dag: add CloneData

Summary: This is the object that will be used to bootstrap a Dag after a clone.

Reviewed By: quark-zju

Differential Revision: D24808328

fbshipit-source-id: 2c7e97c027c84a11e8716f2e288500474990169b

eden/scm/lib/dag/Cargo.toml

@@ -3,6 +3,10 @@ name = "dag"
 version = "0.1.0"
 edition = "2018"
 
+[features]
+default = ["for-tests"]
+for-tests = ["quickcheck"]
+
 [dependencies]
 drawdag = { path = "../drawdag" }
 indexedlog = { path = "../indexedlog" }
@@ -17,6 +21,7 @@ indexmap = "1.0.1"
 itertools = "0.8"
 once_cell = "1"
 parking_lot = "0.10"
+quickcheck = { version = "0.9", optional = true }
 serde = { version = "1", features = ["derive"] }
 tempfile = "3.0.7"
 thiserror = "1"
@@ -27,7 +32,6 @@ bindag = { path = "bindag" }
 mincode = { path = "../mincode" }
 minibench = { path = "../minibench" }
 once_cell = "1"
-quickcheck = "0.9"
 unicode-width = "0.1.7"
 
 [[bench]]

eden/scm/lib/dag/src/clone.rs

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This software may be used and distributed according to the terms of the
+ * GNU General Public License version 2.
+ */
+
+use std::collections::HashMap;
+
+use serde::{Deserialize, Serialize};
+
+use crate::segment::PreparedFlatSegments;
+use crate::Id;
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Serialize, Deserialize)]
+pub struct CloneData<Name> {
+    pub head_id: Id,
+    pub flat_segments: PreparedFlatSegments,
+    pub idmap: HashMap<Id, Name>,
+}
+
+#[cfg(any(test, feature = "for-tests"))]
+use quickcheck::Arbitrary;
+
+#[cfg(any(test, feature = "for-tests"))]
+impl<Name> Arbitrary for CloneData<Name>
+where
+    Name: Arbitrary,
+{
+    fn arbitrary<G: quickcheck::Gen>(g: &mut G) -> Self {
+        let flat_segments = PreparedFlatSegments {
+            segments: Vec::arbitrary(g),
+        };
+        CloneData {
+            head_id: Id::arbitrary(g),
+            flat_segments,
+            idmap: HashMap::arbitrary(g),
+        }
+    }
+}

eden/scm/lib/dag/src/lib.rs

@@ -13,6 +13,7 @@
 //! Building blocks for the commit graph used by source control.
 
 mod bsearch;
+pub mod clone;
 mod default_impl;
 mod delegate;
 pub mod errors;
@@ -27,10 +28,11 @@ pub mod nameset;
 pub mod ops;
 pub mod protocol;
 pub mod render;
-mod segment;
+pub mod segment;
 pub mod spanset;
 pub mod utils;
 
+pub use clone::CloneData;
 pub use id::{Group, Id, VertexName};
 pub use iddag::IdDag;
 pub use idmap::IdMap;