Typed storage pointers

2 files changed, 21 insertions, 0 deletions

diff --git a/lib/kernel/Storage.ml b/lib/kernel/Storage.ml
index 376d839..e6a84ba 100644
--- a/lib/kernel/Storage.ml
+++ b/lib/kernel/Storage.ml
@@ -1,4 +1,16 @@
 module Make (S : Abstract.Storage.STORAGE) = struct
+  module Pointer = struct
+    type 'a t = {
+      addr : S.address;
+      loader : S.transaction -> S.address -> ('a, Concepts.Condition.condition) result
+    }
+
+    let make addr loader = { addr; loader }
+    let address_of { addr; _ } = addr
+    let swap { loader; _ } addr = make addr loader
+    let deref tx { addr; loader } = loader tx addr
+  end
+
   let finish tx = function
     | Ok value ->
        let open Utilities.Result in
diff --git a/lib/kernel/Storage.mli b/lib/kernel/Storage.mli
index 1148fba..9a10984 100644
--- a/lib/kernel/Storage.mli
+++ b/lib/kernel/Storage.mli
@@ -1,4 +1,13 @@
 module Make : functor (S : Abstract.Storage.STORAGE) -> sig
+  module Pointer : sig
+    type 'a t
+
+    val make : S.address -> (S.transaction -> S.address -> ('a, Concepts.Condition.condition) result) -> 'a t
+    val address_of : 'a t -> S.address
+    val swap : 'a t -> S.address -> 'a t
+    val deref : S.transaction -> 'a t -> ('a, Concepts.Condition.condition) result
+  end
+
   val finish : S.transaction -> ('a, Concepts.Condition.condition) result -> ('a, Concepts.Condition.condition) result
   val with_transaction : S.connection -> (S.transaction -> ('a, Concepts.Condition.condition) result) -> ('a, Concepts.Condition.condition) result
   val store_blob : S.transaction -> Concepts.Blob.t -> (Concepts.Hash.hash, Concepts.Condition.condition) result