1 files changed, 59 insertions, 0 deletions
diff --git a/cast/sender/channel/cast_framer.h b/cast/sender/channel/cast_framer.h
new file mode 100644
index 00000000..8fbabfd3
--- /dev/null
+++ b/cast/sender/channel/cast_framer.h
@@ -0,0 +1,59 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CAST_SENDER_CHANNEL_CAST_FRAMER_H_
+#define CAST_SENDER_CHANNEL_CAST_FRAMER_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <memory>
+#include <string>
+
+#include "absl/types/span.h"
+#include "platform/base/error.h"
+
+namespace cast {
+namespace channel {
+
+class CastMessage;
+
+using openscreen::ErrorOr;
+
+// Class for constructing and parsing CastMessage packet data.
+class MessageFramer {
+ public:
+  // Serializes |message_proto| into |message_data|.
+  // Returns true if the message was serialized successfully, false otherwise.
+  static ErrorOr<std::string> Serialize(const CastMessage& message);
+
+  explicit MessageFramer(absl::Span<uint8_t> input_buffer);
+  ~MessageFramer();
+
+  // The number of bytes required from the next |input_buffer| passed to
+  // TryDeserialize to complete the CastMessage being read.  Returns zero if
+  // there has been a parsing error.
+  ErrorOr<size_t> BytesRequested() const;
+
+  // Reads bytes from |input_buffer_| and returns a new CastMessage if one is
+  // fully read.
+  //
+  // |byte_count|     Number of additional bytes available in |input_buffer_|.
+  // Returns a pointer to a parsed CastMessage if a message was received in its
+  // entirety, empty unique_ptr if parsing was successful but didn't produce a
+  // complete message, and an error otherwise.
+  ErrorOr<CastMessage> TryDeserialize(size_t byte_count);
+
+ private:
+  // Total size of the message received so far in bytes (head + body).
+  size_t message_bytes_received_ = 0;
+
+  // Data buffer wherein the caller should place message data for ingest.
+  absl::Span<uint8_t> input_buffer_;
+};
+
+}  // namespace channel
+}  // namespace cast
+
+#endif  // CAST_SENDER_CHANNEL_CAST_FRAMER_H_