1 files changed, 182 insertions, 0 deletions
diff --git a/src/rocksdb/table/block_based/block_like_traits.h b/src/rocksdb/table/block_based/block_like_traits.h
new file mode 100644
index 000000000..d406dbb5d
--- /dev/null
+++ b/src/rocksdb/table/block_based/block_like_traits.h
@@ -0,0 +1,182 @@
+//  Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include "cache/cache_entry_roles.h"
+#include "port/lang.h"
+#include "table/block_based/block.h"
+#include "table/block_based/block_type.h"
+#include "table/block_based/parsed_full_filter_block.h"
+#include "table/format.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+template <typename TBlocklike>
+class BlocklikeTraits;
+
+template <typename T, CacheEntryRole R>
+Cache::CacheItemHelper* GetCacheItemHelperForRole();
+
+template <typename TBlocklike>
+Cache::CreateCallback GetCreateCallback(size_t read_amp_bytes_per_bit,
+                                        Statistics* statistics, bool using_zstd,
+                                        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);
+    *out_obj = reinterpret_cast<void*>(ucd_ptr);
+    *charge = size;
+    return Status::OK();
+  };
+}
+
+template <>
+class BlocklikeTraits<ParsedFullFilterBlock> {
+ public:
+  static ParsedFullFilterBlock* Create(BlockContents&& contents,
+                                       size_t /* read_amp_bytes_per_bit */,
+                                       Statistics* /* statistics */,
+                                       bool /* using_zstd */,
+                                       const FilterPolicy* filter_policy) {
+    return new ParsedFullFilterBlock(filter_policy, std::move(contents));
+  }
+
+  static uint32_t GetNumRestarts(const ParsedFullFilterBlock& /* block */) {
+    return 0;
+  }
+
+  static size_t SizeCallback(void* obj) {
+    assert(obj != nullptr);
+    ParsedFullFilterBlock* ptr = static_cast<ParsedFullFilterBlock*>(obj);
+    return ptr->GetBlockContentsData().size();
+  }
+
+  static Status SaveToCallback(void* from_obj, size_t from_offset,
+                               size_t length, void* out) {
+    assert(from_obj != nullptr);
+    ParsedFullFilterBlock* ptr = static_cast<ParsedFullFilterBlock*>(from_obj);
+    const char* buf = ptr->GetBlockContentsData().data();
+    assert(length == ptr->GetBlockContentsData().size());
+    (void)from_offset;
+    memcpy(out, buf, length);
+    return Status::OK();
+  }
+
+  static Cache::CacheItemHelper* GetCacheItemHelper(BlockType block_type) {
+    (void)block_type;
+    assert(block_type == BlockType::kFilter);
+    return GetCacheItemHelperForRole<ParsedFullFilterBlock,
+                                     CacheEntryRole::kFilterBlock>();
+  }
+};
+
+template <>
+class BlocklikeTraits<Block> {
+ public:
+  static Block* Create(BlockContents&& contents, size_t read_amp_bytes_per_bit,
+                       Statistics* statistics, bool /* using_zstd */,
+                       const FilterPolicy* /* filter_policy */) {
+    return new Block(std::move(contents), read_amp_bytes_per_bit, statistics);
+  }
+
+  static uint32_t GetNumRestarts(const Block& block) {
+    return block.NumRestarts();
+  }
+
+  static size_t SizeCallback(void* obj) {
+    assert(obj != nullptr);
+    Block* ptr = static_cast<Block*>(obj);
+    return ptr->size();
+  }
+
+  static Status SaveToCallback(void* from_obj, size_t from_offset,
+                               size_t length, void* out) {
+    assert(from_obj != nullptr);
+    Block* ptr = static_cast<Block*>(from_obj);
+    const char* buf = ptr->data();
+    assert(length == ptr->size());
+    (void)from_offset;
+    memcpy(out, buf, length);
+    return Status::OK();
+  }
+
+  static Cache::CacheItemHelper* GetCacheItemHelper(BlockType block_type) {
+    switch (block_type) {
+      case BlockType::kData:
+        return GetCacheItemHelperForRole<Block, CacheEntryRole::kDataBlock>();
+      case BlockType::kIndex:
+        return GetCacheItemHelperForRole<Block, CacheEntryRole::kIndexBlock>();
+      case BlockType::kFilterPartitionIndex:
+        return GetCacheItemHelperForRole<Block,
+                                         CacheEntryRole::kFilterMetaBlock>();
+      default:
+        // Not a recognized combination
+        assert(false);
+        FALLTHROUGH_INTENDED;
+      case BlockType::kRangeDeletion:
+        return GetCacheItemHelperForRole<Block, CacheEntryRole::kOtherBlock>();
+    }
+  }
+};
+
+template <>
+class BlocklikeTraits<UncompressionDict> {
+ public:
+  static UncompressionDict* Create(BlockContents&& contents,
+                                   size_t /* read_amp_bytes_per_bit */,
+                                   Statistics* /* statistics */,
+                                   bool using_zstd,
+                                   const FilterPolicy* /* filter_policy */) {
+    return new UncompressionDict(contents.data, std::move(contents.allocation),
+                                 using_zstd);
+  }
+
+  static uint32_t GetNumRestarts(const UncompressionDict& /* dict */) {
+    return 0;
+  }
+
+  static size_t SizeCallback(void* obj) {
+    assert(obj != nullptr);
+    UncompressionDict* ptr = static_cast<UncompressionDict*>(obj);
+    return ptr->slice_.size();
+  }
+
+  static Status SaveToCallback(void* from_obj, size_t from_offset,
+                               size_t length, void* out) {
+    assert(from_obj != nullptr);
+    UncompressionDict* ptr = static_cast<UncompressionDict*>(from_obj);
+    const char* buf = ptr->slice_.data();
+    assert(length == ptr->slice_.size());
+    (void)from_offset;
+    memcpy(out, buf, length);
+    return Status::OK();
+  }
+
+  static Cache::CacheItemHelper* GetCacheItemHelper(BlockType block_type) {
+    (void)block_type;
+    assert(block_type == BlockType::kCompressionDictionary);
+    return GetCacheItemHelperForRole<UncompressionDict,
+                                     CacheEntryRole::kOtherBlock>();
+  }
+};
+
+// Get an CacheItemHelper pointer for value type T and role R.
+template <typename T, CacheEntryRole R>
+Cache::CacheItemHelper* GetCacheItemHelperForRole() {
+  static Cache::CacheItemHelper cache_helper(
+      BlocklikeTraits<T>::SizeCallback, BlocklikeTraits<T>::SaveToCallback,
+      GetCacheEntryDeleterForRole<T, R>());
+  return &cache_helper;
+}
+
+}  // namespace ROCKSDB_NAMESPACE