/** 
 * @file llxfer.h
 * @brief definition of LLXfer class for a single xfer
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#ifndef LL_LLXFER_H
#define LL_LLXFER_H

#include "message.h"
#include "lltimer.h"
#include "llextendedstatus.h"

const S32 LL_XFER_LARGE_PAYLOAD = 7680;
const S32 LL_ERR_FILE_EMPTY     = -44;
const int LL_ERR_FILE_NOT_FOUND = -43;
const int LL_ERR_CANNOT_OPEN_FILE = -42;
const int LL_ERR_EOF = -39;

typedef enum ELLXferStatus {
	e_LL_XFER_UNINITIALIZED,
	e_LL_XFER_REGISTERED,         // a buffer which has been registered as available for a request
	e_LL_XFER_PENDING,            // a transfer which has been requested but is waiting for a free slot
	e_LL_XFER_IN_PROGRESS,
	e_LL_XFER_COMPLETE,
	e_LL_XFER_ABORTED,
	e_LL_XFER_NONE
} ELLXferStatus;

class LLXfer
{
 private:
 protected:
        S32 mChunkSize;
  
 public:
	U64 mID;
	S32 mPacketNum;

	LLHost mRemoteHost;
	S32 mXferSize;

	char *mBuffer;
	U32 mBufferLength;			// Size of valid data, not actual allocated buffer size
	U32 mBufferStartOffset;
	BOOL mBufferContainsEOF;

	ELLXferStatus mStatus;

	BOOL mWaitingForACK;

	void (*mCallback)(void **,S32,LLExtStat);	
	void **mCallbackDataHandle;
	S32 mCallbackResult;

	LLTimer ACKTimer;
	S32 mRetries;

	static const U32 XFER_FILE;
	static const U32 XFER_VFILE;
	static const U32 XFER_MEM;

 private:
 protected:
 public:
	LLXfer (S32 chunk_size);
	virtual ~LLXfer();

	void init(S32 chunk_size);
	virtual void cleanup();

	virtual S32 startSend(U64 xfer_id, const LLHost &remote_host);
	virtual void closeFileHandle();
	virtual S32 reopenFileHandle();
	virtual void sendPacket(S32 packet_num);
	virtual void sendNextPacket();
	virtual void resendLastPacket();
	virtual S32 processEOF();
	virtual S32 startDownload();
	virtual S32 receiveData (char *datap, S32 data_size);
	virtual void abort(S32);

	virtual S32 suck(S32 start_position);
	virtual S32 flush();
	
	virtual S32 encodePacketNum(S32 packet_num, bool is_eof);
	virtual void setXferSize (S32 data_size);
	virtual S32  getMaxBufferSize();

	virtual std::string getFileName();

	virtual U32 getXferTypeTag();

	friend std::ostream& operator<< (std::ostream& os, LLXfer &hh);

};

#endif