Work on the code that frees up memory in LargeVolume.

This commit is contained in:
Daviw Williams 2013-07-05 15:41:16 +02:00
parent 2f2475ad0c
commit 0c55938242
2 changed files with 48 additions and 6 deletions

View File

@ -312,11 +312,15 @@ namespace PolyVox
}
return false;
}
};
void initialise();
};
uint32_t calculateBlockMemoryUsage(void) const;
void flushOldestExcessiveBlocks(void) const;
void flushExcessiveCacheEntries(void) const;
void initialise();
// A trick to implement specialization of template member functions in template classes. See http://stackoverflow.com/a/4951057
template <WrapMode eWrapMode>
VoxelType getVoxelImpl(int32_t uXPos, int32_t uYPos, int32_t uZPos, WrapModeType<eWrapMode>, VoxelType tBorder) const;

View File

@ -246,11 +246,14 @@ namespace PolyVox
template <typename VoxelType>
void LargeVolume<VoxelType>::setTargetMemoryLimitInBytes(uint32_t uTargetMemoryLimitInBytes)
{
// The size of a single uncompressed block of data.
uint32_t uUncompressedBlockSizeInBytes = m_uBlockSideLength * m_uBlockSideLength * m_uBlockSideLength * sizeof(VoxelType);
// The idea number of uncompressed blocks is chosen by gut feeling as much as anything. Part of the
// rationale is that it should let us iterate along any edge without data being pushed out of the cache.
uint32_t uIdealNoOfUncompressedBlocks = m_regValidRegionInBlocks.getWidthInVoxels() + m_regValidRegionInBlocks.getHeightInVoxels() * m_regValidRegionInBlocks.getDepthInVoxels();
// Let's say that we should never use more than half the available memory for the uncompressed block cache.
// Let's (arbitrarily?) say that we should never use more than half the available memory for the uncompressed block cache.
uint32_t uMaxMemoryForUncompressedBlocks = uTargetMemoryLimitInBytes / 2;
uint32_t uMaxFittableNoOfUncompressedBlocks = uMaxMemoryForUncompressedBlocks / uUncompressedBlockSizeInBytes;
@ -607,9 +610,9 @@ namespace PolyVox
//The block is not in the map, so we will have to create a new block and add it.
//Before we do so, we might want to dump some existing data to make space. We
//Only do this if paging is enabled.
if(m_pPager)
/*if(m_pPager)
{
// check wether another block needs to be unloaded before this one can be loaded
// check whether another block needs to be unloaded before this one can be loaded
while(calculateBlockMemoryUsage() > m_uCompressedBlockMemoryLimitInBytes) //FIXME - This calculation of size is slow and should be outside the loop.
{
// find the least recently used block
@ -624,7 +627,9 @@ namespace PolyVox
}
eraseBlock(itUnloadBlock);
}
}
}*/
flushOldestExcessiveBlocks();
// create the new block
Block<VoxelType> newBlock(m_uBlockSideLength, m_pCompressor);
@ -746,6 +751,39 @@ namespace PolyVox
return uMemoryUsage;
}
template <typename VoxelType>
void LargeVolume<VoxelType>::flushOldestExcessiveBlocks(void) const
{
const uint32_t uMemoryUsedForCompressedBlocks = calculateBlockMemoryUsage();
uint32_t uMemoryToReclaim = uMemoryUsedForCompressedBlocks - m_uCompressedBlockMemoryLimitInBytes;
//while(uMemoryToReclaim > 0)
while(calculateBlockMemoryUsage() > m_uCompressedBlockMemoryLimitInBytes) //FIXME - This calculation of size is slow and should be outside the loop.
{
// find the least recently used block
typename std::map<Vector3DInt32, Block<VoxelType>, BlockPositionCompare>::iterator i;
typename std::map<Vector3DInt32, Block<VoxelType>, BlockPositionCompare>::iterator itUnloadBlock = m_pBlocks.begin();
for(i = m_pBlocks.begin(); i != m_pBlocks.end(); i++)
{
if(i->second.timestamp < itUnloadBlock->second.timestamp)
{
itUnloadBlock = i;
}
}
//POLYVOX_ASSERT(itUnloadBlock->second.hasUncompressedData() == false, "This function should never flush blocks with uncompressed data.");
uMemoryToReclaim -= itUnloadBlock->second.calculateSizeInBytes();
eraseBlock(itUnloadBlock);
}
}
template <typename VoxelType>
void LargeVolume<VoxelType>::flushExcessiveCacheEntries(void) const
{
}
template <typename VoxelType>
template <WrapMode eWrapMode>
VoxelType LargeVolume<VoxelType>::getVoxelImpl(int32_t uXPos, int32_t uYPos, int32_t uZPos, WrapModeType<eWrapMode>, VoxelType tBorder) const