rust: Use `&HgPath` instead of `&HgPathBuf` in may APIs

Getting the former (through `Deref`) is almost the only useful thing one can
do with the latter anyway. With this changes, API become more flexible for the
"provider" of these paths which may store something else that Deref’s to HgPath,
such as `std::borrow::Cow<HgPath>`. Using `Cow` can help reduce memory alloactions
and copying.

Differential Revision: https://phab.mercurial-scm.org/D10558

rust/hg-core/src/dirstate.rs

@@ -7,7 +7,8 b''
 
 use crate::errors::HgError;
 use crate::revlog::Node;
-use crate::{utils::hg_path::HgPathBuf, FastHashMap};
+use crate::utils::hg_path::{HgPath, HgPathBuf};
+use crate::FastHashMap;
 use bytes_cast::{unaligned, BytesCast};
 use std::convert::TryFrom;
 
@@ -76,11 +77,11 b' pub const SIZE_FROM_OTHER_PARENT: i32 = '
 
 pub type StateMap = FastHashMap<HgPathBuf, DirstateEntry>;
 pub type StateMapIter<'a> =
-    Box<dyn Iterator<Item = (&'a HgPathBuf, &'a DirstateEntry)> + Send + 'a>;
+    Box<dyn Iterator<Item = (&'a HgPath, &'a DirstateEntry)> + Send + 'a>;
 
 pub type CopyMap = FastHashMap<HgPathBuf, HgPathBuf>;
 pub type CopyMapIter<'a> =
-    Box<dyn Iterator<Item = (&'a HgPathBuf, &'a HgPathBuf)> + Send + 'a>;
+    Box<dyn Iterator<Item = (&'a HgPath, &'a HgPath)> + Send + 'a>;
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 pub enum EntryState {

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

@@ -30,17 +30,22 b' impl DirsMultiset {'
     /// Initializes the multiset from a dirstate.
     ///
     /// If `skip_state` is provided, skips dirstate entries with equal state.
-    pub fn from_dirstate<'a>(
-        dirstate: impl IntoIterator<Item = (&'a HgPathBuf, &'a DirstateEntry)>,
+    pub fn from_dirstate<'a, I, P>(
+        dirstate: I,
         skip_state: Option<EntryState>,
-    ) -> Result<Self, DirstateMapError> {
+    ) -> Result<Self, DirstateMapError>
+    where
+        I: IntoIterator<Item = (P, &'a DirstateEntry)>,
+        P: AsRef<HgPath>,
+    {
         let mut multiset = DirsMultiset {
             inner: FastHashMap::default(),
         };
-        for (filename, DirstateEntry { state, .. }) in dirstate {
+        for (filename, entry) in dirstate {
+            let filename = filename.as_ref();
             // This `if` is optimized out of the loop
             if let Some(skip) = skip_state {
-                if skip != *state {
+                if skip != entry.state {
                     multiset.add_path(filename)?;
                 }
             } else {

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

@@ -260,7 +260,7 b' impl DirstateMap {'
     pub fn set_dirs(&mut self) -> Result<(), DirstateMapError> {
         if self.dirs.is_none() {
             self.dirs = Some(DirsMultiset::from_dirstate(
-                &self.state_map,
+                self.state_map.iter(),
                 Some(EntryState::Removed),
             )?);
         }

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

@@ -4,7 +4,7 b''
 // GNU General Public License version 2 or any later version.
 
 use crate::errors::HgError;
-use crate::utils::hg_path::{HgPath, HgPathBuf};
+use crate::utils::hg_path::HgPath;
 use crate::{
     dirstate::{CopyMap, EntryState, RawEntry, StateMap},
     DirstateEntry, DirstateParents,
@@ -83,8 +83,8 b" pub fn parse_dirstate_entries<'a>("
 }
 
 fn packed_filename_and_copy_source_size(
-    filename: &HgPathBuf,
-    copy_source: Option<&HgPathBuf>,
+    filename: &HgPath,
+    copy_source: Option<&HgPath>,
 ) -> usize {
     filename.len()
         + if let Some(source) = copy_source {
@@ -95,17 +95,17 b' fn packed_filename_and_copy_source_size('
 }
 
 pub fn packed_entry_size(
-    filename: &HgPathBuf,
-    copy_source: Option<&HgPathBuf>,
+    filename: &HgPath,
+    copy_source: Option<&HgPath>,
 ) -> usize {
     MIN_ENTRY_SIZE
         + packed_filename_and_copy_source_size(filename, copy_source)
 }
 
 pub fn pack_entry(
-    filename: &HgPathBuf,
+    filename: &HgPath,
     entry: &DirstateEntry,
-    copy_source: Option<&HgPathBuf>,
+    copy_source: Option<&HgPath>,
     packed: &mut Vec<u8>,
 ) {
     let length = packed_filename_and_copy_source_size(filename, copy_source);
@@ -159,7 +159,7 b' pub fn pack_dirstate('
     let expected_size: usize = state_map
         .iter()
         .map(|(filename, _)| {
-            packed_entry_size(filename, copy_map.get(filename))
+            packed_entry_size(filename, copy_map.get(filename).map(|p| &**p))
         })
         .sum();
     let expected_size = expected_size + PARENT_SIZE * 2;
@@ -171,7 +171,12 b' pub fn pack_dirstate('
 
     for (filename, entry) in state_map.iter_mut() {
         clear_ambiguous_mtime(entry, now);
-        pack_entry(filename, entry, copy_map.get(filename), &mut packed)
+        pack_entry(
+            filename,
+            entry,
+            copy_map.get(filename).map(|p| &**p),
+            &mut packed,
+        )
     }
 
     if packed.len() != expected_size {

rust/hg-core/src/dirstate_tree/dirstate_map.rs

@@ -67,7 +67,7 b' impl Node {'
 
 /// `(full_path, entry, copy_source)`
 type NodeDataMut<'a> = (
-    &'a WithBasename<HgPathBuf>,
+    &'a HgPath,
     &'a mut Option<DirstateEntry>,
     &'a mut Option<HgPathBuf>,
 );
@@ -248,8 +248,7 b" impl<'on_disk> DirstateMap<'on_disk> {"
 
     fn iter_nodes<'a>(
         &'a self,
-    ) -> impl Iterator<Item = (&'a WithBasename<HgPathBuf>, &'a Node)> + 'a
-    {
+    ) -> impl Iterator<Item = (&'a HgPath, &'a Node)> + 'a {
         // Depth first tree traversal.
         //
         // If we could afford internal iteration and recursion,
@@ -276,6 +275,7 b" impl<'on_disk> DirstateMap<'on_disk> {"
                 // Pseudo-recursion
                 let new_iter = child_node.children.iter();
                 let old_iter = std::mem::replace(&mut iter, new_iter);
+                let key = &**key.full_path();
                 stack.push((key, child_node, old_iter));
             }
             // Found the end of a `children.iter()` iterator.
@@ -307,8 +307,11 b" impl<'on_disk> DirstateMap<'on_disk> {"
         std::iter::from_fn(move || {
             while let Some((key, child_node)) = iter.next() {
                 // Pseudo-recursion
-                let data =
-                    (key, &mut child_node.entry, &mut child_node.copy_source);
+                let data = (
+                    &**key.full_path(),
+                    &mut child_node.entry,
+                    &mut child_node.copy_source,
+                );
                 let new_iter = child_node.children.iter_mut();
                 let old_iter = std::mem::replace(&mut iter, new_iter);
                 stack.push((data, old_iter));
@@ -421,14 +424,14 b" impl<'on_disk> super::dispatch::Dirstate"
 
     fn non_normal_or_other_parent_paths(
         &mut self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + '_> {
+    ) -> Box<dyn Iterator<Item = &HgPath> + '_> {
         Box::new(self.iter_nodes().filter_map(|(path, node)| {
             node.entry
                 .as_ref()
                 .filter(|entry| {
                     entry.is_non_normal() || entry.is_from_other_parent()
                 })
-                .map(|_| path.full_path())
+                .map(|_| path)
         }))
     }
 
@@ -439,29 +442,29 b" impl<'on_disk> super::dispatch::Dirstate"
 
     fn iter_non_normal_paths(
         &mut self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + Send + '_> {
+    ) -> Box<dyn Iterator<Item = &HgPath> + Send + '_> {
         self.iter_non_normal_paths_panic()
     }
 
     fn iter_non_normal_paths_panic(
         &self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + Send + '_> {
+    ) -> Box<dyn Iterator<Item = &HgPath> + Send + '_> {
         Box::new(self.iter_nodes().filter_map(|(path, node)| {
             node.entry
                 .as_ref()
                 .filter(|entry| entry.is_non_normal())
-                .map(|_| path.full_path())
+                .map(|_| path)
         }))
     }
 
     fn iter_other_parent_paths(
         &mut self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + Send + '_> {
+    ) -> Box<dyn Iterator<Item = &HgPath> + Send + '_> {
         Box::new(self.iter_nodes().filter_map(|(path, node)| {
             node.entry
                 .as_ref()
                 .filter(|entry| entry.is_from_other_parent())
-                .map(|_| path.full_path())
+                .map(|_| path)
         }))
     }
 
@@ -502,8 +505,8 b" impl<'on_disk> super::dispatch::Dirstate"
         for (path, node) in self.iter_nodes() {
             if node.entry.is_some() {
                 size += packed_entry_size(
-                    path.full_path(),
-                    node.copy_source.as_ref(),
+                    path,
+                    node.copy_source.as_ref().map(|p| &**p),
                 )
             }
         }
@@ -516,9 +519,9 b" impl<'on_disk> super::dispatch::Dirstate"
             if let Some(entry) = opt_entry {
                 clear_ambiguous_mtime(entry, now);
                 pack_entry(
-                    path.full_path(),
+                    path,
                     entry,
-                    copy_source.as_ref(),
+                    copy_source.as_ref().map(|p| &**p),
                     &mut packed,
                 );
             }
@@ -557,7 +560,7 b" impl<'on_disk> super::dispatch::Dirstate"
         Box::new(self.iter_nodes().filter_map(|(path, node)| {
             node.copy_source
                 .as_ref()
-                .map(|copy_source| (path.full_path(), copy_source))
+                .map(|copy_source| (path, &**copy_source))
         }))
     }
 
@@ -569,8 +572,8 b" impl<'on_disk> super::dispatch::Dirstate"
         }
     }
 
-    fn copy_map_get(&self, key: &HgPath) -> Option<&HgPathBuf> {
-        self.get_node(key)?.copy_source.as_ref()
+    fn copy_map_get(&self, key: &HgPath) -> Option<&HgPath> {
+        self.get_node(key)?.copy_source.as_ref().map(|p| &**p)
     }
 
     fn copy_map_remove(&mut self, key: &HgPath) -> Option<HgPathBuf> {
@@ -609,7 +612,7 b" impl<'on_disk> super::dispatch::Dirstate"
 
     fn iter(&self) -> StateMapIter<'_> {
         Box::new(self.iter_nodes().filter_map(|(path, node)| {
-            node.entry.as_ref().map(|entry| (path.full_path(), entry))
+            node.entry.as_ref().map(|entry| (path, entry))
         }))
     }
 }

rust/hg-core/src/dirstate_tree/dispatch.rs

@@ -47,21 +47,21 b' pub trait DirstateMapMethods {'
 
     fn non_normal_or_other_parent_paths(
         &mut self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + '_>;
+    ) -> Box<dyn Iterator<Item = &HgPath> + '_>;
 
     fn set_non_normal_other_parent_entries(&mut self, force: bool);
 
     fn iter_non_normal_paths(
         &mut self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + Send + '_>;
+    ) -> Box<dyn Iterator<Item = &HgPath> + Send + '_>;
 
     fn iter_non_normal_paths_panic(
         &self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + Send + '_>;
+    ) -> Box<dyn Iterator<Item = &HgPath> + Send + '_>;
 
     fn iter_other_parent_paths(
         &mut self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + Send + '_>;
+    ) -> Box<dyn Iterator<Item = &HgPath> + Send + '_>;
 
     fn has_tracked_dir(
         &mut self,
@@ -97,7 +97,7 b' pub trait DirstateMapMethods {'
 
     fn copy_map_contains_key(&self, key: &HgPath) -> bool;
 
-    fn copy_map_get(&self, key: &HgPath) -> Option<&HgPathBuf>;
+    fn copy_map_get(&self, key: &HgPath) -> Option<&HgPath>;
 
     fn copy_map_remove(&mut self, key: &HgPath) -> Option<HgPathBuf>;
 
@@ -163,10 +163,10 b' impl DirstateMapMethods for DirstateMap '
 
     fn non_normal_or_other_parent_paths(
         &mut self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + '_> {
+    ) -> Box<dyn Iterator<Item = &HgPath> + '_> {
         let (non_normal, other_parent) =
             self.get_non_normal_other_parent_entries();
-        Box::new(non_normal.union(other_parent))
+        Box::new(non_normal.union(other_parent).map(|p| &**p))
     }
 
     fn set_non_normal_other_parent_entries(&mut self, force: bool) {
@@ -175,26 +175,26 b' impl DirstateMapMethods for DirstateMap '
 
     fn iter_non_normal_paths(
         &mut self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + Send + '_> {
+    ) -> Box<dyn Iterator<Item = &HgPath> + Send + '_> {
         let (non_normal, _other_parent) =
             self.get_non_normal_other_parent_entries();
-        Box::new(non_normal.iter())
+        Box::new(non_normal.iter().map(|p| &**p))
     }
 
     fn iter_non_normal_paths_panic(
         &self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + Send + '_> {
+    ) -> Box<dyn Iterator<Item = &HgPath> + Send + '_> {
         let (non_normal, _other_parent) =
             self.get_non_normal_other_parent_entries_panic();
-        Box::new(non_normal.iter())
+        Box::new(non_normal.iter().map(|p| &**p))
     }
 
     fn iter_other_parent_paths(
         &mut self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + Send + '_> {
+    ) -> Box<dyn Iterator<Item = &HgPath> + Send + '_> {
         let (_non_normal, other_parent) =
             self.get_non_normal_other_parent_entries();
-        Box::new(other_parent.iter())
+        Box::new(other_parent.iter().map(|p| &**p))
     }
 
     fn has_tracked_dir(
@@ -243,15 +243,15 b' impl DirstateMapMethods for DirstateMap '
     }
 
     fn copy_map_iter(&self) -> CopyMapIter<'_> {
-        Box::new(self.copy_map.iter())
+        Box::new(self.copy_map.iter().map(|(key, value)| (&**key, &**value)))
     }
 
     fn copy_map_contains_key(&self, key: &HgPath) -> bool {
         self.copy_map.contains_key(key)
     }
 
-    fn copy_map_get(&self, key: &HgPath) -> Option<&HgPathBuf> {
-        self.copy_map.get(key)
+    fn copy_map_get(&self, key: &HgPath) -> Option<&HgPath> {
+        self.copy_map.get(key).map(|p| &**p)
     }
 
     fn copy_map_remove(&mut self, key: &HgPath) -> Option<HgPathBuf> {
@@ -279,6 +279,6 b' impl DirstateMapMethods for DirstateMap '
     }
 
     fn iter(&self) -> StateMapIter<'_> {
-        Box::new((&**self).iter())
+        Box::new((&**self).iter().map(|(key, value)| (&**key, value)))
     }
 }

rust/hg-cpython/src/dirstate/copymap.rs

@@ -14,7 +14,8 b' use cpython::{'
 use std::cell::RefCell;
 
 use crate::dirstate::dirstate_map::DirstateMap;
-use hg::{utils::hg_path::HgPathBuf, CopyMapIter};
+use hg::utils::hg_path::HgPath;
+use hg::CopyMapIter;
 
 py_class!(pub class CopyMap |py| {
     data dirstate_map: DirstateMap;
@@ -87,13 +88,13 b' impl CopyMap {'
     }
     fn translate_key(
         py: Python,
-        res: (&HgPathBuf, &HgPathBuf),
+        res: (&HgPath, &HgPath),
     ) -> PyResult<Option<PyBytes>> {
         Ok(Some(PyBytes::new(py, res.0.as_bytes())))
     }
     fn translate_key_value(
         py: Python,
-        res: (&HgPathBuf, &HgPathBuf),
+        res: (&HgPath, &HgPath),
     ) -> PyResult<Option<(PyBytes, PyBytes)>> {
         let (k, v) = res;
         Ok(Some((

rust/hg-cpython/src/dirstate/dirstate_map.rs

@@ -514,13 +514,13 b' impl DirstateMap {'
     }
     fn translate_key(
         py: Python,
-        res: (&HgPathBuf, &DirstateEntry),
+        res: (&HgPath, &DirstateEntry),
     ) -> PyResult<Option<PyBytes>> {
         Ok(Some(PyBytes::new(py, res.0.as_bytes())))
     }
     fn translate_key_value(
         py: Python,
-        res: (&HgPathBuf, &DirstateEntry),
+        res: (&HgPath, &DirstateEntry),
     ) -> PyResult<Option<(PyBytes, PyObject)>> {
         let (f, entry) = res;
         Ok(Some((

rust/hg-cpython/src/dirstate/dispatch.rs

@@ -61,7 +61,7 b' impl DirstateMapMethods for OwningDirsta'
 
     fn non_normal_or_other_parent_paths(
         &mut self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + '_> {
+    ) -> Box<dyn Iterator<Item = &HgPath> + '_> {
         self.get_mut().non_normal_or_other_parent_paths()
     }
 
@@ -71,19 +71,19 b' impl DirstateMapMethods for OwningDirsta'
 
     fn iter_non_normal_paths(
         &mut self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + Send + '_> {
+    ) -> Box<dyn Iterator<Item = &HgPath> + Send + '_> {
         self.get_mut().iter_non_normal_paths()
     }
 
     fn iter_non_normal_paths_panic(
         &self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + Send + '_> {
+    ) -> Box<dyn Iterator<Item = &HgPath> + Send + '_> {
         self.get().iter_non_normal_paths_panic()
     }
 
     fn iter_other_parent_paths(
         &mut self,
-    ) -> Box<dyn Iterator<Item = &HgPathBuf> + Send + '_> {
+    ) -> Box<dyn Iterator<Item = &HgPath> + Send + '_> {
         self.get_mut().iter_other_parent_paths()
     }
 
@@ -141,7 +141,7 b' impl DirstateMapMethods for OwningDirsta'
         self.get().copy_map_contains_key(key)
     }
 
-    fn copy_map_get(&self, key: &HgPath) -> Option<&HgPathBuf> {
+    fn copy_map_get(&self, key: &HgPath) -> Option<&HgPath> {
         self.get().copy_map_get(key)
     }
 

rust/hg-cpython/src/dirstate/non_normal_entries.rs

@@ -12,7 +12,7 b' use cpython::{'
 };
 
 use crate::dirstate::DirstateMap;
-use hg::utils::hg_path::HgPathBuf;
+use hg::utils::hg_path::HgPath;
 use std::cell::RefCell;
 
 py_class!(pub class NonNormalEntries |py| {
@@ -54,16 +54,13 b' impl NonNormalEntries {'
         Ok(true)
     }
 
-    fn translate_key(
-        py: Python,
-        key: &HgPathBuf,
-    ) -> PyResult<Option<PyBytes>> {
+    fn translate_key(py: Python, key: &HgPath) -> PyResult<Option<PyBytes>> {
         Ok(Some(PyBytes::new(py, key.as_bytes())))
     }
 }
 
 type NonNormalEntriesIter<'a> =
-    Box<dyn Iterator<Item = &'a HgPathBuf> + Send + 'a>;
+    Box<dyn Iterator<Item = &'a HgPath> + Send + 'a>;
 
 py_shared_iterator!(
     NonNormalEntriesIterator,