sourcemod/core/logic/CDataPack.h

/**
 * vim: set ts=4 :
 * =============================================================================
 * SourceMod
 * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
 * =============================================================================
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, version 3.0, as published by the
 * Free Software Foundation.
 * 
 * This program 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 program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * As a special exception, AlliedModders LLC gives you permission to link the
 * code of this program (as well as its derivative works) to "Half-Life 2," the
 * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software
 * by the Valve Corporation.  You must obey the GNU General Public License in
 * all respects for all other code used.  Additionally, AlliedModders LLC grants
 * this exception to all derivative works.  AlliedModders LLC defines further
 * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),
 * or <http://www.sourcemod.net/license.php>.
 *
 * Version: $Id$
 */

#ifndef _INCLUDE_SOURCEMOD_CDATAPACK_H_
#define _INCLUDE_SOURCEMOD_CDATAPACK_H_

#include <ISourceMod.h>
#include <amtl/am-vector.h>
#include <amtl/am-string.h>

using namespace SourceMod;

enum CDataPackType {
	Raw,
	Cell,
	Float,
	String,
	Function,
	CellArray,
	FloatArray,
};

class CDataPack
{
public:
	CDataPack();
	~CDataPack();

public: // Originally IDataReader
	/**
	 * @brief Resets the position in the data stream to the beginning.
	 */
	void Reset() const;

	/**
	 * @brief Retrieves the current stream position.
	 *
	 * @return			Index into the stream.
	 */
	size_t GetPosition() const;

	/**
	 * @brief Sets the current stream position.
	 *
	 * @param pos		Index to set the stream at.
	 * @return			True if succeeded, false if out of bounds.
	 */
	bool SetPosition(size_t pos) const;

	/**
	 * @brief Reads one cell from the data stream.
	 *
	 * @return			A cell read from the current position.
	 */
	cell_t ReadCell() const;

	/**
	 * @brief Reads one float from the data stream.
	 *
	 * @return			A float read from the current position.
	 */
	float ReadFloat() const;

	/**
	 * @brief Reads an array of values from the data stream.
	 *
	 * @param len       The size of the array stored at this position to return.
	 * @return			A cell array read from the current position.
	 */
	cell_t *ReadCellArray(cell_t *len) const;
	/**
	 * @brief Reads an array of values from the data stream.
	 *
	 * @param len       The size of the array stored at this position to return.
	 * @return			A cell array read from the current position.
	 */
	cell_t *ReadFloatArray(cell_t *len) const;

	/**
	 * @brief Returns whether or not a specified number of bytes from the current stream
	 *  position to the end can be read.
	 *
	 * @param bytes		Number of bytes to simulate reading.
	 * @return			True if can be read, false otherwise.
	 */
	bool IsReadable(size_t bytes = 0) const;

	/**
	 * @brief Reads a string from the data stream.
	 *
	 * @param len		Optional pointer to store the string length.
	 * @return			Pointer to the string, or NULL if out of bounds.
	 */
	const char *ReadString(size_t *len) const;

	/**
	 * @brief Reads the current position as a generic data type.
	 *
	 * @param size		Optional pointer to store the size of the data type.
	 * @return			Pointer to the data, or NULL if out of bounds.
	 */
	void *ReadMemory(size_t *size) const;

	/**
	 * @brief Reads a function pointer from the data stream.
	 *
	 * @return			A function pointer read from the current position.
	 */
	cell_t ReadFunction() const;

public: // Originally IDataPack
	/**
	 * @brief Resets the used size of the stream back to zero.
	 */
	void ResetSize();

	/**
	 * @brief Packs one cell into the data stream.
	 *
	 * @param cell		Cell value to write.
	 */
	void PackCell(cell_t cell);

	/**
	 * @brief Packs one float into the data stream.
	 *
	 * @param val		Float value to write.
	 */
	void PackFloat(float val);

	/**
	 * @brief Packs one string into the data stream.
	 * The length is recorded as well for buffer overrun protection.
	 *
	 * @param string	String to write.
	 */
	void PackString(const char *string);

	/**
	 * @brief Packs an array of cells into the data stream.
	 *
	 * @param vals		Cells to write.
	 * @param count     Number of cells.
	 */
	void PackCellArray(cell_t const *vals, cell_t count);
	/**
	 * @brief Packs an array of cells into the data stream.
	 *
	 * @param vals		Cells to write.
	 * @param count     Number of cells.
	 */
	void PackFloatArray(cell_t const *vals, cell_t count);

	/**
	 * @brief Creates a generic block of memory in the stream.
	 *
	 * Note that the pointer it returns can be invalidated on further
	 * writing, since the stream size may grow.  You may need to double back
	 * and fetch the pointer again.
	 *
	 * @param size		Size of the memory to create in the stream.
	 * @param addr		Optional pointer to store the relocated memory address.
	 * @return			Current position of the stream beforehand.
	 */
	size_t CreateMemory(size_t size, void **addr);

	/**
	 * @brief Packs one function pointer into the data stream.
	 *
	 * @param function	The function pointer to write.
	 */
	void PackFunction(cell_t function);

public:
	void Initialize();
	inline size_t GetCapacity() const { return this->elements.size(); };
	inline CDataPackType GetCurrentType(void) const { return this->elements[this->position].type; };
	bool RemoveItem(size_t pos = -1);

private:
	typedef union {
		cell_t cval;
		float fval;
		uint8_t *vval;
		std::string *sval;
		cell_t *aval;
	} InternalPackValue;
	
	typedef struct {
		InternalPackValue pData;
		CDataPackType type;
	} InternalPack;

	std::vector<InternalPack> elements;
	mutable size_t position;
};

#endif //_INCLUDE_SOURCEMOD_CDATAPACK_H_