Revert "Avoid dynamic memory allocation on read path (#10453)" (#10541)

Summary:
This reverts commit 0d885e80d4. The original commit causes a ASAN stack-use-after-return failure due to the `CreateCallback` being allocated on stack and then used in another thread when a secondary cache object is promoted to the primary cache.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10541

Reviewed By: gitbw95

Differential Revision: D38850039

Pulled By: anand1976

fbshipit-source-id: 810c592b7de2523693f5bb267159b23b0ee9132c

HISTORY.md

@@ -41,7 +41,6 @@
 
 ### Performance Improvements
 * Instead of constructing `FragmentedRangeTombstoneList` during every read operation, it is now constructed once and stored in immutable memtables. This improves speed of querying range tombstones from immutable memtables.
-* Improve read performance by avoiding dynamic memory allocation.
 * When using iterators with the integrated BlobDB implementation, blob cache handles are now released immediately when the iterator's position changes.
 
 ## Behavior Change

table/block_based/block_based_table_reader.cc

@@ -1251,12 +1251,8 @@ Status BlockBasedTable::GetDataBlockFromCache(
   Statistics* statistics = rep_->ioptions.statistics.get();
   bool using_zstd = rep_->blocks_definitely_zstd_compressed;
   const FilterPolicy* filter_policy = rep_->filter_policy;
-  CacheCreateCallback<TBlocklike> callback(read_amp_bytes_per_bit, statistics,
-                                           using_zstd, filter_policy);
-  // avoid dynamic memory allocation by using the reference (std::ref) of the
-  // callback. Otherwise, binding a functor to std::function will allocate extra
-  // memory from heap.
-  Cache::CreateCallback create_cb(std::ref(callback));
+  Cache::CreateCallback create_cb = GetCreateCallback<TBlocklike>(
+      read_amp_bytes_per_bit, statistics, using_zstd, filter_policy);
 
   // Lookup uncompressed cache first
   if (block_cache != nullptr) {
@@ -1286,11 +1282,8 @@ Status BlockBasedTable::GetDataBlockFromCache(
   BlockContents contents;
   if (rep_->ioptions.lowest_used_cache_tier ==
       CacheTier::kNonVolatileBlockTier) {
-    CacheCreateCallback<BlockContents> special_callback(
+    Cache::CreateCallback create_cb_special = GetCreateCallback<BlockContents>(
         read_amp_bytes_per_bit, statistics, using_zstd, filter_policy);
-    // avoid dynamic memory allocation by using the reference (std::ref) of the
-    // callback. Make sure the callback is only used within this code block.
-    Cache::CreateCallback create_cb_special(std::ref(special_callback));
     block_cache_compressed_handle = block_cache_compressed->Lookup(
         cache_key,
         BlocklikeTraits<BlockContents>::GetCacheItemHelper(block_type),

table/block_based/block_like_traits.h

@@ -21,42 +21,24 @@ template <typename T, CacheEntryRole R>
 Cache::CacheItemHelper* GetCacheItemHelperForRole();
 
 template <typename TBlocklike>
-class CacheCreateCallback {
- public:
-  CacheCreateCallback() = delete;
-  CacheCreateCallback(const CacheCreateCallback&) = delete;
-  CacheCreateCallback(CacheCreateCallback&&) = delete;
-  CacheCreateCallback& operator=(const CacheCreateCallback&) = delete;
-  CacheCreateCallback& operator=(CacheCreateCallback&&) = delete;
-
-  explicit CacheCreateCallback(size_t read_amp_bytes_per_bit,
+Cache::CreateCallback GetCreateCallback(size_t read_amp_bytes_per_bit,
                                         Statistics* statistics, bool using_zstd,
-                               const FilterPolicy* filter_policy)
-      : read_amp_bytes_per_bit_(read_amp_bytes_per_bit),
-        statistics_(statistics),
-        using_zstd_(using_zstd),
-        filter_policy_(filter_policy) {}
-
-  Status operator()(const void* buf, size_t size, void** out_obj,
-                    size_t* charge) {
+                                        const FilterPolicy* filter_policy) {
+  return [read_amp_bytes_per_bit, statistics, using_zstd, filter_policy](
+             const void* buf, size_t size, void** out_obj,
+             size_t* charge) -> Status {
     assert(buf != nullptr);
     std::unique_ptr<char[]> buf_data(new char[size]());
     memcpy(buf_data.get(), buf, size);
     BlockContents bc = BlockContents(std::move(buf_data), size);
     TBlocklike* ucd_ptr = BlocklikeTraits<TBlocklike>::Create(
-        std::move(bc), read_amp_bytes_per_bit_, statistics_, using_zstd_,
-        filter_policy_);
+        std::move(bc), read_amp_bytes_per_bit, statistics, using_zstd,
+        filter_policy);
     *out_obj = reinterpret_cast<void*>(ucd_ptr);
     *charge = size;
     return Status::OK();
-  }
-
- private:
-  const size_t read_amp_bytes_per_bit_;
-  Statistics* statistics_;
-  const bool using_zstd_;
-  const FilterPolicy* filter_policy_;
   };
+}
 
 template <>
 class BlocklikeTraits<BlockContents> {