Fix call chaining CacheBase and CacheAllocator to set EventTracker

Summary:
#### [Cachelib] Fix call chaining CacheBase and CacheAllocator to set EventTracker

**Cache.h Changes:**

* The function `setEventTracker` has been made virtual.
* The functions `setEventTrackerSamplingRate` and `disableEventTracker` have been removed from the `Cache` class. This will be handled by Luna.

**Cache.cpp Changes:**

* The implementation of `getEventTracker` remains unchanged.
* The implementation of `setEventTrackerSamplingRate` has been removed. This will be handled by Luna.

**Impact:**

This diff aims to fix the call chaining between `CacheBase` and `CacheAllocator` to set the `EventTracker`. The changes make the `setEventTracker` function virtual, allowing for proper overriding in derived classes. Additionally, `setEventTrackerSamplingRate` and `disableEventTracker` are not needed as changing and disabling EventTracker will be handled by Luna.

Reviewed By: rlyerly

Differential Revision: D92208056

fbshipit-source-id: 88f0c252345c2e980093e77e67b702299cb29f1f

Author: pbhandar2

cachelib/allocator/Cache.cpp

@@ -634,28 +634,4 @@ void CacheBase::setEventTracker(EventTracker::Config&& config) {
 std::shared_ptr<EventTracker> CacheBase::getEventTracker() const {
   return eventTracker_.load();
 }
-
-void CacheBase::setEventTrackerSamplingRate(uint32_t samplingRate) {
-  if (auto eventTracker = getEventTracker()) {
-    XLOG(INFO) << "Attempting to set sampling rate to " << samplingRate
-               << " for event tracker.";
-    eventTracker->setSamplingRate(samplingRate);
-    XLOG(INFO) << "EventTracker sampling rate is "
-               << eventTracker->getSamplingRate();
-  } else {
-    XLOG(INFO) << "Event tracker is not enabled. "
-                  "Setting EventTracker sampling rate to "
-               << samplingRate << " will have no effect.";
-  }
-}
-
-void CacheBase::disableEventTracker() {
-  if (auto eventTracker = getEventTracker()) {
-    XLOG(INFO) << "Disabling event tracker. Setting eventTracker_ to nullptr.";
-    eventTracker_.store(nullptr);
-  } else {
-    XLOG(INFO) << "Event tracker is already disabled.";
-  }
-}
-
 } // namespace facebook::cachelib

cachelib/allocator/Cache.h

@@ -231,9 +231,7 @@ class CacheBase {
   bool aggregatePoolStats_{false};
 
   std::shared_ptr<EventTracker> getEventTracker() const;
-  void setEventTracker(EventTracker::Config&& config);
-  void setEventTrackerSamplingRate(uint32_t samplingRate);
-  void disableEventTracker();
+  virtual void setEventTracker(EventTracker::Config&& config);
 
  protected:
   // move bytes from one pool to another. The source pool should be at least

cachelib/allocator/CacheAllocator.h

@@ -1255,7 +1255,7 @@ class CacheAllocator : public CacheBase {
   // Set the event tracker for the cache allocator.
   // This overrides the base class method to also propagate the event tracker
   // to the NVM cache if it is enabled.
-  void setEventTracker(EventTracker::Config&& config) {
+  void setEventTracker(EventTracker::Config&& config) override {
     // Call the base class method to set the event tracker
     CacheBase::setEventTracker(std::move(config));