rust-status: add function for sequential traversal of the working directory

This change also introduces helper structs to make things clearer.

Differential Revision: https://phab.mercurial-scm.org/D7928

rust/hg-core/src/dirstate/status.rs

@@ -1,361 +1,536 b''
 // status.rs
 //
 // Copyright 2019 Raphaël Gomès <[e-mail]>
 //
 // This software may be used and distributed according to the terms of the
 // GNU General Public License version 2 or any later version.
 
 //! Rust implementation of dirstate.status (dirstate.py).
 //! It is currently missing a lot of functionality compared to the Python one
 //! and will only be triggered in narrow cases.
 
 use crate::{
     dirstate::SIZE_FROM_OTHER_PARENT,
-    matchers::Matcher,
+    matchers::{Matcher, VisitChildrenSet},
     utils::{
         files::HgMetadata,
         hg_path::{
             hg_path_to_path_buf, os_string_to_hg_path_buf, HgPath, HgPathBuf,
         },
     },
-    CopyMap, DirstateEntry, DirstateMap, EntryState,
+    CopyMap, DirstateEntry, DirstateMap, EntryState, FastHashMap,
 };
 use rayon::prelude::*;
-use std::collections::HashSet;
+use std::borrow::Cow;
+use std::collections::{HashSet, VecDeque};
 use std::fs::{read_dir, DirEntry};
+use std::io::ErrorKind;
+use std::ops::Deref;
 use std::path::Path;
 
 /// Wrong type of file from a `BadMatch`
 /// Note: a lot of those don't exist on all platforms.
 #[derive(Debug)]
 pub enum BadType {
     CharacterDevice,
     BlockDevice,
     FIFO,
     Socket,
     Directory,
     Unknown,
 }
 
 /// Was explicitly matched but cannot be found/accessed
 #[derive(Debug)]
 pub enum BadMatch {
     OsError(i32),
     BadType(BadType),
 }
 
 /// Marker enum used to dispatch new status entries into the right collections.
 /// Is similar to `crate::EntryState`, but represents the transient state of
 /// entries during the lifetime of a command.
 enum Dispatch {
     Unsure,
     Modified,
     Added,
     Removed,
     Deleted,
     Clean,
     Unknown,
     Ignored,
     /// Empty dispatch, the file is not worth listing
     None,
     /// Was explicitly matched but cannot be found/accessed
     Bad(BadMatch),
     Directory {
         /// True if the directory used to be a file in the dmap so we can say
         /// that it's been removed.
         was_file: bool,
     },
 }
 
 type IoResult<T> = std::io::Result<T>;
 
 /// Dates and times that are outside the 31-bit signed range are compared
 /// modulo 2^31. This should prevent hg from behaving badly with very large
 /// files or corrupt dates while still having a high probability of detecting
 /// changes. (issue2608)
 /// TODO I haven't found a way of having `b` be `Into<i32>`, since `From<u64>`
 /// is not defined for `i32`, and there is no `As` trait. This forces the
 /// caller to cast `b` as `i32`.
 fn mod_compare(a: i32, b: i32) -> bool {
     a & i32::max_value() != b & i32::max_value()
 }
 
 /// Return a sorted list containing information about the entries
 /// in the directory.
 ///
 /// * `skip_dot_hg` - Return an empty vec if `path` contains a `.hg` directory
 fn list_directory(
     path: impl AsRef<Path>,
     skip_dot_hg: bool,
 ) -> std::io::Result<Vec<(HgPathBuf, DirEntry)>> {
     let mut results = vec![];
     let entries = read_dir(path.as_ref())?;
 
     for entry in entries {
         let entry = entry?;
         let filename = os_string_to_hg_path_buf(entry.file_name())?;
         let file_type = entry.file_type()?;
         if skip_dot_hg && filename.as_bytes() == b".hg" && file_type.is_dir() {
             return Ok(vec![]);
         } else {
             results.push((HgPathBuf::from(filename), entry))
         }
     }
 
     results.sort_unstable_by_key(|e| e.0.clone());
     Ok(results)
 }
 
 /// The file corresponding to the dirstate entry was found on the filesystem.
 fn dispatch_found(
     filename: impl AsRef<HgPath>,
     entry: DirstateEntry,
     metadata: HgMetadata,
     copy_map: &CopyMap,
     options: StatusOptions,
 ) -> Dispatch {
     let DirstateEntry {
         state,
         mode,
         mtime,
         size,
     } = entry;
 
     let HgMetadata {
         st_mode,
         st_size,
         st_mtime,
         ..
     } = metadata;
 
     match state {
         EntryState::Normal => {
             let size_changed = mod_compare(size, st_size as i32);
             let mode_changed =
                 (mode ^ st_mode as i32) & 0o100 != 0o000 && options.check_exec;
             let metadata_changed = size >= 0 && (size_changed || mode_changed);
             let other_parent = size == SIZE_FROM_OTHER_PARENT;
             if metadata_changed
                 || other_parent
                 || copy_map.contains_key(filename.as_ref())
             {
                 Dispatch::Modified
             } else if mod_compare(mtime, st_mtime as i32) {
                 Dispatch::Unsure
             } else if st_mtime == options.last_normal_time {
                 // the file may have just been marked as normal and
                 // it may have changed in the same second without
                 // changing its size. This can happen if we quickly
                 // do multiple commits. Force lookup, so we don't
                 // miss such a racy file change.
                 Dispatch::Unsure
             } else if options.list_clean {
                 Dispatch::Clean
             } else {
                 Dispatch::Unknown
             }
         }
         EntryState::Merged => Dispatch::Modified,
         EntryState::Added => Dispatch::Added,
         EntryState::Removed => Dispatch::Removed,
         EntryState::Unknown => Dispatch::Unknown,
     }
 }
 
 /// The file corresponding to this Dirstate entry is missing.
 fn dispatch_missing(state: EntryState) -> Dispatch {
     match state {
         // File was removed from the filesystem during commands
         EntryState::Normal | EntryState::Merged | EntryState::Added => {
             Dispatch::Deleted
         }
         // File was removed, everything is normal
         EntryState::Removed => Dispatch::Removed,
         // File is unknown to Mercurial, everything is normal
         EntryState::Unknown => Dispatch::Unknown,
     }
 }
 
 /// Get stat data about the files explicitly specified by match.
 /// TODO subrepos
 fn walk_explicit<'a>(
     files: &'a HashSet<&HgPath>,
     dmap: &'a DirstateMap,
     root_dir: impl AsRef<Path> + Sync + Send,
     options: StatusOptions,
 ) -> impl ParallelIterator<Item = IoResult<(&'a HgPath, Dispatch)>> {
     files.par_iter().filter_map(move |filename| {
         // TODO normalization
         let normalized = filename.as_ref();
 
         let buf = match hg_path_to_path_buf(normalized) {
             Ok(x) => x,
             Err(e) => return Some(Err(e.into())),
         };
         let target = root_dir.as_ref().join(buf);
         let st = target.symlink_metadata();
         match st {
             Ok(meta) => {
                 let file_type = meta.file_type();
                 if file_type.is_file() || file_type.is_symlink() {
                     if let Some(entry) = dmap.get(normalized) {
                         return Some(Ok((
                             normalized,
                             dispatch_found(
                                 &normalized,
                                 *entry,
                                 HgMetadata::from_metadata(meta),
                                 &dmap.copy_map,
                                 options,
                             ),
                         )));
                     }
                 } else {
                     if dmap.contains_key(normalized) {
                         return Some(Ok((normalized, Dispatch::Removed)));
                     }
                 }
             }
             Err(_) => {
                 if let Some(entry) = dmap.get(normalized) {
                     return Some(Ok((
                         normalized,
                         dispatch_missing(entry.state),
                     )));
                 }
             }
         };
         None
     })
 }
 
 #[derive(Debug, Copy, Clone)]
 pub struct StatusOptions {
     /// Remember the most recent modification timeslot for status, to make
     /// sure we won't miss future size-preserving file content modifications
     /// that happen within the same timeslot.
     pub last_normal_time: i64,
     /// Whether we are on a filesystem with UNIX-like exec flags
     pub check_exec: bool,
     pub list_clean: bool,
+    pub list_unknown: bool,
+    pub list_ignored: bool,
+}
+
+/// Dispatch a single file found during `traverse`.
+/// If `file` is a folder that needs to be traversed, it will be pushed into
+/// `work`.
+fn traverse_worker<'a>(
+    work: &mut VecDeque<HgPathBuf>,
+    matcher: &impl Matcher,
+    dmap: &DirstateMap,
+    filename: impl AsRef<HgPath>,
+    dir_entry: &DirEntry,
+    ignore_fn: &impl for<'r> Fn(&'r HgPath) -> bool,
+    dir_ignore_fn: &impl for<'r> Fn(&'r HgPath) -> bool,
+    options: StatusOptions,
+) -> Option<IoResult<(Cow<'a, HgPath>, Dispatch)>> {
+    let file_type = match dir_entry.file_type() {
+        Ok(x) => x,
+        Err(e) => return Some(Err(e.into())),
+    };
+    let filename = filename.as_ref();
+    let entry_option = dmap.get(filename);
+
+    if file_type.is_dir() {
+        // Do we need to traverse it?
+        if !ignore_fn(&filename) || options.list_ignored {
+            work.push_front(filename.to_owned());
+        }
+        // Nested `if` until `rust-lang/rust#53668` is stable
+        if let Some(entry) = entry_option {
+            // Used to be a file, is now a folder
+            if matcher.matches_everything() || matcher.matches(&filename) {
+                return Some(Ok((
+                    Cow::Owned(filename.to_owned()),
+                    dispatch_missing(entry.state),
+                )));
+            }
+        }
+    } else if file_type.is_file() || file_type.is_symlink() {
+        if let Some(entry) = entry_option {
+            if matcher.matches_everything() || matcher.matches(&filename) {
+                let metadata = match dir_entry.metadata() {
+                    Ok(x) => x,
+                    Err(e) => return Some(Err(e.into())),
+                };
+                return Some(Ok((
+                    Cow::Owned(filename.to_owned()),
+                    dispatch_found(
+                        &filename,
+                        *entry,
+                        HgMetadata::from_metadata(metadata),
+                        &dmap.copy_map,
+                        options,
+                    ),
+                )));
+            }
+        } else if (matcher.matches_everything() || matcher.matches(&filename))
+            && !ignore_fn(&filename)
+        {
+            if (options.list_ignored || matcher.exact_match(&filename))
+                && dir_ignore_fn(&filename)
+            {
+                if options.list_ignored {
+                    return Some(Ok((
+                        Cow::Owned(filename.to_owned()),
+                        Dispatch::Ignored,
+                    )));
+                }
+            } else {
+                return Some(Ok((
+                    Cow::Owned(filename.to_owned()),
+                    Dispatch::Unknown,
+                )));
+            }
+        }
+    } else if let Some(entry) = entry_option {
+        // Used to be a file or a folder, now something else.
+        if matcher.matches_everything() || matcher.matches(&filename) {
+            return Some(Ok((
+                Cow::Owned(filename.to_owned()),
+                dispatch_missing(entry.state),
+            )));
+        }
+    }
+    None
+}
+
+/// Walk the working directory recursively to look for changes compared to the
+/// current `DirstateMap`.
+fn traverse<'a>(
+    matcher: &(impl Matcher + Sync),
+    root_dir: impl AsRef<Path>,
+    dmap: &DirstateMap,
+    path: impl AsRef<HgPath>,
+    old_results: FastHashMap<Cow<'a, HgPath>, Dispatch>,
+    ignore_fn: &(impl for<'r> Fn(&'r HgPath) -> bool + Sync),
+    dir_ignore_fn: &(impl for<'r> Fn(&'r HgPath) -> bool + Sync),
+    options: StatusOptions,
+) -> IoResult<FastHashMap<Cow<'a, HgPath>, Dispatch>> {
+    let root_dir = root_dir.as_ref();
+    let mut new_results = FastHashMap::default();
+
+    let mut work = VecDeque::new();
+    work.push_front(path.as_ref().to_owned());
+
+    while let Some(ref directory) = work.pop_front() {
+        if directory.as_bytes() == b".hg" {
+            continue;
+        }
+        let visit_entries = match matcher.visit_children_set(directory) {
+            VisitChildrenSet::Empty => continue,
+            VisitChildrenSet::This | VisitChildrenSet::Recursive => None,
+            VisitChildrenSet::Set(set) => Some(set),
+        };
+        let buf = hg_path_to_path_buf(directory)?;
+        let dir_path = root_dir.join(buf);
+
+        let skip_dot_hg = !directory.as_bytes().is_empty();
+        let entries = match list_directory(dir_path, skip_dot_hg) {
+            Err(e) => match e.kind() {
+                ErrorKind::NotFound | ErrorKind::PermissionDenied => {
+                    new_results.insert(
+                        Cow::Owned(directory.to_owned()),
+                        Dispatch::Bad(BadMatch::OsError(
+                            // Unwrapping here is OK because the error always
+                            // is a real os error
+                            e.raw_os_error().unwrap(),
+                        )),
+                    );
+                    continue;
+                }
+                _ => return Err(e),
+            },
+            Ok(entries) => entries,
+        };
+
+        for (filename, dir_entry) in entries {
+            if let Some(ref set) = visit_entries {
+                if !set.contains(filename.deref()) {
+                    continue;
+                }
+            }
+            // TODO normalize
+            let filename = if directory.is_empty() {
+                filename.to_owned()
+            } else {
+                directory.join(&filename)
+            };
+
+            if !old_results.contains_key(filename.deref()) {
+                if let Some((res, dispatch)) = traverse_worker(
+                    &mut work,
+                    matcher,
+                    &dmap,
+                    &filename,
+                    &dir_entry,
+                    &ignore_fn,
+                    &dir_ignore_fn,
+                    options,
+                )
+                .transpose()?
+                {
+                    new_results.insert(res, dispatch);
+                }
+            }
+        }
+    }
+
+    new_results.extend(old_results.into_iter());
+
+    Ok(new_results)
 }
 
 /// Stat all entries in the `DirstateMap` and mark them for dispatch into
 /// the relevant collections.
 fn stat_dmap_entries(
     dmap: &DirstateMap,
     root_dir: impl AsRef<Path> + Sync + Send,
     options: StatusOptions,
 ) -> impl ParallelIterator<Item = IoResult<(&HgPath, Dispatch)>> {
     dmap.par_iter().map(move |(filename, entry)| {
         let filename: &HgPath = filename;
         let filename_as_path = hg_path_to_path_buf(filename)?;
         let meta = root_dir.as_ref().join(filename_as_path).symlink_metadata();
 
         match meta {
             Ok(ref m)
                 if !(m.file_type().is_file()
                     || m.file_type().is_symlink()) =>
             {
                 Ok((filename, dispatch_missing(entry.state)))
             }
             Ok(m) => Ok((
                 filename,
                 dispatch_found(
                     filename,
                     *entry,
                     HgMetadata::from_metadata(m),
                     &dmap.copy_map,
                     options,
                 ),
             )),
             Err(ref e)
                 if e.kind() == std::io::ErrorKind::NotFound
                     || e.raw_os_error() == Some(20) =>
             {
                 // Rust does not yet have an `ErrorKind` for
                 // `NotADirectory` (errno 20)
                 // It happens if the dirstate contains `foo/bar` and
                 // foo is not a directory
                 Ok((filename, dispatch_missing(entry.state)))
             }
             Err(e) => Err(e),
         }
     })
 }
 
 pub struct DirstateStatus<'a> {
     pub modified: Vec<&'a HgPath>,
     pub added: Vec<&'a HgPath>,
     pub removed: Vec<&'a HgPath>,
     pub deleted: Vec<&'a HgPath>,
     pub clean: Vec<&'a HgPath>,
     pub ignored: Vec<&'a HgPath>,
     pub unknown: Vec<&'a HgPath>,
     pub bad: Vec<(&'a HgPath, BadMatch)>,
 }
 
 fn build_response<'a>(
     results: impl IntoIterator<Item = IoResult<(&'a HgPath, Dispatch)>>,
 ) -> IoResult<(Vec<&'a HgPath>, DirstateStatus<'a>)> {
     let mut lookup = vec![];
     let mut modified = vec![];
     let mut added = vec![];
     let mut removed = vec![];
     let mut deleted = vec![];
     let mut clean = vec![];
     let mut ignored = vec![];
     let mut unknown = vec![];
     let mut bad = vec![];
 
     for res in results.into_iter() {
         let (filename, dispatch) = res?;
         match dispatch {
             Dispatch::Unknown => unknown.push(filename),
             Dispatch::Unsure => lookup.push(filename),
             Dispatch::Modified => modified.push(filename),
             Dispatch::Added => added.push(filename),
             Dispatch::Removed => removed.push(filename),
             Dispatch::Deleted => deleted.push(filename),
             Dispatch::Clean => clean.push(filename),
             Dispatch::Ignored => ignored.push(filename),
             Dispatch::None => {}
             Dispatch::Bad(reason) => bad.push((filename, reason)),
             Dispatch::Directory { .. } => {}
         }
     }
 
     Ok((
         lookup,
         DirstateStatus {
             modified,
             added,
             removed,
             deleted,
             clean,
             ignored,
             unknown,
             bad,
         },
     ))
 }
 
 pub fn status<'a: 'c, 'b: 'c, 'c>(
     dmap: &'a DirstateMap,
     matcher: &'b impl Matcher,
     root_dir: impl AsRef<Path> + Sync + Send + Copy,
     options: StatusOptions,
 ) -> IoResult<(Vec<&'c HgPath>, DirstateStatus<'c>)> {
     let files = matcher.file_set();
     let mut results = vec![];
     if let Some(files) = files {
         results.par_extend(walk_explicit(&files, &dmap, root_dir, options));
     }
 
     if !matcher.is_exact() {
         let stat_results = stat_dmap_entries(&dmap, root_dir, options);
         results.par_extend(stat_results);
     }
 
     build_response(results)
 }