ceph/src/jaegertracing/thrift/lib/ocaml/src/TFramedTransport.ml

   1 open Thrift
   2
   3 module T = Transport
   4
   5 let c_0xff_32 = Int32.of_string "0xff"
   6
   7 (* Copied from OCamlnet rtypes.ml *)
   8 let encode_frame_size x =
   9         let s = String.create 4 in
  10         let n3 = Int32.to_int (Int32.shift_right_logical x 24) land 0xff in
  11         let n2 = Int32.to_int (Int32.shift_right_logical x 16) land 0xff in
  12         let n1 = Int32.to_int (Int32.shift_right_logical x 8) land 0xff in
  13         let n0 = Int32.to_int (Int32.logand x c_0xff_32) in
  14                 String.unsafe_set s 0 (Char.unsafe_chr n3);
  15                 String.unsafe_set s 1 (Char.unsafe_chr n2);
  16                 String.unsafe_set s 2 (Char.unsafe_chr n1);
  17                 String.unsafe_set s 3 (Char.unsafe_chr n0);
  18                 s
  19
  20 let decode_frame_size s =
  21         let n3 = Int32.of_int (Char.code s.[0]) in
  22         let n2 = Int32.of_int (Char.code s.[1]) in
  23         let n1 = Int32.of_int (Char.code s.[2]) in
  24         let n0 = Int32.of_int (Char.code s.[3]) in
  25                 Int32.logor
  26                 (Int32.shift_left n3 24)
  27                 (Int32.logor
  28                         (Int32.shift_left n2 16)
  29                         (Int32.logor
  30                                 (Int32.shift_left n1 8)
  31                                 n0))
  32
  33 class t ?(max_length=Sys.max_string_length) (transport: T.t) =
  34 object (self)
  35         inherit T.t
  36
  37         method isOpen = transport#isOpen
  38         method opn = transport#opn
  39         method close = transport#close
  40
  41         val mutable read_buf = None
  42         val mutable read_buf_offset = 0
  43         val mutable write_buf = ""
  44
  45         method private read_frame =
  46                 let len_buf = String.create 4 in
  47                 assert (transport#readAll len_buf 0 4 = 4);
  48
  49                 let size = Int32.to_int (decode_frame_size len_buf) in
  50
  51                 (if size < 0
  52                 then failwith (Printf.sprintf "Read a negative frame size (%i)!" size));
  53
  54                 (if size > max_length
  55                 then failwith (Printf.sprintf "Frame size (%i) larger than max length (%i)!" size max_length));
  56
  57                 let buf = String.create size in
  58                         assert (transport#readAll buf 0 size = size);
  59                         read_buf <- Some buf;
  60                         read_buf_offset <- 0
  61
  62         method private read_from_frame frame buf off len =
  63                 let to_copy = min len ((String.length frame) - read_buf_offset) in
  64                         String.blit frame read_buf_offset buf off to_copy;
  65                         read_buf_offset <- read_buf_offset + to_copy;
  66                         to_copy
  67
  68         method read buf off len =
  69                 match read_buf with
  70                 | Some frame ->
  71                         let i = self#read_from_frame frame buf off len in
  72                         if i > 0
  73                         then i
  74                         else begin
  75                                 self#read_frame;
  76                                 self#read_from_frame frame buf off len
  77                         end
  78                 | None ->
  79                                 self#read_frame;
  80                                 self#read buf off len
  81
  82         method write buf off len =
  83                 write_buf <- write_buf ^ (String.sub buf off len)
  84
  85         method flush =
  86                 let encoded_size = encode_frame_size (Int32.of_int (String.length write_buf)) in
  87                         transport#write encoded_size 0 (String.length encoded_size);
  88                         transport#write write_buf 0 (String.length write_buf);
  89                         transport#flush;
  90                         write_buf <- ""
  91 end
  92
  93