mojo/public/cpp/bindings/lib/message_internal.cc

// Copyright 2017 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.

#include "mojo/public/cpp/bindings/lib/message_internal.h"

#include "mojo/public/cpp/bindings/lib/array_internal.h"
#include "mojo/public/cpp/bindings/message.h"

namespace mojo {
namespace internal {

namespace {

size_t ComputeHeaderSize(uint32_t flags, size_t payload_interface_id_count) {
  if (payload_interface_id_count > 0) {
    // Version 2
    return sizeof(MessageHeaderV2);
  } else if (flags &
             (Message::kFlagExpectsResponse | Message::kFlagIsResponse)) {
    // Version 1
    return sizeof(MessageHeaderV1);
  } else {
    // Version 0
    return sizeof(MessageHeader);
  }
}

}  // namespace

size_t ComputeSerializedMessageSize(uint32_t flags,
                                    size_t payload_size,
                                    size_t payload_interface_id_count) {
  const size_t header_size =
      ComputeHeaderSize(flags, payload_interface_id_count);
  if (payload_interface_id_count > 0) {
    return Align(header_size + Align(payload_size) +
                 ArrayDataTraits<uint32_t>::GetStorageSize(
                     static_cast<uint32_t>(payload_interface_id_count)));
  }
  return internal::Align(header_size + payload_size);
}

}  // namespace internal
}  // namespace mojo