improve performance of commit-graph variant ever-so-slightly

Author: Byron

gix-revision/src/merge_base.rs

@@ -44,15 +44,24 @@ pub(crate) mod function {
         others: &[ObjectId],
         graph: &mut Graph<'_, '_, Flags>,
     ) -> Result<Option<Vec<ObjectId>>, Error> {
-        let _span = gix_trace::coarse!("gix_revision::merge_base()", ?first, ?others,);
+        let _span = gix_trace::coarse!(
+            "gix_revision::merge_base()",
+            ?first,
+            ?others,
+            paint_graph_size = gix_trace::field::Empty,
+            cleanup_graph_size = gix_trace::field::Empty,
+        );
         if others.is_empty() || others.contains(&first) {
             return Ok(Some(vec![first]));
         }
 
+        graph.clear();
         let bases = paint_down_to_common(first, others, graph)?;
+        _span.record("paint_graph_size", gix_trace::field::display(graph.len()));
         graph.clear();
 
         let bases = remove_redundant(&bases, graph)?;
+        _span.record("cleanup_graph_size", gix_trace::field::display(graph.len()));
         Ok((!bases.is_empty()).then_some(bases))
     }
 
@@ -62,6 +71,7 @@ pub(crate) mod function {
         commits: &[(ObjectId, GenThenTime)],
         graph: &mut Graph<'_, '_, Flags>,
     ) -> Result<Vec<ObjectId>, Error> {
+        let _span = gix_trace::detail!("gix_revision::remove_redundant()", num_commits = %commits.len());
         if commits.is_empty() {
             return Ok(Vec::new());
         }
@@ -217,11 +227,10 @@ pub(crate) mod function {
         type Error = gix_object::decode::Error;
 
         fn try_from(commit: LazyCommit<'_, '_>) -> Result<Self, Self::Error> {
+            let (generation, timestamp) = commit.generation_and_timestamp()?;
             Ok(GenThenTime {
-                generation: commit
-                    .generation()
-                    .unwrap_or(gix_commitgraph::GENERATION_NUMBER_INFINITY),
-                time: commit.committer_timestamp()?,
+                generation: generation.unwrap_or(gix_commitgraph::GENERATION_NUMBER_INFINITY),
+                time: timestamp,
             })
         }
     }