From 75d40b041bea7c82003a360f2dee956ddba893bb Mon Sep 17 00:00:00 2001
From: Armin Ronacher <armin.ronacher@active-4.com>
Date: Thu, 28 Mar 2024 21:52:56 +0100
Subject: [PATCH] Add a way to define a deadline for inline changes (#61)

---
 CHANGELOG.md       |  4 ++++
 src/text/inline.rs |  6 +++---
 src/text/mod.rs    | 20 +++++++++++++++++++-
 3 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b69881a..488a6d7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 All notable changes to similar are documented here.
 
+## 2.5.0
+
+* Added support for `TextDiff::iter_inline_changes_deadline`.  #61
+
 ## 2.4.0
 
 * Fixed a bug where the LCS diff algorithm didn't always call `D::finish`.  (#58)
diff --git a/src/text/inline.rs b/src/text/inline.rs
index 0b252ac..34cfd39 100644
--- a/src/text/inline.rs
+++ b/src/text/inline.rs
@@ -7,7 +7,7 @@ use crate::types::{Algorithm, Change, ChangeTag, DiffOp, DiffTag};
 use crate::{capture_diff_deadline, get_diff_ratio};
 
 use std::ops::Index;
-use std::time::{Duration, Instant};
+use std::time::Instant;
 
 use super::utils::upper_seq_ratio;
 
@@ -195,11 +195,11 @@ impl<'s, T: DiffableStr + ?Sized> fmt::Display for InlineChange<'s, T> {
 }
 
 const MIN_RATIO: f32 = 0.5;
-const TIMEOUT_MS: u64 = 500;
 
 pub(crate) fn iter_inline_changes<'x, 'diff, 'old, 'new, 'bufs, T>(
     diff: &'diff TextDiff<'old, 'new, 'bufs, T>,
     op: &DiffOp,
+    deadline: Option<Instant>,
 ) -> impl Iterator<Item = InlineChange<'x, T>> + 'diff
 where
     T: DiffableStr + ?Sized,
@@ -231,7 +231,7 @@ where
         0..old_lookup.len(),
         &new_lookup,
         0..new_lookup.len(),
-        Some(Instant::now() + Duration::from_millis(TIMEOUT_MS)),
+        deadline,
     );
 
     if get_diff_ratio(&ops, old_lookup.len(), new_lookup.len()) < MIN_RATIO {
diff --git a/src/text/mod.rs b/src/text/mod.rs
index 0a441d1..84e300c 100644
--- a/src/text/mod.rs
+++ b/src/text/mod.rs
@@ -531,6 +531,9 @@ impl<'old, 'new, 'bufs, T: DiffableStr + ?Sized + 'old + 'new> TextDiff<'old, 'n
     /// this function with regards to how it detects those inline changes
     /// is currently not defined and will likely change over time.
     ///
+    /// This method has a hardcoded 500ms deadline which is often not ideal.  For
+    /// fine tuning use [`iter_inline_changes_deadline`](Self::iter_inline_changes_deadline).
+    ///
     /// As of similar 1.2.0 the behavior of this function changes depending on
     /// if the `unicode` feature is enabled or not.  It will prefer unicode word
     /// splitting over word splitting depending on the feature flag.
@@ -544,7 +547,22 @@ impl<'old, 'new, 'bufs, T: DiffableStr + ?Sized + 'old + 'new> TextDiff<'old, 'n
     where
         'slf: 'old + 'new,
     {
-        inline::iter_inline_changes(self, op)
+        inline::iter_inline_changes(self, op, Some(Instant::now() + Duration::from_millis(500)))
+    }
+
+    /// Iterates over the changes the op expands to with inline emphasis with a deadline.
+    ///
+    /// Like [`iter_inline_changes`](Self::iter_inline_changes) but with an explicit deadline.
+    #[cfg(feature = "inline")]
+    pub fn iter_inline_changes_deadline<'slf>(
+        &'slf self,
+        op: &DiffOp,
+        deadline: Option<Instant>,
+    ) -> impl Iterator<Item = InlineChange<'slf, T>> + '_
+    where
+        'slf: 'old + 'new,
+    {
+        inline::iter_inline_changes(self, op, deadline)
     }
 }