Object.hpp

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/****
 * Object.hpp - Definitions and macros common to all object types
 *
 * Copyright 2019 mikee47 <mike@sillyhouse.net>
 *
 * This file is part of the FlashString Library
 *
 * This library is free software: you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation, version 3 or later.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this library.
 * If not, see <https://www.gnu.org/licenses/>.
 *
 * @author: 2018 - Mikee47 <mike@sillyhouse.net>
 *
 ****/
 
#pragma once
 
#include "Utility.hpp"
#include "ObjectBase.hpp"
#include "ObjectIterator.hpp"
 
#define DECLARE_FSTR_OBJECT(name, ObjectType) extern const ObjectType& name;
 
#define DEFINE_FSTR_OBJREF(name, object) const decltype(object)& name PROGMEM = object;
#define DEFINE_FSTR_REF(name) DEFINE_FSTR_OBJREF(name, FSTR_DATA_NAME(name).object)
#define DEFINE_FSTR_REF_LOCAL(name) static constexpr DEFINE_FSTR_REF(name)
#define FSTR_DATA_NAME(name) __fstr__##name
 
#define FSTR_PTR(objref) (&objref)
 
#define FSTR_CHECK_STRUCT(name)                                                                                        \
    static_assert(std::is_standard_layout<decltype(name)>::value, "FSTR structure not Standard Layout");               \
    static_assert(offsetof(decltype(name), data) == sizeof(uint32_t), "FSTR structure alignment error");
 
#define IMPORT_FSTR_OBJECT(name, ObjectType, file)                                                                     \
    IMPORT_FSTR_DATA(FSTR_DATA_NAME(name), file)                                                                       \
    extern "C" __attribute__((visibility("hidden"))) const ObjectType FSTR_DATA_NAME(name);                            \
    DEFINE_FSTR_OBJREF(name, FSTR_DATA_NAME(name))
 
#define IMPORT_FSTR_OBJECT_LOCAL(name, ObjectType, file)                                                               \
    IMPORT_FSTR_DATA(FSTR_DATA_NAME(name), file)                                                                       \
    extern "C" __attribute__((visibility("hidden"))) const ObjectType FSTR_DATA_NAME(name);                            \
    static constexpr DEFINE_FSTR_OBJREF(name, FSTR_DATA_NAME(name))
 
namespace FSTR
{
template <class ObjectType, typename ElementType> class Object : public ObjectBase
{
public:
    using DataPtrType = const ElementType*;
    using Iterator = ObjectIterator<ObjectType, ElementType>;
 
// This is precautionary to prevent misuse. No known fix for C++20
// NB. esp-quick-toolchain 10.3 reports 201703L for C++17,
// and 201709L for C++20 - standard says 202002L.
#if __cplusplus <= 201703L
    Object(const Object&) = delete;
    Object(const Object&&) = delete;
    Object& operator=(const Object&) = delete;
    Object& operator=(const Object&&) = delete;
#endif
 
    Iterator begin() const
    {
        return Iterator(as<ObjectType>(), 0);
    }
 
    Iterator end() const
    {
        return Iterator(as<ObjectType>(), length());
    }
 
    static constexpr const ObjectType& empty()
    {
        return empty_.as<const ObjectType>();
    }
 
    FSTR_INLINE constexpr size_t length() const
    {
        return ObjectBase::length() / sizeof(ElementType);
    }
 
    template <typename ValueType> int indexOf(const ValueType& value) const
    {
        auto& self = as<ObjectType>();
        auto dataptr = self.data();
        auto len = self.length();
        for(unsigned i = 0; i < len; ++i) {
            if(self.unsafeValueAt(dataptr, i) == value) {
                return int(i);
            }
        }
 
        return -1;
    }
 
    FSTR_INLINE ElementType valueAt(unsigned index) const
    {
        return (index < length()) ? unsafeValueAt(data(), index) : ElementType{};
    }
 
    FSTR_INLINE ElementType operator[](unsigned index) const
    {
        return valueAt(index);
    }
 
    FSTR_INLINE size_t elementSize() const
    {
        return sizeof(ElementType);
    }
 
    FSTR_INLINE DataPtrType data() const
    {
        return reinterpret_cast<DataPtrType>(ObjectBase::data());
    }
 
    size_t read(size_t index, ElementType* buffer, size_t count) const
    {
        auto offset = index * sizeof(ElementType);
        count *= sizeof(ElementType);
        return ObjectBase::read(offset, buffer, count) / sizeof(ElementType);
    }
 
    size_t readFlash(size_t index, ElementType* buffer, size_t count) const
    {
        auto offset = index * sizeof(ElementType);
        count *= sizeof(ElementType);
        return ObjectBase::readFlash(offset, buffer, count) / sizeof(ElementType);
    }
 
    FSTR_INLINE ElementType unsafeValueAt(const DataPtrType dataptr, unsigned index) const
    {
        return readValue(dataptr + index);
    }
};
 
} // namespace FSTR