Clarify licensing for Debian.

[ocaml-bitstring.git] / bitmatch.ml

diff --git a/bitmatch.ml b/bitmatch.ml
index 1d4b30f..249bbff 100644 (file)
--- a/bitmatch.ml
+++ b/bitmatch.ml
@@ -4,7 +4,8 @@
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
+ * version 2 of the License, or (at your option) any later version,
+ * with the OCaml linking exception described in COPYING.LIB.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -40,10 +41,19 @@ type bitstring = string * int * int
 (* Functions to create and load bitstrings. *)
 let empty_bitstring = "", 0, 0
 
-let make_bitstring len c = String.make ((len+7) lsr 3) c, 0, len
+let make_bitstring len c =
+  if len >= 0 then String.make ((len+7) lsr 3) c, 0, len
+  else
+    invalid_arg (
+      sprintf "make_bitstring/create_bitstring: len %d < 0" len
+    )
 
 let create_bitstring len = make_bitstring len '\000'
 
+let zeroes_bitstring = create_bitstring
+
+let ones_bitstring len = make_bitstring len '\xff'
+
 let bitstring_of_string str = str, 0, String.length str lsl 3
 
 let bitstring_of_chan chan =
@@ -420,6 +430,11 @@ let extract_int_ne_unsigned =
   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
@@ -480,6 +495,11 @@ let extract_int32_ne_unsigned =
   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
@@ -592,6 +612,11 @@ let extract_int64_ne_unsigned =
   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. *)
 
@@ -726,6 +751,12 @@ let construct_int_ne_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
@@ -737,11 +768,25 @@ let construct_int32_be_unsigned buf v flen _ =
   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*)
-    fun _ _ _ _ -> failwith "construct_int32_le_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 =
@@ -756,6 +801,12 @@ let construct_int64_ne_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.
  *)
@@ -763,6 +814,33 @@ let construct_string buf str =
   let len = String.length str in
   Buffer.add_bits buf str (len lsl 3)
 
+(* Construct from a bitstring. *)
+let construct_bitstring buf (data, off, len) =
+  (* Add individual bits until we get to the next byte boundary of
+   * the underlying string.
+   *)
+  let blen = 7 - ((off + 7) land 7) in
+  let blen = min blen len in
+  let rec loop off len blen =
+    if blen = 0 then (off, len)
+    else (
+      let b, off, len = extract_bit data off len 1 in
+      Buffer.add_bit buf b;
+      loop off len (blen-1)
+    )
+  in
+  let off, len = loop off len blen in
+  assert (len = 0 || (off land 7) = 0);
+
+  (* Add the remaining 'len' bits. *)
+  let data =
+    let off = off lsr 3 in
+    (* XXX dangerous allocation *)
+    if off = 0 then data
+    else String.sub data off (String.length data - off) in
+
+  Buffer.add_bits buf data len
+
 (*----------------------------------------------------------------------*)
 (* Extract a string from a bitstring. *)