// Copyright (c) 1994-2009 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:
// RWsBuffer class, handles buffering and flushing of window server commands
// 
//

#include <e32std.h>
#include "../SERVER/w32cmd.h"
#include "CLIENT.H"
#include "w32comm.h"

// Global functions

GLDEF_C void Assert(TW32Assert aAssert)
	{
	_LIT(KW32AssertCategory,"W32 Assert");
	User::Panic(KW32AssertCategory,aAssert);
	}

GLDEF_C void Panic(TW32Panic aPanic)
	{
	_LIT(KW32PanicCategory,"W32");
	User::Panic(KW32PanicCategory,aPanic);
	}

// Public functions

RWsBuffer::RWsBuffer(RWsSession *aSession) : iSession(aSession), iManager(NULL),
	#if defined(__AUTO_FLUSH)
		iAutoFlush(ETrue),
	#else
		iAutoFlush(EFalse),
	#endif
	iBuf(NULL,0,0), iNext(NULL), iPreviousHandle(0), iBufSize(0), iMaxBufSize(EMinBufferSize),
	iDirectAcessCount(0), iInvalidBitmapArray(EFalse)
	{
	}

TInt WsFbsDestroyCallBack(TAny* aBitmapHandle)
	{
	TInt* bitmapHandle=static_cast<TInt*>(aBitmapHandle);
	RWsBuffer::FlushAllBuffers(aBitmapHandle ? *bitmapHandle : 0);

	return(0);
	}

void RWsBuffer::SetCallBack()
	{
	for(RWsBuffer *buffer=(RWsBuffer *)Dll::Tls();buffer;buffer=buffer->iNext)
		if (buffer==this)
			return;	// Already linked
	iNext=(RWsBuffer *)Dll::Tls();
	Dll::SetTls(this);
	if (iNext==NULL)	// First connection so set callback
		RFbsSession::GetSession()->SetCallBack(TCallBack(WsFbsDestroyCallBack,NULL));
	}

void RWsBuffer::CancelCallBack()
	{
	RWsBuffer *buffer=(RWsBuffer *)Dll::Tls();
	if (buffer==this)
		{
		Dll::SetTls(iNext);
		if (iNext==NULL)
			RFbsSession::GetSession()->ResetCallBack();	// Last connection closing so cancel the callback
		}
	else
		{
		RWsBuffer *prev;
		while(buffer)
			{
			prev=buffer;
			buffer=buffer->iNext;
			if (buffer==this)
				{
				prev->iNext=iNext;
				break;
				}
			}
		}
	}

void RWsBuffer::Close()
	{
	User::Free((TAny *)iBuf.Ptr());
	}

void RWsBuffer::Destroy()
	{
	Flush();
	Close();
	delete this;
	}


TInt RWsBuffer::Flush(const TIpcArgs* aIpcArgs,TBool aRequestFinish)
	{
	iBitmapArray.Reset();
	iInvalidBitmapArray=EFalse;
	if (iBuf.Length()==0)
		{
		return(KErrNone);
		}
	TIpcArgs ipcArgs;
	if (aIpcArgs!=NULL)
		{
		ipcArgs=*aIpcArgs;
		// check that the caller hasn't used the first slot
		ipcArgs.Set(KBufferMessageSlot,TIpcArgs::ENothing);
		__ASSERT_ALWAYS(Mem::Compare(REINTERPRET_CAST(const TUint8*, &ipcArgs), sizeof(TIpcArgs), REINTERPRET_CAST(const TUint8*, aIpcArgs), sizeof(TIpcArgs))==0,Panic(EW32PanicUsingReservedIpcSlot));
		}
	ipcArgs.Set(KBufferMessageSlot,&iBuf);
	TInt ret;
	if(aRequestFinish)
		ret=iSession->DoFlush(ipcArgs);
	else
		ret=iSession->DoSyncMsgBuf(ipcArgs);
	iBuf.Zero();
	iPreviousHandle=0;
	return(ret);
	}

void RWsBuffer::FlushAllBuffers(TInt aBitmapHandle)
	{
	for(RWsBuffer *buffer=(RWsBuffer *)Dll::Tls();buffer;buffer=buffer->iNext)
		{
		if(!aBitmapHandle || buffer->iInvalidBitmapArray || (buffer->iBitmapArray.FindInOrder(aBitmapHandle)!=KErrNotFound))

			buffer->Flush();
		}
	}

inline void RWsBuffer::SetAndLimitMaxBufSize(TInt aMaxBufSize)
	{ // apply upper & lower limits to input buffer size
	if (aMaxBufSize < EMinBufferSize)
		{
		iMaxBufSize = EMinBufferSize;
		}
	else if	(aMaxBufSize > EMaxBufferSize)
		{
		iMaxBufSize = EMaxBufferSize;
		}
	else
		{
		iMaxBufSize = aMaxBufSize;
		}
	}

void RWsBuffer::SetBufferSizeL(TInt aBufSize)
	{
	SetAndLimitMaxBufSize(aBufSize);
	ReAllocBufferL(iMaxBufSize);
	}

void RWsBuffer::SetMaxBufferSizeL(TInt aMaxBufSize)
	{
	SetAndLimitMaxBufSize(aMaxBufSize);

	if (iMaxBufSize < iBufSize)
		{ // shrink to new maximum
		ReAllocBufferL(iMaxBufSize);
		}
	else
		{
		 // initial allocation should be (at least) a quarter of the requested size
		TInt minSize = Max( (iMaxBufSize + 3) >> 2, EMinBufferSize);
		if (minSize > iBufSize)
			{ // new or enlarged buffer
			ReAllocBufferL(minSize);
			}
		}

	__ASSERT_DEBUG((iBufSize >= EMinBufferSize) && (iBufSize <= iMaxBufSize), Assert(EW32AssertBufferLogic));
	}

// Flush() buffer, try to ReAlloc, Leave if the ReAlloc fails.
void RWsBuffer::ReAllocBufferL(TInt aNewSize)
	{
	if (aNewSize != iBufSize)
		{
		Flush();
		if (!ReAllocBuffer(aNewSize))
			{
			User::LeaveNoMemory();
			}
		}
	}

TBool RWsBuffer::ReAllocBuffer(TInt aNewSize)
	{
	TUint8* ptr = const_cast<TUint8*>(iBuf.Ptr());
	__ASSERT_DEBUG((iBufSize == 0) || (ptr != NULL), Assert(EW32AssertBufferLogic));
	const TInt len = iBuf.Length();
	TUint8* newPtr = static_cast<TUint8*>(User::ReAlloc(ptr, aNewSize));
	if (newPtr != NULL)
		{ // realloc was successful
		iBuf.Set(newPtr, len, aNewSize);
		iBufSize = aNewSize;
		return ETrue;
		}
	return EFalse;
	}

/* Expand the buffer, to allow new drawing command to fit.
 
 Called either when trying to store additional commands to queue for Wserv, or
 the trying to send a command bigger than the current buffer size.

 Failure to expand the buffer is a minor problem in the first case but a big 
 problem in the second.

 @param aRequiredSpace Size of buffer increase required.
 @param aMsgSize If expanding the buffer fails then needs this value to know whether Flush() is good enough.
 @return ETrue if there is enough space, EFalse if not.
 */
void RWsBuffer::GrowBuffer(TInt aRequiredSpace, TInt aMsgSize)
	{
	__ASSERT_DEBUG(iBufSize < iMaxBufSize, Assert(EW32AssertBufferLogic));
	// maximum size will be big enough?
	__ASSERT_ALWAYS(aMsgSize <= iMaxBufSize, Panic(EW32PanicDataExceedsBufferLength));
	
	 // double or quad the current size, then limit it
	TInt newSize = Min((iBufSize >= aRequiredSpace) ? iBufSize << 1 : iBufSize << 2, iMaxBufSize);

	if (!ReAllocBuffer(newSize))
		{ // OOM error
		Flush();
		if (aMsgSize > iBufSize)
			{ // message is too big for buffer
			Panic(EW32PanicDataExceedsBufferLength);
			}
		}
	}


TBool RWsBuffer::SetAutoFlush(TBool aState)
	{
	TBool old;

	old=iAutoFlush;
#if defined(__AUTO_FLUSH)
	if (aState)
#else
	iAutoFlush=aState;
	if (iAutoFlush)
#endif
		Flush();
	return(old);
	}

TInt RWsBuffer::DoWrite(TInt aHandle, TUint aOpcode, TBool aFlush, const TIpcArgs* aIpcArgs, const TAny* aData, TInt aLength, const TAny* aData2, TInt aLength2)
	{
	__ASSERT_DEBUG(((TUint32) aOpcode) < 0x8000, Assert(EW32AssertIllegalOpcode));
	__ASSERT_DEBUG((aLength&0x3) == 0, Assert(EW32AssertOddLengthData));
	TInt xtra(0);
	if (aLength2 > 0)
		{
		xtra = 4 - (aLength2&0x3);		// Round data upto a multiple of 4
		if (xtra==4)
			{
			xtra=0;
			}
		}

	const TInt msgSize = aLength + aLength2 + xtra + static_cast<TInt>(sizeof(TWsCmdHeader));
	TInt available = iBuf.MaxLength() - iBuf.Length();
	if (msgSize > available)
		{
		if (iBufSize >= iMaxBufSize)
			{ // buffer is maximum size already
			Flush();
			}
		else
			{ // try to grow buffer
			 if ( (iBuf.Length() + msgSize) > iMaxBufSize)
				{ // growing alone will not make enough extra space
				Flush();
				available = iBufSize;
				}

			const TInt requiredSpace = msgSize - available;
			if (requiredSpace > 0)
				{
				GrowBuffer(requiredSpace, msgSize);
				}
			}
		}

	TWsCmdHeader cmdHeader;
	cmdHeader.iBase.iOpcode = (TInt16)aOpcode;
	cmdHeader.iBase.iCmdLength = (TInt16)(aLength + aLength2 + xtra);

	// For performance reasons we only pass in the handle if it is different
	// from the previous command
	if (aHandle == iPreviousHandle)
		{
		iBuf.Append((TUint8 *)&cmdHeader.iBase,sizeof(cmdHeader.iBase));
		}
	else
		{
		iPreviousHandle = aHandle;
		cmdHeader.iBase.iOpcode|=EWsOpcodeHandle;
		cmdHeader.iDestHandle = aHandle;
		iBuf.Append((TUint8 *)&cmdHeader,sizeof(cmdHeader));
		}

	if (aLength)
		{
		iBuf.Append((TUint8 *)aData, aLength);
		}
	if (aLength2 > 0)
		{
		iBuf.Append((TUint8 *)aData2, aLength2);
		iBuf.AppendFill(0,xtra);
		}

	if (aFlush)
		{
		return Flush(aIpcArgs);
		}
	return KErrNone;
	}

void RWsBuffer::Write(TInt handle,TUint opcode)
	{
	DoWrite(handle, opcode, iAutoFlush, NULL);
	}

void RWsBuffer::Write(TInt handle,TUint opcode,const TAny *pData, TInt length)
	{
	DoWrite(handle, opcode, iAutoFlush, NULL, pData, length);
	}

void RWsBuffer::Write(TInt handle,TUint opcode,const TAny *pData, TInt length,const TAny *pData2, TInt length2)
	{
	DoWrite(handle, opcode, iAutoFlush, NULL, pData, length, pData2, length2);
	}

TInt RWsBuffer::WriteReply(TInt handle,TUint opcode,const TIpcArgs* aIpcArgs)
	{
	return DoWrite(handle, opcode, ETrue, aIpcArgs);
	}

TInt RWsBuffer::WriteReply(TInt handle,TUint opcode,const TAny *pData, TInt length,const TIpcArgs* aIpcArgs)
	{
	return DoWrite(handle, opcode, ETrue, aIpcArgs, pData, length);
	}
	
TInt RWsBuffer::WriteReply(TInt handle,TUint opcode,const TAny *pData,TInt length,const TAny *pData2,TInt length2,const TIpcArgs* aIpcArgs)
	{
	return DoWrite(handle, opcode, ETrue, aIpcArgs, pData, length, pData2, length2);
	}

TInt RWsBuffer::WriteReplyP(TInt aHandle, TUint aOpcode, const TWriteDescriptorType& aReplyBuffer)
	{
	TIpcArgs ipcArgs;
	aReplyBuffer.SetDescriptorOnIpcArgs(ipcArgs);
	return DoWrite(aHandle, aOpcode, ETrue, &ipcArgs);
	}

TInt RWsBuffer::WriteReplyP(TInt aHandle,TUint aOpcode,const TAny *aData,TInt aLength,const TWriteDescriptorType& aReplyBuffer)
	{
	TIpcArgs ipcArgs;
	aReplyBuffer.SetDescriptorOnIpcArgs(ipcArgs);
	return DoWrite(aHandle, aOpcode, ETrue, &ipcArgs, aData, aLength);
	}

TInt RWsBuffer::WriteReplyP(TInt aHandle,TUint aOpcode,const TAny *aData1,TInt aLengthData1,const TAny *aData2,TInt aLengthData2,const TWriteDescriptorType& aReplyBuffer)
	{
	TIpcArgs ipcArgs;
	aReplyBuffer.SetDescriptorOnIpcArgs(ipcArgs);
	return DoWrite(aHandle, aOpcode, ETrue, &ipcArgs, aData1, aLengthData1, aData2, aLengthData2);
	}

TInt RWsBuffer::WriteReplyWs(TUint opcode)
//
// Do a WriteReply using the sessions handle
//
	{
	return(iSession->WriteReply(opcode));
	}

TInt RWsBuffer::WriteReplyWs(const TAny *pData, TInt aLength, TUint aOpcode)
//
// Do a WriteReply using the sessions handle
//
	{
	return(iSession->WriteReply(pData,aLength,aOpcode));
	}

TInt RWsBuffer::WriteReplyWs(const TAny *pData, TInt aLength, const TAny *pData2, TInt aLength2, TUint aOpcode)
//
// Do a WriteReply using the sessions handle
//
	{
	return(iSession->WriteReply(pData,aLength,pData2,aLength2,aOpcode));
	}

TInt RWsBuffer::WriteReplyByProvidingRemoteReadAccess(TInt aHandle,TUint aOpcode,const TAny *aData, TInt aLength,const TReadDescriptorType& aRemoteReadBuffer)
	{
	TIpcArgs ipcArgs;
	aRemoteReadBuffer.SetDescriptorOnIpcArgs(ipcArgs);
	return DoWrite(aHandle, aOpcode, ETrue, &ipcArgs, aData, aLength);
	}

void RWsBuffer::AddToBitmapArray(TInt aBitmapHandle)
	{
	if(aBitmapHandle && !iInvalidBitmapArray)
		{
		if(iBitmapArray.InsertInOrder(aBitmapHandle)==KErrNoMemory)

			iInvalidBitmapArray=ETrue;
		}
	}
	
void RWsBuffer::SetWsGraphicManager(CWsGraphic::CManager* aManager)
	{
	__ASSERT_DEBUG(!WsGraphicManager(),Panic(EW32PanicGraphicInternal));
	iManager = aManager;
	}

CWsGraphic::CManager* RWsBuffer::WsGraphicManager()
	{
	for(RWsBuffer *buffer=(RWsBuffer *)Dll::Tls();buffer;buffer=buffer->iNext)
		if (buffer->iManager)
			return buffer->iManager;	
	return NULL; // does not yet exist
	}