Add a Flatbuffers containing object, and more variants
We now have DetachedBuffers which represent flatbuffers, the new
Flatbuffer object, and Table objects. It should be easy to merge and
copy these various objects now. (And print).
Change-Id: Ie8fcff1e97f0ae5a7ef8a3becb1be467010460dc
diff --git a/aos/flatbuffers.h b/aos/flatbuffers.h
new file mode 100644
index 0000000..6f6fc11
--- /dev/null
+++ b/aos/flatbuffers.h
@@ -0,0 +1,66 @@
+#ifndef AOS_FLATBUFFERS_H_
+#define AOS_FLATBUFFERS_H_
+
+#include "flatbuffers/flatbuffers.h"
+
+namespace aos {
+
+// TODO(austin): FlatbufferBase ? We can associate the type table with it, and
+// make it generic.
+
+// This object associates the message type with the memory storing the
+// flatbuffer. This only stores root tables.
+//
+// From a usage point of view, pointers to the data are very different than
+// pointers to the tables.
+template <typename T>
+class Flatbuffer {
+ public:
+ // Builds a Flatbuffer by taking ownership of the buffer.
+ Flatbuffer(flatbuffers::DetachedBuffer &&buffer)
+ : buffer_(::std::move(buffer)) {}
+
+ // Builds a flatbuffer by taking ownership of the buffer from the other
+ // flatbuffer.
+ Flatbuffer(Flatbuffer &&fb) : buffer_(::std::move(fb.buffer_)) {}
+ Flatbuffer &operator=(Flatbuffer &&fb) {
+ ::std::swap(buffer_, fb.buffer_);
+ return *this;
+ }
+
+ // Constructs an empty flatbuffer of type T.
+ static Flatbuffer<T> Empty() {
+ flatbuffers::FlatBufferBuilder fbb;
+ fbb.ForceDefaults(1);
+ const auto end = fbb.EndTable(fbb.StartTable());
+ fbb.Finish(flatbuffers::Offset<flatbuffers::Table>(end));
+ return Flatbuffer<T>(fbb.Release());
+ }
+
+ // Returns the MiniReflectTypeTable for T.
+ static const flatbuffers::TypeTable *MiniReflectTypeTable() {
+ return T::MiniReflectTypeTable();
+ }
+
+ // Returns a message from the buffer.
+ const T &message() const { return *flatbuffers::GetRoot<T>(buffer_.data()); }
+ // Returns a mutable message. It can be mutated via the flatbuffer rules.
+ T *mutable_message() {
+ return flatbuffers::GetMutableRoot<T>(buffer_.data());
+ }
+
+ // Returns references to the buffer, and the data.
+ const flatbuffers::DetachedBuffer &buffer() const { return buffer_; }
+ const uint8_t *data() const { return buffer_.data(); }
+
+ private:
+ flatbuffers::DetachedBuffer buffer_;
+};
+
+// TODO(austin): Need a fixed buffer version of Flatbuffer.
+// TODO(austin): Need a way to get our hands on the max size. Can start with
+// "large" for now.
+
+} // namespace aos
+
+#endif // AOS_FLATBUFFERS_H_