mojo/public/cpp/system/buffer.cc

// Copyright 2016 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/system/buffer.h"

namespace mojo {

// static
ScopedSharedBufferHandle SharedBufferHandle::Create(uint64_t num_bytes) {
  MojoCreateSharedBufferOptions options = {sizeof(options),
                                           MOJO_CREATE_SHARED_BUFFER_FLAG_NONE};
  SharedBufferHandle handle;
  MojoCreateSharedBuffer(num_bytes, &options, handle.mutable_value());
  return MakeScopedHandle(handle);
}

ScopedSharedBufferHandle SharedBufferHandle::Clone(
    SharedBufferHandle::AccessMode access_mode) const {
  ScopedSharedBufferHandle result;
  if (!is_valid())
    return result;

  MojoDuplicateBufferHandleOptions options = {
      sizeof(options), MOJO_DUPLICATE_BUFFER_HANDLE_FLAG_NONE};
  if (access_mode == AccessMode::READ_ONLY)
    options.flags |= MOJO_DUPLICATE_BUFFER_HANDLE_FLAG_READ_ONLY;
  SharedBufferHandle result_handle;
  MojoDuplicateBufferHandle(value(), &options, result_handle.mutable_value());
  result.reset(result_handle);
  return result;
}

ScopedSharedBufferMapping SharedBufferHandle::Map(uint64_t size) const {
  return MapAtOffset(size, 0);
}

ScopedSharedBufferMapping SharedBufferHandle::MapAtOffset(
    uint64_t size,
    uint64_t offset) const {
  void* buffer = nullptr;
  MojoMapBuffer(value(), offset, size, nullptr, &buffer);
  return ScopedSharedBufferMapping(buffer);
}

uint64_t SharedBufferHandle::GetSize() const {
  MojoSharedBufferInfo buffer_info;
  buffer_info.struct_size = sizeof(buffer_info);
  return MojoGetBufferInfo(value(), nullptr, &buffer_info) == MOJO_RESULT_OK
             ? buffer_info.size
             : 0;
}

}  // namespace mojo