feat: gix::Repository implements all traits for object reading and writing.

That way it becomes usable when merging trees, which benefits from automatic
checking of hashes before writing loose objects.

Author: Byron

gix/src/repository/impls.rs

@@ -1,3 +1,6 @@
+use gix_object::Exists;
+use std::ops::DerefMut;
+
 impl Clone for crate::Repository {
     fn clone(&self) -> Self {
         let mut new = crate::Repository::from_refs_and_objects(
@@ -93,3 +96,55 @@ impl From<crate::Repository> for crate::ThreadSafeRepository {
         }
     }
 }
+
+impl gix_object::Write for crate::Repository {
+    fn write(&self, object: &dyn gix_object::WriteTo) -> Result<gix_hash::ObjectId, gix_object::write::Error> {
+        let mut buf = self.empty_reusable_buffer();
+        object.write_to(buf.deref_mut())?;
+        self.write_buf(object.kind(), &buf)
+    }
+
+    fn write_buf(&self, object: gix_object::Kind, from: &[u8]) -> Result<gix_hash::ObjectId, gix_object::write::Error> {
+        let oid = gix_object::compute_hash(self.object_hash(), object, from);
+        if self.objects.exists(&oid) {
+            return Ok(oid);
+        }
+        self.objects.write_buf(object, from)
+    }
+
+    fn write_stream(
+        &self,
+        kind: gix_object::Kind,
+        size: u64,
+        from: &mut dyn std::io::Read,
+    ) -> Result<gix_hash::ObjectId, gix_object::write::Error> {
+        let mut buf = self.empty_reusable_buffer();
+        let bytes = std::io::copy(from, buf.deref_mut())?;
+        if size != bytes {
+            return Err(format!("Found {bytes} bytes in stream, but had {size} bytes declared").into());
+        }
+        self.write_buf(kind, &buf)
+    }
+}
+
+impl gix_object::FindHeader for crate::Repository {
+    fn try_header(&self, id: &gix_hash::oid) -> Result<Option<gix_object::Header>, gix_object::find::Error> {
+        self.objects.try_header(id)
+    }
+}
+
+impl gix_object::Find for crate::Repository {
+    fn try_find<'a>(
+        &self,
+        id: &gix_hash::oid,
+        buffer: &'a mut Vec<u8>,
+    ) -> Result<Option<gix_object::Data<'a>>, gix_object::find::Error> {
+        self.objects.try_find(id, buffer)
+    }
+}
+
+impl gix_object::Exists for crate::Repository {
+    fn exists(&self, id: &gix_hash::oid) -> bool {
+        self.objects.exists(id)
+    }
+}