Major optimization, rewrite to avoid deep recursion if possible.

[SXSI/xpathcomp.git] / hcons.ml

diff --git a/hcons.ml b/hcons.ml
index eb60385..7bc8823 100644 (file)
--- a/hcons.ml
+++ b/hcons.ml
@@ -1,37 +1,65 @@
 INCLUDE "utils.ml"
-module type S = 
-sig
-  type data
-  type t 
-  val make : data -> t
-  val node : t -> data
-  val hash : t -> int
-  val uid : t -> int
-  val equal : t -> t -> bool
-end
+module type SA =
+  sig
+    type data
+    type t 
+    val make : data -> t
+    val node : t -> data
+    val hash : t -> int
+    val uid : t -> Uid.t
+    val equal : t -> t -> bool
+
+    val with_id : Uid.t -> t
+ end
+
+module type S =
+  sig
+
+    type data
+    type t = private { id : Uid.t;
+                      key : int;
+                      node : data }
+    val make : data -> t
+    val node : t -> data
+    val hash : t -> int
+    val uid : t -> Uid.t
+    val equal : t -> t -> bool
+
+
+    val with_id : Uid.t -> t
+  end
+
 module Make (H : Hashtbl.HashedType) : S with type data = H.t =
 struct
+  let uid_make = Uid.make_maker()
   type data = H.t
-  type t =  { id : int;
-             key : int; 
-             node : data;
-           }
-  
+  type t = { id : Uid.t;
+            key : int;
+            node : data }
   let node t = t.node
-  let hash t = t.key
   let uid t = t.id
-  let gen_uid  =
-    let id = ref ~-1 in 
-      fun () -> incr id;!id
-  let equal = (==)
+  let hash t = t.key
+  let equal t1 t2 = t1 == t2
   module WH = Weak.Make( struct 
                           type _t = t 
                           type t = _t 
                           let hash = hash
-                          let equal a b = a==b || H.equal a.node b.node 
+                          let equal a b = a == b || H.equal a.node b.node 
                         end)
   let pool = WH.create MED_H_SIZE
   let make x = 
-    let cell = { id = gen_uid(); key = H.hash x; node = x } in
+    let cell = { id = uid_make(); key = H.hash x; node = x } in
       WH.merge pool cell
+
+  exception Found of t
+
+  let with_id id = 
+    try
+      WH.iter (fun r -> if r.id == id then raise (Found r))  pool;      
+      raise Not_found
+    with
+      | Found r -> r
+      | e -> raise e
+  ;;
+
 end