src/x_plane_data.erl

   1 -module(x_plane_data).
   2
   3 -include("x_plane_datum_defaults.hrl").
   4
   5 -export_type(
   6     [ t/0
   7     ]).
   8
   9 -export(
  10     [ of_bin/1
  11     ]).
  12
  13 -type parsing_error() ::
  14       packet_unrecognized
  15     | packet_length_invalid
  16     | x_plane_datum:parsing_error()
  17     .
  18
  19 -type t() ::
  20     [x_plane_datum:t()].
  21
  22 -define(BYTE_SIZE_OF_EACH_BLOCK, 36).
  23
  24 -spec of_bin(binary()) ->
  25     hope_result:t(t(), parsing_error()).
  26 of_bin(<<Packet/binary>>) ->
  27     of_bin(Packet, ?DEFAULT_MAX_INDEX).
  28
  29 -spec of_bin(binary(), non_neg_integer()) ->
  30     hope_result:t(t(), parsing_error()).
  31 of_bin(<<"DATA", _PacketIndexByte:1/bytes, ContiguousBlocks/binary>>, MaxIndex) ->
  32     % Packet index byte seems to be changing from X-Plane version to version.
  33     % What is it's meaning?
  34     if byte_size(ContiguousBlocks) rem ?BYTE_SIZE_OF_EACH_BLOCK =:= 0 ->
  35             Blocks = blocks_split(ContiguousBlocks),
  36             ParseBlock = fun (B) -> x_plane_datum:of_bin(B, MaxIndex) end,
  37             hope_list:map_result(Blocks, ParseBlock)
  38     ;  true ->
  39             {error, packet_length_invalid}
  40     end;
  41 of_bin(<<_/binary>>, _) ->
  42     {error, packet_unrecognized}.
  43
  44 -spec blocks_split(binary()) ->
  45     [binary()].
  46 blocks_split(<<>>) ->
  47     [];
  48 blocks_split(<<Block:?BYTE_SIZE_OF_EACH_BLOCK/bytes, Blocks/binary>>) ->
  49     [Block | blocks_split(Blocks)].