compactcas: Changed CasDiskLocation implementation so it can store chunks > 4GB (max is now 1TB)

The offset and size members are now five bytes each, which leaves two bytes which are intended to be used for content-type and flags but are currently unused

Also added some unit tests for compactcas

This change bumps the global storage schema in order to wipe any existing disk state

1 files changed, 33 insertions, 6 deletions

diff --git a/zenstore/compactcas.h b/zenstore/compactcas.h
index 8f7c0213b..a3f3121e6 100644
--- a/zenstore/compactcas.h
+++ b/zenstore/compactcas.h
@@ -23,17 +23,42 @@ namespace zen {
 
 struct CasDiskLocation
 {
-	uint64_t Offset;
-	// If we wanted to be able to store larger chunks using this storage mechanism then
-	// we could make this more like the IoStore index so we can store larger chunks.
-	// I.e use five bytes for size and seven for offset
-	uint32_t Size;
+	CasDiskLocation(uint64_t InOffset, uint64_t InSize)
+	{
+		ZEN_ASSERT(InOffset <= 0xff'ffff'ffff);
+		ZEN_ASSERT(InSize <= 0xff'ffff'ffff);
+
+		memcpy(&m_Offset[0], &InOffset, sizeof m_Offset);
+		memcpy(&m_Size[0], &InSize, sizeof m_Size);
+	}
+
+	CasDiskLocation() = default;
+
+	inline uint64_t GetOffset() const
+	{
+		uint64_t Offset = 0;
+		memcpy(&Offset, &m_Offset, sizeof m_Offset);
+		return Offset;
+	}
+
+	inline uint64_t GetSize() const
+	{
+		uint64_t Size = 0;
+		memcpy(&Size, &m_Size, sizeof m_Size);
+		return Size;
+	}
+
+private:
+	uint8_t m_Offset[5];
+	uint8_t m_Size[5];
 };
 
 struct CasDiskIndexEntry
 {
 	IoHash			Key;
 	CasDiskLocation Location;
+	ZenContentType	ContentType = ZenContentType::kUnknownContentType;
+	uint8_t			Flags		= 0;
 };
 
 #pragma pack(pop)
@@ -61,7 +86,7 @@ struct CasContainerStrategy
 	void				   Initialize(const std::string_view ContainerBaseName, uint64_t Alignment, bool IsNewStore);
 	void				   Flush();
 	void				   Scrub(ScrubContext& Ctx);
-	void				   GarbageCollect(GcContext& GcCtx);
+	void				   CollectGarbage(GcContext& GcCtx);
 
 private:
 	const CasStoreConfiguration&   m_Config;
@@ -81,4 +106,6 @@ private:
 	void MakeSnapshot();
 };
 
+void compactcas_forcelink();
+
 }  // namespace zen