sample.hpp

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// Copyright (c) 2024 Contributors to the Eclipse Foundation
//
// See the NOTICE file(s) distributed with this work for additional
// information regarding copyright ownership.
//
// This program and the accompanying materials are made available under the
// terms of the Apache Software License 2.0 which is available at
// https://www.apache.org/licenses/LICENSE-2.0, or the MIT license
// which is available at https://opensource.org/licenses/MIT.
//
// SPDX-License-Identifier: Apache-2.0 OR MIT
 
#ifndef IOX2_SAMPLE_HPP
#define IOX2_SAMPLE_HPP
 
#include "iox2/bb/slice.hpp"
#include "iox2/header_publish_subscribe.hpp"
#include "iox2/iceoryx2_cxx_deployment.hpp"
#include "iox2/internal/iceoryx2.hpp"
#include "iox2/marker.hpp"
#include "iox2/payload_info.hpp"
#include "iox2/service_type.hpp"
#include "iox2/unique_port_id.hpp"
 
#include <type_traits>
 
#if IOX2_FEATURE_FLATBUFFERS
#include <cstdint>
#include <flatbuffers/flatbuffers.h>
#endif
 
namespace iox2 {
 
template <ServiceType, typename Payload, typename UserHeader>
// NOLINTNEXTLINE(cppcoreguidelines-pro-type-member-init,hicpp-member-init) 'm_sample' is not used directly but only via the initialized 'm_handle'; furthermore, it will be initialized on the call site
class Sample {
    using ValueType = typename PayloadInfo<Payload>::ValueType;
 
  public:
    Sample(Sample&& rhs) noexcept;
    auto operator=(Sample&& rhs) noexcept -> Sample&;
    ~Sample();
 
    Sample(const Sample&) = delete;
    auto operator=(const Sample&) -> Sample& = delete;
 
    template <typename T = Payload,
              typename = std::enable_if_t<!bb::IsSlice<T>::VALUE && !has_flatbuffer_marker<T>(), void>>
    auto payload() const -> const ValueType&;
 
    template <typename T = Payload, typename = std::enable_if_t<bb::IsSlice<T>::VALUE, void>>
    auto payload() const -> bb::ImmutableSlice<ValueType>;
 
#if IOX2_FEATURE_FLATBUFFERS
    template <typename T = Payload, typename = std::enable_if_t<has_flatbuffer_marker<T>(), void>>
    auto payload_bytes() const -> bb::ImmutableSlice<uint8_t>;
 
    template <typename T = Payload, typename = std::enable_if_t<has_flatbuffer_marker<T>(), void>>
    auto payload_root() const -> const typename T::ValueType*;
#endif // IOX2_FEATURE_FLATBUFFERS
 
    template <typename T = UserHeader, typename = std::enable_if_t<!std::is_same<void, UserHeader>::value, T>>
    auto user_header() const -> const T&;
 
    auto header() const -> HeaderPublishSubscribe;
 
    auto origin() const -> UniquePublisherId;
 
  private:
    template <ServiceType, typename, typename>
    friend class Subscriber;
 
    // The sample is defaulted since both members are initialized in Subscriber::receive
    explicit Sample() = default;
    void drop();
 
    iox2_sample_t m_sample;
    iox2_sample_h m_handle = nullptr;
};
 
template <ServiceType S, typename Payload, typename UserHeader>
inline void Sample<S, Payload, UserHeader>::drop() {
    if (m_handle != nullptr) {
        iox2_sample_drop(m_handle);
        m_handle = nullptr;
    }
}
 
// NOLINTNEXTLINE(cppcoreguidelines-pro-type-member-init,hicpp-member-init) m_sample will be initialized in the move assignment operator
template <ServiceType S, typename Payload, typename UserHeader>
inline Sample<S, Payload, UserHeader>::Sample(Sample&& rhs) noexcept {
    *this = std::move(rhs);
}
 
namespace internal {
extern "C" {
void iox2_sample_move(iox2_sample_t*, iox2_sample_t*, iox2_sample_h*);
}
} // namespace internal
 
template <ServiceType S, typename Payload, typename UserHeader>
inline auto Sample<S, Payload, UserHeader>::operator=(Sample&& rhs) noexcept -> Sample& {
    if (this != &rhs) {
        drop();
 
        internal::iox2_sample_move(&rhs.m_sample, &m_sample, &m_handle);
        rhs.m_handle = nullptr;
    }
 
    return *this;
}
 
template <ServiceType S, typename Payload, typename UserHeader>
inline Sample<S, Payload, UserHeader>::~Sample() {
    drop();
}
 
template <ServiceType S, typename Payload, typename UserHeader>
template <typename T, typename>
inline auto Sample<S, Payload, UserHeader>::payload() const -> const ValueType& {
    const void* ptr = nullptr;
 
    iox2_sample_payload(&m_handle, &ptr, nullptr);
 
    return *static_cast<const ValueType*>(ptr);
}
 
template <ServiceType S, typename Payload, typename UserHeader>
template <typename T, typename>
inline auto Sample<S, Payload, UserHeader>::payload() const -> bb::ImmutableSlice<ValueType> {
    const void* ptr = nullptr;
    size_t number_of_elements = 0;
 
    iox2_sample_payload(&m_handle, &ptr, &number_of_elements);
 
    // for the custom payload marker, the slice length is the
    // runtime payload byte size
    auto length = number_of_elements;
    if (std::is_same<ValueType, CustomPayloadMarker>::value) {
        length = iox2_sample_payload_number_of_bytes(&m_handle);
    }
 
    return bb::ImmutableSlice<ValueType>(static_cast<const ValueType*>(ptr), length);
}
 
#if IOX2_FEATURE_FLATBUFFERS
 
template <ServiceType S, typename Payload, typename UserHeader>
template <typename T, typename>
inline auto Sample<S, Payload, UserHeader>::payload_bytes() const -> bb::ImmutableSlice<uint8_t> {
    const void* ptr = nullptr;
    size_t number_of_elements = 0;
 
    iox2_sample_payload(&m_handle, &ptr, &number_of_elements);
    auto payload_offset = header().payload_offset();
    auto payload_len = header().number_of_elements();
 
    return bb::ImmutableSlice<uint8_t>(static_cast<const uint8_t*>(ptr) + payload_offset, payload_len - payload_offset);
}
 
template <ServiceType S, typename Payload, typename UserHeader>
template <typename T, typename>
auto Sample<S, Payload, UserHeader>::payload_root() const -> const typename T::ValueType* {
    return flatbuffers::GetRoot<typename T::ValueType>(payload_bytes().data());
}
 
#endif // IOX2_FEATURE_FLATBUFFERS
 
template <ServiceType S, typename Payload, typename UserHeader>
template <typename T, typename>
inline auto Sample<S, Payload, UserHeader>::user_header() const -> const T& {
    const void* header_ptr = nullptr;
 
    iox2_sample_user_header(&m_handle, &header_ptr);
 
    return *static_cast<const T*>(header_ptr);
}
 
template <ServiceType S, typename Payload, typename UserHeader>
inline auto Sample<S, Payload, UserHeader>::header() const -> HeaderPublishSubscribe {
    iox2_publish_subscribe_header_h header_handle = nullptr;
    iox2_sample_header(&m_handle, nullptr, &header_handle);
 
    return HeaderPublishSubscribe { header_handle };
}
 
template <ServiceType S, typename Payload, typename UserHeader>
inline auto Sample<S, Payload, UserHeader>::origin() const -> UniquePublisherId {
    return header().publisher_id();
}
 
} // namespace iox2
 
#endif