cas: added some GC stubs

4 files changed, 76 insertions, 33 deletions

diff --git a/zenserver/cache/structuredcachestore.cpp b/zenserver/cache/structuredcachestore.cpp
index 5e93ebaa9..b97f0830f 100644
--- a/zenserver/cache/structuredcachestore.cpp
+++ b/zenserver/cache/structuredcachestore.cpp
@@ -116,6 +116,13 @@ ZenCacheStore::Scrub(ScrubContext& Ctx)
 	m_DiskLayer.Scrub(Ctx);
 	m_MemLayer.Scrub(Ctx);
 }
+
+void
+ZenCacheStore::GarbageCollect(GcContext& GcCtx)
+{
+	ZEN_UNUSED(GcCtx);
+}
+
 //////////////////////////////////////////////////////////////////////////
 
 ZenCacheMemoryLayer::ZenCacheMemoryLayer()
@@ -195,6 +202,12 @@ ZenCacheMemoryLayer::Scrub(ScrubContext& Ctx)
 }
 
 void
+ZenCacheMemoryLayer::GarbageCollect(GcContext& GcCtx)
+{
+	ZEN_UNUSED(GcCtx);
+}
+
+void
 ZenCacheMemoryLayer::CacheBucket::Scrub(ScrubContext& Ctx)
 {
 	std::vector<IoHash> BadHashes;
@@ -294,6 +307,7 @@ struct ZenCacheDiskLayer::CacheBucket
 	void Drop();
 	void Flush();
 	void Scrub(ScrubContext& Ctx);
+	void GarbageCollect(GcContext& GcCtx);
 
 	inline bool IsOk() const { return m_Ok; }
 
@@ -611,6 +625,12 @@ ZenCacheDiskLayer::CacheBucket::Scrub(ScrubContext& Ctx)
 }
 
 void
+ZenCacheDiskLayer::CacheBucket::GarbageCollect(GcContext& GcCtx)
+{
+	ZEN_UNUSED(GcCtx);
+}
+
+void
 ZenCacheDiskLayer::CacheBucket::PutLargeObject(const IoHash& HashKey, const ZenCacheValue& Value)
 {
 	WideStringBuilder<128> DataFilePath;
@@ -830,27 +850,10 @@ ZenCacheDiskLayer::Scrub(ScrubContext& Ctx)
 	}
 }
 
-//////////////////////////////////////////////////////////////////////////
-
-ZenCacheTracker::ZenCacheTracker(ZenCacheStore& CacheStore)
-{
-	ZEN_UNUSED(CacheStore);
-}
-
-ZenCacheTracker::~ZenCacheTracker()
-{
-}
-
-void
-ZenCacheTracker::TrackAccess(std::string_view Bucket, const IoHash& HashKey)
-{
-	ZEN_UNUSED(Bucket);
-	ZEN_UNUSED(HashKey);
-}
-
 void
-ZenCacheTracker::Flush()
+ZenCacheDiskLayer::GarbageCollect(GcContext& GcCtx)
 {
+	ZEN_UNUSED(GcCtx);
 }
 
 }  // namespace zen
diff --git a/zenserver/cache/structuredcachestore.h b/zenserver/cache/structuredcachestore.h
index f96757409..011f13323 100644
--- a/zenserver/cache/structuredcachestore.h
+++ b/zenserver/cache/structuredcachestore.h
@@ -56,6 +56,7 @@ public:
 	void Put(std::string_view Bucket, const IoHash& HashKey, const ZenCacheValue& Value);
 	bool DropBucket(std::string_view Bucket);
 	void Scrub(ScrubContext& Ctx);
+	void GarbageCollect(GcContext& GcCtx);
 
 private:
 	struct CacheBucket
@@ -83,6 +84,7 @@ public:
 	bool DropBucket(std::string_view Bucket);
 	void Flush();
 	void Scrub(ScrubContext& Ctx);
+	void GarbageCollect(GcContext& GcCtx);
 
 private:
 	/** A cache bucket manages a single directory containing
@@ -107,6 +109,7 @@ public:
 	bool DropBucket(std::string_view Bucket);
 	void Flush();
 	void Scrub(ScrubContext& Ctx);
+	void GarbageCollect(GcContext& GcCtx);
 
 private:
 	std::filesystem::path m_RootDir;
@@ -116,18 +119,4 @@ private:
 	uint64_t			  m_LastScrubTime		   = 0;
 };
 
-/** Tracks cache entry access, stats and orchestrates cleanup activities
- */
-class ZenCacheTracker
-{
-public:
-	ZenCacheTracker(ZenCacheStore& CacheStore);
-	~ZenCacheTracker();
-
-	void TrackAccess(std::string_view Bucket, const IoHash& HashKey);
-	void Flush();
-
-private:
-};
-
 }  // namespace zen
diff --git a/zenstore/CAS.cpp b/zenstore/CAS.cpp
index 1db2b50bf..808fc8fb3 100644
--- a/zenstore/CAS.cpp
+++ b/zenstore/CAS.cpp
@@ -32,6 +32,15 @@ CasChunkSet::AddChunkToSet(const IoHash& HashToAdd)
 }
 
 void
+CasChunkSet::AddChunksToSet(std::span<const IoHash> HashesToAdd)
+{
+	for (const IoHash& Hash : HashesToAdd)
+	{
+		m_ChunkSet.insert(Hash);
+	}
+}
+
+void
 CasChunkSet::RemoveChunksIf(std::function<bool(const IoHash& CandidateHash)>&& Predicate)
 {
 	for (auto It = begin(m_ChunkSet), ItEnd = end(m_ChunkSet); It != ItEnd;)
@@ -58,6 +67,34 @@ CasChunkSet::IterateChunks(std::function<void(const IoHash& ChunkHash)>&& Callba
 
 //////////////////////////////////////////////////////////////////////////
 
+struct GcContext::GcState
+{
+	CasChunkSet m_CasChunks;
+	CasChunkSet m_CidChunks;
+};
+
+GcContext::GcContext() : m_State(std::make_unique<GcState>())
+{
+}
+
+GcContext::~GcContext()
+{
+}
+
+void
+GcContext::ContributeCids(std::span<const IoHash> Cids)
+{
+	m_State->m_CidChunks.AddChunksToSet(Cids);
+}
+
+void
+GcContext::ContributeCas(std::span<const IoHash> Cas)
+{
+	m_State->m_CasChunks.AddChunksToSet(Cas);
+}
+
+//////////////////////////////////////////////////////////////////////////
+
 void
 ScrubContext::ReportBadChunks(std::span<IoHash> BadChunks)
 {
diff --git a/zenstore/include/zenstore/CAS.h b/zenstore/include/zenstore/CAS.h
index 93454ca6f..1425845a0 100644
--- a/zenstore/include/zenstore/CAS.h
+++ b/zenstore/include/zenstore/CAS.h
@@ -37,7 +37,16 @@ struct CasStoreConfiguration
 class GcContext
 {
 public:
+	GcContext();
+	~GcContext();
+
+	void ContributeCids(std::span<const IoHash> Cid);
+	void ContributeCas(std::span<const IoHash> Hash);
+
 private:
+	struct GcState;
+
+	std::unique_ptr<GcState> m_State;
 };
 
 /** Context object for data scrubbing
@@ -58,10 +67,14 @@ private:
 	bool	 m_Recover	 = true;
 };
 
+/** Manage a set of IoHash values
+ */
+
 class CasChunkSet
 {
 public:
 	void						AddChunkToSet(const IoHash& HashToAdd);
+	void						AddChunksToSet(std::span<const IoHash> HashesToAdd);
 	void						RemoveChunksIf(std::function<bool(const IoHash& CandidateHash)>&& Predicate);
 	void						IterateChunks(std::function<void(const IoHash& ChunkHash)>&& Callback);
 	inline [[nodiscard]] bool	ContainsChunk(const IoHash& Hash) const { return m_ChunkSet.find(Hash) != m_ChunkSet.end(); }
@@ -69,6 +82,7 @@ public:
 	inline [[nodiscard]] size_t GetSize() const { return m_ChunkSet.size(); }
 
 private:
+	// Q: should we protect this with a lock, or is that a higher level concern?
 	std::unordered_set<IoHash> m_ChunkSet;
 };