X-Git-Url: http://git.nguyen.vg/gitweb/?a=blobdiff_plain;f=src%2Ftree.ml;h=b7b856641c9075a97e19c5f82bbbc79b31d08c85;hb=7e27afe6fa006ad355237ccc0695c6493ea57929;hp=166eeea393b083dfef72ddbfdceb5f969dcbd0c2;hpb=1e5a0a6e72f96cf139b6da5511fab850f5da5b84;p=SXSI%2Fxpathcomp.git

diff --git a/src/tree.ml b/src/tree.ml
index 166eeea..b7b8566 100644
--- a/src/tree.ml
+++ b/src/tree.ml
@@ -5,6 +5,7 @@
 (*  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"
@@ -56,6 +57,7 @@ struct
   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 =
@@ -72,18 +74,19 @@ struct
     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_))
+      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
       let s = Buffer.contents t in
-      begin
-	open_tag b "<$>";
-	text b s;
-	close_tag b "<$>";
-      end;
+      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
 
@@ -99,11 +102,11 @@ struct
     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 parser_ b t tag =
@@ -120,17 +123,18 @@ struct
     let finalize () =
       do_text build buf;
       close_tag build "";
-      Logger.print Format.err_formatter "Finished parsing@\n";
-      Logger.print Format.err_formatter "Starting index construction@\n";
-      let r = close_document build in
-      Logger.print Format.err_formatter "Finished index construction@\n";
+      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 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);
-    Logger.print Format.err_formatter "Started parsing@\n";
-    open_document build !Options.sample_factor !Options.disable_text_collection !Options.text_index_type;
+    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
 
@@ -143,19 +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
 
@@ -182,11 +187,16 @@ 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;
@@ -196,8 +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 =
@@ -212,26 +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 *)
 
@@ -247,7 +253,7 @@ 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"
@@ -265,7 +271,7 @@ external tree_tagged_sibling : tree -> [`Tree] Node.t -> Tag.t -> [`Tree] Node.t
 let tagged_sibling t n tag = tree_tagged_sibling t.doc n tag
 
 
-external tree_select_sibling : tree -> [`Tree ] Node.t -> unordered_set -> [`Tree] Node.t = "caml_xml_tree_select_sibling" "noalloc"
+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"
@@ -279,13 +285,13 @@ 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"
@@ -337,16 +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
@@ -358,35 +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
-  Logger.print err_formatter "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
@@ -396,8 +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) =
@@ -405,8 +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
@@ -422,12 +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
@@ -437,22 +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
@@ -470,13 +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
@@ -487,13 +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
@@ -505,32 +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
@@ -538,10 +542,10 @@ let is_node t = t != nil
 let is_root t = t == root
 
 let node_of_t t  =
-  Logger.print err_formatter "Initializing tag structure@\n";
+  LOG ( __ "indexing" 2 "%s\n" "Initializing tag structure");
   let _ = Tag.init (mk_tag_ops t) in
-  Logger.print err_formatter "Starting tag table construction@\n";
-  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
@@ -552,16 +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)
@@ -570,7 +574,7 @@ 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
@@ -580,14 +584,14 @@ 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
@@ -595,34 +599,34 @@ 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 index_prefix;
-    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
@@ -631,30 +635,30 @@ let load ?(sample=64) ?(load_text=true) str =
   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 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 = 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
@@ -665,7 +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)
@@ -698,41 +702,46 @@ 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 =
+  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 true
+	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 ->
-      bit_vector_unsafe_get bv (Node.to_int n)
+      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;
-    bit_vector_unsafe_get bv (Node.to_int node)
+    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
 
@@ -749,3 +758,54 @@ let full_text_query q t s =
   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