Buffer.hpp

#pragma once
 
#include <EngineCore/Utils/MemoryAllocator.hpp>
 
#include "Assert.hpp"
#include "Containers/Span.hpp"
 
namespace Grindstone {
    class Buffer {
    public:
        Buffer() : bufferPtr(nullptr), capacity(0) {}
        Buffer(uint64_t newCapacity) : capacity(newCapacity) {
            this->bufferPtr = static_cast<Byte*>(Grindstone::Memory::AllocatorCore::AllocateRaw(capacity, alignof(Buffer), "Buffer"));
        }
 
        // Copy-Constructor
        Buffer(const Buffer& other) : bufferPtr(nullptr), capacity(other.capacity) {
            bufferPtr = static_cast<Byte*>(Grindstone::Memory::AllocatorCore::AllocateRaw(capacity, alignof(Buffer), "Buffer"));
            memcpy(bufferPtr, other.bufferPtr, capacity);
        }
 
        // Move-Constructor
        Buffer(Buffer&& other) noexcept : capacity(other.capacity), bufferPtr(other.bufferPtr) {
            other.bufferPtr = nullptr;
            other.capacity = 0;
        }
 
        ~Buffer() {
            if (bufferPtr != nullptr) {
                Grindstone::Memory::AllocatorCore::Free(bufferPtr);
                bufferPtr = nullptr;
            }
            capacity = 0;
        }
 
        void ZeroInitialize() {
            if (bufferPtr) {
                memset(bufferPtr, 0, capacity);
            }
        }
 
        [[nodiscard]] virtual Grindstone::Containers::BufferSpan GetSpan(uint64_t segmentOffset, uint64_t segmentSize) {
            Byte* targetPtr = bufferPtr + segmentOffset;
            if (targetPtr < bufferPtr) {
                GS_ASSERT_ENGINE("Start of span is before start of buffer.");
                return {};
            }
 
            if (targetPtr + segmentSize > bufferPtr + capacity) {
                GS_ASSERT_ENGINE("End of span is after end of buffer.");
                return {};
            }
 
            return { targetPtr, segmentSize };
        }
 
        template<typename T>
        [[nodiscard]] Grindstone::Containers::Span<T> GetSpan(uint64_t offset, uint64_t count) {
            Byte* bytePtr = bufferPtr + offset;
            T* targetPtr = reinterpret_cast<T*>(bytePtr);
            if (bytePtr < bufferPtr) {
                GS_ASSERT_ENGINE("Start of span is before start of buffer.");
                return {};
            }
 
            if (reinterpret_cast<Byte*>(bytePtr + (count * sizeof(T))) > bufferPtr + capacity) {
                GS_ASSERT_ENGINE("End of span is after end of buffer.");
                return {};
            }
 
            return { targetPtr, count };
        }
 
        template<typename T>
        [[nodiscard]] T* Get(uint64_t offset) {
            Byte* bytePtr = bufferPtr + offset;
            T* targetPtr = reinterpret_cast<T*>(bytePtr);
            if (bytePtr < bufferPtr) {
                GS_ASSERT_ENGINE("Start of span is before start of buffer.");
                return nullptr;
            }
 
            if (reinterpret_cast<Byte*>(bytePtr + sizeof(T)) > bufferPtr + capacity) {
                GS_ASSERT_ENGINE("End of span is after end of buffer.");
                return nullptr;
            }
 
            return targetPtr;
        }
 
        template<typename T>
        [[nodiscard]] const T* Get(uint64_t offset) const {
            Byte* bytePtr = bufferPtr + offset;
            T* targetPtr = reinterpret_cast<T*>(bytePtr);
            if (bytePtr < bufferPtr) {
                GS_ASSERT_ENGINE("Start of span is before start of buffer.");
                return nullptr;
            }
 
            if (reinterpret_cast<Byte*>(bytePtr + sizeof(T)) > bufferPtr + capacity) {
                GS_ASSERT_ENGINE("End of span is after end of buffer.");
                return nullptr;
            }
 
            return targetPtr;
        }
 
        [[nodiscard]] Byte* Get(uint64_t offset) {
            Byte* bytePtr = bufferPtr + offset;
            if (bytePtr < bufferPtr) {
                GS_ASSERT_ENGINE("Offset is before start of buffer.");
                return nullptr;
            }
 
            if (reinterpret_cast<Byte*>(bytePtr) >= bufferPtr + capacity) {
                GS_ASSERT_ENGINE("Offset is at or after end of buffer.");
                return nullptr;
            }
 
            return bytePtr;
        }
 
        [[nodiscard]] Byte* Get(uint64_t offset) const {
            Byte* bytePtr = bufferPtr + offset;
            if (bytePtr < bufferPtr) {
                GS_ASSERT_ENGINE("Offset is before start of buffer.");
                return nullptr;
            }
 
            if (reinterpret_cast<Byte*>(bytePtr) >= bufferPtr + capacity) {
                GS_ASSERT_ENGINE("Offset is at or after end of buffer.");
                return nullptr;
            }
 
            return bytePtr;
        }
 
        Buffer& operator=(const Buffer& other) {
            if(this == &other) {
                return *this;
            }
 
            capacity = other.capacity;
            bufferPtr = static_cast<Byte*>(Grindstone::Memory::AllocatorCore::AllocateRaw(capacity, alignof(Buffer), "Buffer"));
            memcpy(bufferPtr, other.bufferPtr, capacity);
            return *this;
        }
 
        Buffer& operator=(Buffer&& other) noexcept {
            if (this == &other) {
                return *this;
            }
 
            if (bufferPtr) {
                Grindstone::Memory::AllocatorCore::Free(bufferPtr);
            }
 
            bufferPtr = other.bufferPtr;
            capacity = other.capacity;
 
            other.bufferPtr = nullptr;
            other.capacity = 0;
 
            return *this;
        }
 
        [[nodiscard]] Byte& operator[](int index) {
            return bufferPtr[index];
        }
 
        [[nodiscard]] Byte operator[](int index) const {
            return bufferPtr[index];
        }
 
        explicit operator bool() const {
            return bufferPtr != nullptr;
        }
 
        void Clear() {
            if (bufferPtr != nullptr) {
                Grindstone::Memory::AllocatorCore::Free(bufferPtr);
                bufferPtr = nullptr;
            }
 
            capacity = 0;
        }
 
        [[nodiscard]] Byte* Get() {
            return bufferPtr;
        }
 
        [[nodiscard]] const Byte* Get() const {
            return bufferPtr;
        }
 
        [[nodiscard]] uint64_t GetCapacity() const {
            return capacity;
        }
 
        [[nodiscard]] static Buffer MakeCopiedBuffer(void* srcBufferPtr, const uint64_t capacity) {
            Byte* bufferPtr = static_cast<Byte*>(Grindstone::Memory::AllocatorCore::AllocateRaw(capacity, alignof(Buffer), "Buffer"));
            memcpy(bufferPtr, srcBufferPtr, capacity);
            return Buffer( bufferPtr, capacity );
        }
 
        [[nodiscard]] static Buffer MakeMovedBuffer(void* srcBufferPtr, const uint64_t capacity) {
            Byte* bufferPtr = static_cast<Byte*>(srcBufferPtr);
            return Buffer( bufferPtr, capacity );
        }
 
    protected:
        Buffer(void* bufferPtr, const uint64_t capacity) : bufferPtr(static_cast<Byte*>(bufferPtr)), capacity(capacity) {}
 
        Byte* bufferPtr = nullptr;
        uint64_t capacity = 0;
    };
 
    class ResizableBuffer : public Buffer {
    public:
        ResizableBuffer() : Buffer(), currentPtr(nullptr), size(0) {}
 
        ResizableBuffer(uint64_t capacity) : Buffer() {
            bufferPtr = static_cast<Byte*>(Grindstone::Memory::AllocatorCore::AllocateRaw(capacity, alignof(ResizableBuffer), "ResizableBuffer"));
            currentPtr = bufferPtr;
            this->capacity = capacity;
        }
 
        virtual ~ResizableBuffer() {
            currentPtr = nullptr;
            size = 0;
        }
 
        // Copy-Constructor
        ResizableBuffer(const ResizableBuffer& other) {
            capacity = other.capacity;
            size = other.size;
 
            bufferPtr = static_cast<Byte*>(Grindstone::Memory::AllocatorCore::AllocateRaw(capacity, alignof(ResizableBuffer), "ResizableBuffer"));
            currentPtr = other.currentPtr;
 
            memcpy(bufferPtr, other.bufferPtr, size);
        }
 
        // Copy-Constructor
        ResizableBuffer(ResizableBuffer&& other) noexcept {
            bufferPtr = other.bufferPtr;
            currentPtr = other.currentPtr;
            capacity = other.capacity;
            size = other.size;
 
            other.bufferPtr = nullptr;
            other.currentPtr = nullptr;
            other.capacity = 0;
            other.size = 0;
        }
 
        virtual Grindstone::Containers::BufferSpan GetSpan(uint64_t segmentOffset, uint64_t segmentSize) override {
            Byte* targetPtr = bufferPtr + segmentOffset;
            if (targetPtr < bufferPtr) {
                GS_ASSERT_ENGINE("Start of span is before start of buffer.")
                return Grindstone::Containers::BufferSpan();
            }
 
            if (targetPtr + segmentSize > bufferPtr + size) {
                GS_ASSERT_ENGINE("End of span is after end of used buffer.")
                return Grindstone::Containers::BufferSpan();
            }
 
            return Grindstone::Containers::BufferSpan(targetPtr, segmentSize);
        }
 
        template<typename T>
        Grindstone::Containers::Span<T> GetSpan(uint64_t offset, uint64_t count) {
            T* targetPtr = reinterpret_cast<T*>(bufferPtr + offset);
            if (targetPtr < bufferPtr) {
                GS_ASSERT_ENGINE("Start of span is before start of buffer.");
                return {};
            }
 
            if (targetPtr + count > bufferPtr + capacity) {
                GS_ASSERT_ENGINE("End of span is after end of buffer.");
                return {};
            }
 
            return { targetPtr, count };
        }
 
        void* AddToBuffer(const void* srcPtr, uint64_t srcSize) {
            if (srcPtr == nullptr) {
                GS_ASSERT_ENGINE("Source memory is nullptr.")
                return nullptr;
            }
 
            uint64_t spaceLeft = GetSpaceLeft();
            if (srcSize > spaceLeft) {
                GS_ASSERT_ENGINE("Source memory size is too small to fit.")
                return nullptr;
            }
 
            memcpy(currentPtr, srcPtr, srcSize);
            Byte* prevPtr = currentPtr;
            currentPtr += srcSize;
            size += srcSize;
            return prevPtr;
        }
 
        uint64_t GetSpaceLeft() const {
            return capacity - size;
        }
 
        uint64_t GetUsedSize() const {
            return size;
        }
 
    protected:
        Byte* currentPtr = nullptr;
        uint64_t size = 0;
    };
}