Trying to fix mirage#280

Author: mattiasdrp

bench/bench.ml

@@ -49,7 +49,7 @@ module Context = struct
 
     let hash_size = 30
 
-    let encode s = s
+    let encode s f = f s
 
     let decode s off = String.sub s off key_size
 
@@ -63,7 +63,7 @@ module Context = struct
 
     let v () = random_string value_size
 
-    let encode s = s
+    let encode s f = f s
 
     let decode s off = String.sub s off value_size
 

src/data.ml

@@ -21,7 +21,7 @@ module type Key = sig
       Overestimating the [hash_size] will result in performance drops;
       underestimation will result in undefined behavior. *)
 
-  val encode : t -> string
+  val encode : t -> (string -> unit) -> unit
   (** [encode] is an encoding function. The resultant encoded values must have
       size {!encoded_size}. *)
 
@@ -37,7 +37,7 @@ end
 module type Value = sig
   type t [@@deriving repr]
 
-  val encode : t -> string
+  val encode : t -> (string -> unit) -> unit
 
   val encoded_size : int
 
@@ -88,14 +88,12 @@ module Entry = struct
     let decode_value string off = V.decode string (off + K.encoded_size)
 
     let encode' key value f =
-      let encoded_key = K.encode key in
-      let encoded_value = V.encode value in
-      if String.length encoded_key <> K.encoded_size then
-        raise (Invalid_size encoded_key);
-      if String.length encoded_value <> V.encoded_size then
-        raise (Invalid_size encoded_value);
-      f encoded_key;
-      f encoded_value
+      K.encode key (fun s ->
+          if String.length s <> K.encoded_size then raise (Invalid_size s));
+      V.encode value (fun s ->
+          if String.length s <> K.encoded_size then raise (Invalid_size s));
+      K.encode key f;
+      V.encode value f
 
     let encode { key; value; _ } f = encode' key value f
   end
@@ -116,7 +114,7 @@ end = struct
 
   let hash_size = 30
 
-  let encode s = s
+  let encode s f = f s
 
   let decode s off = String.sub s off L.length
 

test/unix/io_array.ml

@@ -21,8 +21,8 @@ module Entry = struct
   let append_io io (key, value) =
     let encoded_key = Key.encode key in
     let encoded_value = Value.encode value in
-    IO.append io encoded_key;
-    IO.append io encoded_value
+    encoded_key (IO.append io);
+    encoded_value (IO.append io)
 end
 
 module IOArray = Index.Private.Io_array.Make (IO) (Entry)