1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/persistentdata/persistentstorage/dbms/ustor/US_CLSTR.CPP Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,656 @@
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 "US_STD.H"
1.20 +
1.21 +// Class RClusterMap
1.22 +
1.23 +void RClusterMap::InsertL( TClusterId aCluster, TClusterId aPrevious )
1.24 +//
1.25 +// insert the entry into the map
1.26 +//
1.27 + {
1.28 + TIdPair* map = iMap;
1.29 + if ( iEntries == iAlloc )
1.30 + { // ensure there is space
1.31 + TInt size = iAlloc + EGranularity;
1.32 + iMap = map = ( TIdPair* )User::ReAllocL( map, size * sizeof( TIdPair ) );
1.33 + iAlloc = size;
1.34 + }
1.35 + TInt l = 0;
1.36 + TInt r = iEntries;
1.37 + while ( r > l )
1.38 + {
1.39 + TInt m = ( l + r ) >> 1;
1.40 + TClusterId id = map[ m ].iId;
1.41 + __ASSERT( aCluster != id ); // not already present
1.42 + if ( aCluster < id )
1.43 + r = m;
1.44 + else
1.45 + l = m + 1;
1.46 + }
1.47 + TIdPair* p = map + r;
1.48 + TIdPair* e = map + iEntries++;
1.49 + Mem::Move( p + 1, p, ( TUint8* )e - ( TUint8* )p );
1.50 + p->iId = aCluster;
1.51 + p->iPreviousId = aPrevious;
1.52 + }
1.53 +
1.54 +RClusterMap::TIdPair* RClusterMap::At( TClusterId aCluster )
1.55 + {
1.56 + TInt l = 0;
1.57 + TInt r = iEntries;
1.58 + while ( r > l )
1.59 + {
1.60 + TInt m = ( l + r ) >> 1;
1.61 + TClusterId id = iMap[ m ].iId;
1.62 + if ( aCluster < id )
1.63 + r = m;
1.64 + else if ( aCluster > id )
1.65 + l = m + 1;
1.66 + else
1.67 + return iMap + m;
1.68 + }
1.69 + return 0;
1.70 + }
1.71 +
1.72 +void RClusterMap::ResetL( TClusterId aHeadCluster )
1.73 + {
1.74 + iComplete = EFalse;
1.75 + iEntries = 0;
1.76 + InsertL( aHeadCluster, KNullClusterId );
1.77 + iLastMapped = iLastBound = aHeadCluster;
1.78 + iSkipped = ESeparation - 1;
1.79 + }
1.80 +
1.81 +TBool RClusterMap::At( TClusterId aCluster, TClusterId& aPreviousCluster )
1.82 + {
1.83 + TIdPair* p = At( aCluster );
1.84 + if ( p )
1.85 + aPreviousCluster = p->iPreviousId;
1.86 + else if ( aCluster == iLastBound )
1.87 + aPreviousCluster = iLastMapped;
1.88 + else
1.89 + return EFalse;
1.90 + return ETrue;
1.91 + }
1.92 +
1.93 +void RClusterMap::AddL( TClusterId aCluster )
1.94 + {
1.95 + __ASSERT( aCluster != KNullClusterId );
1.96 + if ( --iSkipped < 0 )
1.97 + {
1.98 + InsertL( aCluster, iLastMapped );
1.99 + iLastMapped = aCluster;
1.100 + iSkipped = ESeparation - 1;
1.101 + }
1.102 + iLastBound = aCluster;
1.103 + }
1.104 +
1.105 +void RClusterMap::DropL( TClusterId aCluster, TClusterId aNext )
1.106 +//
1.107 +// Cluster has been deleted, modify entry to contain the next cluster
1.108 +// last cluster in table is never deleted
1.109 +//
1.110 + {
1.111 + if ( aCluster == iLastBound )
1.112 + iLastBound = aNext;
1.113 + TIdPair* entry = At( aCluster );
1.114 + if ( !entry )
1.115 + return; // not in the sparse map
1.116 +// remove entry for cluster->prev
1.117 + TClusterId prev = entry->iPreviousId;
1.118 + Mem::Move( entry, entry + 1, ( TUint8* )( iMap + --iEntries ) - ( TUint8* )entry );
1.119 +//
1.120 + if ( aCluster == iLastMapped )
1.121 + iLastMapped = aNext;
1.122 + else
1.123 + { // find the referring entry next->cluster
1.124 + TIdPair* pnext = iMap;
1.125 + while ( pnext->iPreviousId != aCluster )
1.126 + {
1.127 + ++pnext;
1.128 + __ASSERT( pnext < iMap + iEntries );
1.129 + }
1.130 + if ( pnext->iId == aNext )
1.131 + { // referring entry is the next one => drop a link
1.132 + pnext->iPreviousId = prev;
1.133 + return;
1.134 + }
1.135 + // adjust next->new
1.136 + pnext->iPreviousId = aNext;
1.137 + }
1.138 + // add in new link to replace deleted one
1.139 + InsertL( aNext, prev ); // will not fail allocation as space available
1.140 + }
1.141 +
1.142 +// Class TClusterLinkCache
1.143 +
1.144 +void TClusterLinkCache::Add( TClusterId aCluster, RClusterMap& aMap )
1.145 +//
1.146 +// Add an entry to the cache
1.147 +//
1.148 + {
1.149 + __ASSERT( iEnd != NULL );
1.150 + TClusterId id;
1.151 + __ASSERT( aMap.At( iMap[0], id ) );
1.152 +//
1.153 + TClusterId* p = iEnd;
1.154 + if ( p == &iMap[ RClusterMap::ESeparation ] )
1.155 + { // full, requires a shift down
1.156 + for ( ; !aMap.At( *p, id ); --p )
1.157 + {
1.158 + __ASSERT( p > iMap );
1.159 + }
1.160 + __ASSERT( p > iMap );
1.161 + __ASSERT( Has( id ) );
1.162 +
1.163 + TClusterId* c = iMap;
1.164 + --c;
1.165 + while ( p <= iEnd )
1.166 + *++c = *p++;
1.167 + p = c;
1.168 + }
1.169 + *++p = aCluster;
1.170 + iEnd = p;
1.171 + }
1.172 +
1.173 +void TClusterLinkCache::Add( const TClusterId* aFirst, const TClusterId* aLast )
1.174 +//
1.175 +// Add several linked TClusterIds
1.176 +//
1.177 + {
1.178 + __ASSERT( iEnd != NULL );
1.179 +//
1.180 + TClusterId* p = iEnd;
1.181 + while ( aFirst < aLast && p < &iMap[ RClusterMap::ESeparation ] )
1.182 + *++p = *aFirst++;
1.183 + iEnd = p;
1.184 + }
1.185 +
1.186 +void TClusterLinkCache::Drop( TClusterId aCluster, TClusterId aNext )
1.187 +//
1.188 +// Drop the item if it is in the cache
1.189 +//
1.190 + {
1.191 + TClusterId* p = iEnd;
1.192 + if ( !p )
1.193 + return;
1.194 + if ( *p == aCluster )
1.195 + {
1.196 + *p = aNext;
1.197 + return;
1.198 + }
1.199 + do
1.200 + {
1.201 + if ( p == iMap )
1.202 + return;
1.203 + } while ( *--p != aCluster );
1.204 + __ASSERT( *( p + 1 ) == aNext );
1.205 + for ( ; p < iEnd; ++p )
1.206 + *p = *( p + 1 );
1.207 + iEnd = p - 1;
1.208 + }
1.209 +
1.210 +TBool TClusterLinkCache::Has( TClusterId aCluster ) const
1.211 +//
1.212 +// Check if the cluster id is in the cache
1.213 +// iEnd==0 is a valid state (empty cache)
1.214 +//
1.215 + {
1.216 + for ( const TClusterId* p = iEnd; p >= iMap; )
1.217 + {
1.218 + if ( *p-- == aCluster )
1.219 + return ETrue;
1.220 + }
1.221 + return EFalse;
1.222 + }
1.223 +
1.224 +TBool TClusterLinkCache::At( TClusterId aCluster, TClusterId& aPrevious ) const
1.225 +//
1.226 +// If aCluster is in the cache, return the previous cluster in aPrevious
1.227 +// iEnd==0 is a valid state (empty cache)
1.228 +//
1.229 + {
1.230 + for ( const TClusterId* p = iEnd; p > iMap; )
1.231 + {
1.232 + if ( *p-- == aCluster )
1.233 + {
1.234 + aPrevious = *p;
1.235 + return ETrue;
1.236 + }
1.237 + }
1.238 + return EFalse;
1.239 + }
1.240 +
1.241 +// Class TClusterDes
1.242 +
1.243 +void TClusterDes::InternalizeL(RReadStream& aStream)
1.244 + {
1.245 + aStream>>iNext;
1.246 + iMembership=aStream.ReadUint16L();
1.247 + }
1.248 +
1.249 +void TClusterDes::ExternalizeL(RWriteStream& aStream) const
1.250 + {
1.251 + aStream<<iNext;
1.252 + aStream.WriteUint16L(iMembership);
1.253 + }
1.254 +
1.255 +
1.256 +// Class CClusterCache
1.257 +
1.258 +inline CClusterCache::CClusterCache(CDbStoreDatabase& aDatabase)
1.259 + : iDatabase(aDatabase),iCache(_FOFF(CCluster,iLink))
1.260 + {}
1.261 +
1.262 +CClusterCache* CClusterCache::NewL(CDbStoreDatabase& aDatabase)
1.263 + {
1.264 + CClusterCache* self=new(ELeave) CClusterCache(aDatabase);
1.265 + CleanupStack::PushL(self);
1.266 + // Add the initial clusters
1.267 + for(TInt i=0;i<(EMaxClusters/2);++i)
1.268 + {
1.269 + self->AddClusterL();
1.270 + }
1.271 + CleanupStack::Pop();
1.272 + return self;
1.273 + }
1.274 +
1.275 +LOCAL_C void DeleteCluster(CCluster* aCluster)
1.276 +//
1.277 +// helper function which matches the Apply() prototype
1.278 +//
1.279 + {
1.280 + delete aCluster;
1.281 + }
1.282 +
1.283 +CClusterCache::~CClusterCache()
1.284 + {
1.285 + Apply(DeleteCluster);
1.286 + }
1.287 +
1.288 +LOCAL_C void DiscardCluster(CCluster* aCluster)
1.289 +//
1.290 +// helper function which matches the Apply() prototype
1.291 +//
1.292 + {
1.293 + aCluster->Discard();
1.294 + }
1.295 +
1.296 +void CClusterCache::Discard()
1.297 +//
1.298 +// discard the current changes in all clusters
1.299 +//
1.300 + {
1.301 + Apply(DiscardCluster);
1.302 + }
1.303 +
1.304 +LOCAL_C void FlushClusterL(CCluster* aCluster)
1.305 +//
1.306 +// helper function which matches the Apply() prototype
1.307 +//
1.308 + {
1.309 + aCluster->FlushL();
1.310 + }
1.311 +
1.312 +void CClusterCache::FlushL()
1.313 +//
1.314 +// Flush all the clusters in the cache
1.315 +//
1.316 + {
1.317 + Apply(FlushClusterL);
1.318 + }
1.319 +
1.320 +CCluster* CClusterCache::Cluster(TClusterId aCluster)
1.321 +//
1.322 +// Look for a cluster in the cache
1.323 +//
1.324 + {
1.325 + TDblQueIter<CCluster> iter(iCache);
1.326 + for (CCluster* cluster;(cluster=iter++)!=0;)
1.327 + {
1.328 + if (cluster->Id()==aCluster)
1.329 + return cluster;
1.330 + }
1.331 + return 0;
1.332 + }
1.333 +
1.334 +CCluster& CClusterCache::ClusterL(TClusterId aCluster)
1.335 +//
1.336 +// Get a cluster from the cache or store and move it to the top of the cache
1.337 +// Track hits to the two clusters which most recently dropped out of the cache
1.338 +//
1.339 + {
1.340 + CCluster* cluster=Cluster(aCluster); // check if it is cached
1.341 + iFollowOnHits<<=2;
1.342 + if (!cluster)
1.343 + { // get an empty cluster and read it
1.344 + if (aCluster==iCachePlus1)
1.345 + { // the cluster has recently been discarded
1.346 + iCachePlus1=iCachePlus2; // re-sequence the cache follow-on
1.347 + iFollowOnHits|=0x1;
1.348 + }
1.349 + else if (aCluster==iCachePlus2)
1.350 + iFollowOnHits|=0x2; // the cluster has recently been discarded
1.351 + cluster=&NewClusterL();
1.352 + cluster->ReadL(aCluster);
1.353 + }
1.354 + return Touch(*cluster);
1.355 + }
1.356 +
1.357 +CCluster& CClusterCache::ClusterL()
1.358 +//
1.359 +// Get a new (empty) cluster from the cache and move it to the top
1.360 +//
1.361 + {
1.362 + return Touch(NewClusterL());
1.363 + }
1.364 +
1.365 +CCluster& CClusterCache::Touch(CCluster& aCluster)
1.366 +//
1.367 +// Move a cluster to the top of the LRU list
1.368 +//
1.369 + {
1.370 + aCluster.iLink.Deque();
1.371 + iCache.AddFirst(aCluster);
1.372 + return aCluster;
1.373 + }
1.374 +
1.375 +CCluster& CClusterCache::AddClusterL()
1.376 +//
1.377 +// Add a new cluster to the cache
1.378 +//
1.379 + {
1.380 + __ASSERT(iClusters<EMaxClusters);
1.381 + CCluster& cluster=*CCluster::NewL(Database());
1.382 + iCache.AddLast(cluster);
1.383 + ++iClusters;
1.384 + // move +2 hits into +1 zone and clear +1 hits
1.385 + iFollowOnHits=TUint8((TUint(iFollowOnHits)>>1)&0x55);
1.386 + return cluster;
1.387 + }
1.388 +
1.389 +CCluster& CClusterCache::NewClusterL()
1.390 +//
1.391 +// Get an empty cluster from the cache, but do not touch it
1.392 +// If the hit detector has registered enough near-misses the cache is expanded
1.393 +// by adding another cluster object
1.394 +//
1.395 + {
1.396 + CCluster* cluster=Cluster(KNullClusterId); // look for a discarded cluster first
1.397 + if (cluster)
1.398 + return *cluster;
1.399 +// check for cache expansion
1.400 + TUint detected=iFollowOnHits;
1.401 + if ((detected&(detected-1))!=0 && iClusters<EMaxClusters)
1.402 + return AddClusterL();
1.403 +// retire the last cache entry
1.404 + cluster=iCache.Last();
1.405 + cluster->FlushL();
1.406 + iCachePlus2=iCachePlus1;
1.407 + iCachePlus1=cluster->Id();
1.408 + return *cluster;
1.409 + }
1.410 +
1.411 +void CClusterCache::Apply(void (*aFunc)(CCluster*))
1.412 +//
1.413 +// Apply the function paramater to all clusters in the cache
1.414 +// This function may leave <==> the parameter function may leave
1.415 +//
1.416 + {
1.417 + TDblQueIter<CCluster> iter(iCache);
1.418 + for (CCluster* cluster;(cluster=iter++)!=0;)
1.419 + aFunc(cluster);
1.420 + }
1.421 +
1.422 +// Class CCluster
1.423 +
1.424 +CCluster* CCluster::NewL(CDbStoreDatabase& aDatabase)
1.425 + {
1.426 + return new(ELeave) CCluster(aDatabase);
1.427 + }
1.428 +
1.429 +CCluster::~CCluster()
1.430 + {
1.431 + User::Free(iMap[0]);
1.432 + }
1.433 +
1.434 +void CCluster::AdjustMap(TUint8** aMapEntry,TInt aAdjust)
1.435 +//
1.436 +// Adjust all map entries after aMapEntry
1.437 +//
1.438 + {
1.439 + do *aMapEntry+=aAdjust; while (++aMapEntry<=&iMap[KMaxClustering]);
1.440 + }
1.441 +
1.442 +TInt CCluster::SetSizeL(TInt aSize)
1.443 +//
1.444 +// Set the minimum size for the cluster buffer
1.445 +// Return the offset between the new and old cells
1.446 +//
1.447 + {
1.448 + if (iSize>=aSize)
1.449 + return 0;
1.450 +//
1.451 + aSize+=EGranularity-1; // round to granularity
1.452 + aSize&=~(EGranularity-1);
1.453 + TUint8* base=iMap[0];
1.454 + TInt offset=(TUint8*)User::ReAllocL(base,aSize)-base;
1.455 + iSize=aSize;
1.456 + if (offset)
1.457 + AdjustMap(&iMap[0],offset);
1.458 + return offset;
1.459 + }
1.460 +
1.461 +void CCluster::Discard()
1.462 +//
1.463 +// discard the current changes
1.464 +//
1.465 + {
1.466 + iCluster=KNullClusterId;
1.467 + iModified=EFalse;
1.468 + }
1.469 +
1.470 +void CCluster::Create(TClusterId aClusterId)
1.471 +//
1.472 +// Create a new cluster
1.473 +//
1.474 + {
1.475 + __ASSERT(!iModified);
1.476 +//
1.477 + iCluster=aClusterId;
1.478 + iDes.iNext=KNullClusterId;
1.479 + iDes.iMembership=0;
1.480 + TUint8* base=iMap[0];
1.481 + for (TUint8** ptr=&iMap[1];ptr<=&iMap[KMaxClustering];++ptr)
1.482 + *ptr=base;
1.483 + iModified=ETrue;
1.484 + }
1.485 +
1.486 +void CCluster::Relink(TClusterId aNextClusterId)
1.487 +//
1.488 +// Update the cluster to link to a different cluster
1.489 +//
1.490 + {
1.491 + iDes.iNext=aNextClusterId;
1.492 + iModified=ETrue;
1.493 + }
1.494 +
1.495 +void CCluster::AlterL(MAlter& aAlterer)
1.496 +//
1.497 +// alter all records in the cluster
1.498 +//
1.499 + {
1.500 + TUint members=iDes.iMembership;
1.501 + TUint8* wptr=iMap[0];
1.502 + TUint8* rptr=wptr;
1.503 + for (TUint8** map=&iMap[0];map<&iMap[KMaxClustering];members>>=1,++map)
1.504 + {
1.505 + if (members&1)
1.506 + {
1.507 + TInt size=map[1]-rptr;
1.508 + TInt expand=wptr-rptr+aAlterer.RecordExpansion(rptr,size);
1.509 + if (expand>0)
1.510 + { // requires more space for alteration
1.511 + AdjustL(map,expand+EExpandBuffer,rptr);
1.512 + wptr=map[0]; // compensate for possible moving cache
1.513 + rptr=map[1]-size; // record data is at end of this entry
1.514 + }
1.515 + wptr=aAlterer.AlterRecordL(wptr,rptr,size);
1.516 + rptr+=size;
1.517 + __ASSERT(wptr<=rptr);
1.518 + }
1.519 + else
1.520 + {
1.521 + __ASSERT(map[1]==rptr);
1.522 + }
1.523 + map[1]=wptr;
1.524 + }
1.525 + iModified=ETrue;
1.526 + }
1.527 +
1.528 +TPtrC8 CCluster::RecordL(TInt aIndex)
1.529 +//
1.530 +// Read the cluster and return the record data
1.531 +//
1.532 + {
1.533 + if (!((iDes.iMembership>>aIndex)&1))
1.534 + __LEAVE(KErrNotFound);
1.535 + return TPtrC8(iMap[aIndex],iMap[aIndex+1]-iMap[aIndex]);
1.536 + }
1.537 +
1.538 +TUint8* CCluster::UpdateL(TInt aIndex,TInt aNewSize)
1.539 +//
1.540 +// read the cluster and return a writable descriptor over the new record data
1.541 +//
1.542 + {
1.543 + SetRecordL(aIndex,aNewSize);
1.544 + iDes.iMembership|=(1<<aIndex);
1.545 + return iMap[aIndex];
1.546 + }
1.547 +
1.548 +TBool CCluster::DeleteL(TInt aIndex)
1.549 +//
1.550 +// return whether the cluster is empty or not
1.551 +//
1.552 + {
1.553 + SetRecordL(aIndex,0);
1.554 + iDes.iMembership&=~(1<<aIndex);
1.555 + return iDes.iMembership;
1.556 + }
1.557 +
1.558 +void CCluster::FlushL()
1.559 + {
1.560 + if (iModified)
1.561 + { // Externalize the cluster
1.562 + RDbStoreWriteStream cluster(iDatabase);
1.563 + cluster.ReplaceLC(iDatabase.Store(),iCluster);
1.564 + cluster<<iDes;
1.565 + TUint8** map=&iMap[0];
1.566 + TUint8* base=*map;
1.567 + TUint8* ptr=base;
1.568 + for (TUint members=iDes.iMembership;members!=0;members>>=1)
1.569 + {
1.570 + ++map;
1.571 + if (members&1)
1.572 + {
1.573 + TUint8* end=*map;
1.574 + cluster << TCardinality(end-ptr);
1.575 + ptr=end;
1.576 + }
1.577 + else
1.578 + {
1.579 + __ASSERT(*map==ptr);
1.580 + }
1.581 + }
1.582 + cluster.FilterL(cluster.EMixed,iCluster);
1.583 + cluster.WriteL(base,ptr-base);
1.584 + cluster.CommitL();
1.585 + CleanupStack::PopAndDestroy();
1.586 + iModified=EFalse;
1.587 + }
1.588 + }
1.589 +
1.590 +void CCluster::ReadL(TClusterId aCluster)
1.591 +//
1.592 +// Internalize the cluster
1.593 +//
1.594 + {
1.595 + __ASSERT(iCluster!=aCluster);
1.596 + __ASSERT(!iModified);
1.597 +//
1.598 + iCluster=KNullClusterId;
1.599 + RDbStoreReadStream cluster(iDatabase);
1.600 + cluster.OpenLC(iDatabase.Store(),aCluster);
1.601 + cluster>>iDes;
1.602 + TUint8** map=&iMap[0];
1.603 + TUint8* base=*map;
1.604 + TUint8* ptr=base;
1.605 + for (TUint members=iDes.iMembership;members!=0;members>>=1)
1.606 + {
1.607 + if (members&1)
1.608 + {
1.609 + TCardinality card;
1.610 + cluster >> card;
1.611 + TInt size=card;
1.612 + if (size>KDbStoreMaxRecordLength)
1.613 + __LEAVE(KErrCorrupt);
1.614 + ptr+=size;
1.615 + }
1.616 + *++map=ptr;
1.617 + }
1.618 + while (map<&iMap[KMaxClustering])
1.619 + *++map=ptr;
1.620 + TInt len=ptr-base;
1.621 + base+=SetSizeL(len);
1.622 + cluster.FilterL(cluster.EMixed,aCluster);
1.623 + cluster.ReadL(base,len);
1.624 + CleanupStack::PopAndDestroy();
1.625 + iCluster=aCluster;
1.626 + }
1.627 +
1.628 +void CCluster::SetRecordL(TInt aIndex,TInt aNewSize)
1.629 + {
1.630 + AdjustL(&iMap[aIndex],iMap[aIndex]+aNewSize-iMap[aIndex+1],iMap[aIndex+1]);
1.631 + iModified=ETrue;
1.632 + }
1.633 +
1.634 +void CCluster::AdjustL(TUint8** aMapEntry,TInt aAdjust,TUint8* aData)
1.635 +//
1.636 +// Adjust the record at map entry by aAdjust bytes
1.637 +// Move that entry data as well as the ones following for AlterCluster
1.638 +//
1.639 + {
1.640 + if (!aAdjust)
1.641 + return;
1.642 +//
1.643 + __ASSERT(aAdjust+aMapEntry[1]>=aMapEntry[0]); // record cannot go -ve size
1.644 + __ASSERT(aData>=aMapEntry[0]); // must not save data before this record
1.645 +//
1.646 + aData+=SetSizeL(iMap[KMaxClustering]-iMap[0]+aAdjust);
1.647 + Mem::Copy(aData+aAdjust,aData,iMap[KMaxClustering]-aData);
1.648 + AdjustMap(aMapEntry+1,aAdjust);
1.649 + }
1.650 +
1.651 +// class CCluster::MAlter
1.652 +
1.653 +TInt CCluster::MAlter::RecordExpansion(const TUint8*,TInt)
1.654 +//
1.655 +// default to no expansion
1.656 +//
1.657 + {
1.658 + return 0;
1.659 + }