feat: Add commit::Either::commit_time()

Author: cruessler

gix-traverse/src/commit/mod.rs

@@ -77,14 +77,23 @@ pub enum Either<'buf, 'cache> {
 }
 
 impl Either<'_, '_> {
-    /// Get a commits `tree_id` by either getting it from a [`gix_commitgraph::Graph`], if
+    /// Get a commit’s `tree_id` by either getting it from a [`gix_commitgraph::Graph`], if
     /// present, or a [`gix_object::CommitRefIter`] otherwise.
     pub fn tree_id(self) -> Result<ObjectId, gix_object::decode::Error> {
         match self {
             Self::CommitRefIter(mut commit_ref_iter) => commit_ref_iter.tree_id(),
             Self::CachedCommit(commit) => Ok(commit.root_tree_id().into()),
         }
     }
+
+    /// Get a commit’s `commit_time` by either getting it from a [`gix_commitgraph::Graph`], if
+    /// present, or a [`gix_object::CommitRefIter`] otherwise.
+    pub fn commit_time(self) -> Result<gix_date::SecondsSinceUnixEpoch, gix_object::decode::Error> {
+        match self {
+            Self::CommitRefIter(commit_ref_iter) => commit_ref_iter.committer().map(|c| c.seconds()),
+            Self::CachedCommit(commit) => Ok(commit.committer_timestamp() as gix_date::SecondsSinceUnixEpoch),
+        }
+    }
 }
 
 /// Find information about a commit by either getting it from a [`gix_commitgraph::Graph`], if