compact separate for gc referencer (#533)

- Refactor GCV2 so GcReferencer::RemoveExpiredData returns a store compactor, moving out the actual disk work from deleting items in the index.
- Refactor GCV2 GcResult to reuse GcCompactStoreStats and GcStats
- Make Compacting of stores non-parallell to not eat all the disk I/O when running GC

1 files changed, 3 insertions, 1 deletions

diff --git a/src/zenserver/cache/cachedisklayer.h b/src/zenserver/cache/cachedisklayer.h
index d9884a7bc..2986cedf8 100644
--- a/src/zenserver/cache/cachedisklayer.h
+++ b/src/zenserver/cache/cachedisklayer.h
@@ -334,7 +334,7 @@ private:
 		std::atomic_uint64_t		m_MemCachedSize{};
 
 		virtual std::string						 GetGcName(GcCtx& Ctx) override;
-		virtual void							 RemoveExpiredData(GcCtx& Ctx, GcReferencerStats& Stats) override;
+		virtual GcStoreCompactor*				 RemoveExpiredData(GcCtx& Ctx, GcStats& Stats) override;
 		virtual std::vector<GcReferenceChecker*> CreateReferenceCheckers(GcCtx& Ctx) override;
 
 		void	 BuildPath(PathBuilderBase& Path, const IoHash& HashKey) const;
@@ -403,6 +403,7 @@ private:
 		inline RwLock& LockForHash(const IoHash& Hash) const { return m_ShardedLocks[Hash.Hash[19]]; }
 
 		friend class DiskBucketReferenceChecker;
+		friend class DiskBucketStoreCompactor;
 	};
 
 	inline void TryMemCacheTrim()
@@ -438,6 +439,7 @@ private:
 	ZenCacheDiskLayer(const ZenCacheDiskLayer&) = delete;
 	ZenCacheDiskLayer& operator=(const ZenCacheDiskLayer&) = delete;
 
+	friend class DiskBucketStoreCompactor;
 	friend class DiskBucketReferenceChecker;
 };