From 05fc753866cd526de19eca2775b059a9e8ea0802 Mon Sep 17 00:00:00 2001
From: Udi <udi@speedb.io>
Date: Sun, 25 Dec 2022 14:35:52 +0200
Subject: [PATCH] Print WBM's cache info to log (#312)

---
 cache/cache_reservation_manager.h |  2 ++
 memtable/write_buffer_manager.cc  | 10 ++++++++++
 2 files changed, 12 insertions(+)

diff --git a/cache/cache_reservation_manager.h b/cache/cache_reservation_manager.h
index 08bf59b006..a4762dea4b 100644
--- a/cache/cache_reservation_manager.h
+++ b/cache/cache_reservation_manager.h
@@ -202,6 +202,8 @@ class CacheReservationManagerImpl
   // test are from the same translation units
   static const Cache::CacheItemHelper *TEST_GetCacheItemHelperForRole();
 
+  const Cache *TEST_GetCache() const { return cache_.get(); }
+
  private:
   static constexpr std::size_t kSizeDummyEntry = 256 * 1024;
 
diff --git a/memtable/write_buffer_manager.cc b/memtable/write_buffer_manager.cc
index 88cb6a04af..09e95f1257 100644
--- a/memtable/write_buffer_manager.cc
+++ b/memtable/write_buffer_manager.cc
@@ -270,6 +270,16 @@ std::string WriteBufferManager::GetPrintableOptions() const {
            "wbm.size", buffer_size());
   ret.append(buffer);
 
+  const Cache* cache = nullptr;
+  if (cache_res_mgr_ != nullptr) {
+    cache =
+        static_cast<CacheReservationManagerImpl<CacheEntryRole::kWriteBuffer>*>(
+            cache_res_mgr_.get())
+            ->TEST_GetCache();
+  }
+  snprintf(buffer, kBufferSize, "%*s: %p\n", field_width, "wbm.cache", cache);
+  ret.append(buffer);
+
   snprintf(buffer, kBufferSize, "%*s: %d\n", field_width, "wbm.allow_stalls",
            allow_stall_);
   ret.append(buffer);