Size returned may be longer due to encryption
// on EXT-4 fscrypt. TODO maybe only do it on EXT4?
self.outcome.lock().unwrap().unsure.push(full_path)
} else if dirstate_node.copy_source.is_some()
|| entry.is_from_other_parent()
|| (entry.size >= 0 && (size_changed || mode_changed()))
{
self.outcome.lock().unwrap().modified.push(full_path)
} else {
let mtime = mtime_seconds(&fs_entry.metadata);
if truncate_i64(mtime) != entry.mtime
|| mtime == self.options.last_normal_time
{
self.outcome.lock().unwrap().unsure.push(full_path)
} else if self.options.list_clean {
self.outcome.lock().unwrap().clean.push(full_path)
}
}
}
/// A node in the dirstate tree has no corresponding filesystem entry
fn traverse_dirstate_only(
&self,
hg_path: &'tree HgPath,
dirstate_node: &'tree Node,
) {
self.mark_removed_or_deleted_if_file(hg_path, dirstate_node.state());
dirstate_node.children.par_iter().for_each(
|(child_hg_path, child_node)| {
self.traverse_dirstate_only(
child_hg_path.full_path(),
child_node,
)
},
)
}
/// A node in the dirstate tree has no corresponding *file* on the
/// filesystem
///
/// Does nothing on a "directory" node
fn mark_removed_or_deleted_if_file(
&self,
hg_path: &'tree HgPath,
dirstate_node_state: Option<EntryState>,
) {
if let Some(state) = dirstate_node_state {
if self.matcher.matches(hg_path) {
if let EntryState::Removed = state {
self.outcome.lock().unwrap().removed.push(hg_path.into())
} else {
self.outcome.lock().unwrap().deleted.push(hg_path.into())
}
}
}
}
/// Something in the filesystem has no corresponding dirstate node
fn traverse_fs_only(
&self,
has_ignored_ancestor: bool,
directory_hg_path: &HgPath,
fs_entry: &DirEntry,
) {
let hg_path = directory_hg_path.join(&fs_entry.base_name);
let file_type = fs_entry.metadata.file_type();
let file_or_symlink = file_type.is_file() || file_type.is_symlink();
if file_type.is_dir() {
let is_ignored =
has_ignored_ancestor || (self.ignore_fn)(&hg_path);
let traverse_children = if is_ignored {
// Descendants of an ignored directory are all ignored
self.options.list_ignored
} else {
// Descendants of an unknown directory may be either unknown or
// ignored
self.options.list_unknown || self.options.list_ignored
};
if traverse_children {
let is_at_repo_root = false;
if let Ok(children_fs_entries) = self.read_dir(
&hg_path,
&fs_entry.full_path,
is_at_repo_root,
) {
children_fs_entries.par_iter().for_each(|child_fs_entry| {
self.traverse_fs_only(
is_ignored,
&hg_path,
child_fs_entry,
)
})
}
}
if self.options.collect_traversed_dirs {
self.outcome.lock().unwrap().traversed.push(hg_path.into())
}
} else if file_or_symlink && self.matcher.matches(&hg_path) {
self.mark_unknown_or_ignored(has_ignored_ancestor, hg_path.into())
}
}
fn mark_unknown_or_ignored(
&self,
has_ignored_ancestor: bool,
hg_path: Cow<'tree, HgPath>,
) {
let is_ignored = has_ignored_ancestor || (self.ignore_fn)(&hg_path);
if is_ignored {
if self.options.list_ignored {
self.outcome.lock().unwrap().ignored.push(hg_path)
}
} else {
if self.options.list_unknown {
self.outcome.lock().unwrap().unknown.push(hg_path)
}
}
}
}
#[cfg(unix)] // TODO
fn mtime_seconds(metadata: &std::fs::Metadata) -> i64 {
// Going through `Metadata::modified()` would be portable, but would take
// care to construct a `SystemTime` value with sub-second precision just
// for us to throw that away here.
use std::os::unix::fs::MetadataExt;
metadata.mtime()
}
struct DirEntry {
base_name: HgPathBuf,
full_path: PathBuf,
metadata: std::fs::Metadata,
}
impl DirEntry {
/// Returns **unsorted** entries in the given directory, with name and
/// metadata.
///
/// If a `.hg` sub-directory is encountered:
///
/// * At the repository root, ignore that sub-directory
/// * Elsewhere, we’re listing the content of a sub-repo. Return an empty
/// list instead.
fn read_dir(path: &Path, is_at_repo_root: bool) -> io::Result<Vec<Self>> {
let mut results = Vec::new();
for entry in path.read_dir()? {
let entry = entry?;
let metadata = entry.metadata()?;
let name = get_bytes_from_os_string(entry.file_name());
// FIXME don't do this when cached
if name == b".hg" {
if is_at_repo_root {
// Skip the repo’s own .hg (might be a symlink)
continue;
} else if metadata.is_dir() {
// A .hg sub-directory at another location means a subrepo,
// skip it entirely.
return Ok(Vec::new());
}
}
results.push(DirEntry {
base_name: name.into(),
full_path: entry.path(),
metadata,
})
}
Ok(results)
}
}