Update gix-blame to imara-diff 0.2

Author: cruessler

gix-blame/Cargo.toml

@@ -15,7 +15,7 @@ gix-commitgraph = { version = "^0.30.0", path = "../gix-commitgraph" }
 gix-revwalk = { version = "^0.23.0", path = "../gix-revwalk" }
 gix-trace = { version = "^0.1.14", path = "../gix-trace" }
 gix-date = { version = "^0.11.0", path = "../gix-date" }
-gix-diff = { version = "^0.55.0", path = "../gix-diff", default-features = false, features = ["blob"] }
+gix-diff = { version = "^0.55.0", path = "../gix-diff", default-features = false, features = ["blob", "blob-experimental"] }
 gix-object = { version = "^0.52.0", path = "../gix-object" }
 gix-hash = { version = "^0.20.0", path = "../gix-hash" }
 gix-worktree = { version = "^0.44.0", path = "../gix-worktree", default-features = false, features = ["attributes"] }

gix-blame/src/file/function.rs

@@ -1,6 +1,9 @@
-use std::{num::NonZeroU32, ops::Range};
+use std::num::NonZeroU32;
 
-use gix_diff::{blob::intern::TokenSource, tree::Visit};
+use gix_diff::{
+    blob::{intern::TokenSource, v2::Hunk},
+    tree::Visit,
+};
 use gix_hash::ObjectId;
 use gix_object::{
     bstr::{BStr, BString},
@@ -758,85 +761,65 @@ fn blob_changes(
     diff_algorithm: gix_diff::blob::Algorithm,
     stats: &mut Statistics,
 ) -> Result<Vec<Change>, Error> {
-    /// Record all [`Change`]s to learn about additions, deletions and unchanged portions of a *Source File*.
-    struct ChangeRecorder {
-        last_seen_after_end: u32,
-        hunks: Vec<Change>,
-        total_number_of_lines: u32,
-    }
+    resource_cache.set_resource(
+        previous_oid,
+        gix_object::tree::EntryKind::Blob,
+        previous_file_path,
+        gix_diff::blob::ResourceKind::OldOrSource,
+        &odb,
+    )?;
+    resource_cache.set_resource(
+        oid,
+        gix_object::tree::EntryKind::Blob,
+        file_path,
+        gix_diff::blob::ResourceKind::NewOrDestination,
+        &odb,
+    )?;
 
-    impl ChangeRecorder {
-        /// `total_number_of_lines` is used to fill in the last unchanged hunk if needed
-        /// so that the entire file is represented by [`Change`].
-        fn new(total_number_of_lines: u32) -> Self {
-            ChangeRecorder {
-                last_seen_after_end: 0,
-                hunks: Vec::new(),
-                total_number_of_lines,
-            }
-        }
-    }
+    let outcome = resource_cache.prepare_diff()?;
+    let input = gix_diff::blob::v2::InternedInput::new(
+        outcome.old.data.as_slice().unwrap_or_default(),
+        outcome.new.data.as_slice().unwrap_or_default(),
+    );
+
+    let diff_algorithm: gix_diff::blob::v2::Algorithm = match diff_algorithm {
+        gix_diff::blob::Algorithm::Histogram => gix_diff::blob::v2::Algorithm::Histogram,
+        gix_diff::blob::Algorithm::Myers => gix_diff::blob::v2::Algorithm::Myers,
+        gix_diff::blob::Algorithm::MyersMinimal => gix_diff::blob::v2::Algorithm::MyersMinimal,
+    };
+    let mut diff = gix_diff::blob::v2::Diff::compute(diff_algorithm, &input);
+    diff.postprocess_lines(&input);
 
-    impl gix_diff::blob::Sink for ChangeRecorder {
-        type Out = Vec<Change>;
+    let changes = diff
+        .hunks()
+        .fold((Vec::new(), 0), |(mut hunks, mut last_seen_after_end), hunk| {
+            let Hunk { before, after } = hunk;
 
-        fn process_change(&mut self, before: Range<u32>, after: Range<u32>) {
             // This checks for unchanged hunks.
-            if after.start > self.last_seen_after_end {
-                self.hunks
-                    .push(Change::Unchanged(self.last_seen_after_end..after.start));
+            if after.start > last_seen_after_end {
+                hunks.push(Change::Unchanged(last_seen_after_end..after.start));
             }
 
             match (!before.is_empty(), !after.is_empty()) {
                 (_, true) => {
-                    self.hunks.push(Change::AddedOrReplaced(
+                    hunks.push(Change::AddedOrReplaced(
                         after.start..after.end,
                         before.end - before.start,
                     ));
                 }
                 (true, false) => {
-                    self.hunks.push(Change::Deleted(after.start, before.end - before.start));
+                    hunks.push(Change::Deleted(after.start, before.end - before.start));
                 }
                 (false, false) => unreachable!("BUG: imara-diff provided a non-change"),
             }
-            self.last_seen_after_end = after.end;
-        }
-
-        fn finish(mut self) -> Self::Out {
-            if self.total_number_of_lines > self.last_seen_after_end {
-                self.hunks
-                    .push(Change::Unchanged(self.last_seen_after_end..self.total_number_of_lines));
-            }
-            self.hunks
-        }
-    }
 
-    resource_cache.set_resource(
-        previous_oid,
-        gix_object::tree::EntryKind::Blob,
-        previous_file_path,
-        gix_diff::blob::ResourceKind::OldOrSource,
-        &odb,
-    )?;
-    resource_cache.set_resource(
-        oid,
-        gix_object::tree::EntryKind::Blob,
-        file_path,
-        gix_diff::blob::ResourceKind::NewOrDestination,
-        &odb,
-    )?;
+            last_seen_after_end = after.end;
 
-    let outcome = resource_cache.prepare_diff()?;
-    let input = gix_diff::blob::intern::InternedInput::new(
-        tokens_for_diffing(outcome.old.data.as_slice().unwrap_or_default()),
-        tokens_for_diffing(outcome.new.data.as_slice().unwrap_or_default()),
-    );
-    let number_of_lines_in_destination = input.after.len();
-    let change_recorder = ChangeRecorder::new(number_of_lines_in_destination as u32);
+            (hunks, last_seen_after_end)
+        });
 
-    let res = gix_diff::blob::diff(diff_algorithm, &input, change_recorder);
     stats.blobs_diffed += 1;
-    Ok(res)
+    Ok(changes.0)
 }
 
 fn find_path_entry_in_commit(

gix-blame/tests/blame.rs

@@ -292,11 +292,12 @@ mktest!(
     3
 );
 
-/// As of 2024-09-24, these tests are expected to fail.
+/// As of 2024-09-24, the Myers-related test was expected to fail. Both tests were initially
+/// written when diffing was done by `imara-diff` 0.1. After updating to `imara-diff` 0.2 on
+/// 2025-12-07, the Myers-related test started passing.
 ///
 /// Context: https://github.com/Byron/gitoxide/pull/1453#issuecomment-2371013904
 #[test]
-#[should_panic = "empty-lines-myers"]
 fn diff_disparity() {
     for case in ["empty-lines-myers", "empty-lines-histogram"] {
         let Fixture {