unblock cache bucket drop (#406)

* don't hold exclusive locks while deleting files from a dropped bucket/namespace
* cleaner detection of missing namespace when issuing a drop

2 files changed, 14 insertions, 14 deletions

diff --git a/src/zenstore/include/zenstore/cache/cachedisklayer.h b/src/zenstore/include/zenstore/cache/cachedisklayer.h
index 54ebb324d..b67a043df 100644
--- a/src/zenstore/include/zenstore/cache/cachedisklayer.h
+++ b/src/zenstore/include/zenstore/cache/cachedisklayer.h
@@ -183,15 +183,15 @@ public:
 	PutBatchHandle* BeginPutBatch(std::vector<bool>& OutResult);
 	void			EndPutBatch(PutBatchHandle* Batch) noexcept;
 
-	void Put(std::string_view	  Bucket,
-			 const IoHash&		  HashKey,
-			 const ZenCacheValue& Value,
-			 std::span<IoHash>	  References,
-			 PutBatchHandle*	  OptionalBatchHandle);
-	bool Drop();
-	bool DropBucket(std::string_view Bucket);
-	void Flush();
-	void ScrubStorage(ScrubContext& Ctx);
+	void				  Put(std::string_view	   Bucket,
+							  const IoHash&		   HashKey,
+							  const ZenCacheValue& Value,
+							  std::span<IoHash>	   References,
+							  PutBatchHandle*	   OptionalBatchHandle);
+	std::function<void()> Drop();
+	std::function<void()> DropBucket(std::string_view Bucket);
+	void				  Flush();
+	void				  ScrubStorage(ScrubContext& Ctx);
 
 	void		  DiscoverBuckets();
 	GcStorageSize StorageSize() const;
@@ -240,9 +240,9 @@ public:
 		void			EndPutBatch(PutBatchHandle* Batch) noexcept;
 		void	 Put(const IoHash& HashKey, const ZenCacheValue& Value, std::span<IoHash> References, PutBatchHandle* OptionalBatchHandle);
 		uint64_t MemCacheTrim(GcClock::TimePoint ExpireTime);
-		bool	 Drop();
-		void	 Flush();
-		void	 ScrubStorage(ScrubContext& Ctx);
+		std::function<void()>	Drop();
+		void					Flush();
+		void					ScrubStorage(ScrubContext& Ctx);
 		RwLock::SharedLockScope GetGcReferencerLock();
 
 		struct ReferencesStats
diff --git a/src/zenstore/include/zenstore/cache/structuredcachestore.h b/src/zenstore/include/zenstore/cache/structuredcachestore.h
index 5e056cf2d..48fc17960 100644
--- a/src/zenstore/include/zenstore/cache/structuredcachestore.h
+++ b/src/zenstore/include/zenstore/cache/structuredcachestore.h
@@ -101,8 +101,8 @@ public:
 	void EnumerateBucketContents(std::string_view																		 Bucket,
 								 std::function<void(const IoHash& Key, const CacheValueDetails::ValueDetails& Details)>& Fn) const;
 
-	bool Drop();
-	void Flush();
+	std::function<void()> Drop();
+	void				  Flush();
 
 	// GcStorage
 	virtual void		  ScrubStorage(ScrubContext& ScrubCtx) override;