* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
- * $Id: bitmatch.ml,v 1.12 2008-05-07 14:56:53 rjones Exp $
+ * $Id$
*)
open Printf
+include Bitmatch_types
+include Bitmatch_config
+
(* Enable runtime debug messages. Must also have been enabled
* in pa_bitmatch.ml.
*)
let bitstring_of_file fname =
let chan = open_in_bin fname in
- let bs = bitstring_of_chan chan in
- close_in chan;
- bs
+ try
+ let bs = bitstring_of_chan chan in
+ close_in chan;
+ bs
+ with exn ->
+ close_in chan;
+ raise exn
let bitstring_length (_, _, len) = len
let v = I.byteswap v flen in
v, off, len
+let extract_int_ne_unsigned =
+ if nativeendian = BigEndian
+ then extract_int_be_unsigned
+ else extract_int_le_unsigned
+
+let extract_int_ee_unsigned = function
+ | BigEndian -> extract_int_be_unsigned
+ | LittleEndian -> extract_int_le_unsigned
+ | NativeEndian -> extract_int_ne_unsigned
+
let _make_int32_be c0 c1 c2 c3 =
Int32.logor
(Int32.logor
let v = I32.byteswap v flen in
v, off, len
+let extract_int32_ne_unsigned =
+ if nativeendian = BigEndian
+ then extract_int32_be_unsigned
+ else extract_int32_le_unsigned
+
+let extract_int32_ee_unsigned = function
+ | BigEndian -> extract_int32_be_unsigned
+ | LittleEndian -> extract_int32_le_unsigned
+ | NativeEndian -> extract_int32_ne_unsigned
+
let _make_int64_be c0 c1 c2 c3 c4 c5 c6 c7 =
Int64.logor
(Int64.logor
(Int64.shift_left c6 8))
c7
+let _make_int64_le c0 c1 c2 c3 c4 c5 c6 c7 =
+ _make_int64_be c7 c6 c5 c4 c3 c2 c1 c0
+
(* Extract [1..64] bits. We have to consider endianness and signedness. *)
let extract_int64_be_unsigned data off len flen =
let byteoff = off lsr 3 in
) in
word, off+flen, len-flen
+let extract_int64_le_unsigned data off len flen =
+ let byteoff = off lsr 3 in
+
+ let strlen = String.length data in
+
+ let word =
+ (* Optimize the common (byte-aligned) case. *)
+ if off land 7 = 0 then (
+ let word =
+ let c0 = _get_byte64 data byteoff strlen in
+ let c1 = _get_byte64 data (byteoff+1) strlen in
+ let c2 = _get_byte64 data (byteoff+2) strlen in
+ let c3 = _get_byte64 data (byteoff+3) strlen in
+ let c4 = _get_byte64 data (byteoff+4) strlen in
+ let c5 = _get_byte64 data (byteoff+5) strlen in
+ let c6 = _get_byte64 data (byteoff+6) strlen in
+ let c7 = _get_byte64 data (byteoff+7) strlen in
+ _make_int64_le c0 c1 c2 c3 c4 c5 c6 c7 in
+ Int64.logand word (I64.mask flen)
+ ) else (
+ (* Extract the next 64 bits, slow method. *)
+ let word =
+ let c0, off, len = extract_char_unsigned data off len 8 in
+ let c1, off, len = extract_char_unsigned data off len 8 in
+ let c2, off, len = extract_char_unsigned data off len 8 in
+ let c3, off, len = extract_char_unsigned data off len 8 in
+ let c4, off, len = extract_char_unsigned data off len 8 in
+ let c5, off, len = extract_char_unsigned data off len 8 in
+ let c6, off, len = extract_char_unsigned data off len 8 in
+ let c7, _, _ = extract_char_unsigned data off len 8 in
+ let c0 = Int64.of_int c0 in
+ let c1 = Int64.of_int c1 in
+ let c2 = Int64.of_int c2 in
+ let c3 = Int64.of_int c3 in
+ let c4 = Int64.of_int c4 in
+ let c5 = Int64.of_int c5 in
+ let c6 = Int64.of_int c6 in
+ let c7 = Int64.of_int c7 in
+ _make_int64_le c0 c1 c2 c3 c4 c5 c6 c7 in
+ Int64.logand word (I64.mask flen)
+ ) in
+ word, off+flen, len-flen
+
+let extract_int64_ne_unsigned =
+ if nativeendian = BigEndian
+ then extract_int64_be_unsigned
+ else extract_int64_le_unsigned
+
+let extract_int64_ee_unsigned = function
+ | BigEndian -> extract_int64_be_unsigned
+ | LittleEndian -> extract_int64_le_unsigned
+ | NativeEndian -> extract_int64_ne_unsigned
+
(*----------------------------------------------------------------------*)
(* Constructor functions. *)
*)
let slenbytes = slen lsr 3 in
if slenbytes > 0 then Buffer.add_substring buf str 0 slenbytes;
- t.last <- Char.code str.[slenbytes] lsl (8 - (slen land 7))
+ let last = Char.code str.[slenbytes] in (* last char *)
+ let mask = 0xff lsl (8 - (slen land 7)) in
+ t.last <- last land mask
);
t.len <- len + slen
) else (
(* Target buffer is unaligned. Copy whole bytes using
* add_byte which knows how to deal with an unaligned
- * target buffer, then call _add_bits for the remaining < 8 bits.
+ * target buffer, then call add_bit for the remaining < 8 bits.
*
* XXX This is going to be dog-slow.
*)
let byte = Char.code str.[i] in
add_byte t byte
done;
- _add_bits t (Char.code str.[slenbytes]) (slen - (slenbytes lsl 3))
+ let bitsleft = slen - (slenbytes lsl 3) in
+ if bitsleft > 0 then (
+ let c = Char.code str.[slenbytes] in
+ for i = 0 to bitsleft - 1 do
+ let bit = c land (0x80 lsr i) <> 0 in
+ add_bit t bit
+ done
+ )
);
)
end
(* Add the bytes. *)
I.map_bytes_be (Buffer._add_bits buf) (Buffer.add_byte buf) v flen
+let construct_int_ne_unsigned =
+ if nativeendian = BigEndian
+ then construct_int_be_unsigned
+ else (*construct_int_le_unsigned*)
+ fun _ _ _ _ -> failwith "construct_int_le_unsigned"
+
+let construct_int_ee_unsigned = function
+ | BigEndian -> construct_int_be_unsigned
+ | LittleEndian -> (*construct_int_le_unsigned*)
+ (fun _ _ _ _ -> failwith "construct_int_le_unsigned")
+ | NativeEndian -> construct_int_ne_unsigned
+
(* Construct a field of exactly 32 bits. *)
let construct_int32_be_unsigned buf v flen _ =
Buffer.add_byte buf
Buffer.add_byte buf
(Int32.to_int (Int32.logand v 0xff_l))
+let construct_int32_le_unsigned buf v flen _ =
+ Buffer.add_byte buf
+ (Int32.to_int (Int32.logand v 0xff_l));
+ Buffer.add_byte buf
+ (Int32.to_int ((Int32.logand (Int32.shift_right_logical v 8) 0xff_l)));
+ Buffer.add_byte buf
+ (Int32.to_int ((Int32.logand (Int32.shift_right_logical v 16) 0xff_l)));
+ Buffer.add_byte buf
+ (Int32.to_int (Int32.shift_right_logical v 24))
+
+let construct_int32_ne_unsigned =
+ if nativeendian = BigEndian
+ then construct_int32_be_unsigned
+ else construct_int32_le_unsigned
+
+let construct_int32_ee_unsigned = function
+ | BigEndian -> construct_int32_be_unsigned
+ | LittleEndian -> construct_int32_le_unsigned
+ | NativeEndian -> construct_int32_ne_unsigned
+
(* Construct a field of up to 64 bits. *)
let construct_int64_be_unsigned buf v flen exn =
(* Check value is within range. *)
(* Add the bytes. *)
I64.map_bytes_be (Buffer._add_bits buf) (Buffer.add_byte buf) v flen
+let construct_int64_ne_unsigned =
+ if nativeendian = BigEndian
+ then construct_int64_be_unsigned
+ else (*construct_int64_le_unsigned*)
+ fun _ _ _ _ -> failwith "construct_int64_le_unsigned"
+
+let construct_int64_ee_unsigned = function
+ | BigEndian -> construct_int64_be_unsigned
+ | LittleEndian -> (*construct_int64_le_unsigned*)
+ (fun _ _ _ _ -> failwith "construct_int64_le_unsigned")
+ | NativeEndian -> construct_int64_ne_unsigned
+
(* Construct from a string of bytes, exact multiple of 8 bits
* in length of course.
*)
str.[i] <- Char.chr c;
loop data off len (i+1)
) else if len > 0 then (
- let c, off, len = extract_char_unsigned data off len len in
- str.[i] <- Char.chr c
+ let c, _, _ = extract_char_unsigned data off len len in
+ str.[i] <- Char.chr (c lsl (8-len))
)
in
loop data off len 0;
str
)
+(* To channel. *)
+
+let bitstring_to_chan ((data, off, len) as bits) chan =
+ (* Fail if the bitstring length isn't a multiple of 8. *)
+ if len land 7 <> 0 then invalid_arg "bitstring_to_chan";
+
+ if off land 7 = 0 then
+ (* Easy case: string is byte-aligned. *)
+ output chan data (off lsr 3) (len lsr 3)
+ else (
+ (* Bit-twiddling case: reuse string_of_bitstring *)
+ let str = string_of_bitstring bits in
+ output_string chan str
+ )
+
+let bitstring_to_file bits filename =
+ let chan = open_out_bin filename in
+ try
+ bitstring_to_chan bits chan;
+ close_out chan
+ with exn ->
+ close_out chan;
+ raise exn
+
(*----------------------------------------------------------------------*)
(* Display functions. *)
git.annexia.org / ocaml-bitstring.git / blobdiff