1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/persistentdata/persistentstorage/dbms/pcdbms/utable/UT_WIN.CPP Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,337 @@
1.4 +// Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).
1.5 +// All rights reserved.
1.6 +// This component and the accompanying materials are made available
1.7 +// under the terms of "Eclipse Public License v1.0"
1.8 +// which accompanies this distribution, and is available
1.9 +// at the URL "http://www.eclipse.org/legal/epl-v10.html".
1.10 +//
1.11 +// Initial Contributors:
1.12 +// Nokia Corporation - initial contribution.
1.13 +//
1.14 +// Contributors:
1.15 +//
1.16 +// Description:
1.17 +//
1.18 +
1.19 +#include "UT_STD.H"
1.20 +
1.21 +// Class CDbBasicWindowStage
1.22 +
1.23 +CDbBasicWindowStage::CDbBasicWindowStage(const TDbWindow& aWindow)
1.24 + : iWindow(aWindow), iRecords(EWindowArrayGranularity), iPos(-1)
1.25 + {
1.26 + __ASSERT(aWindow.Size()!=aWindow.ENone);
1.27 + }
1.28 +
1.29 +TBool CDbBasicWindowStage::GetRecord(TDbRecordId& aRecordId)
1.30 + {
1.31 + if (TUint(iPos)>=TUint(iRecords.Count()))
1.32 + return EFalse;
1.33 + aRecordId=iRecords[iPos];
1.34 + return ETrue;
1.35 + }
1.36 +
1.37 +void CDbBasicWindowStage::Reset()
1.38 +//
1.39 +// Reset the window to initial state
1.40 +//
1.41 + {
1.42 + CDbDataStage::Reset();
1.43 + iRecords.Reset();
1.44 + iPos=-1;
1.45 + }
1.46 +
1.47 +TBool CDbBasicWindowStage::EvaluateL(TInt& aWork,TDbRecordId& aRecordId,TBool& aAtRow)
1.48 +//
1.49 +// Do as much work as we can to make the window match the desired shape
1.50 +//
1.51 + {
1.52 + TBool eval=CDbDataStage::EvaluateL(aWork,aRecordId,aAtRow);
1.53 + if (!eval)
1.54 + {
1.55 + eval=DoEvaluateL(aWork);
1.56 + aAtRow=GetRecord(aRecordId);
1.57 + }
1.58 + return eval;
1.59 + }
1.60 +
1.61 +TInt CDbBasicWindowStage::CountL()
1.62 +//
1.63 +// Window'd views only report the evaluated records
1.64 +//
1.65 + {
1.66 + return iRecords.Count();
1.67 + }
1.68 +
1.69 +CDbBasicWindowStage::TGoto CDbBasicWindowStage::GotoL(TInt& /*aWork*/,TDbPosition aPosition,TDbRecordId& aRecordId)
1.70 + {
1.71 + switch (aPosition)
1.72 + {
1.73 + default:
1.74 + __ASSERT(0);
1.75 + break;
1.76 + case EDbFirst:
1.77 + iPos=0;
1.78 + break;
1.79 + case EDbLast:
1.80 + iPos=iRecords.Count()-1;
1.81 + break;
1.82 + case EDbNext:
1.83 + ++iPos;
1.84 + break;
1.85 + case EDbPrevious:
1.86 + --iPos;
1.87 + break;
1.88 + }
1.89 + return GetRecord(aRecordId) ? ESuccess : ENoRow;
1.90 + }
1.91 +
1.92 +TInt CDbBasicWindowStage::Find(TDbRecordId aRecordId,TInt& aPos)
1.93 + {
1.94 + TKeyArrayFix key(0,ECmpTUint32);
1.95 + return iRecords.Find(aRecordId,key,aPos);
1.96 + }
1.97 +
1.98 +TBool CDbBasicWindowStage::GotoL(TDbRecordId aRecordId)
1.99 + {
1.100 + return Find(aRecordId,iPos)==0;
1.101 + }
1.102 +
1.103 +void CDbBasicWindowStage::ReadRowL(TDbRecordId aRecordId)
1.104 + {
1.105 + TRAPD(r,CDbDataStage::ReadRowL(aRecordId));
1.106 + if (r==KErrNotFound)
1.107 + {
1.108 + TInt pos;
1.109 + if (Find(aRecordId,pos)==KErrNone)
1.110 + {
1.111 + iRecords.Delete(pos);
1.112 + if (pos<iPos)
1.113 + --iPos;
1.114 + }
1.115 + }
1.116 + __LEAVE_IF_ERROR(r);
1.117 + }
1.118 +
1.119 +TDbRecordId CDbBasicWindowStage::WriteRowL(TWrite aWrite,TSynch aSynch)
1.120 + {
1.121 + TDbRecordId id=CDbDataStage::WriteRowL(aWrite,ENoSynch);
1.122 + if (aWrite==EAppend && iWindow.Size()==iWindow.EUnlimited)
1.123 + {
1.124 + iRecords.AppendL(id);
1.125 + if (aSynch==ESynch)
1.126 + iPos=iRecords.Count()-1; // follow the append
1.127 + }
1.128 + return id;
1.129 + }
1.130 +
1.131 +CDbBasicWindowStage::TDelete CDbBasicWindowStage::DeleteRowL(TDbRecordId& aRecordId,TSynch)
1.132 +//
1.133 +// Remove the row from the window if it is present
1.134 +//
1.135 + {
1.136 + CDbDataStage::DeleteRowL(aRecordId,ENoSynch);
1.137 + if (GotoL(aRecordId))
1.138 + {
1.139 + iRecords.Delete(iPos);
1.140 + if (GetRecord(aRecordId))
1.141 + return EDeletedAtNext;
1.142 + }
1.143 + return EDeletedAtEnd;
1.144 + }
1.145 +
1.146 +// Class CDbWindowStage
1.147 +
1.148 +CDbWindowStage::CDbWindowStage(const TDbWindow& aWindow)
1.149 + : CDbBasicWindowStage(aWindow), iIterPos(EAtBeginning), iView(EBeginning)
1.150 + {}
1.151 +
1.152 +void CDbWindowStage::Reset()
1.153 +//
1.154 +// Reset the window to initial state
1.155 +//
1.156 + {
1.157 + CDbBasicWindowStage::Reset();
1.158 + iIterPos=EAtBeginning;
1.159 + iView=EBeginning;
1.160 + }
1.161 +
1.162 +TInt CDbWindowStage::WhatToEvaluate()
1.163 +//
1.164 +// count of slots to fill, <0 at beginning, >0 at end. 0 none
1.165 +//
1.166 + {
1.167 + if (iView==EAll)
1.168 + return 0;
1.169 + if (iWindow.Size()==iWindow.EUnlimited)
1.170 + return KMaxTInt;
1.171 + TInt space=iWindow.Size()-iRecords.Count();
1.172 + TInt lag=iPos-iWindow.PreferredPos();
1.173 + switch (iView)
1.174 + {
1.175 + default:
1.176 + __ASSERT(0);
1.177 + case EBeginning:
1.178 + return space+Max(lag,0); // fill up and use forward lag if any
1.179 + case EEnd:
1.180 + return Min(lag,0)-space; // fill up backwards and use rear lag if any
1.181 + case EMiddle:
1.182 + if (lag<0 && iIterPos==EAtBeginning) // use iterator position if we can
1.183 + return lag;
1.184 + if (space+lag>0)
1.185 + return space+lag;
1.186 + if (lag<0)
1.187 + return lag;
1.188 + return 0;
1.189 + }
1.190 + }
1.191 +
1.192 +TDbPosition CDbWindowStage::ResetIterToBeginningL()
1.193 + {
1.194 + for (TInt ii=iRecords.Count();--ii>=0;)
1.195 + {
1.196 + if (CDbDataStage::GotoL(iRecords[0]))
1.197 + return EDbPrevious;
1.198 +// has been deleted, try the next one
1.199 + iRecords.Delete(0);
1.200 + if (iPos>0)
1.201 + --iPos;
1.202 + }
1.203 +// no records to work with, start at the end
1.204 + return EDbLast;
1.205 + }
1.206 +
1.207 +TDbPosition CDbWindowStage::ResetIterToEndL()
1.208 + {
1.209 + for (TInt ii=iRecords.Count();--ii>=0;)
1.210 + {
1.211 + if (CDbDataStage::GotoL(iRecords[ii]))
1.212 + return EDbNext;
1.213 +// has been deleted, try the next one
1.214 + iRecords.Delete(ii);
1.215 + if (iPos>ii)
1.216 + --iPos;
1.217 + }
1.218 +// no records to work with, start at the beginning
1.219 + return EDbFirst;
1.220 + }
1.221 +
1.222 +TDbPosition CDbWindowStage::SetIteratorL(TInt anEval)
1.223 +//
1.224 +// Set the iterator for some work and return the first iterator direction
1.225 +//
1.226 + {
1.227 + switch (iIterPos)
1.228 + {
1.229 + default:
1.230 + __ASSERT(0);
1.231 + case EAtBeginning:
1.232 + if (anEval<0)
1.233 + return EDbPrevious;
1.234 +// turn around iterator to work at end
1.235 + iIterPos=EAtEnd;
1.236 + return ResetIterToEndL();
1.237 + case EAtEnd:
1.238 + if (anEval>0)
1.239 + return EDbNext;
1.240 +// turn around iterator to work at beginning
1.241 + iIterPos=EAtBeginning;
1.242 + return ResetIterToBeginningL();
1.243 + }
1.244 + }
1.245 +
1.246 +void CDbWindowStage::ExtendAtBeginningL(TInt aRecords,TDbPosition aFirst,TInt& aWork)
1.247 + {
1.248 + TDbRecordId id=iRecords.Count()>0 ? iRecords[0] : KDbNullRecordId;
1.249 + while (aRecords>0)
1.250 + {
1.251 + switch (CDbDataStage::GotoL(aWork,aFirst,id))
1.252 + {
1.253 + default:
1.254 + __ASSERT(0);
1.255 + case EExhausted:
1.256 + return;
1.257 + case ESuccess:
1.258 + if (iRecords.Count()==iWindow.Size())
1.259 + { // drop last record
1.260 + iRecords.Delete(iRecords.Count()-1);
1.261 + if (iView==EEnd)
1.262 + iView=EMiddle;
1.263 + }
1.264 + iRecords.InsertL(0,id);
1.265 + ++iPos;
1.266 + if (aFirst==EDbLast)
1.267 + aFirst=EDbPrevious;
1.268 + --aRecords;
1.269 + break;
1.270 + case ENoRow: // no more data that way
1.271 + iView=iView==EEnd ? EAll : EBeginning;
1.272 + return;
1.273 + case ESynchFailure: // have to do some work on the iterator now
1.274 + aFirst=ResetIterToBeginningL();
1.275 + break;
1.276 + }
1.277 + }
1.278 + }
1.279 +
1.280 +void CDbWindowStage::ExtendAtEndL(TInt aRecords,TDbPosition aFirst,TInt& aWork)
1.281 + {
1.282 + TDbRecordId id=iRecords.Count()>0 ? iRecords[iRecords.Count()-1] : KDbNullRecordId;
1.283 + while (aRecords>0)
1.284 + {
1.285 + switch (CDbDataStage::GotoL(aWork,aFirst,id))
1.286 + {
1.287 + default:
1.288 + __ASSERT(0);
1.289 + case EExhausted:
1.290 + return;
1.291 + case ESuccess:
1.292 + if (iRecords.Count()==iWindow.Size())
1.293 + { // drop first record
1.294 + iRecords.Delete(0);
1.295 + --iPos;
1.296 + if (iView==EBeginning)
1.297 + iView=EMiddle;
1.298 + }
1.299 + iRecords.AppendL(id);
1.300 + if (aFirst==EDbFirst)
1.301 + aFirst=EDbNext;
1.302 + --aRecords;
1.303 + break;
1.304 + case ENoRow:
1.305 + iView=iView==EBeginning ? EAll : EEnd;
1.306 + return;
1.307 + case ESynchFailure:
1.308 + aFirst=ResetIterToEndL();
1.309 + break;
1.310 + }
1.311 + }
1.312 + }
1.313 +
1.314 +TBool CDbWindowStage::DoEvaluateL(TInt& aWork)
1.315 +//
1.316 +// Do as much work as we can to make the window match the desired shape
1.317 +//
1.318 + {
1.319 + for (;;)
1.320 + {
1.321 + TInt eval=WhatToEvaluate();
1.322 + if (eval==0)
1.323 + return EFalse;
1.324 + if (aWork<=0)
1.325 + return ETrue;
1.326 + TDbPosition dir=SetIteratorL(eval);
1.327 + if (eval>0)
1.328 + ExtendAtEndL(eval,dir,aWork);
1.329 + else
1.330 + ExtendAtBeginningL(-eval,dir,aWork);
1.331 + }
1.332 + }
1.333 +
1.334 +TBool CDbWindowStage::Unevaluated()
1.335 +//
1.336 +// Return whether it is worth Evaluating
1.337 +//
1.338 + {
1.339 + return WhatToEvaluate()==0 ? CDbDataStage::Unevaluated() : ETrue;
1.340 + }