diff options
Diffstat (limited to 'lib/ocaml/src/TFramedTransport.ml')
-rw-r--r-- | lib/ocaml/src/TFramedTransport.ml | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/lib/ocaml/src/TFramedTransport.ml b/lib/ocaml/src/TFramedTransport.ml new file mode 100644 index 000000000..1be51e763 --- /dev/null +++ b/lib/ocaml/src/TFramedTransport.ml @@ -0,0 +1,93 @@ +open Thrift + +module T = Transport + +let c_0xff_32 = Int32.of_string "0xff" + +(* Copied from OCamlnet rtypes.ml *) +let encode_frame_size x = + let s = String.create 4 in + let n3 = Int32.to_int (Int32.shift_right_logical x 24) land 0xff in + let n2 = Int32.to_int (Int32.shift_right_logical x 16) land 0xff in + let n1 = Int32.to_int (Int32.shift_right_logical x 8) land 0xff in + let n0 = Int32.to_int (Int32.logand x c_0xff_32) in + String.unsafe_set s 0 (Char.unsafe_chr n3); + String.unsafe_set s 1 (Char.unsafe_chr n2); + String.unsafe_set s 2 (Char.unsafe_chr n1); + String.unsafe_set s 3 (Char.unsafe_chr n0); + s + +let decode_frame_size s = + let n3 = Int32.of_int (Char.code s.[0]) in + let n2 = Int32.of_int (Char.code s.[1]) in + let n1 = Int32.of_int (Char.code s.[2]) in + let n0 = Int32.of_int (Char.code s.[3]) in + Int32.logor + (Int32.shift_left n3 24) + (Int32.logor + (Int32.shift_left n2 16) + (Int32.logor + (Int32.shift_left n1 8) + n0)) + +class t ?(max_length=Sys.max_string_length) (transport: T.t) = +object (self) + inherit T.t + + method isOpen = transport#isOpen + method opn = transport#opn + method close = transport#close + + val mutable read_buf = None + val mutable read_buf_offset = 0 + val mutable write_buf = "" + + method private read_frame = + let len_buf = String.create 4 in + assert (transport#readAll len_buf 0 4 = 4); + + let size = Int32.to_int (decode_frame_size len_buf) in + + (if size < 0 + then failwith (Printf.sprintf "Read a negative frame size (%i)!" size)); + + (if size > max_length + then failwith (Printf.sprintf "Frame size (%i) larger than max length (%i)!" size max_length)); + + let buf = String.create size in + assert (transport#readAll buf 0 size = size); + read_buf <- Some buf; + read_buf_offset <- 0 + + method private read_from_frame frame buf off len = + let to_copy = min len ((String.length frame) - read_buf_offset) in + String.blit frame read_buf_offset buf off to_copy; + read_buf_offset <- read_buf_offset + to_copy; + to_copy + + method read buf off len = + match read_buf with + | Some frame -> + let i = self#read_from_frame frame buf off len in + if i > 0 + then i + else begin + self#read_frame; + self#read_from_frame frame buf off len + end + | None -> + self#read_frame; + self#read buf off len + + method write buf off len = + write_buf <- write_buf ^ (String.sub buf off len) + + method flush = + let encoded_size = encode_frame_size (Int32.of_int (String.length write_buf)) in + transport#write encoded_size 0 (String.length encoded_size); + transport#write write_buf 0 (String.length write_buf); + transport#flush; + write_buf <- "" +end + + |