// Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

//

#include <e32base.h>

#include "IPCBuf.h"

#include "SqlPanic.h"

#include "SqlDbSession.h"

/**

Standard, phase-one HIpcBuf factory method.

Created HIpcBuf instance will be used for transfering large text or binary objects from/to SQL server.

The created HIpcBuf instance will be placed in the cleanup stack.

@param aSession A reference to RSqlDbSession instance.

@param aFunction Prepared function code (with all statement handle bits set)

@param aArgs A set of IPC arguments to be sent to the SQL server.

@return A pointer to the created HIpcBuf instance

@leave KErrNoMemory Out of memory.

*/

HIpcBuf* HIpcBuf::NewLC(RSqlDbSession& aSession, TInt aFunction, TIpcArgs& aArgs)

	{

	HIpcBuf* self = new (ELeave) HIpcBuf(aSession);

	self->PushL();

	self->ConstructL(aFunction, aArgs);

	return self;

	}

/**

Standard, phase-one HIpcBuf factory method.

Created HIpcBuf instance will be used for transfering large text or binary objects from/to SQL server.

@param aSession A reference to RSqlDbSession instance.

@param aFunction Prepared function code (with all statement handle bits set)

@param aArgs A set of IPC arguments to be sent to the SQL server.

@return A pointer to the created HIpcBuf instance

@leave KErrNoMemory Out of memory.

*/

HIpcBuf* HIpcBuf::NewL(RSqlDbSession& aSession, TInt aFunction, TIpcArgs& aArgs)

	{

	HIpcBuf* self = NewLC(aSession, aFunction, aArgs);

	CleanupStack::Pop();

	return self;

	}

/**

Standard, phase-two HIpcBuf construction method.

@param aFunction The command code which will be sent to the SQL server

@param aArgs A set of IPC arguments to be sent to the SQL server.

@leave KErrNoMemory Out of memory.

Usage of the IPC call arguments:

Arg 2: [in/out]  IPC buffer

iBuf.iExt: [in]  stream size in bytes

*/

void HIpcBuf::ConstructL(TInt aFunction, TIpcArgs& aArgs)

	{

	TPckg<TIpcStreamBuf> pckg(iBuf);

	aArgs.Set(2, &pckg);

	__SQLLEAVE_IF_ERROR(iHandle = iSession.SendReceive(aFunction, aArgs));

	TUint8* base = iBuf.iData;

	// if reading we already have one buffer-full of data

	TInt avail = Max(0, Min(iBuf.iExt, KIpcBufSize));

	SetBuf(ERead, base, base + avail);

	SetPos(ERead, avail);

	SetBuf(EWrite, base, base);

	SetPos(EWrite, 0);

	}

/**

@param aSession A reference to a sesion object.

*/

HIpcBuf::HIpcBuf(RSqlDbSession& aSession) :

	iSession(aSession),

	iHandle(0),

	iRPos(0),

	iWPos(0)

	{

	iBuf.iExt = -1;

	}

/**

*/

HIpcBuf::~HIpcBuf()

	{

	if(iHandle > 0) //iHandle is valid only when > 0.

		{

		(void)iSession.SendReceive(::MakeMsgCode(ESqlSrvStreamClose, ESqlSrvStreamHandle, iHandle));

		}

	}

/**

Fill the buffer's read area.

*/

TInt HIpcBuf::UnderflowL(TInt)

	{

	// when handle is null there is no data to read from server

	if(!iHandle)

		{

		return 0;

		}

	__SQLASSERT(Avail(ERead) == 0, ESqlPanicInternalError);

	TUint8* base=iBuf.iData;

	IpcWriteL(base,Lag(EWrite));

	SetBuf(EWrite,base,base);

	TInt len=IpcReadL(base,iBuf.ESize);

	SetBuf(ERead,base,base+len);

	return len;

	}

/**

Set up the buffer's write area.

*/

void HIpcBuf::OverflowL()

	{

	__SQLASSERT(Avail(EWrite) == 0, ESqlPanicInternalError);

	TUint8* base = iBuf.iData;

	MovePos(ERead, Lag(ERead));

	SetBuf(ERead, base, base);

	IpcWriteL(base, Lag(EWrite));

	SetBuf(EWrite, base, base + iBuf.ESize);

	}

/**

Destroys HIpcBuf instance.

*/

void HIpcBuf::DoRelease()

	{

	delete this;

	}

/**

Synchronise this buffer with its file, giving up on outstanding writes in case of failure.

*/

void HIpcBuf::DoSynchL()

	{

	TUint8* base = iBuf.iData;

	MovePos(ERead, Lag(ERead));

	TInt lag = Lag(EWrite);

	SetBuf(ERead | EWrite, base, base);

	iBuf.iExt = -1;

	IpcWriteL(base, lag);

	__SQLLEAVE_IF_ERROR(iSession.SendReceive(::MakeMsgCode(ESqlSrvStreamSynch, ESqlSrvStreamHandle, iHandle)));

	}

/**

Read direct from ipc if asked to transfer more than a bufferful.

*/

TInt HIpcBuf::DoReadL(TAny* aPtr, TInt aMaxLength)

	{

	__SQLASSERT(aMaxLength > 0, ESqlPanicInternalError);

	TInt avail = Avail(ERead);

	__SQLASSERT(avail >= 0 && Avail(EWrite) >= 0, ESqlPanicInternalError);

	if(avail > 0)

		{

		TInt len = Min(aMaxLength, avail);

		TUint8* ptr = Ptr(ERead);

		aPtr = Mem::Copy(aPtr, ptr, len);

		SetPtr(ERead, ptr + len);

		aMaxLength -= len;

		if(aMaxLength == 0)

			return len; // that's it

		}

	__SQLASSERT(Avail(ERead) == 0, ESqlPanicInternalError);

	if(aMaxLength < iBuf.ESize)

		return avail + TStreamBuf::DoReadL(aPtr, aMaxLength);

	// when handle is null there is no more data to read from server

	if(!iHandle)

		{

		return 0;

		}

	TUint8* base = iBuf.iData;

	IpcWriteL(base, Lag(EWrite));

	SetBuf(ERead | EWrite, base, base);

	return avail + IpcReadL(aPtr, aMaxLength);

	}

/**

Write direct to ipc if asked to transfer more than a bufferful.

*/

void HIpcBuf::DoWriteL(const TAny* aPtr,TInt aLength)

	{

	__SQLASSERT(aLength > 0, ESqlPanicInternalError);

	TInt avail = Avail(EWrite);

	__SQLASSERT(Avail(ERead) >= 0 && avail >= 0, ESqlPanicInternalError);

	if(avail > 0)

		{

		TInt len = Min(aLength, avail);

		SetPtr(EWrite, Mem::Copy(Ptr(EWrite), aPtr, len));

		aLength -= len;

		if(aLength == 0)

			return; // done

		aPtr = (TUint8*)aPtr + len;

		}

	__SQLASSERT(Avail(EWrite) == 0, ESqlPanicInternalError);

	if(aLength < iBuf.ESize)

		TStreamBuf::DoWriteL(aPtr, aLength);

	else

		{

		TUint8* base = iBuf.iData;

		IpcWriteL(base, Lag(EWrite));

		MovePos(ERead, Lag(ERead));

		SetBuf(ERead | EWrite, base, base);

		IpcWriteL(aPtr, aLength);

		}

	}

/**

Position the mark(s) indicated by aMark at aOffset from aLocation.

*/

TStreamPos HIpcBuf::DoSeekL(TMark aMark, TStreamLocation aLocation, TInt aOffset)

	{

	TUint8* base = iBuf.iData;

	TInt end = EndL();

	switch(aLocation)

		{

	case EStreamBeginning:

		break;

	case EStreamMark:

		switch(aMark)

			{

		case ERead:

			aOffset += Mark(ERead);

			break;

		case EWrite:

			aOffset += Mark(EWrite);

			break;

		default:

			__SQLASSERT_ALWAYS(0, ESqlPanicStreamMarkInvalid);

			break;

			}

		break;

	case EStreamEnd:

		aOffset += end;

		break;

	default:

		__SQLASSERT_ALWAYS(0, ESqlPanicStreamLocationInvalid);

		break;

		}

	TInt r = KErrNone;

	if(aOffset < 0)

		{

		aOffset = 0;

		r = KErrEof;

		}

	else if(aOffset > end)

		{

		aOffset = end;

		r = KErrEof;

		}

	__SQLASSERT_ALWAYS(!(aMark & ~(ERead | EWrite)), ESqlPanicStreamMarkInvalid);

	if(aMark & ERead)

		{

		TInt lag = aOffset - Pos(ERead);

		if(lag >= base - End(ERead) && lag <= 0)

			SetPtr(ERead, End(ERead) + lag);

		else

			{

			SetPos(ERead, aOffset);

			SetBuf(ERead, base, base);

			}

		}

	if(aMark & EWrite && aOffset != Mark(EWrite))

		{

		IpcWriteL(base, Lag(EWrite));

		SetPos(EWrite, aOffset);

		SetBuf(EWrite, base, base);

		}

	__SQLLEAVE_IF_ERROR(r);

	return TStreamPos(aOffset);

	}

/**

Read from the server at the current read position.

Arg 0:            not used

Arg 1: [out]      from which position to read

Arg 2: [in/out]   IPC buffer

Arg 3: [out]      max length of the requested data

*/

TInt HIpcBuf::IpcReadL(TAny* aPtr, TInt aMaxLength)

	{

	__SQLASSERT(aMaxLength >= 0, ESqlPanicInternalError);

	if(aMaxLength == 0)

		return 0;

	TPtr8 des((TUint8*)aPtr, aMaxLength);

	TInt pos = Pos(ERead);

	TInt len = __SQLLEAVE_IF_ERROR(iSession.SendReceive(::MakeMsgCode(ESqlSrvStreamRead, ESqlSrvStreamHandle, iHandle), TIpcArgs(0, pos, &des, aMaxLength)));

	pos += len;

	if(len < aMaxLength)

		iBuf.iExt = pos; // end-of-file encountered

	SetPos(ERead, pos);

	return len;

	}

/**

Write to the server at the current write position.

Arg 0:            not used

Arg 1: [out]      from which position to write

Arg 2: [in/out]   IPC buffer

*/

void HIpcBuf::IpcWriteL(const TAny* aPtr, TInt aLength)

	{

	__SQLASSERT(aLength >= 0, ESqlPanicInternalError);

	if(aLength == 0)

		return;

	TPtrC8 ptr((TUint8*)aPtr, aLength);

	TInt ext = iBuf.iExt;

	iBuf.iExt = -1;

	TInt pos = Pos(EWrite);

	__SQLLEAVE_IF_ERROR(iSession.SendReceive(::MakeMsgCode(ESqlSrvStreamWrite, ESqlSrvStreamHandle, iHandle), TIpcArgs(0, pos, &ptr)));

	pos += aLength;

	if(ext >=0 && pos > ext)

		iBuf.iExt = pos;

	SetPos(EWrite, pos);

	}

/**

Determine the end of the stream

*/

TInt HIpcBuf::EndL()

	{

	TInt ext = iBuf.iExt;

	if(ext < 0)

		{

		iBuf.iExt = ext = __SQLLEAVE_IF_ERROR(iSession.SendReceive(::MakeMsgCode(ESqlSrvStreamSize, ESqlSrvStreamHandle, iHandle)));

		}

	return Max(ext, Mark(EWrite));

	}