Some optimizations

Cargo.toml

@@ -42,7 +42,6 @@ walkdir = "2.3.2"
 terminal_size = "0.2.1"
 const_format = "0.2.22"
 owo-colors = "3.3.0"
-rpds = "0.10.0"
 wu-diff = "0.1.2"
 rayon = "1.5.2"
 tree_magic_mini = "3.0.3"
@@ -65,6 +64,7 @@ version_check = "0.9.4"
 #
 # https://doc.rust-lang.org/cargo/reference/profiles.html#release
 debug = false
+lto = "thin"
 
 [[bin]]
 name = "difft"

src/diff/dijkstra.rs

@@ -44,8 +44,8 @@ fn shortest_vertex_path<'a, 'b>(
                     let (edge, next) = neighbour;
                     let distance_to_next = distance + edge.cost();
 
-                    let found_shorter_route = match &*next.predecessor.borrow() {
-                        Some((prev_shortest, _)) => distance_to_next < *prev_shortest,
+                    let found_shorter_route = match next.predecessor.get() {
+                        Some((prev_shortest, _)) => distance_to_next < prev_shortest,
                         None => true,
                     };
 
@@ -74,7 +74,7 @@ fn shortest_vertex_path<'a, 'b>(
     let mut vertex_route: Vec<&'b Vertex<'a, 'b>> = vec![];
     while let Some((_, node)) = current {
         vertex_route.push(node);
-        current = *node.predecessor.borrow();
+        current = node.predecessor.get();
     }
 
     vertex_route.reverse();
@@ -91,7 +91,7 @@ fn shortest_path_with_edges<'a, 'b>(
 
     for vertex in route.iter().skip(1) {
         let edge = edge_between(prev, vertex);
-        res.push((edge, prev.clone()));
+        res.push((edge, *prev));
         cost += edge.cost();
 
         prev = vertex;

src/diff/graph.rs

@@ -1,18 +1,20 @@
 //! A graph representation for computing tree diffs.
 
 use bumpalo::Bump;
-use rpds::Stack;
 use rustc_hash::FxHashMap;
 use std::{
-    cell::RefCell,
+    cell::{Cell, RefCell},
     cmp::min,
     fmt,
     hash::{Hash, Hasher},
 };
 use strsim::normalized_levenshtein;
 
 use crate::{
-    diff::changes::{insert_deep_unchanged, ChangeKind, ChangeMap},
+    diff::{
+        changes::{insert_deep_unchanged, ChangeKind, ChangeMap},
+        stack::Stack,
+    },
     parse::syntax::{AtomKind, Syntax, SyntaxId},
 };
 use Edge::*;
@@ -48,7 +50,7 @@ use Edge::*;
 #[derive(Debug, Clone)]
 pub struct Vertex<'a, 'b> {
     pub neighbours: RefCell<Option<Vec<(Edge, &'b Vertex<'a, 'b>)>>>,
-    pub predecessor: RefCell<Option<(u64, &'b Vertex<'a, 'b>)>>,
+    pub predecessor: Cell<Option<(u64, &'b Vertex<'a, 'b>)>>,
     pub lhs_syntax: Option<&'a Syntax<'a>>,
     pub rhs_syntax: Option<&'a Syntax<'a>>,
     parents: Stack<EnteredDelimiter<'a>>,
@@ -258,7 +260,7 @@ impl<'a, 'b> Vertex<'a, 'b> {
         let parents = Stack::new();
         Vertex {
             neighbours: RefCell::new(None),
-            predecessor: RefCell::new(None),
+            predecessor: Cell::new(None),
             lhs_syntax,
             rhs_syntax,
             parents,
@@ -442,7 +444,7 @@ pub fn get_set_neighbours<'syn, 'b>(
                 allocate_if_new(
                     Vertex {
                         neighbours: RefCell::new(None),
-                        predecessor: RefCell::new(None),
+                        predecessor: Cell::new(None),
                         lhs_syntax: lhs_parent.next_sibling(),
                         rhs_syntax: rhs_parent.next_sibling(),
                         can_pop_either: can_pop_either_parent(&parents_next),
@@ -467,7 +469,7 @@ pub fn get_set_neighbours<'syn, 'b>(
                 allocate_if_new(
                     Vertex {
                         neighbours: RefCell::new(None),
-                        predecessor: RefCell::new(None),
+                        predecessor: Cell::new(None),
                         lhs_syntax: lhs_parent.next_sibling(),
                         rhs_syntax: v.rhs_syntax,
                         can_pop_either: can_pop_either_parent(&parents_next),
@@ -492,7 +494,7 @@ pub fn get_set_neighbours<'syn, 'b>(
                 allocate_if_new(
                     Vertex {
                         neighbours: RefCell::new(None),
-                        predecessor: RefCell::new(None),
+                        predecessor: Cell::new(None),
                         lhs_syntax: v.lhs_syntax,
                         rhs_syntax: rhs_parent.next_sibling(),
                         can_pop_either: can_pop_either_parent(&parents_next),
@@ -519,7 +521,7 @@ pub fn get_set_neighbours<'syn, 'b>(
                 allocate_if_new(
                     Vertex {
                         neighbours: RefCell::new(None),
-                        predecessor: RefCell::new(None),
+                        predecessor: Cell::new(None),
                         lhs_syntax: lhs_syntax.next_sibling(),
                         rhs_syntax: rhs_syntax.next_sibling(),
                         parents: v.parents.clone(),
@@ -565,7 +567,7 @@ pub fn get_set_neighbours<'syn, 'b>(
                     allocate_if_new(
                         Vertex {
                             neighbours: RefCell::new(None),
-                            predecessor: RefCell::new(None),
+                            predecessor: Cell::new(None),
                             lhs_syntax: lhs_next,
                             rhs_syntax: rhs_next,
                             parents: parents_next,
@@ -603,7 +605,7 @@ pub fn get_set_neighbours<'syn, 'b>(
                     allocate_if_new(
                         Vertex {
                             neighbours: RefCell::new(None),
-                            predecessor: RefCell::new(None),
+                            predecessor: Cell::new(None),
                             lhs_syntax: lhs_syntax.next_sibling(),
                             rhs_syntax: rhs_syntax.next_sibling(),
                             parents: v.parents.clone(),
@@ -633,7 +635,7 @@ pub fn get_set_neighbours<'syn, 'b>(
                     allocate_if_new(
                         Vertex {
                             neighbours: RefCell::new(None),
-                            predecessor: RefCell::new(None),
+                            predecessor: Cell::new(None),
                             lhs_syntax: lhs_syntax.next_sibling(),
                             rhs_syntax: v.rhs_syntax,
                             parents: v.parents.clone(),
@@ -659,7 +661,7 @@ pub fn get_set_neighbours<'syn, 'b>(
                     allocate_if_new(
                         Vertex {
                             neighbours: RefCell::new(None),
-                            predecessor: RefCell::new(None),
+                            predecessor: Cell::new(None),
                             lhs_syntax: lhs_next,
                             rhs_syntax: v.rhs_syntax,
                             parents: parents_next,
@@ -687,7 +689,7 @@ pub fn get_set_neighbours<'syn, 'b>(
                     allocate_if_new(
                         Vertex {
                             neighbours: RefCell::new(None),
-                            predecessor: RefCell::new(None),
+                            predecessor: Cell::new(None),
                             lhs_syntax: v.lhs_syntax,
                             rhs_syntax: rhs_syntax.next_sibling(),
                             parents: v.parents.clone(),
@@ -713,7 +715,7 @@ pub fn get_set_neighbours<'syn, 'b>(
                     allocate_if_new(
                         Vertex {
                             neighbours: RefCell::new(None),
-                            predecessor: RefCell::new(None),
+                            predecessor: Cell::new(None),
                             lhs_syntax: v.lhs_syntax,
                             rhs_syntax: rhs_next,
                             parents: parents_next,
@@ -729,7 +731,7 @@ pub fn get_set_neighbours<'syn, 'b>(
         }
     }
     assert!(
-        res.len() > 0,
+        !res.is_empty(),
         "Must always find some next steps if node is not the end"
     );
 

src/diff/mod.rs

@@ -3,4 +3,5 @@ pub mod dijkstra;
 mod graph;
 pub mod myers_diff;
 pub mod sliders;
+mod stack;
 pub mod unchanged;

src/diff/stack.rs

@@ -0,0 +1,52 @@
+use std::rc::Rc;
+
+#[derive(Debug, Clone, Default, PartialEq, Eq)]
+struct Node<T> {
+    val: T,
+    next: Option<Rc<Node<T>>>,
+}
+
+#[derive(Debug, Clone, Default, PartialEq, Eq)]
+pub struct Stack<T> {
+    head: Option<Rc<Node<T>>>,
+}
+
+impl<T> Stack<T> {
+    pub fn new() -> Self {
+        Self { head: None }
+    }
+
+    pub fn peek(&self) -> Option<&T> {
+        self.head.as_deref().map(|n| &n.val)
+    }
+
+    pub fn pop(&self) -> Option<Stack<T>> {
+        self.head.as_deref().map(|n| Self {
+            head: n.next.clone(),
+        })
+    }
+
+    pub fn push(&self, v: T) -> Stack<T> {
+        Self {
+            head: Some(Rc::new(Node {
+                val: v,
+                next: self.head.clone(),
+            })),
+        }
+    }
+
+    // O(n)
+    pub fn size(&self) -> usize {
+        let mut res = 0;
+        let mut node = &self.head;
+        while let Some(next) = node {
+            res += 1;
+            node = &next.next;
+        }
+        res
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.head.is_none()
+    }
+}

src/display/style.rs

@@ -130,7 +130,7 @@ pub fn split_and_apply(
             let end_col = span.end_col as usize;
 
             // The remaining spans are beyond the end of this line_part.
-            if start_col >= part_start + byte_len(&line_part) {
+            if start_col >= part_start + byte_len(line_part) {
                 break;
             }
 

src/main.rs

@@ -55,7 +55,6 @@ use diff::sliders::fix_all_sliders;
 use options::{DisplayMode, DisplayOptions, FileArgument, Mode, DEFAULT_TAB_WIDTH};
 use owo_colors::OwoColorize;
 use rayon::prelude::*;
-use std::path::PathBuf;
 use std::{env, path::Path};
 use summary::{DiffResult, FileContent};
 use syntax::init_next_prev;
@@ -142,7 +141,7 @@ fn main() {
                 print!("{}", name);
 
                 let mut extensions: Vec<&str> = (*extensions).into();
-                extensions.sort();
+                extensions.sort_unstable();
 
                 for extension in extensions {
                     print!(" .{}", extension);
@@ -179,8 +178,8 @@ fn main() {
                     options::FileArgument::NamedPath(rhs_path),
                 ) if lhs_path.is_dir() && rhs_path.is_dir() => {
                     diff_directories(
-                        &lhs_path,
-                        &rhs_path,
+                        lhs_path,
+                        rhs_path,
                         &display_options,
                         graph_limit,
                         byte_limit,
@@ -403,8 +402,8 @@ fn diff_file_content(
 /// When more than one file is modified, the hg extdiff extension passes directory
 /// paths with the all the modified files.
 fn diff_directories<'a>(
-    lhs_dir: &'a PathBuf,
-    rhs_dir: &'a PathBuf,
+    lhs_dir: &'a Path,
+    rhs_dir: &'a Path,
     display_options: &DisplayOptions,
     graph_limit: usize,
     byte_limit: usize,

src/parse/guess_language.rs

@@ -120,7 +120,7 @@ pub fn language_name(language: Language) -> &'static str {
     }
 }
 
-pub const LANG_EXTENSIONS: &'static [(Language, &[&str])] = &[
+pub const LANG_EXTENSIONS: &[(Language, &[&str])] = &[
     (
         Bash,
         &[

src/parse/syntax.rs

@@ -246,7 +246,7 @@ impl<'a> Syntax<'a> {
     ) -> &'a Syntax<'a> {
         // If a parser hasn't cleaned up \r on CRLF files with
         // comments, discard it.
-        if content.ends_with("\r") {
+        if content.ends_with('\r') {
             content = &content[..content.len() - 1];
         }