CSerializable.h

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2020, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */
#pragma once

#include <mrpt/rtti/CObject.h>
#include <mrpt/serialization/serialization_frwds.h>
#include <cstdint>

// Make this frwd decl independent of MRPT_HAS_MATLAB in config.h:
/** Forward declaration for mxArray (avoid #including as much as possible to
 * speed up compiling) */
using mxArray = struct mxArray_tag;

namespace mrpt::serialization
{
/** The virtual base class which provides a unified interface for all persistent
 *objects in MRPT.
 *  Many important properties of this class are inherited from
 *mrpt::rtti::CObject.
 * Refer to the library tutorial: \ref mrpt_serialization_grp
 * \sa CArchive
 * \ingroup mrpt_serialization_grp
 */
class CSerializable : public mrpt::rtti::CObject
{
    friend class CArchive;
    friend class CSchemeArchiveBase;

    // This must be added to any CObject derived class:
    DEFINE_VIRTUAL_MRPT_OBJECT(CSerializable)

    ~CSerializable() override = default;

   protected:
    /** @name CSerializable virtual methods
     *  @{ */
    /** Must return the current versioning number of the object. Start in zero
     * for new classes, and increments each time there is a change in the stored
     * format.
     */
    virtual uint8_t serializeGetVersion() const = 0;
    /** Pure virtual method for writing (serializing) to an abstract archive.
     *  Users don't call this method directly. Instead, use `stream << object;`.
     *  \exception std::exception On any I/O error
     */
    virtual void serializeTo(CArchive& out) const = 0;
    /** Pure virtual method for reading (deserializing) from an abstract
     *archive. Users don't call this method directly. Instead, use `stream >>
     *object;`. \param in The input binary stream where the object data must
     *read from. \param version The version of the object stored in the stream:
     *use this version number in your code to know how to read the incoming
     *data. \exception std::exception On any I/O error
     */
    virtual void serializeFrom(CArchive& in, uint8_t serial_version) = 0;
    /** Virtual method for writing (serializing) to an abstract
     *  schema based archive.
     */
    virtual void serializeTo(CSchemeArchiveBase& out) const
    {
        const std::string err =
            std::string(this->GetRuntimeClass()->className) +
            std::string(" : class does not support schema based serialization");
        THROW_EXCEPTION(err);
    }
    /** Virtual method for reading (deserializing) from an abstract
     *  schema based archive.
     */
    virtual void serializeFrom(CSchemeArchiveBase& in)
    {
        const std::string err =
            std::string(this->GetRuntimeClass()->className) +
            std::string(" : class does not support schema based serialization");
        THROW_EXCEPTION(err);
    }
    /** @} */

   public:
    /** Introduces a pure virtual method responsible for writing to a `mxArray`
     * Matlab object, typically a MATLAB `struct` whose contents are documented
     * in each derived class. \return A new `mxArray` (caller is responsible of
     * memory freeing) or nullptr is class does not support conversion to
     * MATLAB.
     */
    virtual mxArray* writeToMatlab() const { return nullptr; }
};  // End of class def.

/** \addtogroup noncstream_serialization Non-CStream serialization functions (in
 * #include <mrpt/serializatin/CSerializable.h>)
 * \ingroup mrpt_serialization_grp
 * @{ */

/** Converts (serializes) an MRPT object into an array of bytes.
 * \param o The object to be serialized.
 * \param out_vector The vector which at return will contain the data. Size will
 * be set automatically.
 * \sa OctetVectorToObject, ObjectToString
 */
void ObjectToOctetVector(
    const CSerializable* o, std::vector<uint8_t>& out_vector);

/** Converts back (de-serializes) a sequence of binary data into a MRPT object,
 * without prior information about the object's class.
 * \param in_data The serialized input data representing the object.
 * \param obj The newly created object will be stored in this smart pointer.
 * \exception None On any internal exception, this function returns a nullptr
 * pointer.
 * \sa ObjectToOctetVector, StringToObject
 */
void OctetVectorToObject(
    const std::vector<uint8_t>& in_data, CSerializable::Ptr& obj);

/** @} */
/** This declaration must be inserted in all CSerializable classes definition,
 * within the class declaration. */
#define DEFINE_SCHEMA_SERIALIZABLE()                                          \
   protected:                                                                 \
    /*! @name CSerializable virtual methods for schema based archives*/       \
    /*! @{ */                                                                 \
    void serializeTo(mrpt::serialization::CSchemeArchiveBase& out)            \
        const override;                                                       \
    void serializeFrom(mrpt::serialization::CSchemeArchiveBase& in) override; \
/*! @} */

/** For use inside all serializeTo(CSchemeArchiveBase) methods */
#define SCHEMA_SERIALIZE_DATATYPE_VERSION(ser_version)                     \
    do                                                                     \
    {                                                                      \
        out["datatype"] = std::string(this->GetRuntimeClass()->className); \
        out["version"] = ser_version;                                      \
    } while (false)

/** For use inside serializeFrom(CSchemeArchiveBase) methods */
#define SCHEMA_DESERIALIZE_DATATYPE_VERSION()                                  \
    version = static_cast<int>(in["version"]);                                 \
    const std::string read_typename{static_cast<std::string>(in["datatype"])}; \
    const std::string expected_typename{this->GetRuntimeClass()->className};   \
    if (expected_typename != read_typename)                                    \
    {                                                                          \
        THROW_EXCEPTION(mrpt::format(                                          \
            "Schema deserializing class `%s` but expected `%s`",               \
            read_typename.c_str(), expected_typename.c_str()));                \
    }

/** This declaration must be inserted in all CSerializable classes definition,
 * within the class declaration. */
#define DEFINE_SERIALIZABLE(class_name, NS)                                  \
    DEFINE_MRPT_OBJECT(class_name, NS)                                       \
   protected:                                                                \
    /*! @name CSerializable virtual methods */                               \
    /*! @{ */                                                                \
    uint8_t serializeGetVersion() const override;                            \
    void serializeTo(mrpt::serialization::CArchive& out) const override;     \
    void serializeFrom(                                                      \
        mrpt::serialization::CArchive& in, uint8_t serial_version) override; \
/*! @} */

/** To be added to all CSerializable-classes implementation files.
 * This registers the class name with the NameSpace prefix.
 */
#define IMPLEMENTS_SERIALIZABLE(class_name, base, NameSpace) \
    IMPLEMENTS_MRPT_OBJECT(class_name, base, NameSpace)

/** This declaration must be inserted in virtual CSerializable classes
 * definition: */
#define DEFINE_VIRTUAL_SERIALIZABLE(class_name) \
    DEFINE_VIRTUAL_MRPT_OBJECT(class_name)

/** This must be inserted as implementation of some required members for
 *  virtual CSerializable classes:
 */
#define IMPLEMENTS_VIRTUAL_SERIALIZABLE(class_name, base_class, NS) \
    IMPLEMENTS_VIRTUAL_MRPT_OBJECT(class_name, base_class, NS)

#define IMPLEMENTS_VIRTUAL_SERIALIZABLE_NS_PREFIX(class_name, base_class, NS) \
    IMPLEMENTS_VIRTUAL_MRPT_OBJECT_NS_PREFIX(class_name, base_class, NS)

/** This must be inserted if a custom conversion method for MEX API is
 * implemented in the class */
#define DECLARE_MEX_CONVERSION                           \
    /*! @name Virtual methods for MRPT-MEX conversion */ \
    /*! @{ */                                            \
   public:                                               \
    mxArray* writeToMatlab() const override;             \
/*! @} */

/** This must be inserted if a custom conversion method for MEX API is
 * implemented in the class */
#define DECLARE_MEXPLUS_FROM(complete_type)    \
    namespace mexplus                          \
    {                                          \
    template <typename T>                      \
    mxArray* from(const T& value);             \
    template <>                                \
    mxArray* from(const complete_type& value); \
    }

#define IMPLEMENTS_MEXPLUS_FROM(complete_type) \
    namespace mexplus                          \
    {                                          \
    template <>                                \
    mxArray* from(const complete_type& var)    \
    {                                          \
        return var.writeToMatlab();            \
    }                                          \
    }
}  // namespace mrpt::serialization