Parse Clutter Filter Map (Message 15)

wxdata/source/scwx/wsr88d/rda/message_factory.cpp

@@ -0,0 +1,130 @@
+#include <scwx/wsr88d/rda/message_factory.hpp>
+
+#include <scwx/util/vectorbuf.hpp>
+#include <scwx/wsr88d/rda/clutter_filter_map.hpp>
+
+#include <istream>
+#include <unordered_map>
+#include <vector>
+
+#include <boost/log/trivial.hpp>
+
+namespace scwx
+{
+namespace wsr88d
+{
+namespace rda
+{
+
+static const std::string logPrefix_ = "[scwx::wsr88d::rda::message_factory] ";
+
+typedef std::function<std::unique_ptr<Message>(MessageHeader&&, std::istream&)>
+   CreateMessageFunction;
+
+static const std::unordered_map<uint8_t, CreateMessageFunction> create_ {
+   {15, ClutterFilterMap::Create}};
+
+static std::vector<char> messageData_;
+static size_t            bufferedSize_;
+static util::vectorbuf   messageBuffer_(messageData_);
+static std::istream      messageBufferStream_(&messageBuffer_);
+
+MessageInfo MessageFactory::Create(std::istream& is)
+{
+   MessageInfo   info;
+   MessageHeader header;
+   info.headerValid  = header.Parse(is);
+   info.messageValid = info.headerValid;
+
+   if (info.headerValid && create_.find(header.message_type()) == create_.end())
+   {
+      BOOST_LOG_TRIVIAL(warning)
+         << logPrefix_ << "Unknown message type: "
+         << static_cast<unsigned>(header.message_type());
+      info.messageValid = false;
+   }
+
+   if (info.messageValid)
+   {
+      uint16_t segment       = header.message_segment_number();
+      uint16_t totalSegments = header.number_of_message_segments();
+      uint8_t  messageType   = header.message_type();
+      size_t   dataSize      = header.message_size() * 2 - MessageHeader::SIZE;
+
+      std::istream* messageStream = nullptr;
+
+      if (totalSegments == 1)
+      {
+         BOOST_LOG_TRIVIAL(trace) << logPrefix_ << "Found Message "
+                                  << static_cast<unsigned>(messageType);
+         messageStream = &is;
+      }
+      else
+      {
+         BOOST_LOG_TRIVIAL(trace)
+            << logPrefix_ << "Found Message "
+            << static_cast<unsigned>(messageType) << " Segment " << segment
+            << "/" << totalSegments;
+
+         if (segment == 1)
+         {
+            // Estimate total message size
+            messageData_.reserve(dataSize * totalSegments);
+            bufferedSize_ = 0;
+         }
+
+         if (messageData_.capacity() < bufferedSize_ + dataSize)
+         {
+            BOOST_LOG_TRIVIAL(debug)
+               << logPrefix_ << "Bad size estimate, increasing size";
+
+            // Estimate remaining size
+            uint16_t remainingSegments =
+               std::max<uint16_t>(totalSegments - segment + 1, 100u);
+            size_t remainingSize = remainingSegments * dataSize;
+
+            messageData_.reserve(bufferedSize_ + remainingSize);
+         }
+
+         is.read(messageData_.data() + bufferedSize_, dataSize);
+         bufferedSize_ += dataSize;
+
+         if (is.eof())
+         {
+            BOOST_LOG_TRIVIAL(warning)
+               << logPrefix_ << "End of file reached trying to buffer message";
+            info.messageValid = false;
+            messageData_.shrink_to_fit();
+            bufferedSize_ = 0;
+         }
+         else if (segment == totalSegments)
+         {
+            messageBuffer_.update_read_pointers(bufferedSize_);
+            header.set_message_size(
+               static_cast<uint16_t>(bufferedSize_ / 2 + MessageHeader::SIZE));
+
+            messageStream = &messageBufferStream_;
+         }
+      }
+
+      if (messageStream != nullptr)
+      {
+         info.message =
+            create_.at(messageType)(std::move(header), *messageStream);
+         messageData_.shrink_to_fit();
+         bufferedSize_ = 0;
+      }
+   }
+   else if (info.headerValid)
+   {
+      // Seek to the end of the current message
+      is.seekg(header.message_size() * 2 - rda::MessageHeader::SIZE,
+               std::ios_base::cur);
+   }
+
+   return info;
+}
+
+} // namespace rda
+} // namespace wsr88d
+} // namespace scwx