Plumb recoverEvictionPolicy through Navy config layers

Summary:
Wires the recoverEvictionPolicy flag from BlockCache::Config through
the CacheLib Navy configuration layers so consumers can enable it.

Config plumbing chain:
- BlockCacheConfig (NavyConfig.h): setter/getter/member
- BlockCacheProto (Factory.h): virtual interface
- BlockCacheProtoImpl (Factory.cpp): implementation
- NavySetup.cpp: bridges BlockCacheConfig to BlockCacheProto

This is a pure plumbing change — no behavior change without a consumer
setting the flag.

Reviewed By: rlyerly

Differential Revision: D100237072

fbshipit-source-id: 2e02357ddd8a68cae82adc061dfa99a9de4cf436

Author: Marko Mitic

cachelib/allocator/nvmcache/NavyConfig.h

@@ -555,6 +555,11 @@ class BlockCacheConfig {
     return *this;
   }
 
+  BlockCacheConfig& setRecoverEvictionPolicy(bool enable) noexcept {
+    recoverEvictionPolicy_ = enable;
+    return *this;
+  }
+
   BlockCacheConfig& setAllocatorCount(uint32_t numAllocators) noexcept {
     allocatorsPerPriority_ = {numAllocators};
     return *this;
@@ -617,6 +622,8 @@ class BlockCacheConfig {
 
   bool isCleanRegionFastPath() const { return cleanRegionFastPath_; }
 
+  bool isRecoverEvictionPolicy() const { return recoverEvictionPolicy_; }
+
   bool isCombinedEntryBlockEnabled() const { return useCombinedEntryBlock_; }
 
   const BlockCacheReinsertionConfig& getReinsertionConfig() const {
@@ -668,6 +675,9 @@ class BlockCacheConfig {
   // Retry immediately if clean regions are empty and reclaims are in-flight.
   bool cleanRegionFastPath_{false};
 
+  // Whether to persist and recover eviction policy ordering across restarts.
+  bool recoverEvictionPolicy_{false};
+
   // Whether to use Combined entry block (For index entries and small sized
   // items).
   // Only FixedSizeIndex will support this and it doesn't work with

cachelib/allocator/nvmcache/NavySetup.cpp

@@ -180,6 +180,8 @@ uint64_t setupBlockCache(const navy::BlockCacheConfig& blockCacheConfig,
       blockCacheConfig.isRegionManagerFlushAsync());
 
   blockCache->setCleanRegionFastPath(blockCacheConfig.isCleanRegionFastPath());
+  blockCache->setRecoverEvictionPolicy(
+      blockCacheConfig.isRecoverEvictionPolicy());
   blockCache->setUseCombinedEntryBlock(
       blockCacheConfig.isCombinedEntryBlockEnabled());
   blockCache->setNumAllocatorsPerPriority(

cachelib/navy/Factory.cpp

@@ -135,6 +135,10 @@ class BlockCacheProtoImpl final : public BlockCacheProto {
     config_.cleanRegionFastPath = enable;
   }
 
+  void setRecoverEvictionPolicy(bool enable) override {
+    config_.recoverEvictionPolicy = enable;
+  }
+
   void setUseCombinedEntryBlock(bool useCombinedEntryBlock) override {
     config_.useCombinedEntryBlock = useCombinedEntryBlock;
   }

cachelib/navy/Factory.h

@@ -95,6 +95,9 @@ class BlockCacheProto {
   // (Optional) Enable the clean region fast path in getCleanRegion().
   virtual void setCleanRegionFastPath(bool enable) = 0;
 
+  // (Optional) Persist and recover eviction policy ordering across restarts.
+  virtual void setRecoverEvictionPolicy(bool enable) = 0;
+
   // (Optional) Set if the combined entry block is enabled.
   virtual void setUseCombinedEntryBlock(bool useCombinedEntryBlock) = 0;