2 files changed, 25 insertions, 52 deletions

diff --git a/lib/runtime/Context.ml b/lib/runtime/Context.ml
index 10422e4..000f5d6 100644
--- a/lib/runtime/Context.ml
+++ b/lib/runtime/Context.ml
@@ -1,60 +1,30 @@
 module Error = struct
   open Concepts.Condition
 
-  let budget_exhausted ~requested ~remaining =
-    condition "budget-exhausted" "An evaluation asked for more budget than it had left"
-      ("requested" |=| Concepts.Value.Integer requested
-      & "remaining" |=| Concepts.Value.Integer remaining)
-
   let not_a_directory segment =
     condition "not-a-directory" "A path segment named an object with no Directory protocol"
       ("segment" |=| Concepts.Value.String segment)
 end
 
-type budget = int Atomic.t
-
-let charge_budget budget n =
+let resolve { Protocols.Context.root; _ } name =
   let open Utilities.Result in
-  let* _ =
-    Utilities.Atomic.mswap budget (fun remaining ->
-        if remaining >= n then Ok (remaining - n)
-        else Error (Error.budget_exhausted ~requested:n ~remaining) )
+  let rec walk handle = function
+    | [] -> Ok (Protocols.Handle.copy handle)
+    | segment :: rest ->
+       let* directory =
+         Protocols.Directory.from handle
+         |> Option.to_result ~none:(Error.not_a_directory segment)
+       in
+       let* found = Protocols.Directory.find directory segment in
+       match found with
+       | None -> Ok None
+       | Some child ->
+          Fun.protect ~finally:(fun () -> Protocols.Handle.release child)
+            (fun () -> walk child rest)
   in
-  Ok ()
-
-class context ~root ~budget ~cancelled =
-  object (self)
-    val root : Protocols.Handle.t = root
-    val budget : budget = budget
-    val cancelled : unit -> bool = cancelled
-
-    method resolve (name : string) :
-        (Protocols.Handle.t option, Concepts.Condition.condition) result =
-      let open Utilities.Result in
-      let rec walk handle = function
-        | [] -> Ok (Protocols.Handle.copy handle)
-        | segment :: rest ->
-            let* directory = Protocols.Directory.from handle
-              |> Option.to_result ~none:(Error.not_a_directory segment)
-            in
-            let* found = Protocols.Directory.find directory segment in
-            match found with
-            | None -> Ok None
-            | Some child ->
-                Fun.protect ~finally:(fun () -> Protocols.Handle.release child)
-                  (fun () -> walk child rest)
-      in
-      String.split_on_char '/' name |> List.filter (fun segment -> segment <> "") |> walk root
-
-    method cancelled = cancelled ()
-    method charge n = charge_budget budget n
-    method nest ?authority:(_ : string BatSet.t option) () =
-      (new context ~root ~budget ~cancelled :> Protocols.Context.implementation)
-
-    initializer ignore self
-  end
-
-let over ~root ?(budget = max_int) ?(cancelled = fun () -> false) () =
-  Protocols.Context.make (new context ~root ~budget:(Atomic.make budget) ~cancelled)
+  String.split_on_char '/' name |> List.filter (fun segment -> segment <> "") |> walk root
 
-let remaining (_ : Protocols.Context.t) : int option = failwith "not implemented"
+let over ~snapshot ~root ?(cancelled = fun () -> false) () =
+  { Protocols.Context.snapshot
+  ; root
+  ; status = (fun () -> if cancelled () then `Cancelled else `Live) }
diff --git a/lib/runtime/Context.mli b/lib/runtime/Context.mli
index 31ef194..6e7ab2f 100644
--- a/lib/runtime/Context.mli
+++ b/lib/runtime/Context.mli
@@ -1,8 +1,11 @@
+val resolve :
+  Protocols.Context.t ->
+  string ->
+  (Protocols.Handle.t option, Concepts.Condition.condition) result
+
 val over :
+  snapshot:Concepts.Hash.hash ->
   root:Protocols.Handle.t ->
-  ?budget:int ->
   ?cancelled:(unit -> bool) ->
   unit ->
   Protocols.Context.t
-
-val remaining : Protocols.Context.t -> int option