Signed-off-by: Magnus Therning <[email protected]>
uuid/uuid.ml | 39 ++++++++++++++++++++++++++++++++------- uuid/uuid.mli | 3 +++ 2 files changed, 35 insertions(+), 7 deletions(-)
# HG changeset patch # User Magnus Therning <[email protected]> # Date 1283529435 -3600 # Node ID f11174c80076be4e3351c63466ae6d1aaf5a367a # Parent a6aa72c10a1ab1e1f9a41cde012945d3a1a39d00 Add functions to get UUIDs of different qualities. Signed-off-by: Magnus Therning <[email protected]> diff -r a6aa72c10a1a -r f11174c80076 uuid/uuid.ml --- a/uuid/uuid.ml Fri Sep 03 16:57:08 2010 +0100 +++ b/uuid/uuid.ml Fri Sep 03 16:57:15 2010 +0100 @@ -30,12 +30,34 @@ let cookie_of_string s = s -(* FIXME: using /dev/random is too slow but using /dev/urandom is too - deterministic. *) -let dev_random = "/dev/urandom" +let dev_random = "/dev/random" +let dev_urandom = "/dev/urandom" -let read_random n = - let ic = open_in_bin dev_random in +let rnd_array n = + let fstbyte i = 0xff land i in + let sndbyte i = fstbyte (i lsr 8) in + let thdbyte i = sndbyte (i lsr 8) in + let rec rnd_list n acc = match n with + | 0 -> acc + | 1 -> + let b = fstbyte (Random.bits ()) in + b :: acc + | 2 -> + let r = Random.bits () in + let b1 = fstbyte r in + let b2 = sndbyte r in + b1 :: b2 :: acc + | n -> + let r = Random.bits () in + let b1 = fstbyte r in + let b2 = sndbyte r in + let b3 = thdbyte r in + rnd_list (n - 3) (b1 :: b2 :: b3 :: acc) + in + Array.of_list (rnd_list n []) + +let read_array dev n = + let ic = open_in_bin dev in try let result = Array.init n (fun _ -> input_byte ic) in close_in ic; @@ -50,10 +72,13 @@ uuid.(6) uuid.(7) uuid.(8) uuid.(9) uuid.(10) uuid.(11) uuid.(12) uuid.(13) uuid.(14) uuid.(15) -let make_uuid() = uuid_of_int_array (read_random 16) +let make_uuid_prng () = uuid_of_int_array (rnd_array 16) +let make_uuid_urnd () = uuid_of_int_array (read_array dev_urandom 16) +let make_uuid_rnd () = uuid_of_int_array (read_array dev_random 16) +let make_uuid = make_uuid_urnd let make_cookie() = - let bytes = Array.to_list (read_random 64) in + let bytes = Array.to_list (read_array dev_urandom 64) in String.concat "" (List.map (Printf.sprintf "%1x") bytes) let int_array_of_uuid s = diff -r a6aa72c10a1a -r f11174c80076 uuid/uuid.mli --- a/uuid/uuid.mli Fri Sep 03 16:57:08 2010 +0100 +++ b/uuid/uuid.mli Fri Sep 03 16:57:15 2010 +0100 @@ -27,6 +27,9 @@ (** Create a fresh UUID *) val make_uuid : unit -> 'a t +val make_uuid_prng : unit -> 'a t +val make_uuid_urnd : unit -> 'a t +val make_uuid_rnd : unit -> 'a t (** Create a UUID from a string. *) val of_string : string -> 'a t
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