gc: implemented CID remapping for GC

2 files changed, 50 insertions, 2 deletions

diff --git a/zenstore/gc.cpp b/zenstore/gc.cpp
index c3cb77b69..278f09b0b 100644
--- a/zenstore/gc.cpp
+++ b/zenstore/gc.cpp
@@ -1,8 +1,11 @@
 // Copyright Epic Games, Inc. All Rights Reserved.
 
-#include <zenstore/CAS.h>
 #include <zenstore/gc.h>
 
+#include <zenstore/CAS.h>
+#include <zenstore/cidstore.h>
+#include <zencore/logging.h>
+
 namespace zen {
 
 //////////////////////////////////////////////////////////////////////////
@@ -35,6 +38,12 @@ GcContext::ContributeCas(std::span<const IoHash> Cas)
 }
 
 void
+GcContext::IterateCids(std::function<void(const IoHash&)> Callback)
+{
+	m_State->m_CidChunks.IterateChunks([&](const IoHash& Hash) { Callback(Hash); });
+}
+
+void
 GcContext::FilterCids(std::span<const IoHash> Cid, std::function<void(const IoHash&)> KeepFunc)
 {
 	m_State->m_CidChunks.FilterChunks(Cid, [&](const IoHash& Hash) { KeepFunc(Hash); });
@@ -51,7 +60,7 @@ GcContext::IsDeletionMode() const
 {
 	return m_State->m_DeletionMode;
 }
-void 
+void
 GcContext::SetDeletionMode(bool NewState)
 {
 	m_State->m_DeletionMode = NewState;
@@ -134,6 +143,33 @@ CasGc::CollectGarbage()
 		Contributor->GatherReferences(GcCtx);
 	}
 
+	if (CidStore* CidStore = m_CidStore)
+	{
+		std::vector<IoHash> CasHashes;
+
+		int UnknownChunks = 0;
+
+		GcCtx.IterateCids([&](const IoHash& Hash) {
+			IoHash Cas = CidStore->RemapCid(Hash);
+
+			if (Cas == IoHash::Zero)
+			{
+				++UnknownChunks;
+			}
+			else
+			{
+				CasHashes.push_back(Cas);
+			}
+		});
+
+		if (UnknownChunks)
+		{
+			ZEN_WARN("found {} unknown CIDs", UnknownChunks);
+		}
+
+		GcCtx.ContributeCas(CasHashes);
+	}
+
 	// Then trim storage
 
 	for (GcStorage* Storage : m_GcStorage)
@@ -143,6 +179,12 @@ CasGc::CollectGarbage()
 }
 
 void
+CasGc::SetCidStore(CidStore* Cids)
+{
+	m_CidStore = Cids;
+}
+
+void
 CasGc::OnNewCidReferences(std::span<IoHash> Hashes)
 {
 	ZEN_UNUSED(Hashes);
diff --git a/zenstore/include/zenstore/gc.h b/zenstore/include/zenstore/gc.h
index 46b588570..560642803 100644
--- a/zenstore/include/zenstore/gc.h
+++ b/zenstore/include/zenstore/gc.h
@@ -6,6 +6,7 @@
 #include <zencore/thread.h>
 
 #include <span>
+#include <functional>
 
 #define ZEN_USE_REF_TRACKING 0	// This is not currently functional
 
@@ -13,6 +14,7 @@ namespace zen {
 
 class CasStore;
 class CasGc;
+class CidStore;
 struct IoHash;
 
 /** Garbage Collection context object
@@ -27,6 +29,8 @@ public:
 	void ContributeCids(std::span<const IoHash> Cid);
 	void ContributeCas(std::span<const IoHash> Hash);
 
+	void IterateCids(std::function<void(const IoHash&)> Callback);
+
 	void FilterCids(std::span<const IoHash> Cid, std::function<void(const IoHash&)> KeepFunc);
 	void FilterCas(std::span<const IoHash> Cas, std::function<void(const IoHash&)> KeepFunc);
 
@@ -91,6 +95,7 @@ public:
 
 	void CollectGarbage();
 
+	void SetCidStore(CidStore* Cids);
 	void OnNewCidReferences(std::span<IoHash> Hashes);
 	void OnCommittedCidReferences(std::span<IoHash> Hashes);
 	void OnDroppedCidReferences(std::span<IoHash> Hashes);
@@ -99,6 +104,7 @@ private:
 	RwLock						m_Lock;
 	std::vector<GcContributor*> m_GcContribs;
 	std::vector<GcStorage*>		m_GcStorage;
+	CidStore*					m_CidStore;
 };
 
 }  // namespace zen