ocaml/stdlib/ephemeron.ml

574 lines
19 KiB
OCaml

(***********************************************************************)
(* *)
(* OCaml *)
(* *)
(* Damien Doligez, projet Para, INRIA Rocquencourt *)
(* *)
(* Copyright 1997 Institut National de Recherche en Informatique et *)
(* en Automatique. All rights reserved. This file is distributed *)
(* under the terms of the GNU Library General Public License, with *)
(* the special exception on linking described in file ../LICENSE. *)
(* *)
(***********************************************************************)
module type SeededS = sig
include Hashtbl.SeededS
val stats_alive: 'a t -> Hashtbl.statistics
(** same as {!stats} but only count the alive bindings *)
end
module type S = sig
include Hashtbl.S
val stats_alive: 'a t -> Hashtbl.statistics
(** same as {!stats} but only count the alive bindings *)
end
module GenHashTable = struct
type equal =
| ETrue | EFalse
| EDead (** the garbage collector reclaimed the data *)
module MakeSeeded(H: sig
type t
type 'a container
val create: t -> 'a -> 'a container
val hash: int -> t -> int
val equal: t -> 'a container -> equal
val get_data: 'a container -> 'a option
val get_key: 'a container -> t option
val set_data: 'a container -> 'a -> unit
val check_key: 'a container -> bool
end) : SeededS with type key = H.t
= struct
type 'a t =
{ mutable size: int; (* number of entries *)
mutable data: 'a bucketlist array; (* the buckets *)
mutable seed: int; (* for randomization *)
initial_size: int; (* initial array size *)
}
and 'a bucketlist =
| Empty
| Cons of int (** hash of the key *) * 'a H.container * 'a bucketlist
(** the hash of the key is kept in order to test the equality of the hash
before the key. Same reason than for Weak.Make *)
type key = H.t
let rec power_2_above x n =
if x >= n then x
else if x * 2 > Sys.max_array_length then x
else power_2_above (x * 2) n
let prng = lazy (Random.State.make_self_init())
let create ?(random = (Hashtbl.is_randomized ())) initial_size =
let s = power_2_above 16 initial_size in
let seed = if random then Random.State.bits (Lazy.force prng) else 0 in
{ initial_size = s; size = 0; seed = seed; data = Array.make s Empty }
let clear h =
h.size <- 0;
let len = Array.length h.data in
for i = 0 to len - 1 do
h.data.(i) <- Empty
done
let reset h =
let len = Array.length h.data in
if len = h.initial_size then
clear h
else begin
h.size <- 0;
h.data <- Array.make h.initial_size Empty
end
let copy h = { h with data = Array.copy h.data }
let key_index h hkey =
hkey land (Array.length h.data - 1)
let resize indexfun h =
let odata = h.data in
let osize = Array.length odata in
let nsize = osize * 2 in
if nsize < Sys.max_array_length then begin
let ndata = Array.make nsize Empty in
h.data <- ndata; (* so that indexfun sees the new bucket count *)
let rec insert_bucket = function
Empty -> ()
| Cons(key, data, rest) ->
insert_bucket rest; (* preserve original order of elements *)
let nidx = indexfun h key in
ndata.(nidx) <- Cons(key, data, ndata.(nidx)) in
for i = 0 to osize - 1 do
insert_bucket odata.(i)
done
end
let add h key info =
let hkey = H.hash h.seed key in
let i = key_index h hkey in
let container = H.create key info in
let bucket = Cons(hkey, container, h.data.(i)) in
h.data.(i) <- bucket;
h.size <- h.size + 1;
if h.size > Array.length h.data lsl 1 then resize key_index h
let remove h key =
let hkey = H.hash h.seed key in
let rec remove_bucket = function
| Empty -> Empty
| Cons(hk, c, next) when hkey = hk ->
begin match H.equal key c with
| ETrue -> h.size <- h.size - 1; next
| EFalse -> Cons(hk, c, remove_bucket next)
| EDead -> remove_bucket next (** The key have been reclaimed *)
end
| Cons(hk,c,next) -> Cons(hk, c, remove_bucket next) in
let i = key_index h hkey in
h.data.(i) <- remove_bucket h.data.(i)
let rec find_rec key hkey = function
| Empty ->
raise Not_found
| Cons(hk, c, rest) when hkey = hk ->
begin match H.equal key c with
| ETrue ->
begin match H.get_data c with
| None ->
(** This case is not impossible because the gc can run between
H.equal and H.get_data *)
(** TODO? remove this dead key *)
find_rec key hkey rest
| Some d -> d
end
| EFalse -> find_rec key hkey rest
| EDead ->
(** TODO? remove this dead key *)
find_rec key hkey rest
end
| Cons(_, _, rest) ->
find_rec key hkey rest
let find h key =
let hkey = H.hash h.seed key in
(** TODO inline 3 iteration *)
find_rec key hkey (h.data.(key_index h hkey))
let find_all h key =
let hkey = H.hash h.seed key in
let rec find_in_bucket = function
| Empty -> []
| Cons(hk, c, rest) when hkey = hk ->
begin match H.equal key c with
| ETrue -> begin match H.get_data c with
| None ->
(** TODO? remove this dead key *)
find_in_bucket rest
| Some d -> d::find_in_bucket rest
end
| EFalse -> find_in_bucket rest
| EDead ->
(** TODO? remove this dead key *)
find_in_bucket rest
end
| Cons(_, _, rest) ->
find_in_bucket rest in
find_in_bucket h.data.(key_index h hkey)
let replace h key info =
let hkey = H.hash h.seed key in
let rec replace_bucket = function
| Empty -> raise Not_found
| Cons(hk, c, next) when hkey = hk ->
begin match H.equal key c with
| ETrue -> begin match H.get_data c with
| None ->
(** Can this case really happend? *)
(** TODO? remove this dead key *)
replace_bucket next
| Some d -> H.set_data c info
end
| EFalse -> replace_bucket next
| EDead ->
(** TODO? remove this dead key *)
replace_bucket next
end
| Cons(_,_,next) -> replace_bucket next
in
let i = key_index h hkey in
let l = h.data.(i) in
try
replace_bucket l
with Not_found ->
let container = H.create key info in
h.data.(i) <- Cons(hkey, container, l);
h.size <- h.size + 1;
if h.size > Array.length h.data lsl 1 then resize key_index h
let mem h key =
let hkey = H.hash h.seed key in
let rec mem_in_bucket = function
| Empty ->
false
| Cons(hk, c, rest) when hk = hkey ->
begin match H.equal key c with
| ETrue -> true
| EFalse -> mem_in_bucket rest
| EDead ->
(** TODO? remove this dead key *)
mem_in_bucket rest
end
| Cons(hk, c, rest) -> mem_in_bucket rest in
mem_in_bucket h.data.(key_index h hkey)
let iter f h =
let rec do_bucket = function
| Empty ->
()
| Cons(_, c, rest) ->
begin match H.get_key c, H.get_data c with
| None, _ | _, None -> (** TODO? remove this dead key? *) ()
| Some k, Some d -> f k d
end; do_bucket rest in
let d = h.data in
for i = 0 to Array.length d - 1 do
do_bucket d.(i)
done
let fold f h init =
let rec do_bucket b accu =
match b with
Empty ->
accu
| Cons(_, c, rest) ->
let accu = begin match H.get_key c, H.get_data c with
| None, _ | _, None -> (** TODO? remove this dead key? *) accu
| Some k, Some d -> f k d accu
end in
do_bucket rest accu in
let d = h.data in
let accu = ref init in
for i = 0 to Array.length d - 1 do
accu := do_bucket d.(i) !accu
done;
!accu
let filter_map_inplace f h =
let rec do_bucket = function
| Empty ->
Empty
| Cons(hk, c, rest) ->
match H.get_key c, H.get_data c with
| None, _ | _, None ->
do_bucket rest
| Some k, Some d ->
match f k d with
| None ->
do_bucket rest
| Some new_d ->
H.set_key_data c k new_d;
Cons(hk, c, do_bucket rest)
in
let d = h.data in
for i = 0 to Array.length d - 1 do
d.(i) <- do_bucket d.(i)
done
let length h = h.size
let rec bucket_length accu = function
| Empty -> accu
| Cons(_, _, rest) -> bucket_length (accu + 1) rest
let stats h =
let mbl =
Array.fold_left (fun m b -> max m (bucket_length 0 b)) 0 h.data in
let histo = Array.make (mbl + 1) 0 in
Array.iter
(fun b ->
let l = bucket_length 0 b in
histo.(l) <- histo.(l) + 1)
h.data;
{ Hashtbl.num_bindings = h.size;
num_buckets = Array.length h.data;
max_bucket_length = mbl;
bucket_histogram = histo }
let rec bucket_length_alive accu = function
| Empty -> accu
| Cons(_, c, rest) when H.check_key c ->
bucket_length_alive (accu + 1) rest
| Cons(_, _, rest) -> bucket_length_alive accu rest
let stats_alive h =
let size = ref 0 in
let mbl =
Array.fold_left (fun m b -> max m (bucket_length_alive 0 b)) 0 h.data in
let histo = Array.make (mbl + 1) 0 in
Array.iter
(fun b ->
let l = bucket_length_alive 0 b in
size := !size + l;
histo.(l) <- histo.(l) + 1)
h.data;
{ Hashtbl.num_bindings = !size;
num_buckets = Array.length h.data;
max_bucket_length = mbl;
bucket_histogram = histo }
end
end
module ObjEph = Obj.Ephemeron
let _obj_opt : Obj.t option -> 'a option = fun x ->
match x with
| None -> x
| Some v -> Some (Obj.obj v)
(** The previous function is typed so this one is also correct *)
let obj_opt : Obj.t option -> 'a option = fun x -> Obj.magic x
module K1 = struct
type ('k,'d) t = ObjEph.eph
let create () : ('k,'d) t = ObjEph.create 1
let get_key (t:('k,'d) t) : 'k option = obj_opt (ObjEph.get_key t 0)
let get_key_copy (t:('k,'d) t) : 'k option = obj_opt (ObjEph.get_key_copy t 0)
let set_key (t:('k,'d) t) (k:'k) : unit = ObjEph.set_key t 0 (Obj.repr k)
let unset_key (t:('k,'d) t) : unit = ObjEph.unset_key t 0
let check_key (t:('k,'d) t) : bool = ObjEph.check_key t 0
let blit_key (t1:('k,'d) t) (t2:('k,'d) t): unit =
ObjEph.blit_key t1 0 t2 0 1
let get_data (t:('k,'d) t) : 'd option = obj_opt (ObjEph.get_data t)
let get_data_copy (t:('k,'d) t) : 'd option = obj_opt (ObjEph.get_data_copy t)
let set_data (t:('k,'d) t) (d:'d) : unit = ObjEph.set_data t (Obj.repr d)
let unset_data (t:('k,'d) t) : unit = ObjEph.unset_data t
let check_data (t:('k,'d) t) : bool = ObjEph.check_data t
let blit_data (t1:(_,'d) t) (t2:(_,'d) t) : unit = ObjEph.blit_data t1 t2
module MakeSeeded (H:Hashtbl.SeededHashedType) =
GenHashTable.MakeSeeded(struct
type 'a container = (H.t,'a) t
type t = H.t
let create k d =
let c = create () in
set_data c d;
set_key c k;
c
let hash = H.hash
let equal k c =
(** {!get_key_copy} is not used because the equality of the user can be
the physical equality *)
match get_key c with
| None -> GenHashTable.EDead
| Some k' ->
if H.equal k k' then GenHashTable.ETrue else GenHashTable.EFalse
let get_data = get_data
let get_key = get_key
let set_data = set_data
let check_key = check_key
end)
module Make(H: Hashtbl.HashedType): (S with type key = H.t) =
struct
include MakeSeeded(struct
type t = H.t
let equal = H.equal
let hash (seed: int) x = H.hash x
end)
let create sz = create ~random:false sz
end
end
module K2 = struct
type ('k1, 'k2, 'd) t = ObjEph.eph
let create () : ('k1,'k2,'d) t = ObjEph.create 1
let get_key1 (t:('k1,'k2,'d) t) : 'k1 option = obj_opt (ObjEph.get_key t 0)
let get_key1_copy (t:('k1,'k2,'d) t) : 'k1 option =
obj_opt (ObjEph.get_key_copy t 0)
let set_key1 (t:('k1,'k2,'d) t) (k:'k1) : unit =
ObjEph.set_key t 0 (Obj.repr k)
let unset_key1 (t:('k1,'k2,'d) t) : unit = ObjEph.unset_key t 0
let check_key1 (t:('k1,'k2,'d) t) : bool = ObjEph.check_key t 0
let get_key2 (t:('k1,'k2,'d) t) : 'k2 option = obj_opt (ObjEph.get_key t 1)
let get_key2_copy (t:('k1,'k2,'d) t) : 'k2 option =
obj_opt (ObjEph.get_key_copy t 1)
let set_key2 (t:('k1,'k2,'d) t) (k:'k2) : unit =
ObjEph.set_key t 1 (Obj.repr k)
let unset_key2 (t:('k1,'k2,'d) t) : unit = ObjEph.unset_key t 1
let check_key2 (t:('k1,'k2,'d) t) : bool = ObjEph.check_key t 1
let blit_key1 (t1:('k1,_,_) t) (t2:('k1,_,_) t) : unit =
ObjEph.blit_key t1 0 t2 0 1
let blit_key2 (t1:(_,'k2,_) t) (t2:(_,'k2,_) t) : unit =
ObjEph.blit_key t1 1 t2 1 1
let blit_key12 (t1:('k1,'k2,_) t) (t2:('k1,'k2,_) t) : unit =
ObjEph.blit_key t1 0 t2 0 2
let get_data (t:('k1,'k2,'d) t) : 'd option = obj_opt (ObjEph.get_data t)
let get_data_copy (t:('k1,'k2,'d) t) : 'd option =
obj_opt (ObjEph.get_data_copy t)
let set_data (t:('k1,'k2,'d) t) (d:'d) : unit =
ObjEph.set_data t (Obj.repr d)
let unset_data (t:('k1,'k2,'d) t) : unit = ObjEph.unset_data t
let check_data (t:('k1,'k2,'d) t) : bool = ObjEph.check_data t
let blit_data (t1:(_,_,'d) t) (t2:(_,_,'d) t) : unit = ObjEph.blit_data t1 t2
module MakeSeeded
(H1:Hashtbl.SeededHashedType)
(H2:Hashtbl.SeededHashedType) =
GenHashTable.MakeSeeded(struct
type 'a container = (H1.t,H2.t,'a) t
type t = H1.t * H2.t
let create (k1,k2) d =
let c = create () in
set_data c d;
set_key1 c k1; set_key2 c k2;
c
let hash seed (k1,k2) =
H1.hash seed k1 + H2.hash seed k2 * 65599
let equal (k1,k2) c =
match get_key1 c, get_key2 c with
| None, _ | _ , None -> GenHashTable.EDead
| Some k1', Some k2' ->
if H1.equal k1 k1' && H2.equal k2 k2'
then GenHashTable.ETrue else GenHashTable.EFalse
let get_data = get_data
let get_key c =
match get_key1 c, get_key2 c with
| None, _ | _ , None -> None
| Some k1', Some k2' -> Some (k1', k2')
let set_data = set_data
let check_key c = check_key1 c && check_key2 c
end)
module Make(H1: Hashtbl.HashedType)(H2: Hashtbl.HashedType):
(S with type key = H1.t * H2.t) =
struct
include MakeSeeded
(struct
type t = H1.t
let equal = H1.equal
let hash (seed: int) x = H1.hash x
end)
(struct
type t = H2.t
let equal = H2.equal
let hash (seed: int) x = H2.hash x
end)
let create sz = create ~random:false sz
end
end
module Kn = struct
type ('k,'d) t = ObjEph.eph
let create n : ('k,'d) t = ObjEph.create n
let length (k:('k,'d) t) : int = ObjEph.length k
let get_key (t:('k,'d) t) (n:int) : 'k option = obj_opt (ObjEph.get_key t n)
let get_key_copy (t:('k,'d) t) (n:int) : 'k option =
obj_opt (ObjEph.get_key_copy t n)
let set_key (t:('k,'d) t) (n:int) (k:'k) : unit =
ObjEph.set_key t n (Obj.repr k)
let unset_key (t:('k,'d) t) (n:int) : unit = ObjEph.unset_key t n
let check_key (t:('k,'d) t) (n:int) : bool = ObjEph.check_key t n
let blit_key (t1:('k,'d) t) (o1:int) (t2:('k,'d) t) (o2:int) (l:int) : unit =
ObjEph.blit_key t1 o1 t2 o2 l
let get_data (t:('k,'d) t) : 'd option = obj_opt (ObjEph.get_data t)
let get_data_copy (t:('k,'d) t) : 'd option = obj_opt (ObjEph.get_data_copy t)
let set_data (t:('k,'d) t) (d:'d) : unit = ObjEph.set_data t (Obj.repr d)
let unset_data (t:('k,'d) t) : unit = ObjEph.unset_data t
let check_data (t:('k,'d) t) : bool = ObjEph.check_data t
let blit_data (t1:(_,'d) t) (t2:(_,'d) t) : unit = ObjEph.blit_data t1 t2
module MakeSeeded (H:Hashtbl.SeededHashedType) =
GenHashTable.MakeSeeded(struct
type 'a container = (H.t,'a) t
type t = H.t array
let create k d =
let c = create (Array.length k) in
set_data c d;
for i=0 to Array.length k -1 do
set_key c i k.(i);
done;
c
let hash seed k =
let h = ref 0 in
for i=0 to Array.length k -1 do
h := H.hash seed k.(i) * 65599 + !h;
done;
!h
let equal k c =
let len = Array.length k in
let len' = length c in
if len != len' then GenHashTable.EFalse
else
let rec equal_array k c i =
if i < 0 then GenHashTable.ETrue
else
match get_key c i with
| None -> GenHashTable.EDead
| Some ki ->
if H.equal k.(i) ki
then equal_array k c (i-1)
else GenHashTable.EFalse
in
equal_array k c (len-1)
let get_data = get_data
let get_key c =
let len = length c in
if len = 0 then Some [||]
else
match get_key c 0 with
| None -> None
| Some k0 ->
let rec fill a i =
if i < 1 then Some a
else
match get_key c i with
| None -> None
| Some ki ->
a.(i) <- ki;
fill a (i-1)
in
let a = Array.make len k0 in
fill a (len-1)
let set_data = set_data
let check_key c =
let rec check c i =
i < 0 || (check_key c i && check c (i-1)) in
check c (length c - 1)
end)
module Make(H: Hashtbl.HashedType): (S with type key = H.t array) =
struct
include MakeSeeded(struct
type t = H.t
let equal = H.equal
let hash (seed: int) x = H.hash x
end)
let create sz = create ~random:false sz
end
end