iw4x-client/src/Utils/Stream.hpp

namespace Utils
{
	class Stream
	{
	private:
		int CriticalSectionState;
		unsigned int BlockSize[Game::MAX_XFILE_COUNT];
		std::vector<Game::XFILE_BLOCK_TYPES> StreamStack;
		std::string Buffer;

	public:
		class Reader
		{
		public:
			Reader(Utils::Memory::Allocator* allocator, std::string buffer) : Buffer(buffer), Allocator(allocator), Position(0) {}

			std::string ReadString();
			const char* ReadCString();

			char ReadByte();

			void* Read(size_t size, size_t count = 1);
			template <typename T> T* ReadArray(size_t count = 1)
			{
				return reinterpret_cast<T*>(Read(sizeof(T), count));
			}
			template <typename T> T Read()
			{
				T obj;

				for (unsigned int i = 0; i < sizeof(T); ++i)
				{
					reinterpret_cast<char*>(&obj)[i] = ReadByte();
				}

				return obj;
			}

			bool End();
			void Seek(unsigned int position);

		private:
			unsigned int Position;
			std::string Buffer;
			Utils::Memory::Allocator* Allocator;
		};

		enum Alignment
		{
			ALIGN_2,
			ALIGN_4,
			ALIGN_8,
			ALIGN_16,
			ALIGN_32,
			ALIGN_64,
			ALIGN_128,
			ALIGN_256,
			ALIGN_512,
			ALIGN_1024,
			ALIGN_2048,
		};

		Stream();
		Stream(size_t size);
		~Stream();

		size_t Length();
		size_t Capacity();

		char* Save(const void * _str, size_t size, size_t count = 1);
		char* Save(Game::XFILE_BLOCK_TYPES stream, const void * _str, size_t size, size_t count);
		char* Save(Game::XFILE_BLOCK_TYPES stream, int value, size_t count);
		template <typename T> char* Save(T* object)
		{
			return SaveArray<T>(object, 1);
		}
		template <typename T> char* SaveArray(T* array, size_t count)
		{
			return Save(array, sizeof(T), count);
		}

		char* SaveString(std::string string);
		char* SaveString(const char* string);
		char* SaveString(const char* string, size_t len);
		char* SaveByte(unsigned char byte, size_t count = 1);
		char* SaveNull(size_t count = 1);
		char* SaveMax(size_t count = 1);

		char* SaveText(std::string string);

		void Align(Alignment align);
		bool PushBlock(Game::XFILE_BLOCK_TYPES stream);
		bool PopBlock();
		bool IsValidBlock(Game::XFILE_BLOCK_TYPES stream);
		void IncreaseBlockSize(Game::XFILE_BLOCK_TYPES stream, unsigned int size);
		void IncreaseBlockSize(unsigned int size);
		Game::XFILE_BLOCK_TYPES GetCurrentBlock();
		unsigned int GetBlockSize(Game::XFILE_BLOCK_TYPES stream);

		DWORD GetPackedOffset();

		char* Data();
		char* At();
		template <typename T> T* Dest()
		{
			return reinterpret_cast<T*>(this->At());
		}
		template <typename T> static inline void ClearPointer(T** object)
		{
			*object = reinterpret_cast<T*>(-1);
		}

		void ToBuffer(std::string& outBuffer);
		std::string ToBuffer();

		// Enter/Leave critical sections in which reallocations are not allowed.
		// If buffer reallocation is detected, the operation has to be terminated
		// and more memory has to be allocated next time. This will have to be done
		// by editing the code though.
		void EnterCriticalSection();
		void LeaveCriticalSection();
		bool IsCriticalSection();


		// This represents packed offset in streams:
		// - lowest 28 bits store the value/offset
		// - highest 4 bits store the stream block
		class Offset
		{
		public:
			union
			{
				struct
				{
					uint32_t offset : 28;
					Game::XFILE_BLOCK_TYPES block : 4;
				};
				uint32_t packed;
				void* pointer;
			};

			Offset() : packed(0) {};
			Offset(Game::XFILE_BLOCK_TYPES _block, uint32_t _offset) : offset(_offset), block(_block) {};

			// The game needs it to be incremented
			uint32_t GetPackedOffset() 
			{ 
				return this->packed + 1;
			};

			uint32_t GetUnpackedOffset()
			{
				Offset lOffset = *this;
				lOffset.packed--;
				return lOffset.offset;
			};

			int GetUnpackedBlock()
			{
				Offset lOffset = *this;
				lOffset.packed--;
				return lOffset.block;
			};
		};
	};
}