X-Git-Url: http://git.nguyen.vg/gitweb/?a=blobdiff_plain;f=src%2Ftree.ml;h=b7b856641c9075a97e19c5f82bbbc79b31d08c85;hb=7e27afe6fa006ad355237ccc0695c6493ea57929;hp=587e649261b305a0d3d5a7c9aae954eb703a9713;hpb=3878364d77115ce1ed2839cc631a9f73001bc438;p=SXSI%2Fxpathcomp.git

diff --git a/src/tree.ml b/src/tree.ml
index 587e649..b7b8566 100644
--- a/src/tree.ml
+++ b/src/tree.ml
@@ -5,9 +5,9 @@
 (*  Distributed under the terms of the LGPL (see LICENCE)                     *)
 (******************************************************************************)
 INCLUDE "debug.ml"
+INCLUDE "log.ml"
 INCLUDE "utils.ml"
 
-
 external init_lib : unit -> unit = "sxsi_cpp_init"
 
 exception CPlusPlusError of string
@@ -20,7 +20,6 @@ type node = [ `Tree ] Node.t
 
 type tree
 
-
 external register_tag : tree -> string -> Tag.t = "caml_xml_tree_register_tag"
 
 external tag_name : tree -> Tag.t -> string = "caml_xml_tree_get_tag_name"
@@ -53,18 +52,41 @@ module TreeBuilder =
 struct
   type t
   external create : unit -> t = "caml_xml_tree_builder_create"
-  external open_document : t -> bool -> int -> bool -> int -> unit = "caml_xml_tree_builder_open_document"
+  external open_document : t -> int -> bool -> int -> unit = "caml_xml_tree_builder_open_document"
   external close_document : t -> tree = "caml_xml_tree_builder_close_document"
-  external open_tag : t -> string -> unit = "caml_xml_tree_builder_new_open_tag"
-  external close_tag : t -> string -> unit = "caml_xml_tree_builder_new_closing_tag"
-  external text : t -> string -> unit = "caml_xml_tree_builder_new_text"
+  external open_tag : t -> string -> unit = "caml_xml_tree_builder_open_tag"
+  external close_tag : t -> string -> unit = "caml_xml_tree_builder_close_tag"
+  external text : t -> string -> unit = "caml_xml_tree_builder_text"
+  external trim : string -> string = "caml_trim"
+
+  let is_whitespace s =
+    let rec loop len i =
+      if i < len then
+	let c = s.[i] in
+	(c == '\n' || c == '\t' || c == ' ') && loop len (i+1)
+      else
+	true
+    in
+    loop (String.length s) 0
+
+
+  let display_count =
+    let event_counter = ref 0 in
+    (fun parser_ ->
+      incr event_counter;
+      if !event_counter land 0xffffff == 0 then
+        Logger.print Format.err_formatter "Current position: %i@\n@?" (Expat.get_current_byte_index parser_))
 
 
   let do_text b t =
     if Buffer.length t > 0 then begin
-      open_tag b "<$>";
-      text b (Buffer.contents t);
-      close_tag b "<$>";
+      let s = Buffer.contents t in
+      if (!Config.index_empty_texts) || not (is_whitespace s) then
+	begin
+	  open_tag b "<$>";
+	  text b s;
+	  close_tag b "<$>";
+	end;
       Buffer.clear t
     end
 
@@ -72,26 +94,26 @@ struct
     let atname = "<@>" ^ name in
     open_tag b atname;
     open_tag b "<@$>";
-      text b value;
-      close_tag b "<@$>";
-      close_tag b atname
+    text b value;
+    close_tag b "<@$>";
+    close_tag b atname
 
-  let start_element_handler b t tag attr_list =
+  let start_element_handler parser_ b t tag attr_list =
     do_text b t;
     open_tag b tag;
     match attr_list with
-	[] -> ()
-      | l ->
-	open_tag b "<@>";
-	List.iter (fun (name, value) -> output_attr b name value) l;
-	  close_tag b "<@>"
+      [] -> ()
+    | l ->
+      open_tag b "<@>";
+      List.iter (fun (name, value) -> output_attr b name value) l;
+      close_tag b "<@>"
 
 
-  let end_element_handler b t tag =
+  let end_element_handler parser_ b t tag =
     do_text b t;
     close_tag b tag
 
-  let character_data_handler _b t text =
+  let character_data_handler parser_ _ t text =
     Buffer.add_string t text
 
   let create_parser () =
@@ -101,13 +123,18 @@ struct
     let finalize () =
       do_text build buf;
       close_tag build "";
-      close_document build
+      LOG ( __ "parsing" 2 "%s\n" "Finished parsing");
+      LOG ( __ "indexing" 2 "%s\n" "Starting index construction");
+      let r = close_document build
+      in
+      LOG ( __ "indexing" 2 "%s\n" "Finished index construction");
+      r
     in
-    Expat.set_start_element_handler parser_ (start_element_handler build buf);
-    Expat.set_end_element_handler parser_ (end_element_handler build buf);
-    Expat.set_character_data_handler parser_ (character_data_handler build buf);
-    open_document build !Options.index_empty_texts !Options.sample_factor
-      !Options.disable_text_collection !Options.text_index_type;
+    Expat.set_start_element_handler parser_ (start_element_handler parser_ build buf);
+    Expat.set_end_element_handler parser_ (end_element_handler parser_ build buf);
+    Expat.set_character_data_handler parser_ (character_data_handler parser_ build buf);
+    LOG ( __ "parsing" 2 "%s\n" "Started parsing");
+    open_document build !Config.sample_factor !Config.disable_text_collection !Config.text_index_type;
     open_tag build "";
     parser_, finalize
 
@@ -120,21 +147,20 @@ struct
     let in_chan = open_in file in
     let buffer = String.create 4096 in
     let parser_, finalizer = create_parser () in
-    let () =
+    let parse () =
       try
 	while true do
 	  let read = input in_chan buffer 0 4096 in
 	  if read == 0 then raise End_of_file else
             Expat.parse_sub parser_ buffer 0 read;
-	  done
+	done
 
       with
-	| End_of_file -> close_in in_chan
-	| e -> raise e
+      | End_of_file -> close_in in_chan
+      | e -> raise e
     in
-      finalizer ()
-
-
+    Utils.time ~msg:"Parsing XML file" parse ();
+    Utils.time ~msg:"Creating tree and text-collection index" finalizer ()
 
 end
 
@@ -144,16 +170,33 @@ end
 type bit_vector = string
 
 external bool_of_int : int -> bool = "%identity"
+external int_of_bool : bool -> int = "%identity"
 
 let bit_vector_unsafe_get v i =
   bool_of_int
     (((Char.code (String.unsafe_get v (i lsr 3))) lsr (i land 7)) land 1)
+let chr (c:int) : char = Obj.magic (c land 0xff)
+let bit_vector_unsafe_set v i b =
+  let j = i lsr 3 in
+  let c = Char.code v.[j] in
+  let bit = int_of_bool b in
+  let mask = bit lsl (i land 7) in
+  if b then v.[j] <- chr (c lor mask) else v.[j] <- (chr (c land (lnot mask)))
+
+let bit_vector_create n =
+  let len = if n <= 0 then 0 else (n - 1) / 8 + 1 in
+  String.make len '\000'
+
+type tag_list
+
+external tag_list_alloc : int -> tag_list = "caml_tag_list_alloc"
+external tag_list_set : tag_list -> int -> Tag.t -> unit = "caml_tag_list_set" "noalloc"
 
 type t = {
   doc : tree;
   elements: Ptset.Int.t;
   attributes: Ptset.Int.t;
-  attribute_array : Tag.t array;
+  attribute_array : tag_list;
   children : Ptset.Int.t array;
   siblings : Ptset.Int.t array;
   descendants: Ptset.Int.t array;
@@ -163,8 +206,8 @@ type t = {
 
 let tag_operations t = mk_tag_ops t.doc
 (*
-external parse_xml_uri : string -> int -> bool -> bool -> int -> tree = "caml_call_shredder_uri"
-external parse_xml_string :  string -> int -> bool -> bool -> int -> tree = "caml_call_shredder_string"
+  external parse_xml_uri : string -> int -> bool -> bool -> int -> tree = "caml_call_shredder_uri"
+  external parse_xml_string :  string -> int -> bool -> bool -> int -> tree = "caml_call_shredder_string"
 *)
 external tree_print_xml_fast3 : tree -> [`Tree ] Node.t -> Unix.file_descr -> unit = "caml_xml_tree_print"
 let print_xml t n fd =
@@ -179,26 +222,22 @@ external nullt : unit -> 'a Node.t = "caml_xml_tree_nullt"
 let nil : [`Tree ] Node.t = Node.nil
 let root : [`Tree ] Node.t = Node.null
 
-type unordered_set
-
-external unordered_set_alloc : int -> unordered_set = "caml_unordered_set_alloc"
-external unordered_set_length : unordered_set -> int = "caml_unordered_set_length"
-external unordered_set_insert : unordered_set -> int -> unit = "caml_unordered_set_set" "noalloc"
 
 module HPtset = Hashtbl.Make(Ptset.Int)
 
 let vector_htbl = HPtset.create MED_H_SIZE
+let reinit () = HPtset.clear vector_htbl
 
-let unordered_set_of_set s =
+let tag_list_of_set s =
   try
     HPtset.find vector_htbl s
   with
-      Not_found ->
-	let v = unordered_set_alloc (Ptset.Int.cardinal s) in
-	let _ = Ptset.Int.iter (fun e -> unordered_set_insert v e) s in
-	  HPtset.add vector_htbl s v; v
-
-let ptset_to_vector = unordered_set_of_set
+    Not_found ->
+      let v = tag_list_alloc (Ptset.Int.cardinal s + 1) in
+      let i = ref 0 in
+      let () = Ptset.Int.iter (fun e -> tag_list_set v !i e; incr i) s in
+      let () = tag_list_set v !i Tag.nullt in
+      HPtset.add vector_htbl s v; v
 
 (** tree interface *)
 
@@ -214,28 +253,26 @@ let first_element t n = tree_first_element t.doc n
 external tree_tagged_child : tree -> [`Tree] Node.t -> Tag.t -> [`Tree] Node.t = "caml_xml_tree_tagged_child" "noalloc"
 let tagged_child t n tag = tree_tagged_child t.doc n tag
 
-external tree_select_child : tree -> [`Tree ] Node.t -> unordered_set -> [`Tree] Node.t = "caml_xml_tree_select_child" "noalloc"
+external tree_select_child : tree -> [`Tree ] Node.t -> tag_list -> [`Tree] Node.t = "caml_xml_tree_select_child" "noalloc"
 let select_child t n tag_set = tree_select_child t.doc n tag_set
 
 external tree_last_child : tree -> [`Tree] Node.t -> [`Tree] Node.t = "caml_xml_tree_last_child" "noalloc"
 let last_child t n = tree_last_child t.doc n
 
 
-
 external tree_next_sibling : tree -> [`Tree] Node.t -> [`Tree] Node.t = "caml_xml_tree_next_sibling"  "noalloc"
 let next_sibling t n = tree_next_sibling t.doc n
 
 external tree_next_element : tree -> [`Tree] Node.t -> [`Tree] Node.t = "caml_xml_tree_next_element"  "noalloc"
 let next_element t n = tree_next_element t.doc n
 
-external tree_next_node_before : tree -> [`Tree] Node.t -> [`Tree] Node.t -> [`Tree] Node.t = "caml_xml_tree_next_node_before"  "noalloc"
-let next_node_before t n ctx = tree_next_node_before t.doc n ctx
 
-external tree_tagged_following_sibling : tree -> [`Tree] Node.t -> Tag.t -> [`Tree] Node.t = "caml_xml_tree_tagged_following_sibling" "noalloc"
-let tagged_following_sibling t n tag = tree_tagged_following_sibling t.doc n tag
+external tree_tagged_sibling : tree -> [`Tree] Node.t -> Tag.t -> [`Tree] Node.t = "caml_xml_tree_tagged_sibling" "noalloc"
+let tagged_sibling t n tag = tree_tagged_sibling t.doc n tag
 
-external tree_select_following_sibling : tree -> [`Tree ] Node.t -> unordered_set -> [`Tree] Node.t = "caml_xml_tree_select_following_sibling" "noalloc"
-let select_following_sibling t n tag_set = tree_select_following_sibling t.doc n tag_set
+
+external tree_select_sibling : tree -> [`Tree ] Node.t -> tag_list -> [`Tree] Node.t = "caml_xml_tree_select_sibling" "noalloc"
+let select_sibling t n tag_set = tree_select_sibling t.doc n tag_set
 
 external tree_prev_sibling : tree -> [`Tree] Node.t -> [`Tree] Node.t = "caml_xml_tree_prev_sibling" "noalloc"
 let prev_sibling t n = tree_prev_sibling t.doc n
@@ -248,23 +285,18 @@ let tagged_descendant t n tag = tree_tagged_descendant t.doc n tag
 external tree_tagged_next : tree -> [`Tree ] Node.t -> Tag.t -> [`Tree ] Node.t = "caml_xml_tree_tagged_next" "noalloc"
 let tagged_next t n tag = tree_tagged_next t.doc n tag
 
-external tree_select_descendant : tree -> [`Tree ] Node.t -> unordered_set -> [`Tree] Node.t = "caml_xml_tree_select_descendant" "noalloc"
+external tree_select_descendant : tree -> [`Tree ] Node.t -> tag_list -> [`Tree] Node.t = "caml_xml_tree_select_descendant" "noalloc"
 let select_descendant t n tag_set = tree_select_descendant t.doc n tag_set
 
 external tree_tagged_following_before : tree -> [`Tree ] Node.t -> Tag.t -> [`Tree ] Node.t -> [`Tree ] Node.t = "caml_xml_tree_tagged_following_before" "noalloc"
 let tagged_following_before t n tag ctx = tree_tagged_following_before t.doc n tag ctx
 
-external tree_select_following_before : tree -> [`Tree ] Node.t -> unordered_set -> [`Tree] Node.t -> [`Tree] Node.t = "caml_xml_tree_select_following_before" "noalloc"
+external tree_select_following_before : tree -> [`Tree ] Node.t -> tag_list -> [`Tree] Node.t -> [`Tree] Node.t = "caml_xml_tree_select_following_before" "noalloc"
 let select_following_before t n tag_set ctx = tree_select_following_before t.doc n tag_set ctx
 
 external tree_parent : tree -> [`Tree] Node.t -> [`Tree] Node.t = "caml_xml_tree_parent" "noalloc"
 let parent t n = tree_parent t.doc n
 
-external tree_binary_parent : tree -> [`Tree] Node.t -> [`Tree] Node.t = "caml_xml_tree_binary_parent"
-  "noalloc"
-let binary_parent t n = tree_binary_parent t.doc n
-
-
 external tree_tag : tree -> [`Tree] Node.t -> Tag.t = "caml_xml_tree_tag" "noalloc"
 let tag t n = tree_tag t.doc n
 
@@ -288,31 +320,22 @@ let tags t tag =
 
 open Format
 let dump_tag_table t =
-  eprintf "Child tags:\n%!";
-  Array.iteri
-    (fun tag set -> eprintf "%s: %a\n%!"
-      (Tag.to_string tag) TagSet.print (TagSet.inj_positive set))
-    t.children;
-  eprintf "-----------------------------\n%!";
-  eprintf "Descendant tags:\n%!";
-  Array.iteri
-    (fun tag set -> eprintf "%s: %a\n%!"
-      (Tag.to_string tag) TagSet.print (TagSet.inj_positive set))
-    t.descendants;
-  eprintf "-----------------------------\n%!";
-  eprintf "Sibling tags:\n%!";
-  Array.iteri
-    (fun tag set -> eprintf "%s: %a\n%!"
-      (Tag.to_string tag) TagSet.print (TagSet.inj_positive set))
-    t.siblings;
-  eprintf "-----------------------------\n%!";
-  eprintf "Following tags:\n%!";
-  Array.iteri
-    (fun tag set -> eprintf "%s: %a\n%!"
-      (Tag.to_string tag) TagSet.print (TagSet.inj_positive set))
-    t.followings;
-   eprintf "-----------------------------\n%!"
-
+  let tag = ref 0 in
+  let printer ppf set =
+    Logger.print ppf "%s: %a"
+      (Tag.to_string !tag) TagSet.print (TagSet.inj_positive set);
+    incr tag
+  in
+  let set_printer msg set =
+    tag := 0;
+    Logger.print err_formatter "%s :@\n" msg;
+    Pretty.pp_print_array ~sep:pp_force_newline printer err_formatter set;
+    Logger.print err_formatter "-----------------------------@\n";
+  in
+  set_printer "Child tags" t.children;
+  set_printer "Descendant tags" t.descendants;
+  set_printer "Sibling tags" t.siblings;
+  set_printer "Following tags" t.followings
 
 external tree_subtree_tags : tree -> [`Tree] Node.t -> Tag.t -> int = "caml_xml_tree_subtree_tags" "noalloc"
 let subtree_tags t n tag = tree_subtree_tags t.doc n tag
@@ -320,16 +343,25 @@ let subtree_tags t n tag = tree_subtree_tags t.doc n tag
 external tree_subtree_size : tree -> [`Tree] Node.t -> int = "caml_xml_tree_subtree_size" "noalloc"
 let subtree_size t n = tree_subtree_size t.doc n
 
+let rec iter_array_tag i a len tree node acc =
+  if i == len then acc
+  else
+    iter_array_tag (i+1) a len tree node
+      (acc - (tree_subtree_tags tree node a.(i)))
+
+external tree_subtree_elements : tree -> [`Tree] Node.t -> int = "caml_xml_tree_subtree_elements" "noalloc"
+
+let subtree_elements t node =
+  tree_subtree_elements t.doc node
+(*
 let subtree_elements t node =
   let size = tree_subtree_size t.doc node - 1 in
-    if size == 0 then 0
-    else let size = size - (tree_subtree_tags t.doc node Tag.pcdata) in
-      if size < 2 then size else
-	let acc = ref size in
-	  for i = 0 to Array.length t.attribute_array - 1 do
-	    acc := !acc - tree_subtree_tags t.doc node t.attribute_array.(i)
-	  done;
-	  !acc
+  if size <= 0 then 0
+  else let size = size - (tree_subtree_tags t.doc node Tag.pcdata) in
+       if size < 3 then size else
+	 let a = t.attribute_array  in
+	 iter_array_tag 0 a (Array.length a) t.doc node size
+*)
 
 external tree_closing : tree -> [`Tree] Node.t -> [`Tree] Node.t = "caml_xml_tree_closing" "noalloc"
 let closing t n = tree_closing t.doc n
@@ -341,35 +373,24 @@ external tree_size : tree -> int = "caml_xml_tree_size" "noalloc"
 let size t = tree_size 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
-;;
+
 
 module TagS =
-  struct
-    include Ptset.Make (
-      struct type t = int
-	     type data = t
-	     external hash : t -> int = "%identity"
-	     external uid : t -> Uid.t = "%identity"
-	     external equal : t -> t -> bool = "%eq"
-	     external make : t -> int = "%identity"
-	     external node : t -> int = "%identity"
-	     external stats : unit -> unit = "%identity"
-      end
-    )
-    let to_ptset s = fold (Ptset.Int.add) s Ptset.Int.empty
-  end
+struct
+  include Ptset.Make (
+    struct type t = int
+           type data = t
+	   external hash : t -> int = "%identity"
+	   external uid : t -> Uid.t = "%identity"
+	   external equal : t -> t -> bool = "%eq"
+	   external make : t -> int = "%identity"
+	   external node : t -> int = "%identity"
+	   external stats : unit -> unit = "%identity"
+           external init : unit -> unit = "%identity"
+    end
+  )
+  let to_ptset s = fold (Ptset.Int.add) s Ptset.Int.empty
+end
 
 module TSTSCache =
   Hashtbl.Make(struct type t = TagS.t * TagS.t
@@ -379,8 +400,8 @@ module TSTSCache =
 		      let equal u v =
 			let u1,u2 = u
 			and v1,v2 = v in
-			  u1 == v1 && u2 == v2
-	       end)
+			u1 == v1 && u2 == v2
+  end)
 module TagTSCache =
   Hashtbl.Make(struct type t = Tag.t * TagS.t
 		      let hash (x, y) =
@@ -388,8 +409,8 @@ module TagTSCache =
 		      let equal u v =
 			let u1,u2 = u
 			and v1,v2 = v in
-			  u1 == v1 && u2 == v2
-	       end)
+			u1 == v1 && u2 == v2
+  end)
 
 let add_cache = TagTSCache.create 1023
 let union_cache = TSTSCache.create 1023
@@ -405,12 +426,12 @@ let _subset x y =
     if y == TagS.empty then false
     else
       let key = (x, y) in
-	try
-	  TSTSCache.find subset_cache key
-	with
-	  | Not_found ->
-	      let z = TagS.subset x y in
-		TSTSCache.add subset_cache key z; z
+      try
+	TSTSCache.find subset_cache key
+      with
+      | Not_found ->
+	let z = TagS.subset x y in
+	TSTSCache.add subset_cache key z; z
 
 let order ((x, y) as z) =
   if x.TagS.Node.id <= y.TagS.Node.id then z
@@ -420,22 +441,22 @@ let _union x y =
   if _subset x y then y
   else if _subset y x then x
   else
-   let key = order (x, y) in
-     try
-       TSTSCache.find union_cache key
+    let key = order (x, y) in
+    try
+      TSTSCache.find union_cache key
     with
-      | Not_found ->
-	  let z = TagS.union x y in
-	    TSTSCache.add union_cache key z; z
+    | Not_found ->
+      let z = TagS.union x y in
+      TSTSCache.add union_cache key z; z
 
 let _add t s =
   let key = (t,s) in
-    try
-      TagTSCache.find add_cache key
-    with
-      | Not_found ->
-	  let z = TagS.add t s in
-	    TagTSCache.add add_cache key z;z
+  try
+    TagTSCache.find add_cache key
+  with
+  | Not_found ->
+    let z = TagS.add t s in
+    TagTSCache.add add_cache key z;z
 
 let child_sibling_labels tree =
   let table_c = Array.create (tree_num_tags tree) TagS.empty in
@@ -453,13 +474,13 @@ let child_sibling_labels tree =
       let siblings = loop (tree_next_sibling tree node) in
       let () =
 	let tn = table_n.(tag) in
-	  if _subset siblings tn then ()
-	  else table_n.(tag) <- _union tn siblings
+	if _subset siblings tn then ()
+	else table_n.(tag) <- _union tn siblings
       in
-	_add tag siblings
+      _add tag siblings
   in
-    ignore (loop root);
-    table_c, table_n
+  ignore (loop root);
+  table_c, table_n
 
 let descendant_labels tree =
   let table_d = Array.create (tree_num_tags tree) TagS.empty in
@@ -470,13 +491,13 @@ let descendant_labels tree =
       let tag = tree_tag tree node in
       let () =
 	let td = table_d.(tag) in
-	  if _subset d1 td then ()
-	  else table_d.(tag) <- _union td d1;
+	if _subset d1 td then ()
+	else table_d.(tag) <- _union td d1;
       in
-	_add tag (_union d1 d2)
+      _add tag (_union d1 d2)
   in
-    ignore (loop root);
-    table_d
+  ignore (loop root);
+  table_d
 
 let collect_labels tree =
   let table_f = Array.create (tree_num_tags tree) TagS.empty in
@@ -488,32 +509,32 @@ let collect_labels tree =
       let tag = tree_tag tree node in
       let () =
 	let tf = table_f.(tag) in
-	  if _subset followings tf then ()
-	  else table_f.(tag) <- _union tf followings in
+	if _subset followings tf then ()
+	else table_f.(tag) <- _union tf followings in
       let () =
 	let tn = table_n.(tag) in
-	  if _subset foll_siblings tn then ()
-	  else table_n.(tag) <- _union tn foll_siblings in
+	if _subset foll_siblings tn then ()
+	else table_n.(tag) <- _union tn foll_siblings in
       let children, n_descendants, n_followings =
 	loop (tree_last_child tree node) TagS.empty TagS.empty followings
       in
       let () =
 	let tc = table_c.(tag) in
-	  if _subset children tc then ()
-	  else table_c.(tag) <- _union tc children
+	if _subset children tc then ()
+	else table_c.(tag) <- _union tc children
       in
       let () =
 	let td = table_d.(tag) in
-	  if _subset n_descendants td then ()
-	  else table_d.(tag) <- _union td n_descendants
+	if _subset n_descendants td then ()
+	else table_d.(tag) <- _union td n_descendants
       in
-	loop (tree_prev_sibling tree node)
-	  (_add tag foll_siblings)
-	  (_add tag (_union n_descendants descendants))
-	  (_add tag n_followings)
+      loop (tree_prev_sibling tree node)
+	(_add tag foll_siblings)
+	(_add tag (_union n_descendants descendants))
+	(_add tag n_followings)
   in
-    ignore (loop root TagS.empty TagS.empty TagS.empty);
-    table_f, table_n, table_c, table_d
+  ignore (loop root TagS.empty TagS.empty TagS.empty);
+  table_f, table_n, table_c, table_d
 
 
 let is_nil t = t == nil
@@ -521,8 +542,10 @@ let is_node t = t != nil
 let is_root t = t == root
 
 let node_of_t t  =
+  LOG ( __ "indexing" 2 "%s\n" "Initializing tag structure");
   let _ = Tag.init (mk_tag_ops t) in
-  let f, n, c, d = time collect_labels t ~msg:"Building tag relationship table" in
+  LOG ( __ "indexing" 2 "%s\n" "Starting tag table construction");
+  let f, n, c, d = Utils.time ~msg:"Building tag relationship table" collect_labels t in
   let c = Array.map TagS.to_ptset c in
   let n = Array.map TagS.to_ptset n in
   let f = Array.map TagS.to_ptset f in
@@ -533,16 +556,16 @@ let node_of_t t  =
     (Ptset.Int.remove Tag.pcdata
        (Ptset.Int.diff d.(Tag.document_node) attributes))
   in
-    { doc= t;
-      attributes = attributes;
-      attribute_array = Array.of_list (Ptset.Int.elements attributes);
-      elements = elements;
-      children = c;
-      siblings = n;
-      descendants = d;
-      followings = f
+  { doc= t;
+    attributes = attributes;
+    attribute_array = tag_list_of_set attributes;
+    elements = elements;
+    children = c;
+    siblings = n;
+    descendants = d;
+    followings = f
 
-    }
+  }
 
 
 let parse_xml_uri str = node_of_t (TreeBuilder.parse_file str)
@@ -551,24 +574,24 @@ let parse_xml_string str = node_of_t (TreeBuilder.parse_string str)
 let size t = tree_size t.doc;;
 
 let magic_string = "SXSI_INDEX"
-let version_string = "3"
+let version_string = "4"
 
 let pos fd =
   Unix.lseek fd 0  Unix.SEEK_CUR
 
-let pr_pos fd = Printf.eprintf "At position %i\n%!" (pos fd)
+let pr_pos fd = Logger.print err_formatter "At position %i@\n" (pos fd)
 
 let write fd s =
   let sl = String.length s in
   let ssl = Printf.sprintf "%020i" sl in
-    ignore (Unix.write fd ssl 0 20);
-    ignore (Unix.write fd s 0 (String.length s))
+  ignore (Unix.write fd ssl 0 20);
+  ignore (Unix.write fd s 0 (String.length s))
 
 let rec really_read fd buffer start length =
   if length <= 0 then () else
     match Unix.read fd buffer start length with
-	0 -> raise End_of_file
-      | r -> really_read fd buffer (start + r) (length - r);;
+      0 -> raise End_of_file
+    | r -> really_read fd buffer (start + r) (length - r);;
 
 let read fd =
   let buffer = String.create 20 in
@@ -576,64 +599,66 @@ let read fd =
   let size = int_of_string buffer in
   let buffer = String.create size in
   let _ =  really_read fd buffer 0 size in
-    buffer
+  buffer
 
 let save_tag_table channel t =
   let t = Array.map (fun s -> Array.of_list (Ptset.Int.elements s)) t in
-    Marshal.to_channel channel t []
+  Marshal.to_channel channel t []
 
 let save t str =
   let fd = Unix.openfile str [ Unix.O_WRONLY;Unix.O_TRUNC;Unix.O_CREAT] 0o644 in
   let out_c = Unix.out_channel_of_descr fd in
+  let index_prefix = Filename.chop_suffix str ".srx" in
   let _ = set_binary_mode_out out_c true in
-    output_string out_c magic_string;
-    output_char out_c '\n';
-    output_string out_c version_string;
-    output_char out_c '\n';
-    save_tag_table out_c t.children;
-    save_tag_table out_c t.siblings;
-    save_tag_table out_c t.descendants;
-    save_tag_table out_c t.followings;
+  output_string out_c magic_string;
+  output_char out_c '\n';
+  output_string out_c version_string;
+  output_char out_c '\n';
+  save_tag_table out_c t.children;
+  save_tag_table out_c t.siblings;
+  save_tag_table out_c t.descendants;
+  save_tag_table out_c t.followings;
     (* 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 str;
-    close_out out_c
+  flush out_c;
+  ignore (Unix.lseek fd (pos_out out_c) Unix.SEEK_SET);
+  tree_save t.doc fd index_prefix;
+  close_out out_c
 ;;
 let load_tag_table channel =
   let table : int array array = Marshal.from_channel channel in
-    Array.map (fun a -> Ptset.Int.from_list (Array.to_list a)) table
+  Array.map (fun a -> Ptset.Int.from_list (Array.to_list a)) table
 
 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 index_prefix = Filename.chop_suffix str ".srx" in
   let _ = set_binary_mode_in in_c true in
   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 vs = input_line in_c in if vs <> version_string then failwith "Unsupported index format");
     let c = load_tag_table in_c in
     let s = load_tag_table in_c in
     let d = load_tag_table in_c in
     let f = load_tag_table in_c in
-      c,s,d,f
+    c,s,d,f
   in
   let c, s, d, f = time ~msg:"Loading tag table"(load_table) () in
   ignore(Unix.lseek fd (pos_in in_c) Unix.SEEK_SET);
-    let xml_tree = tree_load fd str load_text sample in
-    let () = Tag.init (Obj.magic xml_tree) in
-    let attributes = Ptset.Int.add Tag.attribute d.(Tag.attribute) in
-    let elements = Ptset.Int.add Tag.document_node
-      (Ptset.Int.remove Tag.pcdata
-	 (Ptset.Int.diff d.(Tag.document_node) attributes))
-    in
-    let tree = { doc = xml_tree;
-		 attributes = attributes;
-		 attribute_array = Array.of_list (Ptset.Int.elements attributes);
-		 elements = elements;
-		 children = c;
-		 siblings = s;
-		 descendants = d;
-		 followings = f
+  let xml_tree = tree_load fd index_prefix load_text sample in
+  let () = Tag.init (Obj.magic xml_tree) in
+  let attributes = Ptset.Int.add Tag.attribute d.(Tag.attribute) in
+  let elements = Ptset.Int.add Tag.document_node
+    (Ptset.Int.remove Tag.pcdata
+       (Ptset.Int.diff d.(Tag.document_node) attributes))
+  in
+  let tree = { doc = xml_tree;
+	       attributes = attributes;
+	       attribute_array = tag_list_of_set attributes;
+	       elements = elements;
+	       children = c;
+	       siblings = s;
+	       descendants = d;
+	       followings = f
 	     }
   in close_in in_c;
   tree
@@ -644,7 +669,7 @@ let load ?(sample=64) ?(load_text=true) str =
 let equal a b = a == b
 
 let nts = function
-    -1 -> "Nil"
+-1 -> "Nil"
   | i -> Printf.sprintf "Node (%i)"  i
 
 let dump_node t = nts (Node.to_int t)
@@ -658,17 +683,17 @@ type query_result = { bv : bit_vector;
 external tree_flush : tree -> Unix.file_descr -> unit = "caml_xml_tree_flush"
 let flush t fd = tree_flush t.doc fd
 
-external text_prefix : tree -> string -> query_result = "caml_text_collection_prefix_bv"
-let text_prefix t s = text_prefix t.doc s
+external text_prefix : tree -> string -> bool -> query_result = "caml_text_collection_prefix_bv"
+let text_prefix t s b = text_prefix t.doc s b
 
-external text_suffix : tree -> string -> query_result = "caml_text_collection_suffix_bv"
-let text_suffix t s = text_suffix t.doc s
+external text_suffix : tree -> string -> bool -> query_result = "caml_text_collection_suffix_bv"
+let text_suffix t s b = text_suffix t.doc s b
 
-external text_equals : tree -> string -> query_result = "caml_text_collection_equals_bv"
-let text_equals t s = text_equals t.doc s
+external text_equals : tree -> string -> bool -> query_result = "caml_text_collection_equals_bv"
+let text_equals t s b = text_equals t.doc s b
 
-external text_contains : tree -> string -> query_result = "caml_text_collection_contains_bv"
-let text_contains t s = text_contains t.doc s
+external text_contains : tree -> string -> bool -> query_result = "caml_text_collection_contains_bv"
+let text_contains t s b = text_contains t.doc s b
 
 
 module Predicate = Hcons.Make (
@@ -677,60 +702,110 @@ module Predicate = Hcons.Make (
     type t = (_t -> node -> bool) ref
     let hash t = Hashtbl.hash t
     let equal t1 t2 = t1 == t2
-end)
+  end)
 
 let string_of_query query =
-    match query with
-      | `Prefix -> "starts-with"
-      | `Suffix -> "ends-with"
-      | `Equals -> "equals"
-      | `Contains -> "contains"
+  match query with
+  | `Prefix -> "starts-with"
+  | `Suffix -> "ends-with"
+  | `Equals -> "equals"
+  | `Contains -> "contains"
 ;;
 
 let query_fun = function
-      | `Prefix -> text_prefix
-      | `Suffix -> text_suffix
-      | `Equals -> text_equals
-      | `Contains -> text_contains
+  | `Prefix -> text_prefix
+  | `Suffix -> text_suffix
+  | `Equals -> text_equals
+  | `Contains -> text_contains
 ;;
 
 let _pred_cache = Hashtbl.create 17
 ;;
 let mk_pred query s =
-  let f = query_fun query in
+  LOG ( __ "bottom-up" 3 "Calling mk_pred for '%s'\n" s);
+  let f = query_fun query  in
   let memo = ref (fun _ _ -> failwith "Undefined") in
   memo := begin fun tree node ->
     let results =
       try Hashtbl.find _pred_cache (query,s) with
-	  Not_found ->
-	    time ~count:1 ~msg:(Printf.sprintf "Computing text query %s(%s)"
-				  (string_of_query query) s)
-	      (f tree) s
+	Not_found ->
+	  time ~count:1 ~msg:(Printf.sprintf "Computing text query %s(%s)"
+				(string_of_query query) s)
+	    (f tree) s true
     in
     let bv = results.bv in
     memo := begin fun _ n ->
-      let b =
-	bit_vector_unsafe_get bv (Node.to_int n)
-      in
-      D_TRACE_(Printf.eprintf "Result of memoized call to query %s is %b for node %i\n" s b (Node.to_int n));
-      b
+      let r = bit_vector_unsafe_get bv (Node.to_int n) in
+      LOG( __  "bottom-up" 3 "Running predicate on node %i = %b@\n" (Node.to_int n) r);
+      r
     end;
-    let b = bit_vector_unsafe_get bv (Node.to_int node) in
-    D_TRACE_(Printf.eprintf "Result is %b for node %i\n" b (Node.to_int node));
-    b
+    let r = bit_vector_unsafe_get bv (Node.to_int node) in
+    LOG( __  "bottom-up" 3 "Running predicate on node %i = %b@\n" (Node.to_int node) r);
+    r
   end;
   Predicate.make memo
 
 
-let full_text_prefix t s = (text_prefix t s).pos
+let full_text_prefix t s = (text_prefix t s true).pos
 
-let full_text_suffix t s = (text_suffix t s).pos
+let full_text_suffix t s = (text_suffix t s true).pos
 
-let full_text_equals t s = (text_equals t s).pos
+let full_text_equals t s = (text_equals t s true).pos
 
-let full_text_contains t s = (text_contains t s).pos
+let full_text_contains t s = (text_contains t s true).pos
 
 let full_text_query q t s =
-  let res = (query_fun q) t s in
+  let res = (query_fun q) t s true in
   Hashtbl.replace _pred_cache (q,s) res;
   res.pos
+
+let stats tree =
+      let h = Hashtbl.create 1024 in
+      let depth = ref 0 in
+      let numleaves = ref 0 in
+      let numtexts = ref 0 in
+    let rec traverse tree t p d =
+      if is_nil t then
+	let oldc =
+	  try
+	    Hashtbl.find h p
+	  with Not_found -> 0
+	in
+	Hashtbl.replace h p (oldc + 1);
+	if d > !depth then depth := d;
+	incr numleaves
+      else
+	let label = tree_tag tree t in
+	if label == Tag.pcdata || label == Tag.attribute_data then incr numtexts;
+	iter_siblings tree t (label::p) (d+1)
+    and iter_siblings tree t p d =
+      if is_nil t then () else
+	let fs = tree_first_child tree t in
+	traverse tree fs p d;
+	let ns = tree_next_sibling tree t in
+	iter_siblings tree ns p d
+    in
+    traverse tree.doc root [] 0;
+    let sumdepth = Hashtbl.fold (fun p c acc -> (List.length p) * c + acc) h 0 in
+    let alltags = Ptset.Int.union tree.elements tree.attributes in
+    Logger.print err_formatter "Statistics :@\n\
+Average depth: %f@\n\
+Longest path: %i@\n\
+Number of distinct paths: %i@\n\
+Number of nodes: %i@\n\
+Number of leaves: %i@\n\
+Number of pcdata/cdata nodes: %i@\n\
+Number of distinct tags: %i@\n\
+Largest tag id: %i@\n@?"
+      (float_of_int sumdepth /. float_of_int !numleaves)
+      !depth
+      (Hashtbl.length h)
+      (tree_subtree_size tree.doc root)
+      !numleaves
+      !numtexts
+      (Ptset.Int.cardinal alltags)
+      (Ptset.Int.max_elt alltags)
+
+
+type tree_pointer = tree
+let get_tree_pointer x = x.doc