From 8327c54db16df6a4c801f347b6c2444e1aefec67 Mon Sep 17 00:00:00 2001
From: Stefan Filip <sfilip@fb.com>
Date: Tue, 1 Dec 2020 09:57:24 -0800
Subject: [PATCH] dag: add DagImportCloneData::import_clone_data

Summary:
This method reconstructs a dag from clone data.

At the moment we only have a clone data construction method in Mononoke. It's
the Dags job to construct and import the clone_data. We'll consolidate that at
a later time.

Reviewed By: quark-zju

Differential Revision: D24954823

fbshipit-source-id: fe92179ec80f71234fc8f1cf7709f5104aabb4fb
---
 eden/scm/lib/dag/src/namedag.rs | 17 +++++++++++++++++
 eden/scm/lib/dag/src/ops.rs     |  7 +++++++
 2 files changed, 24 insertions(+)

diff --git a/eden/scm/lib/dag/src/namedag.rs b/eden/scm/lib/dag/src/namedag.rs
index 5a6197f481..895a6c4518 100644
--- a/eden/scm/lib/dag/src/namedag.rs
+++ b/eden/scm/lib/dag/src/namedag.rs
@@ -9,6 +9,7 @@
 //!
 //! Combination of IdMap and IdDag.
 
+use crate::clone::CloneData;
 use crate::delegate;
 use crate::errors::bug;
 use crate::errors::programming;
@@ -24,6 +25,7 @@ use crate::nameset::hints::Hints;
 use crate::nameset::NameSet;
 use crate::ops::DagAddHeads;
 use crate::ops::DagAlgorithm;
+use crate::ops::DagImportCloneData;
 use crate::ops::DagPersistent;
 use crate::ops::IdConvert;
 use crate::ops::IdMapSnapshot;
@@ -227,6 +229,21 @@ where
     }
 }
 
+impl<IS, M, P, S> DagImportCloneData for AbstractNameDag<IdDag<IS>, M, P, S>
+where
+    IS: IdDagStore,
+    M: IdMapAssignHead,
+{
+    fn import_clone_data(&mut self, clone_data: CloneData<VertexName>) -> Result<()> {
+        for (id, name) in clone_data.idmap {
+            self.map.insert(id, name.as_ref())?;
+        }
+        self.dag
+            .build_segments_volatile_from_prepared_flat_segments(&clone_data.flat_segments)?;
+        Ok(())
+    }
+}
+
 impl<IS, M, P, S> AbstractNameDag<IdDag<IS>, M, P, S>
 where
     IS: IdDagStore,
diff --git a/eden/scm/lib/dag/src/ops.rs b/eden/scm/lib/dag/src/ops.rs
index 6fdb92ce13..b68bbc8e4c 100644
--- a/eden/scm/lib/dag/src/ops.rs
+++ b/eden/scm/lib/dag/src/ops.rs
@@ -7,6 +7,7 @@
 
 //! DAG and Id operations (mostly traits)
 
+use crate::clone::CloneData;
 use crate::default_impl;
 use crate::id::Group;
 use crate::id::Id;
@@ -169,6 +170,12 @@ pub trait DagAddHeads {
         F: Fn(VertexName) -> Result<Vec<VertexName>>;
 }
 
+/// Import a generated `CloneData` object into the DAG.
+pub trait DagImportCloneData {
+    /// Updates the DAG using a `CloneData` object.
+    fn import_clone_data(&mut self, clone_data: CloneData<VertexName>) -> Result<()>;
+}
+
 /// Persistent the DAG on disk.
 pub trait DagPersistent {
     /// Write in-memory DAG to disk. This might also pick up changes to