From 177eb16becfd3c902ef98de946f94744fc7a0578 Mon Sep 17 00:00:00 2001
From: David Williams <david@volumesoffun.com>
Date: Wed, 17 Sep 2014 21:40:27 +0200
Subject: [PATCH] Tidying and commenting.

---
 .../include/PolyVoxCore/LargeVolume.h         |  2 -
 .../include/PolyVoxCore/LargeVolume.inl       | 40 +++++--------------
 2 files changed, 11 insertions(+), 31 deletions(-)

diff --git a/library/PolyVoxCore/include/PolyVoxCore/LargeVolume.h b/library/PolyVoxCore/include/PolyVoxCore/LargeVolume.h
index df966f6f..f5b22a07 100644
--- a/library/PolyVoxCore/include/PolyVoxCore/LargeVolume.h
+++ b/library/PolyVoxCore/include/PolyVoxCore/LargeVolume.h
@@ -315,8 +315,6 @@ namespace PolyVox
 	
 		std::shared_ptr< UncompressedBlock<VoxelType> > getUncompressedBlock(int32_t uBlockX, int32_t uBlockY, int32_t uBlockZ) const;
 
-		void eraseBlock(typename SharedPtrBlockMap::iterator itUncompressedBlock) const;
-
 		// The block data
 		mutable WeakPtrBlockMap m_pAllBlocks;
 		mutable SharedPtrBlockMap m_pRecentlyUsedBlocks;
diff --git a/library/PolyVoxCore/include/PolyVoxCore/LargeVolume.inl b/library/PolyVoxCore/include/PolyVoxCore/LargeVolume.inl
index 38f05adf..bb164054 100644
--- a/library/PolyVoxCore/include/PolyVoxCore/LargeVolume.inl
+++ b/library/PolyVoxCore/include/PolyVoxCore/LargeVolume.inl
@@ -407,10 +407,10 @@ namespace PolyVox
 
 		//Replaced the for loop here as the call to
 		//eraseBlock was invalidating the iterator.
-		while (m_pRecentlyUsedBlocks.size() > 0)
+		/*while (m_pRecentlyUsedBlocks.size() > 0)
 		{
 			eraseBlock(m_pRecentlyUsedBlocks.begin());
-		}
+		}*/
 	}
 
 	////////////////////////////////////////////////////////////////////////////////
@@ -419,7 +419,7 @@ namespace PolyVox
 	template <typename VoxelType>
 	void LargeVolume<VoxelType>::flush(Region regFlush)
 	{
-		POLYVOX_THROW_IF(!m_pPager, invalid_operation, "You cannot flush data out of the volume because it was created without a pager attached.");
+		/*POLYVOX_THROW_IF(!m_pPager, invalid_operation, "You cannot flush data out of the volume because it was created without a pager attached.");
 
 		Vector3DInt32 v3dStart;
 		for(int i = 0; i < 3; i++)
@@ -454,7 +454,7 @@ namespace PolyVox
 					}
 				} // for z
 			} // for y
-		} // for x
+		} // for x*/
 	}
 
 	////////////////////////////////////////////////////////////////////////////////
@@ -501,28 +501,6 @@ namespace PolyVox
 		this->m_fDiagonalLength = sqrtf(static_cast<float>(this->getWidth() * this->getWidth() + this->getHeight() * this->getHeight() + this->getDepth() * this->getDepth()));
 	}
 
-	template <typename VoxelType>
-	void LargeVolume<VoxelType>::eraseBlock(typename SharedPtrBlockMap::iterator itUncompressedBlock) const
-	{
-		POLYVOX_ASSERT(m_pPager, "A block should never be erased if there is no pager attached to handle it");
-
-		std::shared_ptr< UncompressedBlock<VoxelType> > pUncompressedBlock = itUncompressedBlock->second;
-
-		// This should never happen as blocks are deleted based on being least recently used.
-		// I the case that we are flushing we delete all blocks, but the flush function will
-		// reset the 'm_pLastAccessedBlock' anyway to prevent it being accidentally reused.
-		//POLYVOX_ASSERT(pUncompressedBlock != m_pLastAccessedBlock, "Attempted to delete last accessed block.");
-
-		// Before deleting the block we may need to recompress its data. We
-		// only do this if the data has been modified since it was decompressed.
-		
-
-		//delete itUncompressedBlock->second;
-
-		// We can now remove the block data from memory.
-		m_pRecentlyUsedBlocks.erase(itUncompressedBlock);
-	}
-
 	template <typename VoxelType>
 	std::shared_ptr< UncompressedBlock<VoxelType> > LargeVolume<VoxelType>::getUncompressedBlock(int32_t uBlockX, int32_t uBlockY, int32_t uBlockZ) const
 	{
@@ -578,12 +556,16 @@ namespace PolyVox
 			// The block was not found so we will create a new one.
 			pUncompressedBlock = std::make_shared< UncompressedBlock<VoxelType> >(v3dBlockPos, m_uBlockSideLength, m_pPager);
 
+			// As we are loading a new block we should try to ensure we don't go over our target memory usage.
 			while (m_pRecentlyUsedBlocks.size() + 1 > m_uMaxNumberOfUncompressedBlocks) // +1 ready for new block we will add next.
 			{
+				// This should never hit, because it should not have been possible for
+				// the user to limit the number of blocks if they did not provide a pager.
+				POLYVOX_ASSERT(m_pPager, "A valid pager is required to limit number of blocks");
+
 				// Find the least recently used block. Hopefully this isn't too slow.
-				typename SharedPtrBlockMap::iterator i;
 				typename SharedPtrBlockMap::iterator itUnloadBlock = m_pRecentlyUsedBlocks.begin();
-				for (i = m_pRecentlyUsedBlocks.begin(); i != m_pRecentlyUsedBlocks.end(); i++)
+				for (typename SharedPtrBlockMap::iterator i = m_pRecentlyUsedBlocks.begin(); i != m_pRecentlyUsedBlocks.end(); i++)
 				{
 					if (i->second->m_uBlockLastAccessed < itUnloadBlock->second->m_uBlockLastAccessed)
 					{
@@ -592,7 +574,7 @@ namespace PolyVox
 				}
 
 				// Erase the least recently used block
-				eraseBlock(itUnloadBlock);
+				m_pRecentlyUsedBlocks.erase(itUnloadBlock);
 			}
 
 			// Add our new block to the maps.