src/marnav/ais/message_12.cpp

   1 #include <marnav/ais/message_12.hpp>
   2
   3 namespace marnav
   4 {
   5 namespace ais
   6 {
   7 constexpr message_id message_12::ID;
   8 constexpr std::size_t message_12::SIZE_BITS_HEAD;
   9 constexpr std::size_t message_12::SIZE_BITS_MAX;
  10 constexpr std::size_t message_12::SIZE_TEXT_MAX;
  11
  12 message_12::message_12()
  13         : message(ID)
  14 {
  15 }
  16
  17 message_12::message_12(const raw & bits)
  18         : message(ID)
  19 {
  20         if ((bits.size() < SIZE_BITS_HEAD) || (bits.size() > SIZE_BITS_MAX))
  21                 throw std::invalid_argument{"invalid number of bits in ais/message_12"};
  22         read_data(bits);
  23 }
  24
  25 void message_12::read_data(const raw & bits)
  26 {
  27         get(bits, repeat_indicator);
  28         get(bits, mmsi);
  29         get(bits, seqno);
  30         get(bits, dest_mmsi);
  31         get(bits, retransmit);
  32
  33         auto rest = bits.size() - SIZE_BITS_HEAD;
  34         if (rest > 0) {
  35                 rest = std::min(rest, SIZE_BITS_MAX - SIZE_BITS_HEAD);
  36                 text = read_string(bits, 72, rest / 6);
  37         }
  38 }
  39
  40 raw message_12::get_data() const
  41 {
  42         raw bits(SIZE_BITS_HEAD);
  43
  44         bits.set(type(), 0, 6);
  45         set(bits, repeat_indicator);
  46         set(bits, mmsi);
  47         set(bits, seqno);
  48         set(bits, dest_mmsi);
  49         set(bits, retransmit);
  50
  51         if (text.size() > 0) {
  52                 // compute number of bits, must be on a 8-bit boundary
  53                 auto size = text.size() * 6;
  54                 if ((size % 8) != 0)
  55                         size += 8 - (size % 8);
  56
  57                 if (size <= SIZE_BITS_MAX - SIZE_BITS_HEAD) {
  58                         // append a temporary bitset to the real one
  59                         raw t(size);
  60                         write_string(t, 0, text.size(), text);
  61                         bits.append(t);
  62                 }
  63         }
  64
  65         return bits;
  66 }
  67
  68 void message_12::set_seqno(uint32_t t)
  69 {
  70         if (t > 3u)
  71                 throw std::invalid_argument{"set_seqno out of range [0..3]"};
  72         seqno = t;
  73 }
  74
  75 void message_12::set_text(const std::string & t)
  76 {
  77         text = t.substr(0, std::min(t.size(), SIZE_TEXT_MAX));
  78 }
  79 }
  80 }