2 files changed, 57 insertions, 0 deletions
diff --git a/lib/kernel/BranchIndex.ml b/lib/kernel/BranchIndex.ml
new file mode 100644
index 0000000..d1efa9a
--- /dev/null
+++ b/lib/kernel/BranchIndex.ml
@@ -0,0 +1,29 @@
+type address = Concepts.Hash.hash
+type root = address
+type branch_name = string
+type branch_state_root = address
+
+let default_branch_name = "master"
+
+module Branch_name = struct
+  type t = branch_name
+
+  let encode name = Concepts.Codec.Bencode.(String name |> to_blob)
+  let compare left right = Concepts.Ordering.of_int (String.compare left right)
+
+  let decode blob =
+    Concepts.Codec.Bencode.of_blob blob |> Utilities.Result.fmap Concepts.Codec.Bencode.as_string
+end
+
+module Make (Store : Abstract.Storage.STORAGE) = struct
+  module Tree = Merkle.Make (Store) (Branch_name)
+
+  type tree = Tree.node
+
+  let empty = Tree.empty
+  let hash_of = Tree.hash_of
+  let persist = Tree.persist
+  let find = Tree.find
+  let find_branch = Tree.lookup
+  let put_branch = Tree.insert
+end
diff --git a/lib/kernel/BranchIndex.mli b/lib/kernel/BranchIndex.mli
new file mode 100644
index 0000000..5a867bf
--- /dev/null
+++ b/lib/kernel/BranchIndex.mli
@@ -0,0 +1,28 @@
+type address = Concepts.Hash.hash
+type root = address
+type branch_name = string
+type branch_state_root = address
+
+val default_branch_name : branch_name
+
+module Make (Store : Abstract.Storage.STORAGE) : sig
+  type tree
+
+  val empty : tree
+  val hash_of : tree -> root
+  val persist : Store.transaction -> tree -> (root, Concepts.Condition.condition) result
+  val find : Store.transaction -> root -> (tree option, Concepts.Condition.condition) result
+
+  val find_branch :
+    Store.transaction ->
+    branch_name ->
+    tree ->
+    (branch_state_root option, Concepts.Condition.condition) result
+
+  val put_branch :
+    Store.transaction ->
+    branch_name ->
+    branch_state_root ->
+    tree ->
+    (tree, Concepts.Condition.condition) result
+end