type t = { id : int;
key : int; (* hash *)
- node : node }
+ node : node;
+ }
and node =
| Empty
| Leaf of int
| Branch of int * int * t * t
+
+(* faster if outside of a module *)
+let hash_node x = match x with
+ | Empty -> 0
+ | Leaf i -> (i+1) land max_int
+ (* power of 2 +/- 1 are fast ! *)
+ | Branch (b,i,l,r) ->
+ ((b lsl 1)+ b + i+(i lsl 4) + (l.key lsl 5)-l.key
+ + (r.key lsl 7) - r.key) land max_int
+
module Node =
struct
type _t = t
type t = _t
- let hash x = x.key
- let hash_node = function
- | Empty -> 0
- | Leaf i -> i+1
- (* power of 2 +/- 1 are fast ! *)
- | Branch (b,i,l,r) ->
- (b lsl 1)+ b + i+(i lsl 4) + (l.key lsl 5)-l.key
- + (r.key lsl 7) - r.key
- let hash_node x = (hash_node x) land max_int
- let equal x y = match (x.node,y.node) with
+ external hash : t -> int = "%field1"
+ let equal x y =
+ if x.id == y.id || x.key == y.key || x.node == y.node then true
+ else
+ match (x.node,y.node) with
| Empty,Empty -> true
| Leaf k1, Leaf k2 when k1 == k2 -> true
| Branch(p1,m1,l1,r1), Branch(p2,m2,l2,r2) when m1==m2 && p1==p2 &&
| _ -> false
end
-module WH = Weak.Make(Node)
-
+module WH =Weak.Make(Node)
+(* struct
+ include Hashtbl.Make(Node)
+ let merge h v =
+ if mem h v then v
+ else (add h v v;v)
+end
+*)
let pool = WH.create 4093
(* Neat trick thanks to Alain Frisch ! *)
let _ = WH.add pool empty
-let is_empty = function { id = 0 } -> true | _ -> false
+let is_empty s = s.id==0
let rec norm n =
let v = { id = gen_uid ();
- key = Node.hash_node n;
+ key = hash_node n;
node = n }
in
WH.merge pool v
(* WH.merge pool *)
-let branch (p,m,l,r) = norm (Branch(p,m,l,r))
+let branch p m l r = norm (Branch(p,m,l,r))
let leaf k = norm (Leaf k)
(* To enforce the invariant that a branch contains two non empty sub-trees *)
let branch_ne = function
| (_,_,e,t) when is_empty e -> t
| (_,_,t,e) when is_empty e -> t
- | (p,m,t0,t1) -> branch (p,m,t0,t1)
+ | (p,m,t0,t1) -> branch p m t0 t1
(********** from here on, only use the smart constructors *************)
let zero_bit k m = (k land m) == 0
-let singleton k = if k < 0 then failwith "singleton" else leaf k
+let singleton k = leaf k
let rec mem k n = match n.node with
| Empty -> false
let hbit = Array.init 256 naive_highest_bit
let highest_bit_32 x =
- let n = x lsr 24 in if n != 0 then hbit.(n) lsl 24
- else let n = x lsr 16 in if n != 0 then hbit.(n) lsl 16
- else let n = x lsr 8 in if n != 0 then hbit.(n) lsl 8
- else hbit.(x)
+ let n = x lsr 24 in if n != 0 then Array.unsafe_get hbit n lsl 24
+ else let n = x lsr 16 in if n != 0 then Array.unsafe_get hbit n lsl 16
+ else let n = x lsr 8 in if n != 0 then Array.unsafe_get hbit n lsl 8
+ else Array.unsafe_get hbit x
let highest_bit_64 x =
let n = x lsr 32 in if n != 0 then (highest_bit_32 n) lsl 32
let branching_bit p0 p1 = highest_bit (p0 lxor p1)
- let join (p0,t0,p1,t1) =
+ let join p0 t0 p1 t1 =
let m = branching_bit p0 p1 in
if zero_bit p0 m then
- branch (mask p0 m, m, t0, t1)
+ branch (mask p0 m) m t0 t1
else
- branch (mask p0 m, m, t1, t0)
+ branch (mask p0 m) m t1 t0
let match_prefix k p m = (mask k m) == p
let add k t =
let rec ins n = match n.node with
| Empty -> leaf k
- | Leaf j -> if j == k then n else join (k, leaf k, j, n)
+ | Leaf j -> if j == k then n else join k (leaf k) j n
| Branch (p,m,t0,t1) ->
if match_prefix k p m then
if zero_bit k m then
- branch (p, m, ins t0, t1)
+ branch p m (ins t0) t1
else
- branch (p, m, t0, ins t1)
+ branch p m t0 (ins t1)
else
- join (k, leaf k, p, n)
+ join k (leaf k) p n
in
ins t
(* should run in O(1) thanks to Hash consing *)
- let equal = (=)
+ let equal a b = a==b || a.id == b.id
- let compare = compare
+ let compare a b = if a == b then 0 else a.id - b.id
- let rec merge (s,t) =
+ let rec merge s t =
if (equal s t) (* This is cheap thanks to hash-consing *)
then s
else
| _, Leaf k -> add k s
| Branch (p,m,s0,s1), Branch (q,n,t0,t1) ->
if m == n && match_prefix q p m then
- branch (p, m, merge (s0,t0), merge (s1,t1))
+ branch p m (merge s0 t0) (merge s1 t1)
else if m > n && match_prefix q p m then
if zero_bit q m then
- branch (p, m, merge (s0,t), s1)
+ branch p m (merge s0 t) s1
else
- branch (p, m, s0, merge (s1,t))
- else if m < n && match_prefix p q n then
-
+ branch p m s0 (merge s1 t)
+ else if m < n && match_prefix p q n then
if zero_bit p n then
- branch (q, n, merge (s,t0), t1)
+ branch q n (merge s t0) t1
else
- branch (q, n, t0, merge (s,t1))
+ branch q n t0 (merge s t1)
else
(* The prefixes disagree. *)
- join (p, s, q, t)
+ join p s q t
- let union s t = merge (s,t)
+
let rec subset s1 s2 = (equal s1 s2) ||
match (s1.node,s2.node) with
subset l1 r2 && subset r1 r2
else
false
+
+ let union s t =
+ merge s t
let rec inter s1 s2 =
- if (equal s1 s2)
+ if equal s1 s2
then s1
else
match (s1.node,s2.node) with
| _, Leaf k2 -> if mem k2 s1 then s2 else empty
| Branch (p1,m1,l1,r1), Branch (p2,m2,l2,r2) ->
if m1 == m2 && p1 == p2 then
- merge (inter l1 l2, inter r1 r2)
+ merge (inter l1 l2) (inter r1 r2)
else if m1 > m2 && match_prefix p2 p1 m1 then
inter (if zero_bit p2 m1 then l1 else r1) s2
else if m1 < m2 && match_prefix p1 p2 m2 then
empty
let rec diff s1 s2 =
- if (equal s1 s2)
+ if equal s1 s2
then empty
else
match (s1.node,s2.node) with
| _, Leaf k2 -> remove k2 s1
| Branch (p1,m1,l1,r1), Branch (p2,m2,l2,r2) ->
if m1 == m2 && p1 == p2 then
- merge (diff l1 l2, diff r1 r2)
+ merge (diff l1 l2) (diff r1 r2)
else if m1 > m2 && match_prefix p2 p1 m1 then
if zero_bit p2 m1 then
- merge (diff l1 s2, r1)
+ merge (diff l1 s2) r1
else
- merge (l1, diff r1 s2)
+ merge l1 (diff r1 s2)
else if m1 < m2 && match_prefix p1 p2 m2 then
if zero_bit p1 m2 then diff s1 l2 else diff s1 r2
else
let hash s = s.key
let from_list l = List.fold_left (fun acc i -> add i acc) empty l
+
+type int_vector
+
+external int_vector_alloc : int -> int_vector = "caml_int_vector_alloc"
+external int_vector_set : int_vector -> int -> int -> unit = "caml_int_vector_set"
+external int_vector_length : int_vector -> int = "caml_int_vector_length"
+external int_vector_empty : unit -> int_vector = "caml_int_vector_empty"
+
+let empty_vector = int_vector_empty ()
+
+let to_int_vector_ext s =
+ let l = cardinal s in
+ let v = int_vector_alloc l in
+ let i = ref 0 in
+ iter (fun e -> int_vector_set v !i e; incr i) s;
+ v
+
+let hash_vectors = Hashtbl.create 4097
+
+let to_int_vector s =
+ try
+ Hashtbl.find hash_vectors s.key
+ with
+ Not_found ->
+ let v = to_int_vector_ext s in
+ Hashtbl.add hash_vectors s.key v;
+ v
+
+
projects / SXSI / xpathcomp.git / blobdiff