When using the cache, allow using the entire graph.

That way, multiple calls to merge-base can be more optimal.

Note that this is a breaking change, but there wasn't a release yet
so there is no need to mark it.

Author: Byron

gitoxide-core/src/repository/merge_base.rs

@@ -20,7 +20,8 @@ pub fn merge_base(
         .collect::<Result<_, _>>()?;
 
     let cache = repo.commit_graph_if_enabled()?;
-    let bases = repo.merge_bases_many_with_cache(first_id, &other_ids, cache.as_ref())?;
+    let mut graph = repo.revision_graph(cache.as_ref());
+    let bases = repo.merge_bases_many_with_graph(first_id, &other_ids, &mut graph)?;
     if bases.is_empty() {
         bail!("No base found for {first} and {others}", others = others.join(", "))
     }

gix/src/repository/mod.rs

@@ -93,8 +93,8 @@ pub mod merge_base {
 
 ///
 #[cfg(feature = "revision")]
-pub mod merge_base_with_cache {
-    /// The error returned by [Repository::merge_base_with_cache()](crate::Repository::merge_base_with_cache()).
+pub mod merge_base_with_graph {
+    /// The error returned by [Repository::merge_base_with_cache()](crate::Repository::merge_base_with_graph()).
     #[derive(Debug, thiserror::Error)]
     #[allow(missing_docs)]
     pub enum Error {

gix/src/repository/revision.rs

@@ -39,7 +39,7 @@ impl crate::Repository {
     /// Obtain the best merge-base between commit `one` and `two`, or fail if there is none.
     ///
     /// # Performance
-    /// For repeated calls, prefer [`merge_base_with_cache()`](crate::Repository::merge_base_with_cache()).
+    /// For repeated calls, prefer [`merge_base_with_cache()`](crate::Repository::merge_base_with_graph()).
     /// Also be sure to [set an object cache](crate::Repository::object_cache_size_if_unset) to accelerate repeated commit lookups.
     #[cfg(feature = "revision")]
     pub fn merge_base(
@@ -60,47 +60,44 @@ impl crate::Repository {
     }
 
     /// Obtain the best merge-base between commit `one` and `two`, or fail if there is none, providing a
-    /// commit-graph `cache` to potentially greatly accelerate the operation.
+    /// commit-graph `graph` to potentially greatly accelerate the operation by reusing graphs from previous runs.
     ///
     /// # Performance
     /// Be sure to [set an object cache](crate::Repository::object_cache_size_if_unset) to accelerate repeated commit lookups.
     #[cfg(feature = "revision")]
-    pub fn merge_base_with_cache(
+    pub fn merge_base_with_graph(
         &self,
         one: impl Into<gix_hash::ObjectId>,
         two: impl Into<gix_hash::ObjectId>,
-        cache: Option<&gix_commitgraph::Graph>,
-    ) -> Result<Id<'_>, super::merge_base_with_cache::Error> {
+        graph: &mut gix_revwalk::Graph<'_, '_, gix_revwalk::graph::Commit<gix_revision::merge_base::Flags>>,
+    ) -> Result<Id<'_>, super::merge_base_with_graph::Error> {
         use crate::prelude::ObjectIdExt;
         let one = one.into();
         let two = two.into();
-        let mut graph = self.revision_graph(cache);
-        let bases = gix_revision::merge_base(one, &[two], &mut graph)?.ok_or(
-            super::merge_base_with_cache::Error::NotFound {
+        let bases =
+            gix_revision::merge_base(one, &[two], graph)?.ok_or(super::merge_base_with_graph::Error::NotFound {
                 first: one,
                 second: two,
-            },
-        )?;
+            })?;
         Ok(bases[0].attach(self))
     }
 
     /// Obtain all merge-bases between commit `one` and `others`, or an empty list if there is none, providing a
-    /// commit-graph `cache` to potentially greatly accelerate the operation.
+    /// commit-graph `graph` to potentially greatly accelerate the operation.
     ///
     /// # Performance
     /// Be sure to [set an object cache](crate::Repository::object_cache_size_if_unset) to accelerate repeated commit lookups.
     #[doc(alias = "merge_bases_many", alias = "git2")]
     #[cfg(feature = "revision")]
-    pub fn merge_bases_many_with_cache(
+    pub fn merge_bases_many_with_graph(
         &self,
         one: impl Into<gix_hash::ObjectId>,
         others: &[gix_hash::ObjectId],
-        cache: Option<&gix_commitgraph::Graph>,
+        graph: &mut gix_revwalk::Graph<'_, '_, gix_revwalk::graph::Commit<gix_revision::merge_base::Flags>>,
     ) -> Result<Vec<Id<'_>>, gix_revision::merge_base::Error> {
         use crate::prelude::ObjectIdExt;
         let one = one.into();
-        let mut graph = self.revision_graph(cache);
-        Ok(gix_revision::merge_base(one, others, &mut graph)?
+        Ok(gix_revision::merge_base(one, others, graph)?
             .unwrap_or_default()
             .into_iter()
             .map(|id| id.attach(self))