X-Git-Url: http://git.nguyen.vg/gitweb/?a=blobdiff_plain;f=tree.ml;h=ee5e76b059d690e86c2169a08f5525f1cd408616;hb=df5fdb22632be887ecd9f5c46a014e7e970148a2;hp=b1b1d15cb084e050a85d8b11626c998d14ee2935;hpb=609094fe14ca90cd5417ee22de621f76d1d0ec94;p=SXSI%2Fxpathcomp.git

diff --git a/tree.ml b/tree.ml
index b1b1d15..ee5e76b 100644
--- a/tree.ml
+++ b/tree.ml
@@ -20,39 +20,39 @@ type tree
 type 'a node = private int
 type node_kind = [`Text | `Tree ]
 
-type t = { 
-  doc : tree;	          
+type t = {
+  doc : tree;
   ttable : (Tag.t,(Ptset.Int.t*Ptset.Int.t*Ptset.Int.t*Ptset.Int.t)) Hashtbl.t;
 }
 
-external inode : 'a node -> int = "%identity"  
-external nodei : int -> 'a node = "%identity"  
+external inode : 'a node -> int = "%identity"
+external nodei : int -> 'a node = "%identity"
 let compare_node x y = (inode x) - (inode y)
 let equal_node : 'a node -> 'a node -> bool = (==)
 
-  
-external parse_xml_uri : string -> int -> bool -> bool -> tree = "caml_call_shredder_uri"         
+
+external parse_xml_uri : string -> int -> bool -> bool -> tree = "caml_call_shredder_uri"
 external parse_xml_string :  string -> int -> bool -> bool -> tree = "caml_call_shredder_string"
 external tree_print_xml_fast3 : tree -> [`Tree ] node -> Unix.file_descr ->unit = "caml_xml_tree_print"
-external tree_save : tree -> Unix.file_descr -> unit = "caml_xml_tree_save"
-external tree_load : Unix.file_descr -> bool -> int -> tree = "caml_xml_tree_load"
-  
+external tree_save : tree -> Unix.file_descr -> string -> unit = "caml_xml_tree_save"
+external tree_load : Unix.file_descr -> string -> bool -> int -> tree = "caml_xml_tree_load"
+
 external nullt : unit -> 'a node = "caml_xml_tree_nullt"
 
 let nil : [`Tree ] node = nodei ~-1
 let nulldoc : [`Text ] node = nodei ~-1
 let root : [`Tree ] node = nodei 0
 
-external text_get_text : tree -> [`Text] node -> string = "caml_text_collection_get_text" 		
-external text_is_empty : tree -> [`Text ] node -> bool = "caml_text_collection_empty_text" 
+external text_get_text : tree -> [`Text] node -> string = "caml_text_collection_get_text"
+external text_is_empty : tree -> [`Text ] node -> bool = "caml_text_collection_empty_text"
 
 let text_is_empty t n = (equal_node nulldoc n) || text_is_empty t n
 
-external text_is_prefix : tree -> string -> bool = "caml_text_collection_is_prefix" 
-external text_is_suffix : tree -> string -> bool = "caml_text_collection_is_suffix" 
-external text_is_equal : tree -> string -> bool = "caml_text_collection_is_equal" 
-external text_is_contains : tree -> string -> bool = "caml_text_collection_is_contains" 
-external text_is_lessthan : tree -> string -> bool = "caml_text_collection_is_lessthan" 
+external text_is_prefix : tree -> string -> bool = "caml_text_collection_is_prefix"
+external text_is_suffix : tree -> string -> bool = "caml_text_collection_is_suffix"
+external text_is_equal : tree -> string -> bool = "caml_text_collection_is_equal"
+external text_is_contains : tree -> string -> bool = "caml_text_collection_is_contains"
+external text_is_lessthan : tree -> string -> bool = "caml_text_collection_is_lessthan"
 
 external text_count : tree -> string -> int = "caml_text_collection_count"
 external text_count_prefix : tree -> string -> int = "caml_text_collection_count_prefix"
@@ -67,7 +67,7 @@ external text_equals : tree -> string -> [`Text ] node array = "caml_text_collec
 external text_contains : tree -> string -> [`Text ] node array = "caml_text_collection_contains"
 external text_lessthan : tree -> string -> [`Text ] node array = "caml_text_collection_lessthan"
 
-    
+
 external tree_root : tree -> [`Tree] node = "caml_xml_tree_root"  "noalloc"
 external tree_size : tree -> int = "caml_xml_tree_size" "noalloc"
 external tree_subtree_size : tree -> [`Tree] node -> int = "caml_xml_tree_subtree_size" "noalloc"
@@ -95,7 +95,7 @@ external tree_last_child : tree -> [`Tree] node -> [`Tree] node = "caml_xml_tree
 external tree_next_sibling : tree -> [`Tree] node -> [`Tree] node = "caml_xml_tree_next_sibling"  "noalloc"
 external tree_next_element : tree -> [`Tree] node -> [`Tree] node = "caml_xml_tree_next_element"  "noalloc"
 external tree_prev_sibling : tree -> [`Tree] node -> [`Tree] node = "caml_xml_tree_prev_sibling" "noalloc"
-external tree_tagged_child : tree -> [`Tree] node -> Tag.t -> [`Tree] node = "caml_xml_tree_tagged_child" "noalloc" 
+external tree_tagged_child : tree -> [`Tree] node -> Tag.t -> [`Tree] node = "caml_xml_tree_tagged_child" "noalloc"
 
 type unordered_set
 external unordered_set_alloc : int -> unordered_set = "caml_unordered_set_alloc"
@@ -128,13 +128,23 @@ external tree_closing : tree -> [`Tree] node -> [`Tree] node = "caml_xml_tree_cl
 external tree_is_open : tree -> [`Tree] node -> bool = "caml_xml_tree_is_open" "noalloc"
 
 
-external benchmark_jump : tree -> Tag.t -> unit = "caml_benchmark_jump" "noalloc"
+external benchmark_jump : tree -> Tag.t -> int = "caml_benchmark_jump" "noalloc"
 
 let benchmark_jump t s = benchmark_jump t.doc s
 
-external benchmark_fsns : tree -> unit = "caml_benchmark_fsns" "noalloc"
+external benchmark_fcns : tree -> int = "caml_benchmark_fcns" "noalloc"
+external benchmark_fene : tree -> int = "caml_benchmark_fene" "noalloc"
+external benchmark_iter : tree -> int = "caml_benchmark_iter" "noalloc"
+
+let benchmark_fcns t = benchmark_fcns t.doc
+
+let benchmark_fene t = benchmark_fene t.doc
+
+let benchmark_iter t = benchmark_iter t.doc
 
-let benchmark_fsns t = benchmark_fsns t.doc
+external benchmark_lcps : tree -> unit = "caml_benchmark_lcps" "noalloc"
+
+let benchmark_lcps t = benchmark_lcps t.doc
 
 
 
@@ -156,7 +166,7 @@ module HPtset = Hashtbl.Make(Ptset.Int)
 let vector_htbl = HPtset.create MED_H_SIZE
 
 let ptset_to_vector s =
-  try 
+  try
     HPtset.find vector_htbl s
   with
       Not_found ->
@@ -164,33 +174,48 @@ let ptset_to_vector s =
 	let _ = Ptset.Int.iter (fun e -> unordered_set_insert v e) s in
 	  HPtset.add vector_htbl s v; v
 
-      
+
 
 let subtree_size t i = tree_subtree_size t.doc i
 let subtree_elements t i = tree_subtree_elements t.doc i
 let text_size t = text_size t.doc
 
-module MemUnion = Hashtbl.Make (struct 
+module MemUnion = Hashtbl.Make (struct
       type t = Ptset.Int.t*Ptset.Int.t
-      let equal (x,y) (z,t) = x == z || y == t
+      let equal (x,y) (z,t) = x == z && y == t
       let equal a b = equal a b || equal b a
       let hash (x,y) =   (* commutative hash *)
-	let x = Ptset.Int.uid x 
-	and y = Ptset.Int.uid y 
+	let x = Uid.to_int (Ptset.Int.uid x)
+	and y = Uid.to_int (Ptset.Int.uid y)
 	in
-	  if x <= y then HASHINT2(x,y) else HASHINT2(y,x)
+	if x <= y then HASHINT2(x,y) else HASHINT2(y,x)
     end)
 
 module MemAdd = Hashtbl.Make (
-  struct 
+  struct
     type t = Tag.t*Ptset.Int.t
     let equal (x,y) (z,t) = (x == z)&&(y == t)
-    let hash (x,y) =  HASHINT2(x,Ptset.Int.uid y)
+    let hash (x,y) =  HASHINT2(x,Uid.to_int  (Ptset.Int.uid y))
   end)
 
+module MemUpdate = struct
+include  Hashtbl.Make (
+    struct
+      type t = Tag.t*Ptset.Int.t*Ptset.Int.t*Ptset.Int.t*Ptset.Int.t
+      let equal (a1,b1,c1,d1,e1)  (a2,b2,c2,d2,e2) = a1==a2 &&
+	b1 == b2 && c1 == c2 && d1 == d2 && e1 == e2
+      let hash (a,b,c,d,e) =
+	HASHINT4(HASHINT2(a,Uid.to_int (Ptset.Int.uid b)),
+		 Uid.to_int (Ptset.Int.uid c),
+		 Uid.to_int (Ptset.Int.uid d),
+		 Uid.to_int (Ptset.Int.uid e))
+    end)
+
+end
+
 let collect_tags tree =
   let _ = Printf.eprintf "Collecting Tags\n%!" in
-(*  let h_union = MemUnion.create BIG_H_SIZE in
+  let h_union = MemUnion.create BIG_H_SIZE in
   let pt_cup s1 s2 =
       try
 	MemUnion.find h_union (s1,s2)
@@ -198,84 +223,82 @@ let collect_tags tree =
 	| Not_found -> let s = Ptset.Int.union s1 s2
 	  in
 	    MemUnion.add h_union (s1,s2) s;s
-  in    
+  in
   let h_add = MemAdd.create BIG_H_SIZE in
-  let pt_add t s =  
+  let pt_add t s =
     try MemAdd.find h_add (t,s)
     with
       | Not_found -> let r = Ptset.Int.add t s in
 	  MemAdd.add h_add (t,s) r;r
-  in *)
-  let pt_cup = Ptset.Int.union in
-  let pt_add = Ptset.Int.add in
+  in
   let h = Hashtbl.create BIG_H_SIZE in
-  let update t sc sb ss sa = 
-    let schild,sbelow,ssibling,safter =  
+  let update t sc sb ss sa =
+    let schild,sbelow,ssibling,safter =
       try
-	Hashtbl.find h t 
+	Hashtbl.find h t
       with
-	| Not_found -> 
+	| Not_found ->
 	    (Ptset.Int.empty,Ptset.Int.empty,Ptset.Int.empty,Ptset.Int.empty)
     in
-      Hashtbl.replace h t 
-	(pt_cup sc schild,pt_cup sbelow sb, pt_cup ssibling ss, pt_cup safter sa) 
+      Hashtbl.replace h t
+	(pt_cup sc schild,pt_cup sbelow sb, pt_cup ssibling ss, pt_cup safter sa)
   in
-  let rec loop right id acc_after = 
+  let rec loop right id acc_after =
     if  id == nil
     then Ptset.Int.empty,Ptset.Int.empty,acc_after else
     let sibling2,desc2,after2 = loop true (tree_next_sibling tree id) acc_after in
     let child1,desc1,after1   = loop false (tree_first_child tree id) after2  in
     let tag = tree_tag tree id in
     update tag child1 desc1 sibling2 after2;
-    ( pt_add tag sibling2, 
+    ( pt_add tag sibling2,
       pt_add tag (pt_cup desc1 desc2),
       if right then pt_cup after1 (pt_cup desc1 desc2) else acc_after )
   in
-  let _ = loop false (tree_root tree) Ptset.Int.empty in 
+  let _ = loop false (tree_root tree) Ptset.Int.empty in
   let _ = Printf.eprintf "Finished\n%!" in
     h
-			  
-			  
-    
+
+
+
 
 let contains_array = ref [| |]
-let contains_index = Hashtbl.create 4096 
+let contains_index = Hashtbl.create 4096
 let in_array _ i =
   try
     Hashtbl.find contains_index i
   with
       Not_found -> false
 
-let init_textfun f t s = 
-  let a = match f with 
-    | `CONTAINS -> text_contains t.doc s 
-    | `STARTSWITH -> text_prefix t.doc s 
-    | `ENDSWITH -> text_suffix t.doc s 
-    | `EQUALS -> text_equals t.doc s 
+let init_textfun f t s =
+  let a = match f with
+    | `CONTAINS -> text_contains t.doc s
+    | `STARTSWITH -> text_prefix t.doc s
+    | `ENDSWITH -> text_suffix t.doc s
+    | `EQUALS -> text_equals t.doc s
   in
     (*Array.fast_sort (compare) a; *)
     contains_array := a;
     Array.iter (fun x -> Hashtbl.add contains_index x true) !contains_array
-      
+
 let count_contains t s = text_count_contains t.doc s
 
 let init_naive_contains t s =
   let i,j = tree_doc_ids t.doc (tree_root t.doc)
   in
   let regexp = Str.regexp_string s in
-  let matching arg = 
+  let matching arg =
     try
       let _ = Str.search_forward regexp arg 0;
       in true
     with _ -> false
   in
-  let rec loop n acc l = 
+  let rec loop n acc l =
     if n >= j then acc,l
     else
       let s = text_get_text t.doc n
       in
-	if matching s 
-	then loop (nodei ((inode n)+1)) (n::acc) (l+1) 
+	if matching s
+	then loop (nodei ((inode n)+1)) (n::acc) (l+1)
 	else loop (nodei ((inode n)+1)) acc l
   in
   let acc,l = loop i [] 0 in
@@ -295,21 +318,21 @@ let array_find a i j =
          else loop (idx+1) x y
   in
     if a.(0) > j || a.(l-1) < i then nulldoc
-    else loop !last_idx i j 
-	  
-let text_below tree t = 
+    else loop !last_idx i j
+
+let text_below tree t =
   let l = Array.length !contains_array in
   let i,j = tree_doc_ids tree.doc t in
   let id = if l == 0 then i else (array_find !contains_array i j) in
   tree_parent_node tree.doc id
-    
+
 let text_next tree t root =
   let l = Array.length !contains_array in
-  let inf = nodei((inode(snd(tree_doc_ids tree.doc t)))+1) in    
-  let _,j = tree_doc_ids tree.doc root in      
+  let inf = nodei((inode(snd(tree_doc_ids tree.doc t)))+1) in
+  let _,j = tree_doc_ids tree.doc root in
   let id = if l == 0 then if inf > j then nulldoc else  inf
   else array_find !contains_array inf j
-  in 
+  in
   tree_parent_node tree.doc id
 
 
@@ -317,7 +340,7 @@ let text_next tree t root =
 module DocIdSet = struct
   include Set.Make (struct type t = [`Text] node
 			   let compare = compare_node end)
-    
+
 end
 let is_nil t = t == nil
 
@@ -326,7 +349,7 @@ let is_root t = t == root
 
 let node_of_t t  =
   let _ = Tag.init (Obj.magic t) in
-  let table = collect_tags t 
+  let table = collect_tags t
   in (*
   let _ = Hashtbl.iter (fun t (c,d,ns,f) ->
 			  Printf.eprintf "Tag %s has:\n" (Tag.to_string t);
@@ -340,9 +363,9 @@ let node_of_t t  =
 			  Ptset.Int.iter (fun t -> Printf.eprintf "%s "(Tag.to_string t)) f;
 			  Printf.eprintf "\n\n%!";) table
   in
-			  
-     *)			  
-    { doc= t; 
+
+     *)
+    { doc= t;
       ttable = table;
     }
 
@@ -351,16 +374,16 @@ let finalize _ = Printf.eprintf "Release the string list !\n%!"
 
 let parse f str =
   node_of_t
-    (f str 
-       !Options.sample_factor 
+    (f str
+       !Options.sample_factor
        !Options.index_empty_texts
        !Options.disable_text_collection)
-    
+
 let parse_xml_uri str = parse parse_xml_uri str
 let parse_xml_string str =  parse parse_xml_string str
 
 let size t = tree_size t.doc;;
-     
+
 external pool : tree -> Tag.pool = "%identity"
 
 let magic_string = "SXSI_INDEX"
@@ -371,7 +394,7 @@ let pos fd =
 
 let pr_pos fd = Printf.eprintf "At position %i\n%!" (pos fd)
 
-let write fd s = 
+let write fd s =
   let sl = String.length s in
   let ssl = Printf.sprintf "%020i" sl in
     ignore (Unix.write fd ssl 0 20);
@@ -390,7 +413,7 @@ let read fd =
   let buffer = String.create size in
   let _ =  really_read fd buffer 0 size in
     buffer
-    
+
 
 let save t str =
   let fd = Unix.openfile str [ Unix.O_WRONLY;Unix.O_TRUNC;Unix.O_CREAT] 0o644 in
@@ -404,22 +427,22 @@ let save t str =
     (* we need to move the fd to the correct position *)
     flush out_c;
     ignore (Unix.lseek fd (pos_out out_c) Unix.SEEK_SET);
-    tree_save t.doc fd;
+    tree_save t.doc fd str;
     close_out out_c
 ;;
 
-let load ?(sample=64) ?(load_text=true) str = 
+let load ?(sample=64) ?(load_text=true) str =
   let fd = Unix.openfile str [ Unix.O_RDONLY ] 0o644 in
   let in_c = Unix.in_channel_of_descr fd in
   let _ = set_binary_mode_in in_c true in
-  let load_table () = 
+  let load_table () =
     (let ms = input_line in_c in if ms <> magic_string then failwith "Invalid index file");
     (let vs = input_line in_c in if vs <> version_string then failwith "Invalid version file");
     let table : (Tag.t,(Ptset.Int.t*Ptset.Int.t*Ptset.Int.t*Ptset.Int.t)) Hashtbl.t =
-      Marshal.from_channel in_c 
+      Marshal.from_channel in_c
     in
     let ntable = Hashtbl.create (Hashtbl.length table) in
-      Hashtbl.iter (fun k (s1,s2,s3,s4) -> 
+      Hashtbl.iter (fun k (s1,s2,s3,s4) ->
 		      let ss1 = Ptset.Int.fold (Ptset.Int.add) s1 Ptset.Int.empty
 		      and ss2 = Ptset.Int.fold (Ptset.Int.add) s2 Ptset.Int.empty
 		      and ss3 = Ptset.Int.fold (Ptset.Int.add) s3 Ptset.Int.empty
@@ -435,32 +458,32 @@ let load ?(sample=64) ?(load_text=true) str =
   let _ = Printf.eprintf "\nLoading tag table : " in
   let ntable = time (load_table) () in
   ignore(Unix.lseek fd (pos_in in_c) Unix.SEEK_SET);
-  let tree = { doc = tree_load fd load_text sample;
+  let tree = { doc = tree_load fd str load_text sample;
 	       ttable = ntable;}
   in close_in in_c;
   tree
-  
+
 
 
 
 let tag_pool t = pool t.doc
-  
+
 let compare = compare_node
 
 let equal a b = a == b
-   
+
 let nts = function
     -1 -> "Nil"
   | i -> Printf.sprintf "Node (%i)"  i
-      
+
 let dump_node t = nts (inode t)
 
 let is_left t n = tree_is_first_child t.doc n
 
 
 
-let is_below_right t n1 n2 = 
-  tree_is_ancestor t.doc (tree_parent t.doc n1) n2 
+let is_below_right t n1 n2 =
+  tree_is_ancestor t.doc (tree_parent t.doc n1) n2
   && not (tree_is_ancestor t.doc n1 n2)
 
 let is_binary_ancestor t n1 n2 =
@@ -469,12 +492,12 @@ let is_binary_ancestor t n1 n2 =
   n2 > n1 && n2 < fin
 (*  (is_below_right t n1 n2) ||
     (tree_is_ancestor t.doc n1 n2) *)
-    
-let parent t n = tree_parent t.doc n
 
-let first_child t = (); fun n -> tree_first_child t.doc n
-let first_element t = (); fun n -> tree_first_element t.doc n
+let parent t n = tree_parent t.doc n
 
+let first_child t = let doc = t.doc in ();fun n -> tree_first_child doc n
+let first_element t = let doc = t.doc in (); fun n -> tree_first_element doc n
+let first_element t n = tree_first_element t.doc n
 (* these function will be called in two times: first partial application
    on the tag, then application of the tag and the tree, then application of
    the other arguments. We use the trick to let the compiler optimize application
@@ -486,8 +509,9 @@ let select_child t = fun ts ->
   let v = ptset_to_vector ts in ();
     fun n -> tree_select_child t.doc n v
 
-let next_sibling t = (); fun n ->  tree_next_sibling t.doc n
-let next_element t = (); fun n ->  tree_next_element t.doc n
+let next_sibling t = let doc = t.doc in (); fun n ->  tree_next_sibling doc n
+let next_element t = let doc = t.doc in (); fun n ->  tree_next_element doc n
+let next_element t n = tree_next_element t.doc n
 
 let tagged_following_sibling t tag = (); fun n -> tree_tagged_following_sibling t.doc n tag
 
@@ -496,21 +520,22 @@ let select_following_sibling t = fun ts ->
     fun n -> tree_select_following_sibling t.doc n v
 
 let next_sibling_below t = (); fun n _ -> tree_next_sibling t.doc n
-let next_element_below t = (); fun n _ ->  tree_next_element t.doc n
+let next_element_below t = (); fun n _ -> tree_next_element t.doc n
+
 let tagged_following_sibling_below t tag = (); fun n  _ -> tree_tagged_following_sibling t.doc n tag
 
-let select_following_sibling_below t = fun ts -> 
+let select_following_sibling_below t = fun ts ->
   let v = (ptset_to_vector ts) in ();
      fun n  _ -> tree_select_following_sibling t.doc n v
 
 let id t n = tree_node_xml_id t.doc n
-	
+
 let tag t n = if n == nil then Tag.nullt else tree_tag t.doc n
 
-let tagged_descendant t tag = 
-  let doc = t.doc in (); fun n -> tree_tagged_descendant doc n tag 
+let tagged_descendant t tag =
+  let doc = t.doc in (); fun n -> tree_tagged_descendant doc n tag
 
-let select_descendant t = fun ts -> 
+let select_descendant t = fun ts ->
   let v = (ptset_to_vector ts) in ();
     fun n -> tree_select_descendant t.doc n v
 
@@ -536,7 +561,7 @@ let array_find a i j =
 	  else loop (idx+1) x y
   in
     if a.(0) > j || a.(l-1) < i then nil
-    else loop !last_idx i j 
+    else loop !last_idx i j
 
 
 
@@ -544,25 +569,25 @@ let array_find a i j =
   let stack = ref []
   let init_stack () = stack := []
   let push x = stack:= x::!stack
-  let peek () = match !stack with 
+  let peek () = match !stack with
      p::_ -> p
     | _ -> failwith "peek"
   let pop () = match !stack with
      p::r -> stack:=r; p
     | _ -> failwith "pop"
 
-  let next t = nodei ( (inode t) + 1 ) 
-  let next2 t = nodei ( (inode t) + 2 ) 
-  let next3 t = nodei ( (inode t) + 3 ) 
-    
+  let next t = nodei ( (inode t) + 1 )
+  let next2 t = nodei ( (inode t) + 2 )
+  let next3 t = nodei ( (inode t) + 3 )
+
   let print_xml_fast2  =
     let _ = init_stack () in
-    let h = Hashtbl.create MED_H_SIZE in    
+    let h = Hashtbl.create MED_H_SIZE in
     let tag_str t = try Hashtbl.find h t with
        Not_found -> let s = Tag.to_string t in
        Hashtbl.add h t s;s
     in
-    let h_att = Hashtbl.create MED_H_SIZE in    
+    let h_att = Hashtbl.create MED_H_SIZE in
     let att_str t = try Hashtbl.find h_att t with
        Not_found -> let s = Tag.to_string t in
       let attname = String.sub s 3 ((String.length s) -3) in
@@ -574,20 +599,20 @@ let array_find a i j =
 	if t <= fin then
 	if tree_is_open tree t then
 	(* opening tag *)
-	if tag == Tag.pcdata then 
+	if tag == Tag.pcdata then
 	begin
 	  output_string outc (text_get_text tree (tree_my_text_unsafe tree t));
 	  loop (next2 t) (* skip closing $ *)
 	end
 	else
 	let tagstr = tag_str tag in
-	let _ = output_char outc '<';	 
+	let _ = output_char outc '<';
 	output_string outc tagstr in
 	let t' = next t in
 	if tree_is_open tree t' then
 	let _ = push tagstr in
 	let tag' = tree_tag tree t' in
-	if tag' == Tag.attribute then let t'' = loop_attr (next t') 0 in 
+	if tag' == Tag.attribute then let t'' = loop_attr (next t') 0 in
 	output_string outc ">";	loop t'' else (output_string outc ">";loop_tag t' tag')
 	else (* closing with no content *)
 	let _ = output_string outc "/>" in
@@ -601,8 +626,8 @@ let array_find a i j =
 	  loop (next t);
 	end
       and loop t = loop_tag t (tree_tag tree t)
-      and loop_attr t n = 
-	if tree_is_open tree t then 
+      and loop_attr t n =
+	if tree_is_open tree t then
 	let attname = att_str (tree_tag tree t) in
 	output_char outc ' ';
 	output_string outc attname;
@@ -616,23 +641,23 @@ let array_find a i j =
       in loop t
 
   let print_xml_fast  =
-    let h = Hashtbl.create MED_H_SIZE in    
+    let h = Hashtbl.create MED_H_SIZE in
     let tag_str t = try Hashtbl.find h t with
        Not_found -> let s = Tag.to_string t in
        Hashtbl.add h t s;s
     in
-    let h_att = Hashtbl.create MED_H_SIZE in    
+    let h_att = Hashtbl.create MED_H_SIZE in
     let att_str t = try Hashtbl.find h_att t with
        Not_found -> let s = Tag.to_string t in
       let attname = String.sub s 3 ((String.length s) -3) in
       Hashtbl.add h_att t attname;attname
     in fun outc tree t ->
-    let rec loop ?(print_right=true) t = 
-      if t != nil 
-      then 
+    let rec loop ?(print_right=true) t =
+      if t != nil
+      then
 	let tagid = tree_tag tree.doc t in
 	  if tagid==Tag.pcdata
-	  then 
+	  then
 	    begin
  	      let tid =  tree_my_text_unsafe tree.doc t in
 	      output_string outc (text_get_text tree.doc tid);
@@ -641,20 +666,20 @@ let array_find a i j =
 	    end
 	  else
 	    let tagstr = tag_str tagid in
-	    let l = first_child tree t 
-	    and r = next_sibling tree t 
+	    let l = first_child tree t
+	    and r = next_sibling tree t
 	    in
 	      output_char outc  '<';
 	      output_string outc tagstr;
 	      if l == nil then output_string outc  "/>"
-	      else 
+	      else
 		if (tag tree l) == Tag.attribute then
 		  begin
 		    loop_attributes (first_child tree l);
 		    if (next_sibling tree l) == nil then output_string outc  "/>"
-		    else  
-		      begin 
-			output_char outc  '>'; 
+		    else
+		      begin
+			output_char outc  '>';
 			loop (next_sibling tree l);
 			output_string outc  "</";
 			output_string outc  tagstr;
@@ -663,14 +688,14 @@ let array_find a i j =
 		  end
 		else
 		  begin
-		    output_char outc  '>'; 
+		    output_char outc  '>';
 		    loop l;
 		    output_string outc "</";
 		    output_string outc tagstr;
 		    output_char outc '>';
 		  end;
 	      if print_right then loop r
-    and loop_attributes a = 
+    and loop_attributes a =
       if a != nil
       then
       let attname = att_str (tag tree a) in
@@ -684,28 +709,28 @@ let array_find a i j =
 	loop_attributes (next_sibling tree a)
     in
 	loop ~print_right:false t
-	  
-	  
-    let print_xml_fast outc tree t = 
+
+
+    let print_xml_fast outc tree t =
       if (tag tree t) = Tag.document_node then
 	print_xml_fast outc tree (first_child tree t)
-      else print_xml_fast outc tree t 
-	
-let tags_children t tag = 
+      else print_xml_fast outc tree t
+
+let tags_children t tag =
   let a,_,_,_ = Hashtbl.find t.ttable tag in a
-let tags_below t tag = 
+let tags_below t tag =
   let _,a,_,_ = Hashtbl.find t.ttable tag in a
-let tags_siblings t tag = 
+let tags_siblings t tag =
   let _,_,a,_ = Hashtbl.find t.ttable tag in a
-let tags_after t tag = 
+let tags_after t tag =
   let _,_,_,a = Hashtbl.find t.ttable tag in a
 
 
 let tags t tag = Hashtbl.find t.ttable tag
 
 
-let rec binary_parent t n = 
-  let r = 
+let rec binary_parent t n =
+  let r =
   if tree_is_first_child t.doc n
   then tree_parent t.doc n
   else tree_prev_sibling t.doc n
@@ -721,20 +746,20 @@ let subtree_tags t tag = ();
 
 let get_text t n =
   let tid = tree_my_text t.doc n in
-    if tid == nulldoc then "" else 
+    if tid == nulldoc then "" else
       text_get_text t.doc tid
 
 
-let dump_tree fmt tree = 
+let dump_tree fmt tree =
   let rec loop t n =
     if t != nil then
       let tag = (tree_tag tree.doc t ) in
       let tagstr = Tag.to_string tag in
 	let tab = String.make n ' ' in
 
-	  if tag == Tag.pcdata || tag == Tag.attribute_data 
-	  then 
-	    Format.fprintf fmt "%s<%s>%s</%s>\n" 
+	  if tag == Tag.pcdata || tag == Tag.attribute_data
+	  then
+	    Format.fprintf fmt "%s<%s>%s</%s>\n"
 	      tab tagstr (text_get_text tree.doc (tree_my_text tree.doc t)) tagstr
 	  else begin
 	    Format.fprintf fmt "%s<%s>\n" tab tagstr;
@@ -746,16 +771,32 @@ let dump_tree fmt tree =
     loop root 0
 ;;
 
-	
-let print_xml_fast3 t = tree_print_xml_fast3 t.doc
 
+let print_xml_fast3 t = tree_print_xml_fast3 t.doc
 
 
 
 
+let stats t =
+  let tree = t.doc in
+  let rec loop left node acc_d total_d num_leaves =
+    if node == nil then
+    (acc_d+total_d,if left then num_leaves+1 else num_leaves)
+    else
+    let d,td = loop true (tree_first_child tree node) (acc_d+1) total_d num_leaves in
+    loop false (tree_next_sibling tree  node) (acc_d)  d td
+  in
+  let a,b = loop true root 0 0 0
+  in
+  Printf.eprintf "Average depth: %f, number of leaves %i\n%!" ((float_of_int a)/. (float_of_int b)) b
+;;
 
 
 
 
 
 
+let test_prefix t s = Array.length (text_prefix t.doc s)
+let test_suffix t s = Array.length (text_suffix t.doc s)
+let test_contains t s = Array.length (text_contains t.doc s)
+let test_equals t s = Array.length (text_equals t.doc s)