add session object and protocol with pinning

1 files changed, 27 insertions, 0 deletions

diff --git a/lib/kernel/Session.ml b/lib/kernel/Session.ml
new file mode 100644
index 0000000..75bf8c9
--- /dev/null
+++ b/lib/kernel/Session.ml
@@ -0,0 +1,27 @@
+module Make (S : Abstract.Storage.STORAGE) = struct
+  module SI = Storage.Make (S)
+  module B = Branch.Make (S)
+
+  class session storage state =
+    object (self)
+      inherit Lifecycle.null
+      inherit Identity.of_id
+      method to_string = "session"
+      val storage : S.connection = storage
+      val state : Protocols.Session.state Atomic.t = Atomic.make state
+      method state = Atomic.get state
+      method pin state' = Atomic.set state state'
+      method protocols = Protocols.[Directory.make self; Session.make self]
+      method list = Ok (BatFingerTree.singleton "branch")
+
+      method find =
+        function
+        | "branch" ->
+            SI.with_read storage (fun tx ->
+                B.load tx storage (Atomic.get state).Protocols.Session.snapshot )
+            |> Result.map Option.some
+        | _ -> Ok None
+    end
+
+  let make storage state = new session storage state |> Protocols.Handle.make
+end