WIP - bit assignement for CasDiskLocation

2 files changed, 59 insertions, 14 deletions

diff --git a/zenstore/compactcas.cpp b/zenstore/compactcas.cpp
index 2dcc9aa7c..27f0d0e29 100644
--- a/zenstore/compactcas.cpp
+++ b/zenstore/compactcas.cpp
@@ -25,10 +25,10 @@ namespace zen {
 
 struct CasDiskIndexHeader
 {
-	static constexpr uint32_t ExpectedMagic		= 0x75696478;  // 'uidx';
-	static constexpr uint32_t CurrentVersion	= 1;
-	uint32_t				  Magic				= ExpectedMagic;
-	uint32_t				  Version			= CurrentVersion;
+	static constexpr uint32_t ExpectedMagic	 = 0x75696478;	// 'uidx';
+	static constexpr uint32_t CurrentVersion = 1;
+	uint32_t				  Magic			 = ExpectedMagic;
+	uint32_t				  Version		 = CurrentVersion;
 	uint32_t				  PayloadAlignement;
 	uint32_t				  Reserved0 = 0;
 	uint64_t				  MaxBlockSize;
@@ -1004,11 +1004,8 @@ CasContainerStrategy::OpenContainer(bool IsNewStore)
 				uint64_t		   ExpectedEntryCount = (Size - sizeof(sizeof(CasDiskIndexHeader))) / sizeof(CasDiskIndexEntry);
 				CasDiskIndexHeader Header;
 				SmallObjectIndex.Read(&Header, sizeof(Header), 0);
-				if (Header.Magic == CasDiskIndexHeader::ExpectedMagic &&
-					Header.Version == CasDiskIndexHeader::CurrentVersion &&
-					Header.MaxBlockSize > 0 &&
-					Header.PayloadAlignement > 0 &&
-					Header.EntryCount == ExpectedEntryCount)
+				if (Header.Magic == CasDiskIndexHeader::ExpectedMagic && Header.Version == CasDiskIndexHeader::CurrentVersion &&
+					Header.MaxBlockSize > 0 && Header.PayloadAlignement > 0 && Header.EntryCount == ExpectedEntryCount)
 				{
 					std::vector<CasDiskIndexEntry> Entries{Header.EntryCount};
 					SmallObjectIndex.Read(Entries.data(), Header.EntryCount * sizeof(CasDiskIndexEntry), sizeof(CasDiskIndexHeader));
@@ -1017,7 +1014,7 @@ CasContainerStrategy::OpenContainer(bool IsNewStore)
 					{
 						m_LocationMap[Entry.Key] = Entry.Location;
 					}
-					m_MaxBlockSize = Header.MaxBlockSize;
+					m_MaxBlockSize	   = Header.MaxBlockSize;
 					m_PayloadAlignment = Header.PayloadAlignement;
 				}
 			}
diff --git a/zenstore/compactcas.h b/zenstore/compactcas.h
index fcb6eec4c..5f58ccab1 100644
--- a/zenstore/compactcas.h
+++ b/zenstore/compactcas.h
@@ -8,6 +8,7 @@
 #include <zenstore/gc.h>
 
 #include <atomic>
+#include <limits>
 #include <unordered_map>
 
 namespace spdlog {
@@ -23,9 +24,56 @@ namespace zen {
 
 struct CasDiskLocation
 {
-	uint16_t BlockIndex;
-	uint32_t Offset;
+	// 20 bits blockindex
+	// 28 bits offset
+	// 32 bits size
+
+	CasDiskLocation(uint32_t BlockIndex, uint64_t Offset, uint64_t Size)
+	{
+		ZEN_ASSERT(BlockIndex < (1L << 20));
+		ZEN_ASSERT(Offset < (1L << 28));
+		ZEN_ASSERT(Size <= std::numeric_limits<std::uint32_t>::max());
+
+		m_Size						  = static_cast<uint32_t>(Size);
+		m_BlockIndexLowBits			  = static_cast<uint16_t>(BlockIndex & 0xffff);
+		m_OffsetLowBits				  = static_cast<uint16_t>(Offset & 0xffff);
+		m_BlockIndexAndOffsetHighBits = static_cast<uint16_t>(((BlockIndex >> 16) & 0xf) | (((Offset >> 16) & 0xfff) << 4));
+	}
+
+	CasDiskLocation() = default;
+
+	inline uint32_t GetBlockIndex() const
+	{
+		return (static_cast<uint32_t>(m_BlockIndexAndOffsetHighBits & 0xf) << 16) | m_BlockIndexLowBits;
+	}
+	inline uint64_t Offset() const { return (static_cast<uint64_t>(m_BlockIndexAndOffsetHighBits & 0xfff0) << 8) | m_OffsetLowBits; }
+	inline uint64_t Size() const { return m_Size; }
+
+private:
+	uint32_t m_Size;
+	uint16_t m_BlockIndexLowBits;
+	uint16_t m_OffsetLowBits;
+	uint16_t m_BlockIndexAndOffsetHighBits;
+
+#if 0
+	// 24 bits blockindex
+	// 24 bits offset
+	// 32 bits size
+	inline uint32_t GetBlockIndex() const
+	{
+		return (static_cast<uint32_t>(BlockIndexHighBits) << 16) | BlockIndexLowBits;
+	}
+	inline uint32_t Offset() const
+	{ 
+		return (static_cast<uint32_t>(OffsetHighBits) << 16) | OffsetLowBits;
+	}
+
 	uint32_t Size;
+	uint16_t BlockIndexLowBits;
+	uint16_t OffsetLowBits;
+	uint8_t	 BlockIndexHighBits;
+	uint8_t	 OffsetHighBits;
+#endif
 };
 
 struct CasDiskIndexEntry
@@ -52,7 +100,7 @@ static_assert(sizeof(CasDiskIndexEntry) == 32);
 
 struct CasContainerStrategy final : public GcStorage
 {
-	static constexpr uint32_t DefaultMaxBlockSize	   = 1u << 30;	// 1 Gb
+	static constexpr uint32_t DefaultMaxBlockSize = 1u << 30;  // 1 Gb
 
 	CasContainerStrategy(const CasStoreConfiguration& Config, CasGc& Gc);
 	~CasContainerStrategy();
@@ -78,7 +126,7 @@ private:
 	spdlog::logger&				   m_Log;
 	uint64_t					   m_PayloadAlignment;
 	uint64_t					   m_MaxBlockSize;
-	bool						   m_IsInitialized	  = false;
+	bool						   m_IsInitialized = false;
 	TCasLogFile<CasDiskIndexEntry> m_CasLog;
 	std::string					   m_ContainerBaseName;