// Copyright (c) 1998-2009 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:

 // Order-by stage for the cursor data "pipeline"

 // 

 //

 #include "UT_STD.H"

 #include "D32COMP.H"

 #ifdef _DEBUG

 #define _CHECK_ORDERING		// forces a full test of the ordering after sorting

 #endif

 #define MAX( a, b ) ( (a) > (b) ? (a) : (b) )

 /* The key structure.

 Each key value is always aligned on a 32-bit boundary to allow word reads and writes

 integral values are always atored as 32-bit values just as for the row buffer

 Text columns are encoded as follows (trailing padding is omitted from the description)

   Text8 columns			<byte n><n ASCII characters>

   n is the [character] length of the column

   Text16 columns		<short n><n UNICODE characters>

   n is the [character] length of the column

   LongText8 columns		<word n><n ASCII characters>

                  or		<word n|ETrunc><32 ASCII characters><blobId>

   n is [byte] size of the column

   LongText16 columns	<word n><n/2 UNICODE characters>

                   or	<word n|ETrunc><16 UNICODE characters><blobId>

   n is [byte] size of the column

 */

 class CDbOrderByStage::HOrdering

 	{

 private:

 	struct TKeyCol

 		{

 		TDbColNo iOrdinal;

 		TUint8 iType;

 		TUint8 iOrder;

 		TUint8 iLength;

 		};

 	struct TBlobKey

 		{

 		enum {ETrunc=(TInt)0x80000000};

 		enum {ETruncSize=32};		// store 32 bytes of truncated BLOBs

 	public:

 		inline TInt Size() const;

 	public:

 		TInt iSize;

 		union {TUint8 iData8[ETruncSize]; TUint16 iData16[ETruncSize>>1];};

 		TDbBlobId iId;

 		};

 public:

 	static HOrdering* NewL(CDbTable& aTable,const CDbKey& aKey);

 	TAny* EntryL(TAny* aPtr,const RDbTableRow& aRow) const;

 	TInt CompareL(const TAny* aLeft,const TAny* aRight) const;

 	TInt MaxSize() const;

 private:

 	inline HOrdering(TInt aCount,TDbTextComparison aComparison,CDbTable& aTable);

 	MStreamBuf* BlobLC(TDbBlobId aId,TDbColType aType) const;

 	TInt CompareLongText8L(const TBlobKey& aLeft,const TBlobKey& aRight) const;

 	TInt CompareLongText16L(const TBlobKey& aLeft,const TBlobKey& aRight) const;

 private:

 	CDbTable& iTable;

 	const TTextOps& iTextOps;

 	const TKeyCol* iEndOfKeys;

 	TKeyCol iKeys[1];	// one or more keys

 	};

 // Class HDbOrdering

 inline TInt CDbOrderByStage::HOrdering::TBlobKey::Size() const

 	{

 	TInt size=_FOFF(TBlobKey,iData8[iSize+3]);

 	return (size&ETrunc) ? sizeof(TBlobKey) : size&~3;

 	}

 inline CDbOrderByStage::HOrdering::HOrdering(TInt aCount,TDbTextComparison aComparison,CDbTable& aTable) :

 	iTable(aTable),

 	iTextOps(TTextOps::Ops(aComparison)),

 	iEndOfKeys(&iKeys[aCount])

 	{

 	}

 //

 // Construct the ordering based on the key definition (must be valid for the table)

 // and the column set provided

 //

 CDbOrderByStage::HOrdering* CDbOrderByStage::HOrdering::NewL(CDbTable& aTable,const CDbKey& aKey)

 	{

 	TInt count=aKey.Count();

 	__ASSERT(count>0);

 	HOrdering* self=new(User::AllocLC(_FOFF(HOrdering,iKeys[count])))

 								HOrdering(count,aKey.Comparison(),aTable);

 	TKeyCol* pKey=&self->iKeys[0];

 	const HDbColumnSet& columns=aTable.Def().Columns();

 	for (TInt ii=0;ii<count;++pKey,++ii)

 		{

 		const TDbKeyCol& key=aKey[ii];

 		pKey->iOrder=TUint8(key.iOrder);

 		pKey->iOrdinal=columns.ColNoL(key.iName);

 		if (pKey->iOrdinal==KDbNullColNo)

 			__LEAVE(KErrNotFound);

 		const TDbColumnDef& col=columns[pKey->iOrdinal];

 		switch (pKey->iType=col.iType)

 			{

 		default:

 			break;

 		case EDbColText8:

 		case EDbColText16:

 			{

 			TInt l=col.iMaxLength;

 			if (l<256)

 				{

 				pKey->iLength=TUint8(l);

 				break;

 				}

 			}

 			// fall through to argument error

 		case EDbColBinary:

 		case EDbColLongBinary:

 			__LEAVE(KErrArgument);

 			}

 		}

 	CleanupStack::Pop();

 	return self;

 	}

 TInt CDbOrderByStage::HOrdering::MaxSize() const

 	{

 	TInt maxsize=0;

 	const TKeyCol* const end=iEndOfKeys;

 	const TKeyCol* key=&iKeys[0];

 	__ASSERT(key<end);

 	do	{

 		TInt s;

 		switch (key->iType)

 			{

 		default:

 			s=sizeof(TUint32);

 			break;

 		case EDbColInt64:

 			s=sizeof(TInt64);

 			break;

 		case EDbColDateTime:

 			s=sizeof(TTime);

 			break;

 		case EDbColReal64:

 			s=sizeof(TReal64);

 			break;

 		case EDbColText8:

 			s=Align4(key->iLength+1);

 			break;

 		case EDbColText16:

 			s=Align4((key->iLength<<1)+1);

 			break;

 		case EDbColLongText8:

 		case EDbColLongText16:

 			s=MAX(__Align8(sizeof(TUint32)+KDbMaxInlineBlobSize),sizeof(TBlobKey));

 			break;

 			}

 		maxsize+=s;

 		} while (++key<end);

 	return maxsize;

 	}

 MStreamBuf* CDbOrderByStage::HOrdering::BlobLC(TDbBlobId aId,TDbColType aType) const

 	{

 	return iTable.BlobsL()->ReadLC(aId,aType);

 	}

 //

 // Construct an entry at aPtr from the record given

 // iMaxSize bytes are assumed to be available at aPtr

 // return the actual size of the entry

 //

 TAny* CDbOrderByStage::HOrdering::EntryL(TAny* aPtr,const RDbTableRow& aRow) const

 	{

 	__ASSERT(Align4(aPtr)==aPtr);

 	TUint32* ptr=(TUint32*)aPtr;		// 32-bit words are nice

 	const TKeyCol* const end=iEndOfKeys;

 	const TKeyCol* key=iKeys;

 	__ASSERT(key<end);

 	do	{

 		const TDbCell* cell=aRow.ColCell(key->iOrdinal);

 		TDbColType type=TDbColType(key->iType);

 		if (cell->Length()==0)

 			{	// null column

 			const TUint K64BitColumnMask=(1u<<EDbColInt64)|(1u<<EDbColReal64)|(1u<<EDbColDateTime);

 			*ptr++=0;

 			if (K64BitColumnMask&(1u<<type))

 				*ptr++=0;		// 8-byte column

 			continue;

 			}

 		switch (type)

 			{

 		default:

 			__ASSERT(0);

 		case EDbColBit:

 		case EDbColUint8:

 		case EDbColUint16:

 		case EDbColUint32:

 		case EDbColInt8:

 		case EDbColInt16:

 		case EDbColInt32:

 		case EDbColReal32:

 			*ptr++=*(const TUint32*)cell->Data();

 			break;

 		case EDbColInt64:

 		case EDbColDateTime:

 		case EDbColReal64:

 			{

 			const TUint32* data=(const TUint32*)cell->Data();

 			*ptr++=*data++;

 			*ptr++=*data;

 			}

 			break;

 		case EDbColText8:

 			{

 			TInt size=cell->Length();

 			*(TUint8*)ptr=TUint8(size);

 			ptr=(TUint32*)Align4(Mem::Copy(PtrAdd(ptr,1),cell->Data(),size));

 			}

 			break;

 		case EDbColText16:

 			{

 			TInt size=cell->Length();

 			*(TUint16*)ptr=TUint16(size>>1);

 			ptr=(TUint32*)Align4(Mem::Copy(PtrAdd(ptr,2),cell->Data(),size));

 			}

 			break;

 		case EDbColLongText8:

 		case EDbColLongText16:

 			{

 			const TDbBlob& blob=*(const TDbBlob*)cell->Data();

 			TInt size=blob.Size();

 			if (blob.IsInline())

 				{

 				*ptr++=size;

 				ptr=(TUint32*)Align4(Mem::Copy(ptr,blob.Data(),size));

 				}

 			else

 				{

 				TInt rsize=size;

 				if (size>TBlobKey::ETruncSize)

 					{

 					size|=TBlobKey::ETrunc;

 					rsize=TBlobKey::ETruncSize;

 					}

 				*ptr++=size;

 				BlobLC(blob.Id(),TDbColType(key->iType))->ReadL(ptr,rsize);

 				CleanupStack::PopAndDestroy();

 				ptr=Align4(PtrAdd(ptr,rsize));

 				if (size&TBlobKey::ETrunc)

 					*ptr++=blob.Id();

 				}

 			}

 			break;

 			}

 		} while (++key<end);

 	return ptr;

 	}

 TInt CDbOrderByStage::HOrdering::CompareLongText8L( const CDbOrderByStage::HOrdering::TBlobKey& aLeft, const CDbOrderByStage::HOrdering::TBlobKey& aRight ) const

 	{

 	TUint sizel = aLeft.iSize;

 	TUint sizer = aRight.iSize;

 	TUint s = sizel;

 	if ( sizer < s )

 		s = sizer;

 	if ( s > static_cast<TUint>( TBlobKey::ETruncSize ) && ( ( sizel | sizer ) & static_cast<TUint>( TBlobKey::ETrunc ) ) )

 		s = TBlobKey::ETruncSize;

 	TInt rr = iTextOps.Compare( aLeft.iData8, s, aRight.iData8, s );

 	if ( rr )

 		return rr;

 //

 // matches up to the same-length inlined data...

 // now it gets interesting

 //

 	if ( ( ( sizel | sizer ) & static_cast<TUint>( TBlobKey::ETrunc ) ) == 0 )

 		return sizel - sizer;		// neither are truncated

 	if ( s == sizel )

 		return -1;		// left completely match against truncated right

 	if ( s == sizer )

 		return 1;		// right completely matched against truncated left

 	s = Min( TInt( sizel & ~TBlobKey::ETrunc ), TInt( sizer & ~TBlobKey::ETrunc ) );		// minimum real length

 	if ( sizel & static_cast<TUint>( TBlobKey::ETrunc ) )

 		{

 		MStreamBuf& bufL = *BlobLC( aLeft.iId, EDbColLongText8 );

 		if ( sizer & static_cast<TUint>( TBlobKey::ETrunc ) )

 			{	// both out-of-line

 			rr = Comp::Compare8L( bufL, *BlobLC( aRight.iId, EDbColLongText8 ), s, iTextOps );

 			CleanupStack::PopAndDestroy();

 			}

 		else	// left side only out-of-line

 			rr = Comp::Compare8L( bufL, aRight.iData8, s, iTextOps );

 		}

 	else

 		{	// right side only out-of-line

 		__ASSERT( sizer & static_cast<TUint>( TBlobKey::ETrunc ) );

 		rr = -Comp::Compare8L( *BlobLC( aRight.iId, EDbColLongText8 ), aLeft.iData8, s, iTextOps );

 		}

 	CleanupStack::PopAndDestroy();

 	return rr ? rr : ( sizel & ~TBlobKey::ETrunc ) - ( sizer & ~TBlobKey::ETrunc );

 	}

 TInt CDbOrderByStage::HOrdering::CompareLongText16L( const CDbOrderByStage::HOrdering::TBlobKey& aLeft, const CDbOrderByStage::HOrdering::TBlobKey& aRight ) const

 	{

 	TUint sizeL = aLeft.iSize  & ~TBlobKey::ETrunc; // set truncation bit to 0 to get true size

 	TUint sizeR = aRight.iSize & ~TBlobKey::ETrunc;

 	TBool truncL = aLeft.iSize  & TBlobKey::ETrunc; // data is truncated if TBlobKey::ETrunc bit is 1

 	TBool truncR = aRight.iSize & TBlobKey::ETrunc;

 	if (!(truncL | truncR)) // neither side is truncated, compare full strings

 		{		

 		return iTextOps.Order( aLeft.iData16, sizeL>>1, aRight.iData16, sizeR>>1 );

 		}

 	TInt result;

 	TUint sizeMin = Min( TInt(sizeL), TInt(sizeR) ); // minimum real length

 	if ( truncL )

 		{

 		MStreamBuf& bufL = *BlobLC( aLeft.iId, EDbColLongText16 );

 		if ( truncR )

 			{	// both out-of-line

 			result = Comp::Compare16L( bufL, *BlobLC( aRight.iId, EDbColLongText16 ), sizeMin, iTextOps );

 			CleanupStack::PopAndDestroy();

 			}

 		else	// left side only out-of-line

 			result = Comp::Compare16L( bufL, aRight.iData16, sizeMin, iTextOps );

 		}

 	else

 		{	// right side only out-of-line

 		__ASSERT( truncR );

 		result = -Comp::Compare16L( *BlobLC( aRight.iId, EDbColLongText16 ), aLeft.iData16, sizeMin, iTextOps );

 		}

 	CleanupStack::PopAndDestroy();

 	return result ? result : ( sizeL ) - ( sizeR );

 	}

 TInt CDbOrderByStage::HOrdering::CompareL(const TAny* aLeft,const TAny* aRight) const

 //

 // compare the keys

 //

 	{

 	const TUint8* left=(const TUint8*)aLeft;

 	const TUint8* right=(const TUint8*)aRight;

 	const TKeyCol* end=iEndOfKeys;

 	const TKeyCol* key=&iKeys[0];

 	TInt rr;

 	for (;;)

 		{

 		switch (key->iType)

 			{

 		default:

 			__ASSERT(0);

 		case EDbColBit:

 		case EDbColUint8:

 		case EDbColUint16:

 		case EDbColUint32:

 			rr=Comp::Compare(*(const TUint32*)left,*(const TUint32*)right);

 			left+=sizeof(TUint32);

 			right+=sizeof(TUint32);

 			break;

 		case EDbColInt8:

 		case EDbColInt16:

 		case EDbColInt32:

 			rr=Comp::Compare(*(const TInt32*)left,*(const TInt32*)right);

 			left+=sizeof(TInt32);

 			right+=sizeof(TInt32);

 			break;

 		case EDbColInt64:

 			rr=Comp::Compare(*(const TInt64*)left,*(const TInt64*)right);

 			left+=sizeof(TInt64);

 			right+=sizeof(TInt64);

 			break;

 		case EDbColDateTime:

 			rr=Comp::Compare(*(const TTime*)left,*(const TTime*)right);

 			left+=sizeof(TTime);

 			right+=sizeof(TTime);

 			break;

 		case EDbColReal32:

 			rr=Comp::Compare(*(const TReal32*)left,*(const TReal32*)right);

 			left+=sizeof(TReal32);

 			right+=sizeof(TReal32);

 			break;

 		case EDbColReal64:

 			rr=Comp::Compare(*(const TReal64*)left,*(const TReal64*)right);

 			left+=sizeof(TReal64);

 			right+=sizeof(TReal64);

 			break;

 		case EDbColText8:

 			{

 			TInt sizel=*left++;

 			TInt sizer=*right++;

 			rr=iTextOps.Compare(left,sizel,right,sizer);

 			left=Align4(left+sizel);

 			right=Align4(right+sizer);

 			}

 			break;

 		case EDbColText16:

 			{

 			const TUint16* l16=reinterpret_cast<const TUint16*>(left);

 			const TUint16* r16=reinterpret_cast<const TUint16*>(right);

 			TInt sizel=*l16++;

 			TInt sizer=*r16++;

 			rr=iTextOps.Order(l16,sizel,r16,sizer);

 			left=Align4(reinterpret_cast<const TUint8*>(l16+sizel));

 			right=Align4(reinterpret_cast<const TUint8*>(r16+sizer));

 			}

 			break;

 		case EDbColLongText8:

 			{

 			const TBlobKey* ltext=(const TBlobKey*)left;

 			const TBlobKey* rtext=(const TBlobKey*)right;

 			rr=CompareLongText8L(*ltext,*rtext);

 			left+=ltext->Size();

 			right+=rtext->Size();

 			}

 			break;

 		case EDbColLongText16:

 			{

 			const TBlobKey* ltext=(const TBlobKey*)left;

 			const TBlobKey* rtext=(const TBlobKey*)right;

 			rr=CompareLongText16L(*ltext,*rtext);

 			left+=ltext->Size();

 			right+=rtext->Size();

 			}

 			break;

 			}

 		if (rr!=0)

 			break;

 		if (++key==end)

 			break;

 		}

 	return key->iOrder==TDbKeyCol::EAsc ? rr : -rr;

 	}

 //

 NONSHARABLE_CLASS(CDbOrderByStage::CKeys) : public CBase

 	{

 public:		// should be private but VC++ 4.0 whinges

 	struct TKey

 		{

 		TUint32 iId;

 		TUint8 iKey[4];		// and then some

 		};

 private:

 	enum {EKeysGranularity=32};

 	struct TPage

 		{

 		TPage* iNext;

 		TKey iEntries[1];

 		};

 	enum {EMinPageSize=0x200,EMinKeyElements=2};

 public:

 	CKeys(TInt aMaxKeySize);

 	~CKeys();

 //

 	void AddL(TDbRecordId aRecordId,const RDbTableRow& aRow,const HOrdering& aOrder);

 	void SortL(const HOrdering& aOrder);

 	void GetRecordsL(CArrayFix<TDbRecordId>& aRecords);

 #ifdef _CHECK_ORDERING

 	void VerifyOrderingL(const HOrdering& aOrder);

 #endif

 private:

 	void SortL(TKey* aData[],TInt aElem,const HOrdering& aOrder);

 	TKey& NewKeyL();

 	void KeyComplete(TAny* aEnd);

 	void Release();

 private:

 	RPointerArray<TKey> iKeys;

 	TInt iMaxKeySize;

 	TInt iPageSize;

 	TPage* iPages;

 	TKey* iNext;

 	TKey* iEnd;

 	};

 // Class CDbOrderByStage::CKeys

 CDbOrderByStage::CKeys::CKeys(TInt aMaxKeySize)

 	:iKeys(EKeysGranularity),iMaxKeySize(_FOFF(TKey,iKey[aMaxKeySize])),

 	 iPageSize(Max(EMinPageSize+iMaxKeySize,iMaxKeySize*EMinKeyElements))

 	{}

 CDbOrderByStage::CKeys::~CKeys()

 	{

 	iKeys.Close();

 	Release();

 	}

 void CDbOrderByStage::CKeys::SortL(CDbOrderByStage::CKeys::TKey* aData[],TInt aElem,const HOrdering& aOrder)

 //

 // Sort the array of row keys

 // Uses Heap-sort

 //

 	{

 	__ASSERT(aElem>1);

 	TInt heap=aElem>>1;

 	--aElem;

 	for (;;)

 		{

 		TKey* key;

 		if (heap!=0)

 			key=aData[--heap];

 		else

 			{

 			key=aData[aElem];

 			aData[aElem]=aData[0];

 			if (--aElem==0)

 				{

 				aData[0]=key;

 				break;

 				}

 			}

 		TInt ix=heap;

 		TInt parent;

 		for (parent=ix;;parent=ix)

 			{

 			ix=(ix<<1)+1;

 			if (ix<=aElem)

 				{

 				if (ix<aElem && aOrder.CompareL(aData[ix]->iKey,aData[ix+1]->iKey)<0)

 					++ix;

 				}

 			else

 				break;

 			if (aOrder.CompareL(aData[ix]->iKey,key->iKey)<=0)

 				break;

 			aData[parent]=aData[ix];

 			}

 		aData[parent]=key;

 		}

 	}

 void CDbOrderByStage::CKeys::AddL(TDbRecordId aRecordId,const RDbTableRow& aRow,const HOrdering& aOrder)

 //

 // Create a key for the row and store it

 //

 	{

 	TKey& key=NewKeyL();

 	key.iId=aRecordId.Value();

 	TAny* end=aOrder.EntryL(&key.iKey[0],aRow);

 	__LEAVE_IF_ERROR(iKeys.Append(&key));

 	KeyComplete(end);

 	}

 void CDbOrderByStage::CKeys::SortL(const HOrdering& aOrder)

 	{

 	TInt elem=iKeys.Count();

 	if (elem>1)

 		SortL(&iKeys[0],elem,aOrder);

 	}

 void CDbOrderByStage::CKeys::GetRecordsL(CArrayFix<TDbRecordId>& aRecords)

 	{

 	TInt elem=iKeys.Count();

 	if (elem==0)

 		return;

 	TKey** const base=&iKeys[0];

 	TKey** ptr=base+elem;

 	do	{

 		--ptr;

 		*REINTERPRET_CAST(TDbRecordId*,ptr)=(*ptr)->iId;

 		} while (ptr>base);

 	Release();		// discard key memory before adding records

 	aRecords.InsertL(0,REINTERPRET_CAST(const TDbRecordId*,base),elem);

 	iKeys.Reset();

 	}

 void CDbOrderByStage::CKeys::Release()

 //

 // Discard all of the allocated pages

 //

 	{

 	TPage* p=iPages;

 	while (p)

 		{

 		TPage* n=p->iNext;

 		User::Free(p);

 		p=n;

 		}

 	iPages=0;

 	iNext=iEnd=0;

 	}

 CDbOrderByStage::CKeys::TKey& CDbOrderByStage::CKeys::NewKeyL()

 //

 // Allocate a key entry for the raw key data

 //

 	{

 	TKey* p=iNext;

 	if (PtrAdd(p,iMaxKeySize)>iEnd)

 		{	// not enough space for a maximum key

 		TPage* page=iPages;

 		if (page)

 			{	// compress the current page

 			__DEBUG(page=(TPage*))User::ReAlloc(page,(TUint8*)iNext-(TUint8*)page);

 			__ASSERT(page==iPages);		// if it moves we are dead

 			}

 		page=(TPage*)User::AllocL(_FOFF(TPage,iEntries)+iPageSize);

 		page->iNext=iPages;

 		iPages=page;

 		p=iNext=&page->iEntries[0];

 		iEnd=PtrAdd(p,iPageSize);

 		}

 	return *p;

 	}

 void CDbOrderByStage::CKeys::KeyComplete(TAny* aEnd)

 //

 // Key is complete, prepare for the next one

 //

 	{

 	__ASSERT(aEnd==Align4(aEnd));

 	__ASSERT(iNext<=aEnd&&aEnd<=iEnd);

 	iNext=STATIC_CAST(TKey*,aEnd);

 	}

 #ifdef _CHECK_ORDERING

 void CDbOrderByStage::CKeys::VerifyOrderingL(const HOrdering& aOrder)

 	{

 // this performs a full O(N*N) comparison of the record set

 	if (iKeys.Count()==0)

 		return;

 	TKey* const* data=&iKeys[0];

 	for (TInt ii=iKeys.Count();--ii>=0;)

 		{

 		for (TInt jj=iKeys.Count();--jj>=0;)

 			{

 			TInt rr=aOrder.CompareL(data[ii]->iKey,data[jj]->iKey);

 			if (ii==jj)

 				__ASSERT_ALWAYS(rr==0,User::Invariant());

 			else if (ii<jj)

 				__ASSERT_ALWAYS(rr<=0,User::Invariant());

 			else

 				__ASSERT_ALWAYS(rr>=0,User::Invariant());

 			}

 		}

 	}

 #endif

 // Class CDbOrderByStage

 inline const RDbTableRow& CDbOrderByStage::Row()

 	{return iRow;}

 inline CDbOrderByStage::CKeys& CDbOrderByStage::Keys()

 	{__ASSERT(iKeys);return *iKeys;}

 inline const CDbOrderByStage::HOrdering& CDbOrderByStage::Order()

 	{__ASSERT(iOrder);return *iOrder;}

 CDbOrderByStage::CDbOrderByStage(const RDbTableRow& aRow)

 	: CDbBasicWindowStage(KDbUnlimitedWindow),iRow(aRow)

 	{

 	__ASSERT(iState==EReset);

 	}

 CDbOrderByStage::~CDbOrderByStage()

 	{

 	delete iOrder;

 	delete iKeys;

 	}

 void CDbOrderByStage::ConstructL(const CDbKey& aOrderBy)

 //

 // Build the key structures to support the partial and complete ordering

 //

 	{

 	iOrder=HOrdering::NewL(Row().Table(),aOrderBy);

 	}

 void CDbOrderByStage::Reset()

 //

 // Reset the window to initial state

 //

 	{

 	delete iKeys;

 	iKeys=0;

 	iState=EReset;

 	CDbBasicWindowStage::Reset();

 	}

 TBool CDbOrderByStage::ReadL(TInt& aWork,TDbPosition aNext)

 //

 // Read some more record keys

 //

 	{

 	TDbRecordId id(KDbNullRecordIdValue);

 	TGoto r;

 	while ((r=CDbDataStage::GotoL(aWork,aNext,id))==ESuccess)

 		{

 		CDbDataStage::ReadRowL(id);

 		Keys().AddL(id,Row(),Order());

 		aNext=EDbNext;

 		}

 	switch (r)

 		{

 	default:

 		__ASSERT(0);

 	case ESynchFailure:

 		__LEAVE(KErrNotReady);

 	case EExhausted:

 		return ETrue;

 	case ENoRow:

 		return EFalse;

 		}

 	}

 TBool CDbOrderByStage::DoEvaluateL(TInt& aWork)

 //

 // Build the key collection, and finally sort it

 //

 	{

 	TState s=iState;

 	iState=EFailed;

 	switch (s)

 		{

 	default:

 		__ASSERT(0);

 	case EFailed:

 		__LEAVE(KErrNotReady);

 	case EReset:

 		__ASSERT(!iKeys);

 		iKeys=new(ELeave) CKeys(Order().MaxSize());

 		// drop through to EEvaluate

 	case EEvaluate:

 		if (ReadL(aWork,s==EReset ? EDbFirst : EDbNext))

 			{

 			iState=EEvaluate;

 			return ETrue;

 			}

 		// drop through to ESort

 	case ESort:

 		Keys().SortL(Order());

 #ifdef _CHECK_ORDERING

 		Keys().VerifyOrderingL(Order());

 #endif

 		// drop through to EAdd

 	case EAdd:

 		Keys().GetRecordsL(iRecords);

 		delete iKeys;

 		iKeys=0;

 		// drop through to EComplete

 	case EComplete:

 		iState=EComplete;

 		return EFalse;

 		}

 	}

 TBool CDbOrderByStage::Unevaluated()

 //

 // Return whether it is worth Evaluating

 //

 	{

 	if (iState==EComplete)

 		return CDbDataStage::Unevaluated();

 	return iState!=EFailed;

 	}

 // Class CDbReorderWindowStage

 CDbReorderWindowStage::CDbReorderWindowStage()

 	: CDbBasicWindowStage(KDbUnlimitedWindow),iRows(EGranularity)

 	{

 	__ASSERT(iState==EReset);

 	}

 CDbReorderWindowStage::~CDbReorderWindowStage()

 	{

 	iRows.Close();

 	}

 void CDbReorderWindowStage::Reset()

 //

 // Reset the window to initial state

 //

 	{

 	iRows.Reset();

 	iState=EReset;

 	CDbBasicWindowStage::Reset();

 	}

 TBool CDbReorderWindowStage::ReadL(TInt& aWork,TDbPosition aNext)

 //

 // Read some more row ids

 //

 	{

 	TDbRecordId id(KDbNullRecordIdValue);

 	TGoto r;

 	while ((r=CDbDataStage::GotoL(aWork,aNext,id))==ESuccess)

 		{

 		__LEAVE_IF_ERROR(iRows.Append(id.Value()));

 		aNext=EDbNext;

 		}

 	switch (r)

 		{

 	default:

 		__ASSERT(0);

 	case ESynchFailure:

 		__LEAVE(KErrNotReady);

 	case EExhausted:

 		return ETrue;

 	case ENoRow:

 		return EFalse;

 		}

 	}

 TBool CDbReorderWindowStage::DoEvaluateL(TInt& aWork)

 //

 // Build the key collection, and finally sort it

 //

 	{

 	TState s=iState;

 	iState=EFailed;

 	switch (s)

 		{

 	default:

 		__ASSERT(0);

 	case EFailed:

 		__LEAVE(KErrNotReady);

 	case EReset:

 	case EEvaluate:

 		if (ReadL(aWork,s==EReset ? EDbFirst : EDbNext))

 			{

 			iState=EEvaluate;

 			return ETrue;

 			}

 		if (iRows.Count())

 			{

 			iRows.Sort();

 			iRecords.AppendL((const TDbRecordId*)&iRows[0],iRows.Count());

 			iRows.Reset();

 			}

 	case EComplete:

 		iState=EComplete;

 		return EFalse;

 		}

 	}

 TBool CDbReorderWindowStage::Unevaluated()

 //

 // Return whether it is worth Evaluating

 //

 	{

 	if (iState==EComplete)

 		return CDbDataStage::Unevaluated();

 	return iState!=EFailed;

 	}