From 17124c74271232448ed38b066d5b00c6471fb047 Mon Sep 17 00:00:00 2001
From: Dan Davison <dandavison7@gmail.com>
Date: Wed, 24 May 2023 20:07:34 -0400
Subject: Performance tweaks

---
 src/edits.rs         | 21 +++++++++++++++++----
 src/handlers/hunk.rs |  8 ++++++--
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/src/edits.rs b/src/edits.rs
index b6e1ad9f..d571f2d2 100644
--- a/src/edits.rs
+++ b/src/edits.rs
@@ -43,15 +43,28 @@ where
     let mut annotated_plus_lines = Vec::<Vec<(EditOperation, &str)>>::new();
     let mut line_alignment = Vec::<(Option<usize>, Option<usize>)>::new();
 
+    let tokenized_minus_lines = minus_lines
+        .iter()
+        .map(|line| tokenize(line, tokenization_regex));
+
+    let tokenized_plus_lines: Vec<Vec<&str>> = plus_lines
+        .iter()
+        .map(|line| tokenize(line, tokenization_regex))
+        .collect();
+
     let mut plus_index = 0; // plus lines emitted so far
 
-    'minus_lines_loop: for (minus_index, minus_line) in minus_lines.iter().enumerate() {
+    'minus_lines_loop: for ((minus_index, minus_line), tokenized_minus_line) in
+        minus_lines.iter().enumerate().zip(tokenized_minus_lines)
+    {
         let mut considered = 0; // plus lines considered so far as match for minus_line
-        for plus_line in &plus_lines[plus_index..] {
+        for (plus_offset, plus_line) in plus_lines[plus_index..].iter().enumerate() {
+            // Compute edit operations transforming minus line into plus line
             let alignment = align::Alignment::new(
-                tokenize(minus_line, tokenization_regex),
-                tokenize(plus_line, tokenization_regex),
+                tokenized_minus_line.clone(),
+                tokenized_plus_lines[plus_index + plus_offset].clone(),
             );
+            // Use edit operations to annotate minus and plus line
             let (annotated_minus_line, annotated_plus_line, distance) = annotate(
                 alignment,
                 noop_deletions[minus_index],
diff --git a/src/handlers/hunk.rs b/src/handlers/hunk.rs
index b5c777c2..2b1d075a 100644
--- a/src/handlers/hunk.rs
+++ b/src/handlers/hunk.rs
@@ -75,8 +75,12 @@ impl<'a> StateMachine<'a> {
         {
             self.painter.paint_buffered_minus_and_plus_lines();
         }
-        if let State::HunkHeader(_, parsed_hunk_header, line, raw_line) = &self.state.clone() {
-            self.emit_hunk_header_line(parsed_hunk_header, line, raw_line)?;
+        if let State::HunkHeader(_, parsed_hunk_header, line, raw_line) = &self.state {
+            self.emit_hunk_header_line(
+                &parsed_hunk_header.clone(),
+                &line.clone(),
+                &raw_line.clone(),
+            )?;
         }
         self.state = match new_line_state(&self.line, &self.raw_line, &self.state, self.config) {
             Some(HunkMinus(diff_type, raw_line)) => {
-- 
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