OpenLCP/protocol/esta/sacn/receiver.cpp

/*
  receiver.cpp

  Copyright (c) 2020 Kevin Matz (kevin.matz@gmail.com)

  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
*/

#include "config.h"
#include "pdu.h"
#include "receiver.h"
#include "sacn.h"
#include "universearbitrator.h"

namespace sACN {

/**
 * @brief Receiver::Receiver
 * @param cid
 * @param fctn
 *
 * Constructor.  Register RLP vector callbacks.
 */
Receiver::Receiver(UUID::uuid cid, std::string fctn)
  : Component(cid, fctn)
  , discovery_enabled_(false)
{
  RlpRegisterVector(VECTOR_ROOT_E131_DATA, std::bind(&Receiver::dataReceiver,
                                                  this, std::placeholders::_1));
  RlpRegisterVector(VECTOR_ROOT_E131_EXTENDED, std::bind(&Receiver::extendedReceiver,
                                                  this, std::placeholders::_1));
}


/**
 * @brief Receiver::~Receiver
 */
Receiver::~Receiver()
{
  for (auto& [num, _] : universes_)
    Receiver::unsubscribe(num);
}


/**
 * @brief Receiver::subscribe
 * @param num
 */
void Receiver::subscribe(const uint16_t num)
{
  if (num == sACN::E131_DISCOVERY_UNIVERSE || universes_.count(num))
    return;
  const auto [it, ok] = universes_.emplace(num, std::make_shared<Universe>(nullptr, this));
  if (!ok)
    return;
  auto univ = it->second;
  univ->metadata()->universe = num;
}


/**
 * @brief Receiver::unsubscribe
 * @param num
 */
void Receiver::unsubscribe(const uint16_t num)
{
  if (universes_.count(num))
    universes_.erase(num);
}


/**
 * @brief Receiver::universe
 * @param num
 * @return
 */
std::shared_ptr<Universe> Receiver::universe(const uint16_t num) const
{
  if (!universes_.count(num))
    return nullptr;
#ifdef RTTI_ENABLED
  return std::dynamic_pointer_cast<Universe>(universes_.at(num));
#else
  return std::static_pointer_cast<Universe>(universes_.at(num));
#endif
}


/**
 * @brief Receiver::discoveryStart
 */
void Receiver::discoveryStart()
{
  subscribe(sACN::E131_DISCOVERY_UNIVERSE);
  discovery_enabled_ = true;
}


/**
 * @brief Receiver::discoveryStop
 */
void Receiver::discoveryStop()
{
  unsubscribe(sACN::E131_DISCOVERY_UNIVERSE);
  discovery_enabled_ = false;
  discovered.clear();
  for (const auto& cb : discoveryCallbacks_)
      cb();
}


/**
 * @brief Receiver::onDiscovered
 * @param cb something that wants to know about available universes.
 */
void Receiver::onDiscovered(const std::function<void()> cb)
{
  discoveryCallbacks_.push_back(cb);
}


/**
 * @brief Receiver::dataReceiver - dispatcher of RLP DATA PDU
 * @param root a shared pointer to the PDU
 *
 * Receive VECTOR_ROOT_E131_DATA vector'd packets.
 */
void Receiver::dataReceiver(ACN::PDU::Message<ACN::RLP::Pdu> root)
{
  root->createDataBlock<DATA::Pdu>();
  // a PDU::Block is guaranteed to have been instantiated, but if the input
  // stream failed, it will not list any PDU.  OK to loop without checking
  // the state of the stream.
#ifdef RTTI_ENABLED
  auto block = std::dynamic_pointer_cast<ACN::PDU::Block<DATA::Pdu>>(root->data());
#else
  auto block = std::static_pointer_cast<ACN::PDU::Block<DATA::Pdu>>(root->data());
#endif
  for(auto const &frame : *block->pdu)
    {
      /// > \cite sACN 6.2.1 E1.31 Data Packet: Vector
      /// >
      /// > Sources sending an E1.31 Data Packet shall set the E1.31 Layer's
      /// > Vector to VECTOR_E131_DATA_PACKET. This value indicates that the
      /// > E1.31 framing layer is wrapping a DMP PDU.
      switch(frame->vector()) {
        case VECTOR_E131_DATA_PACKET:
          dataFrameHandler(frame);
          break;
        default:
          break;
        }
    }
}


/**
 * @brief Receiver::extendedReceiver - dispatcher of RLP EXTENDED PDU
 * @param root a shared pointer to the PDU
 *
 * Receive VECTOR_ROOT_E131_EXTENDED vector'd packets.
 */
void Receiver::extendedReceiver(ACN::PDU::Message<ACN::RLP::Pdu> root)
{
  root->createDataBlock<EXTENDED::Pdu>();
  // a PDU::Block is guaranteed to have been instantiated, but if the input
  // stream failed, it will not list any PDU.  OK to loop without checking
  // the state of the stream.
#ifdef RTTI_ENABLED
  auto block = std::dynamic_pointer_cast<ACN::PDU::Block<EXTENDED::Pdu>>(root->data());
#else
  auto block = std::static_pointer_cast<ACN::PDU::Block<EXTENDED::Pdu>>(root->data());
#endif
  for(auto const &frame : *block->pdu)
    {
      switch(frame->vector()) {
        /// \cite sACN 6.3 E1.31 Synchronization Packet Framing Layer
        case VECTOR_E131_EXTENDED_SYNCHRONIZATION:
          syncFrameHandler(frame);
          break;
         /// \cite sACN 6.4 E1.31 Universe Discovery Packet Framing Layer
        case VECTOR_E131_EXTENDED_DISCOVERY:
          if (discovery_enabled_)
            discoveryFrameHandler(frame);
          break;
        default:
          break;
        }
    }
}


/**
 * @brief Receiver::dataFrameHandler
 * @param frame
 *
 * Receive `VECTOR_ROOT_E131_DATA -> VECTOR_E131_DATA_PACKET` vector'd packets.
 *
 * Merging will be based on frame header.  PDU data will be read as a block of
 * DMP PDUs and passed to the universe.
 */
void Receiver::dataFrameHandler(ACN::PDU::Message<DATA::Pdu> frame)
{
#ifdef RTTI_ENABLED
    auto metadata = std::dynamic_pointer_cast<DATA::data_header>(frame->header());
#else
    auto metadata = std::static_pointer_cast<DATA::data_header>(frame->header());
#endif

  if (!universes_.count(metadata->universe))
    return; // not subscribed to this universe

  auto universe = universes_.at(metadata->universe)->arbitrator()->sourceUniverse(*metadata);
  if (!universe)
    universe = universes_.at(metadata->universe)->arbitrator()->addNewSource(*metadata);

  /// > \cite sACN 6.2.6 E1.31 Data Packet: Options
  /// >
  /// > Preview_Data: Bit 7 (most significant bit)
  /// > This bit, when set to 1, indicates that the data in this packet is
  /// > intended for use in visualization or media server preview applications
  /// > and shall not be used to generate live output.
  /// \bug Preview_Data flag causes the frame to be ignored.
  if (metadata->options.preview_data)
    return;

  /// > \cite sACN 6.2.6 E1.31 Data Packet: Options
  /// >
  /// > Stream_Terminated: Bit 6
  /// >
  /// > allow E1.31 sources to terminate transmission of a stream or of
  /// > universe synchronization without waiting for a timeout to occur.
  if (metadata->options.stream_terminated)
    {
      /// Remove the terminated universe as sources.
      /// The universe may keep itself, in a terminated state, for hold-last-look.
      universes_.at(metadata->universe)->arbitrator()->deleteSourceUniverse(*metadata);
      /// > Any property values in an E1.31 Data Packet containing this bit
      /// > shall be ignored.
      return;
    }

  /// > \cite sACN 6.2.4.1 Synchronization Address Usage in an E1.31 Data Packet
  /// >
  /// > a value of 0 in the Synchronization Address indicates that the universe
  /// > data is not synchronized.
  if (metadata->sync_address == 0 ||
    /// > \cite sACN 6.2.6 E1.31 Data Packet: Options Force_Synchronization
    /// >
    /// > This bit indicates whether to lock or revert to an unsynchronized
    /// > state when synchronization is lost. When set to 0, components that
    /// > had been operating in a synchronized state shall not update with
    /// > any new packets until synchronization resumes. When set to 1, once
    /// > synchronization has been lost, components that had been operating
    /// > in a synchronized state need not wait for a new E1.31
    /// > Synchronization Packet in order to update to the next E1.31 Data
    /// > Packet.
      (universe->isSyncronized() &&
       metadata->options.force_synchronization &&
       universe->rxRate() == 0))
  {
    universe->resetSynchronization();
  }
  else
  {
    subscribe(metadata->sync_address);
#ifdef RTTI_ENABLED
    auto block = std::dynamic_pointer_cast<ACN::PDU::Block<ACN::DMP::Pdu>>(frame->data());
#else
    auto block = std::static_pointer_cast<ACN::PDU::Block<ACN::DMP::Pdu>>(frame->data());
#endif
    if (!block->pdu->empty())
      {
#ifdef RTTI_ENABLED
        auto dmp = std::dynamic_pointer_cast<ACN::DMP::Pdu>(block->pdu->front());
        auto list = std::dynamic_pointer_cast<ACN::DMP::address_pair_list>(dmp->data());
#else
        auto dmp = std::static_pointer_cast<ACN::DMP::Pdu>(block->pdu->front());
        auto list = std::static_pointer_cast<ACN::DMP::address_pair_list>(dmp->data());
#endif
        if (!list->properties.empty())
          {
            const auto & [_, data] = list->properties.front();
            universe->setMetadata(metadata);
            universe->setSyncData(data);
          }
      }
    return;
  }

  /// > \cite sACN 6.7.2 Sequence Numbering
  /// >
  /// > Having first received a packet with sequence number A,
  /// > a second packet with sequence number B arrives.
  /// > If, using signed 8-bit binary arithmetic, B - A
  /// > is less than or equal to 0, but greater than -20,
  /// > then the packet containing sequence number B shall be deemed out of
  /// > sequence and discarded.
  auto a = universe->metadata()->sequence_number;
  auto b = metadata->sequence_number;
  int dif = b - a;
  if (dif <= 0 && dif > -20)
    return; // too far out of sequence

  // PDU data will be a block of DMP
#ifdef RTTI_ENABLED
  auto block = std::dynamic_pointer_cast<ACN::PDU::Block<ACN::DMP::Pdu>>(frame->data());
#else
  auto block = std::static_pointer_cast<ACN::PDU::Block<ACN::DMP::Pdu>>(frame->data());
#endif
  universe->setMetadata(metadata);
  universe->DmpReceiver(block);

  // do ArbitratingUniverse maintence tasks
  universes_.at(metadata->universe)->arbitrator()->refresh();
}


/**
 * @brief Receiver::syncFrameHandler
 * @param frame
 */
void Receiver::syncFrameHandler(ACN::PDU::Message<EXTENDED::Pdu> frame)
{
#ifdef RTTI_ENABLED
  auto header = std::dynamic_pointer_cast<EXTENDED::sync_header>(frame->header());
#else
  auto header = std::static_pointer_cast<EXTENDED::sync_header>(frame->header());
#endif
  universes_.at(header->sync_address)->synchronize(header->sequence_number);
}


/**
 * @brief Receiver::discoveryFrameHandler
 * @param frame
 */
void Receiver::discoveryFrameHandler(ACN::PDU::Message<EXTENDED::Pdu> frame) {
#ifdef RTTI_ENABLED
  auto block = std::dynamic_pointer_cast<ACN::PDU::Block<EXTENDED::DISCOVERY::Pdu>>(frame->data());
#else
  auto block = std::static_pointer_cast<ACN::PDU::Block<EXTENDED::DISCOVERY::Pdu>>(frame->data());
#endif
  for(auto const &pdu : *block->pdu)
    {
      /// > \cite sACN 8 Universe Discovery Layer
      /// >
      /// > Universe Discovery data only appears in E1.31 Universe Discovery
      /// > Packets and shall not be included in E1.31 Data Packets or E1.31
      /// > Synchronization Packets.
      switch(pdu->vector()) {
        case VECTOR_UNIVERSE_DISCOVERY_UNIVERSE_LIST:
          discoveryListHanlder(pdu);
          break;
        default:
          break;
        }
    }
}


/**
 * @brief Receiver::discoveryListHanlder
 * @param pdu
 */
void Receiver::discoveryListHanlder(ACN::PDU::Message<EXTENDED::DISCOVERY::Pdu> pdu) {
#ifdef RTTI_ENABLED
    auto rlpHeader = std::dynamic_pointer_cast<ACN::RLP::rlp_header>
        (pdu->parent()->parent()->header());
    auto frameHeader = std::dynamic_pointer_cast<EXTENDED::discovery_header>
        (pdu->parent()->header());
    auto header = std::dynamic_pointer_cast<EXTENDED::DISCOVERY::discovery_list_header>
        (pdu->header());
    auto data = std::dynamic_pointer_cast<EXTENDED::DISCOVERY::discovery_list_data>
        (pdu->data());
#else
    auto rlpHeader = std::static_pointer_cast<ACN::RLP::rlp_header>
        (pdu->parent()->parent()->header());
    auto frameHeader = std::static_pointer_cast<EXTENDED::discovery_header>
        (pdu->parent()->header());
    auto header = std::static_pointer_cast<EXTENDED::DISCOVERY::discovery_list_header>
        (pdu->header());
    auto data = std::static_pointer_cast<EXTENDED::DISCOVERY::discovery_list_data>
        (pdu->data());
#endif

  // on the first page:
  if (header->page == 0)
    // wipe all known discoveries from this CID
    for (auto disc = discovered.begin(); disc != discovered.end();)
      {
        if (disc->get()->source == rlpHeader->cid)
          disc = discovered.erase(disc);
        else
          ++disc;
      }

  for (auto& found : data->found)
    {
      found->source = rlpHeader->cid;
      found->description = frameHeader->source_name;
      discovered.insert(found);
    }

  // on the last page:
  if (header->page == header->last_page)
    // notify that changes are complete
    for (const auto& cb : discoveryCallbacks_)
      cb();
}


}; // SACN