Rearranged some code to try and improve the robustness of block paging and compression.

This commit is contained in:
Daviw Williams 2013-11-12 16:47:57 +01:00
parent 1c5a3f7ef5
commit 85d8bdb30c
2 changed files with 24 additions and 37 deletions

View File

@ -319,8 +319,8 @@ namespace PolyVox
uint32_t calculateBlockMemoryUsage(void) const;
void flushOldestExcessiveBlocks(void) const;
void flushExcessiveCacheEntries(void) const;
void ensureCompressedBlockMapHasFreeSpace(void) const;
void ensureUncompressedBlockMapHasFreeSpace(void) const;
void initialise();

View File

@ -625,17 +625,14 @@ namespace PolyVox
if(itBlock != m_pBlocks.end())
{
pBlock = itBlock->second;
pBlock->m_uBlockLastAccessed = ++m_uTimestamper;
return pBlock;
}
else
{
ensureCompressedBlockMapHasFreeSpace();
// The block wasn't found so we create a new one
pBlock = new CompressedBlock<VoxelType>;
// It's important to set the timestamp before we flush later.
pBlock->m_uBlockLastAccessed = ++m_uTimestamper;
// Pass the block to the Pager to give it a chance to initialise it with any data
Vector3DInt32 v3dLower(v3dBlockPos.getX() << m_uBlockSideLengthPower, v3dBlockPos.getY() << m_uBlockSideLengthPower, v3dBlockPos.getZ() << m_uBlockSideLengthPower);
Vector3DInt32 v3dUpper = v3dLower + Vector3DInt32(m_uBlockSideLength-1, m_uBlockSideLength-1, m_uBlockSideLength-1);
@ -644,12 +641,10 @@ namespace PolyVox
// Add the block to the map
itBlock = m_pBlocks.insert(std::make_pair(v3dBlockPos, pBlock)).first;
// Paging in this new block may mean we are now using too much memory. If necessary, flush some old blocks.
flushOldestExcessiveBlocks();
return pBlock;
}
pBlock->m_uBlockLastAccessed = ++m_uTimestamper;
return pBlock;
}
template <typename VoxelType>
@ -666,30 +661,22 @@ namespace PolyVox
return m_pLastAccessedBlock;
}
UncompressedBlock<VoxelType>* pUncompressedBlock = 0;
typename UncompressedBlockMap::iterator itUncompressedBlock = m_pUncompressedBlockCache.find(v3dBlockPos);
// check whether the block is already loaded
if(itUncompressedBlock != m_pUncompressedBlockCache.end())
{
UncompressedBlock<VoxelType>* pUncompressedBlock = itUncompressedBlock->second;
pUncompressedBlock->m_uBlockLastAccessed = ++m_uTimestamper;
m_pLastAccessedBlock = pUncompressedBlock;
m_v3dLastAccessedBlockPos = v3dBlockPos;
return pUncompressedBlock;
pUncompressedBlock = itUncompressedBlock->second;
}
else
{
// At this point we just create a new block.
UncompressedBlock<VoxelType>* pUncompressedBlock = new UncompressedBlock<VoxelType>(m_uBlockSideLength);
// At this point we know that the uncompresed block did not exist in the cache. We will
// create it and add it to the cache, which means we need to make sure there is space.
ensureUncompressedBlockMapHasFreeSpace();
// It's important to set the timestamp before we flush later.
pUncompressedBlock->m_uBlockLastAccessed = ++m_uTimestamper;
// We set these before flushing because the flush can cause block to be erased, and there
// is a test to make sure the block which is being erase is not the last accessed block.
m_pLastAccessedBlock = pUncompressedBlock;
m_v3dLastAccessedBlockPos = v3dBlockPos;
// We can now create a new block.
pUncompressedBlock = new UncompressedBlock<VoxelType>(m_uBlockSideLength);
// An uncompressed bock is always backed by a compressed one, and this is created by getCompressedBlock() if it doesn't
// already exist. If it does already exist and has data then we bring this across into the ucompressed version.
@ -703,14 +690,14 @@ namespace PolyVox
// Add our new block to the map.
m_pUncompressedBlockCache.insert(std::make_pair(v3dBlockPos, pUncompressedBlock));
}
// Our block cache may now have grown too large. Flush some entries if necessary.
// FIXME - Watch out for flushing the block we just created!
flushExcessiveCacheEntries();
pUncompressedBlock->m_uBlockLastAccessed = ++m_uTimestamper;
m_pLastAccessedBlock = pUncompressedBlock;
m_v3dLastAccessedBlockPos = v3dBlockPos;
return pUncompressedBlock;
}
}
////////////////////////////////////////////////////////////////////////////////
/// Note: This function needs reviewing for accuracy...
@ -762,7 +749,7 @@ namespace PolyVox
}
template <typename VoxelType>
void LargeVolume<VoxelType>::flushOldestExcessiveBlocks(void) const
void LargeVolume<VoxelType>::ensureCompressedBlockMapHasFreeSpace(void) const
{
while(m_pBlocks.size() > m_uMaxNumberOfBlocksInMemory)
{
@ -784,7 +771,7 @@ namespace PolyVox
}
template <typename VoxelType>
void LargeVolume<VoxelType>::flushExcessiveCacheEntries(void) const
void LargeVolume<VoxelType>::ensureUncompressedBlockMapHasFreeSpace(void) const
{
while(m_pUncompressedBlockCache.size() > m_uMaxNumberOfUncompressedBlocks)
{