iceoryx_posh/mepoo/chunk_header.hpp

Namespaces

Name
iox
iox::popo
iox::mepoo

Classes

	Name
struct	iox::mepoo::NoUserHeader Helper struct to use as default template parameter when no user-header is used.
struct	iox::mepoo::ChunkHeader

Source code

// Copyright (c) 2019 - 2020 by Robert Bosch GmbH. All rights reserved.
// Copyright (c) 2020 - 2022 by Apex.AI Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// SPDX-License-Identifier: Apache-2.0
#ifndef IOX_POSH_MEPOO_CHUNK_HEADER_HPP
#define IOX_POSH_MEPOO_CHUNK_HEADER_HPP

#include "iceoryx_posh/iceoryx_posh_types.hpp"
#include "iceoryx_posh/internal/popo/building_blocks/unique_port_id.hpp"
#include "iceoryx_posh/mepoo/chunk_settings.hpp"

#include <cstdint>

namespace iox
{
namespace popo
{
template <typename T>
class ChunkSender;
}

namespace mepoo
{
struct NoUserHeader
{
};

struct ChunkHeader
{
    using UserPayloadOffset_t = uint32_t;

    ChunkHeader(const uint32_t chunkSize, const ChunkSettings& chunkSettings) noexcept;

    // copy/move ctors/assignment operators are deleted since the calculations for the user-header and user-payload
    // alignment are dependent on the address of the this pointer
    ChunkHeader(const ChunkHeader&) = delete;
    ChunkHeader(ChunkHeader&&) = delete;

    ChunkHeader& operator=(const ChunkHeader&) = delete;
    ChunkHeader& operator=(ChunkHeader&&) = delete;

    static constexpr uint8_t CHUNK_HEADER_VERSION{1U};

    static constexpr uint16_t NO_USER_HEADER{0x0000};
    static constexpr uint16_t UNKNOWN_USER_HEADER{0xFFFF};

    uint8_t chunkHeaderVersion() const noexcept;

    uint16_t userHeaderId() const noexcept;

    void* userHeader() noexcept;

    const void* userHeader() const noexcept;

    void* userPayload() noexcept;

    const void* userPayload() const noexcept;

    static ChunkHeader* fromUserPayload(void* const userPayload) noexcept;

    static const ChunkHeader* fromUserPayload(const void* const userPayload) noexcept;

    static ChunkHeader* fromUserHeader(void* const userHeader) noexcept;

    static const ChunkHeader* fromUserHeader(const void* const userHeader) noexcept;

    uint32_t usedSizeOfChunk() const noexcept;

    uint32_t chunkSize() const noexcept;

    uint32_t userHeaderSize() const noexcept;

    uint32_t userPayloadSize() const noexcept;

    uint32_t userPayloadAlignment() const noexcept;

    popo::UniquePortId originId() const noexcept;

    uint64_t sequenceNumber() const noexcept;

  private:
    template <typename T>
    friend class popo::ChunkSender;

    void setOriginId(const popo::UniquePortId originId) noexcept;

    void setSequenceNumber(const uint64_t sequenceNumber) noexcept;

    uint64_t overflowSafeUsedSizeOfChunk() const noexcept;

  private:
    // the order of these members must be changed carefully and if this happens, the m_chunkHeaderVersion
    // needs to be adapted in order to be able to detect incompatibilities between publisher/subscriber
    // or record&replay, m_chunkSize and m_chunkHeaderVersion should therefore neither changed the type,
    // nor the position

    // size of the whole chunk, including the header
    uint32_t m_chunkSize{0U};
    uint8_t m_chunkHeaderVersion{CHUNK_HEADER_VERSION};
    // reserved for future functionality and used to indicate the padding bytes; currently not used and set to `0`
    uint8_t m_reserved{0};
    // currently just a placeholder
    uint16_t m_userHeaderId{NO_USER_HEADER};
    popo::UniquePortId m_originId{popo::InvalidPortId};
    uint64_t m_sequenceNumber{0U};
    uint32_t m_userHeaderSize{0U};
    uint32_t m_userPayloadSize{0U};
    uint32_t m_userPayloadAlignment{1U};
    UserPayloadOffset_t m_userPayloadOffset{sizeof(ChunkHeader)};
};

} // namespace mepoo
} // namespace iox

#endif // IOX_POSH_MEPOO_CHUNK_HEADER_HPP

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Updated on 2 April 2022 at 16:37:47 CEST