remove gc v1 (#121)

* kill gc v1
* block use of gc v1 from zen command line
* warn and flip to gcv2 if --gc-v2=false is specified for zenserver

4 files changed, 17 insertions, 100 deletions

diff --git a/src/zenstore/include/zenstore/blockstore.h b/src/zenstore/include/zenstore/blockstore.h
index a98ca5375..d4c2be73f 100644
--- a/src/zenstore/include/zenstore/blockstore.h
+++ b/src/zenstore/include/zenstore/blockstore.h
@@ -127,13 +127,12 @@ public:
 	typedef std::vector<std::pair<size_t, BlockStoreLocation>> MovedChunksArray;
 	typedef std::vector<size_t>								   ChunkIndexArray;
 
-	typedef std::function<void(const MovedChunksArray& MovedChunks, const ChunkIndexArray& RemovedChunks)> ReclaimCallback;
-	typedef std::function<bool(const MovedChunksArray& MovedChunks, uint64_t FreedDiskSpace)>			   CompactCallback;
-	typedef std::function<uint64_t()>																	   ClaimDiskReserveCallback;
-	typedef std::function<bool(size_t ChunkIndex, const void* Data, uint64_t Size)>						   IterateChunksSmallSizeCallback;
-	typedef std::function<bool(size_t ChunkIndex, BlockStoreFile& File, uint64_t Offset, uint64_t Size)>   IterateChunksLargeSizeCallback;
-	typedef std::function<void(const BlockStoreLocation& Location)>										   WriteChunkCallback;
-	typedef std::function<bool(uint32_t BlockIndex, std::span<const size_t> ChunkIndexes)>				   IterateChunksCallback;
+	typedef std::function<bool(const MovedChunksArray& MovedChunks, uint64_t FreedDiskSpace)>			 CompactCallback;
+	typedef std::function<uint64_t()>																	 ClaimDiskReserveCallback;
+	typedef std::function<bool(size_t ChunkIndex, const void* Data, uint64_t Size)>						 IterateChunksSmallSizeCallback;
+	typedef std::function<bool(size_t ChunkIndex, BlockStoreFile& File, uint64_t Offset, uint64_t Size)> IterateChunksLargeSizeCallback;
+	typedef std::function<void(const BlockStoreLocation& Location)>										 WriteChunkCallback;
+	typedef std::function<bool(uint32_t BlockIndex, std::span<const size_t> ChunkIndexes)>				 IterateChunksCallback;
 
 	struct BlockUsageInfo
 	{
@@ -162,16 +161,6 @@ public:
 	IoBuffer TryGetChunk(const BlockStoreLocation& Location) const;
 	void	 Flush(bool ForceNewBlock);
 
-	ReclaimSnapshotState GetReclaimSnapshotState();
-	void				 ReclaimSpace(
-						const ReclaimSnapshotState&			   Snapshot,
-						const std::vector<BlockStoreLocation>& ChunkLocations,
-						const ChunkIndexArray&				   KeepChunkIndexes,
-						uint32_t							   PayloadAlignment,
-						bool								   DryRun,
-						const ReclaimCallback&				   ChangeCallback	   = [](const MovedChunksArray&, const ChunkIndexArray&) {},
-						const ClaimDiskReserveCallback&		   DiskReserveCallback = []() { return 0; });
-
 	bool IterateChunks(const std::span<const BlockStoreLocation>& ChunkLocations, const IterateChunksCallback& Callback);
 
 	bool IterateBlock(std::span<const BlockStoreLocation>	ChunkLocations,
diff --git a/src/zenstore/include/zenstore/cache/cachedisklayer.h b/src/zenstore/include/zenstore/cache/cachedisklayer.h
index f38776b6e..f8ce8641c 100644
--- a/src/zenstore/include/zenstore/cache/cachedisklayer.h
+++ b/src/zenstore/include/zenstore/cache/cachedisklayer.h
@@ -183,8 +183,6 @@ public:
 	bool DropBucket(std::string_view Bucket);
 	void Flush();
 	void ScrubStorage(ScrubContext& Ctx);
-	void GatherReferences(GcContext& GcCtx);
-	void CollectGarbage(GcContext& GcCtx);
 
 	void		  DiscoverBuckets();
 	GcStorageSize StorageSize() const;
@@ -231,8 +229,6 @@ public:
 		bool	 Drop();
 		void	 Flush();
 		void	 ScrubStorage(ScrubContext& Ctx);
-		void	 GatherReferences(GcContext& GcCtx);
-		void	 CollectGarbage(GcContext& GcCtx);
 		RwLock::SharedLockScope GetGcReferencerLock();
 		bool					GetReferences(GcCtx& Ctx, bool StateIsAlreadyLocked, std::vector<IoHash>& OutReferences);
 
diff --git a/src/zenstore/include/zenstore/cache/structuredcachestore.h b/src/zenstore/include/zenstore/cache/structuredcachestore.h
index 9160db667..50e40042a 100644
--- a/src/zenstore/include/zenstore/cache/structuredcachestore.h
+++ b/src/zenstore/include/zenstore/cache/structuredcachestore.h
@@ -49,7 +49,7 @@ class JobQueue;
 
  */
 
-class ZenCacheNamespace final : public GcStorage, public GcContributor
+class ZenCacheNamespace final : public GcStorage
 {
 public:
 	struct Configuration
@@ -104,12 +104,8 @@ public:
 	bool Drop();
 	void Flush();
 
-	// GcContributor
-	virtual void GatherReferences(GcContext& GcCtx) override;
-
 	// GcStorage
 	virtual void		  ScrubStorage(ScrubContext& ScrubCtx) override;
-	virtual void		  CollectGarbage(GcContext& GcCtx) override;
 	virtual GcStorageSize StorageSize() const override;
 
 	Configuration			  GetConfig() const { return m_Configuration; }
diff --git a/src/zenstore/include/zenstore/gc.h b/src/zenstore/include/zenstore/gc.h
index b79f1b9df..e191a0930 100644
--- a/src/zenstore/include/zenstore/gc.h
+++ b/src/zenstore/include/zenstore/gc.h
@@ -283,64 +283,6 @@ public:
 
 //////// End GC V2
 
-/** Garbage Collection context object
- */
-class GcContext
-{
-public:
-	GcContext(const GcClock::TimePoint& CacheExpireTime, const GcClock::TimePoint& ProjectStoreExpireTime);
-	~GcContext();
-
-	void AddRetainedCids(std::span<const IoHash> Cid);
-	void SetExpiredCacheKeys(const std::string& CacheKeyContext, std::vector<IoHash>&& ExpiredKeys);
-
-	void IterateCids(std::function<void(const IoHash&)> Callback);
-
-	void FilterCids(std::span<const IoHash> Cid, std::function<void(const IoHash&)> KeepFunc);
-	void FilterCids(std::span<const IoHash> Cid, std::function<void(const IoHash&, bool)>&& FilterFunc);
-
-	void			  AddDeletedCids(std::span<const IoHash> Cas);
-	const HashKeySet& DeletedCids();
-
-	std::span<const IoHash> ExpiredCacheKeys(const std::string& CacheKeyContext) const;
-
-	bool SkipCid() const;
-	void SetSkipCid(bool NewState);
-
-	bool IsDeletionMode() const;
-	void SetDeletionMode(bool NewState);
-
-	bool CollectSmallObjects() const;
-	void CollectSmallObjects(bool NewState);
-
-	GcClock::TimePoint CacheExpireTime() const;
-	GcClock::TimePoint ProjectStoreExpireTime() const;
-
-	void	 DiskReservePath(const std::filesystem::path& Path);
-	uint64_t ClaimGCReserve();
-
-private:
-	struct GcState;
-
-	std::unique_ptr<GcState> m_State;
-};
-
-/** GC root contributor
-
-	Higher level data structures provide roots for the garbage collector,
-	which ultimately determine what is garbage and what data we need to
-	retain.
-
- */
-class GcContributor
-{
-public:
-	virtual void GatherReferences(GcContext& GcCtx) = 0;
-
-protected:
-	virtual ~GcContributor() {}
-};
-
 struct GcStorageSize
 {
 	uint64_t DiskSize{};
@@ -353,7 +295,6 @@ class GcStorage
 {
 public:
 	virtual void		  ScrubStorage(ScrubContext& ScrubCtx) = 0;
-	virtual void		  CollectGarbage(GcContext& GcCtx)	   = 0;
 	virtual GcStorageSize StorageSize() const				   = 0;
 
 protected:
@@ -392,14 +333,10 @@ public:
 
 	//////// End GC V2
 
-	void AddGcContributor(GcContributor* Contributor);
-	void RemoveGcContributor(GcContributor* Contributor);
-
 	void AddGcStorage(GcStorage* Contributor);
 	void RemoveGcStorage(GcStorage* Contributor);
 
-	GcStorageSize CollectGarbage(GcContext& GcCtx);
-	void		  ScrubStorage(ScrubContext& GcCtx);
+	void ScrubStorage(ScrubContext& GcCtx);
 
 	GcStorageSize TotalStorageSize() const;
 
@@ -407,14 +344,13 @@ public:
 	void					SetDiskWriteBlocker(const DiskWriteBlocker* Monitor) { m_DiskWriteBlocker = Monitor; }
 
 private:
-	bool						CheckGCCancel() { return m_CancelGC.load(); }
-	LoggerRef					Log() { return m_Log; }
-	LoggerRef					m_Log;
-	mutable RwLock				m_Lock;
-	std::vector<GcContributor*> m_GcContribs;
-	std::vector<GcStorage*>		m_GcStorage;
-	CidStore*					m_CidStore		   = nullptr;
-	const DiskWriteBlocker*		m_DiskWriteBlocker = nullptr;
+	bool					CheckGCCancel() { return m_CancelGC.load(); }
+	LoggerRef				Log() { return m_Log; }
+	LoggerRef				m_Log;
+	mutable RwLock			m_Lock;
+	std::vector<GcStorage*> m_GcStorage;
+	CidStore*				m_CidStore		   = nullptr;
+	const DiskWriteBlocker* m_DiskWriteBlocker = nullptr;
 
 	std::vector<GcReferencer*>		m_GcReferencers;
 	std::vector<GcReferenceLocker*> m_GcReferencerLockers;
@@ -432,7 +368,7 @@ enum class GcSchedulerStatus : uint32_t
 
 enum class GcVersion : uint32_t
 {
-	kV1,
+	kV1_Deprecated,
 	kV2
 };
 
@@ -449,7 +385,7 @@ struct GcSchedulerConfig
 	uint64_t			  DiskSizeSoftLimit					= 0;
 	uint64_t			  MinimumFreeDiskSpaceToAllowWrites = 1ul << 28;
 	std::chrono::seconds  LightweightInterval{};
-	GcVersion			  UseGCVersion						= GcVersion::kV1;
+	GcVersion			  UseGCVersion						= GcVersion::kV2;
 	uint32_t			  CompactBlockUsageThresholdPercent = 90;
 	bool				  Verbose							= false;
 	bool				  SingleThreaded					= false;