GDALRasterBlock *GDALArrayBandBlockCache::TryGetLockedBlockRef( int nXBlockOff,
int nYBlockOff )
{
GDALRasterBlock *poBlock;
int nBlockIndex = 0;
/* -------------------------------------------------------------------- */
/* Simple case for single level caches. */
/* -------------------------------------------------------------------- */
if( !bSubBlockingActive )
{
nBlockIndex = nXBlockOff + nYBlockOff * poBand->nBlocksPerRow;
while( TRUE )
{
poBlock = u.papoBlocks[nBlockIndex];
if( poBlock == NULL )
return NULL;
if( poBlock->TakeLock() )
break;
}
}
else
{
/* -------------------------------------------------------------------- */
/* Identify our subblock. */
/* -------------------------------------------------------------------- */
int nSubBlock = TO_SUBBLOCK(nXBlockOff)
+ TO_SUBBLOCK(nYBlockOff) * nSubBlocksPerRow;
/* -------------------------------------------------------------------- */
/* Check within subblock. */
/* -------------------------------------------------------------------- */
GDALRasterBlock **papoSubBlockGrid = u.papapoBlocks[nSubBlock];
if( papoSubBlockGrid == NULL )
return NULL;
int nBlockInSubBlock = WITHIN_SUBBLOCK(nXBlockOff)
+ WITHIN_SUBBLOCK(nYBlockOff) * SUBBLOCK_SIZE;
while( TRUE )
{
poBlock = papoSubBlockGrid[nBlockInSubBlock];
if( poBlock == NULL )
return NULL;
if( poBlock->TakeLock() )
break;
}
}
return poBlock;
}
GDALRasterBlock *GDALHashSetBandBlockCache::TryGetLockedBlockRef(
int nXBlockOff, int nYBlockOff )
{
GDALRasterBlock oBlockForLookup(nXBlockOff, nYBlockOff);
GDALRasterBlock* poBlock;
{
CPLLockHolderOptionalLockD( hLock );
auto oIter = m_oSet.find(&oBlockForLookup);
if( oIter == m_oSet.end() )
return nullptr;
poBlock = *oIter;
}
if( !poBlock->TakeLock() )
return nullptr;
return poBlock;
}