better cbor handling

1 files changed, 49 insertions, 0 deletions

diff --git a/src/audio/include/stream_message.hpp b/src/audio/include/stream_message.hpp
index 2791dcd8..cbd7c733 100644
--- a/src/audio/include/stream_message.hpp
+++ b/src/audio/include/stream_message.hpp
@@ -1,11 +1,60 @@
 #pragma once
 
+#include <stdint.h>
+
+#include <functional>
+#include <optional>
+
+#include "cbor.h"
+#include "result.hpp"
+
 namespace audio {
 
+extern const int kEncoderFlags;
+extern const int kDecoderFlags;
+
 enum MessageType {
   TYPE_UNKNOWN,
   TYPE_CHUNK_HEADER,
   TYPE_STREAM_INFO,
 };
 
+template <typename Writer>
+auto WriteMessage(MessageType type,
+                  Writer&& writer,
+                  uint8_t* buffer,
+                  size_t length) -> cpp::result<size_t, CborError> {
+  CborEncoder root;
+  CborEncoder container;
+
+  cbor_encoder_init(&root, buffer, length, kEncoderFlags);
+  cbor_encoder_create_array(&root, &container, 2);
+  cbor_encode_uint(&container, type);
+
+  std::optional<CborError> inner_err = std::invoke(writer, container);
+  if (inner_err) {
+    return cpp::fail(inner_err.value());
+  }
+
+  cbor_encoder_close_container(&root, &container);
+  return cbor_encoder_get_buffer_size(&root, buffer);
+}
+
+template <typename Result, typename Reader>
+auto ReadMessage(Reader&& reader, uint8_t* buffer, size_t length)
+    -> cpp::result<Result, CborError> {
+  CborParser parser;
+  CborValue root;
+  CborValue container;
+
+  cbor_parser_init(buffer, length, kDecoderFlags, &parser, &root);
+  cbor_value_enter_container(&root, &container);
+  // Skip the type header
+  cbor_value_advance_fixed(&container);
+
+  return std::invoke(reader, container);
+}
+
+auto ReadMessageType(uint8_t* buffer, size_t length) -> MessageType;
+
 }  // namespace audio