From: Kim Nguyễn <kn@lri.fr>
Date: Thu, 15 May 2014 13:43:40 +0000 (+0200)
Subject: Implement a look-up table cache based on hashconsing to speed up automata evaluation.
X-Git-Url: http://git.nguyen.vg/gitweb/?p=tatoo.git;a=commitdiff_plain;h=df5ce50d29b10bfdf26aff02c83d0a7ec614228a

Implement a look-up table cache based on hashconsing to speed up automata evaluation.
---

diff --git a/src/run.ml b/src/run.ml
index a39d8b4..39df8fe 100644
--- a/src/run.ml
+++ b/src/run.ml
@@ -20,7 +20,23 @@ INCLUDE "debug.ml"
 module Make (T : Tree.S) =
 struct
 
-  let eval_form phi tree node fcs nss pars selfs =
+  let int (x : bool) : int = Obj.magic x
+  let kint (x : Tree.NodeKind.t) : int = Obj.magic x
+  let summary tree node parent fc ns =
+    (int (ns != T.nil)) lor
+      ((int (fc != T.nil)) lsl 1) lor
+      ((int (node == T.next_sibling tree parent)) lsl 2) lor
+      ((int (node == T.first_child tree parent)) lsl 3) lor
+      ((kint (T.kind tree node)) lsl 4)
+
+  let has_next_sibling summary : bool = Obj.magic (summary land 1)
+  let has_first_child summary : bool = Obj.magic ((summary lsr 1) land 1)
+  let is_next_sibling summary : bool = Obj.magic ((summary lsr 2) land 1)
+  let is_first_child summary : bool = Obj.magic ((summary lsr 3) land 1)
+  let kind summary : Tree.NodeKind.t  = Obj.magic (summary lsr 4)
+
+
+  let eval_form phi node_summary f_set n_set p_set s_set =
     let rec loop phi =
       let open Boolean in
       match Ata.Formula.expr phi with
@@ -30,21 +46,19 @@ struct
       | And (phi1, phi2) -> loop phi1 && loop phi2
       | Atom (a, b) -> b == Ata.(
         match Atom.node a with
-          Is_first_child -> let par = T.parent tree node in
-                           (T.first_child tree par) == node
-        | Is_next_sibling -> let par = T.parent tree node in
-                            (T.next_sibling tree par) == node
-        | Is k -> k == T.kind tree node
-        | Has_first_child -> T.nil != T.first_child tree node
-        | Has_next_sibling -> T.nil != T.next_sibling tree node
+          Is_first_child -> is_first_child node_summary
+        | Is_next_sibling -> is_next_sibling node_summary
+        | Is k -> k == kind node_summary
+        | Has_first_child -> has_first_child node_summary
+        | Has_next_sibling -> has_next_sibling node_summary
         | Move (m, q) ->
           let set =
             match m with
-              `First_child -> fcs
-            | `Next_sibling -> nss
+              `First_child -> f_set
+            | `Next_sibling -> n_set
             | `Parent
-            | `Previous_sibling -> pars
-            | `Stay -> selfs
+            | `Previous_sibling -> p_set
+            | `Stay -> s_set
           in
           StateSet.mem q set
       )
@@ -52,47 +66,47 @@ struct
     loop phi
 
 
-  let eval_trans_aux trans tree node fcs nss pars selfs =
+  let eval_trans_aux trans_list node_summary f_set n_set p_set s_set =
     let open Ata in
     TransList.fold (fun trs acc ->
       let q, _ , phi = Transition.node trs in
-      let res = eval_form phi tree node fcs nss pars selfs in
-      if false then begin
-      Format.eprintf "Formula %a evaluates to %b with context: (fcs=%a, nss=%a, pars=%a, olds=%a) @\n@."
-        Formula.print phi res
-        StateSet.print fcs
-        StateSet.print nss
-        StateSet.print pars
-        StateSet.print selfs
-      end;
-      if res then
+      if eval_form phi node_summary f_set n_set p_set s_set then
         StateSet.add q acc
       else
-        acc) trans selfs
+        acc) trans_list s_set
 
-  let eval_trans trans tree node fcs nss pars sstates =
-    let rec loop olds =
+  let eval_trans trans_list node_summary f_set n_set p_set s_set =
+    let rec loop old_s =
 
-      let news = eval_trans_aux trans tree node fcs nss pars olds in
-      if false then begin
-        Format.eprintf "Saturating formula: olds=%a, news=%a@\n@."
-        StateSet.print olds
-        StateSet.print news
-      end;
-      if news == olds then olds else
-        loop news
+      let new_s =
+        eval_trans_aux trans_list node_summary f_set n_set p_set old_s
+      in
+      if new_s == old_s then old_s else loop new_s
     in
-    let r = loop sstates in
-    if false then begin
-      Format.eprintf "Evaluating transitions (fcs=%a, nss=%a, pars=%a, olds=%a):@\n\t%a@."
-      StateSet.print fcs
-      StateSet.print nss
-      StateSet.print pars
-      StateSet.print sstates
-      (Ata.TransList.print ~sep:"\n\t") trans;
-    Format.eprintf "Got %a@\n@." StateSet.print r;
-    end;
-    r
+    loop s_set
+
+  let dummy_set = StateSet.singleton State.dummy
+  let count = ref 0
+  let total = ref 0
+  let () = at_exit (fun () -> Format.eprintf "Cache miss: %i/%i\n%!" !count !total)
+
+  let eval_trans auto cache set tag node_summary f_set n_set p_set s_set =
+    incr total;
+    let i = (tag.QName.id :> int) in
+    let j = node_summary in
+    let k = (f_set.StateSet.id :> int) in
+    let l = (n_set.StateSet.id :> int) in
+    let m = (p_set.StateSet.id :> int) in
+    let n = (s_set.StateSet.id :> int) in
+    let res = Cache.N6.find cache i j k l m n in
+    if res == dummy_set then begin
+      incr count;
+      let trans_list = Ata.get_trans auto tag set in
+      let res = eval_trans trans_list node_summary f_set n_set p_set s_set in
+      Cache.N6.add cache i j k l m n res;
+      res
+    end
+    else res
 
 
   let auto_run auto tree prev_nodes td_states bu_states exit_states _i =
@@ -101,7 +115,9 @@ struct
         StateSet.print td_states
         StateSet.print bu_states
         StateSet.print exit_states;
-    let rec loop res node parset =
+    let td_cache = Cache.N6.create dummy_set in
+    let bu_cache = Cache.N6.create dummy_set in
+    let rec loop res node parent parent_set =
       if node == T.nil then StateSet.empty else begin
         let set,lset,rset =
         if Sequence.is_empty prev_nodes then
@@ -116,13 +132,20 @@ struct
             StateSet.(empty,empty,empty)
         in
         let tag = T.tag tree node in
-        let td_trans = Ata.get_trans auto tag td_states in
-        let status1 = eval_trans td_trans tree node lset rset parset set in
-        let fcs = loop res (T.first_child tree node) status1 in
+        let first_child = T.first_child tree node in
+        let next_sibling = T.next_sibling tree node in
+        let node_summary = summary tree node parent first_child next_sibling in
+
+        let status1 =
+          eval_trans auto td_cache td_states tag node_summary lset rset parent_set set
+        in
+        let fcs = loop res first_child node status1 in
         let rres = Sequence.create () in
-        let nss = loop rres (T.next_sibling tree node) status1 in
-        let bu_trans = Ata.get_trans auto tag bu_states in
-        let status2 = eval_trans bu_trans tree node fcs nss parset status1 in
+        let nss = loop rres next_sibling node status1 in
+
+        let status2 =
+          eval_trans auto bu_cache bu_states tag node_summary fcs nss parent_set status1
+        in
         let mstates = StateSet.inter status2 exit_states in
         if false then begin
         Format.eprintf "On node %i (tag : %a) status0 = %a, status1 = %a, fcs = %a, nss = %a, par = %a, status2 = %a, mstates = %a@\n@."
@@ -132,7 +155,7 @@ struct
           StateSet.print status1
           StateSet.print fcs
           StateSet.print nss
-          StateSet.print parset
+          StateSet.print parent_set
           StateSet.print status2
           StateSet.print mstates;
         end;
@@ -145,7 +168,7 @@ struct
       end
     in
     let res = Sequence.create () in
-    ignore (loop res (T.root tree) StateSet.empty);
+    ignore (loop res (T.root tree) T.nil StateSet.empty);
     if false then Format.eprintf "Finished pass: %i @\n-----------------------@\n@." _i;
     res