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diff --git a/src/rocksdb/db/table_cache.h b/src/rocksdb/db/table_cache.h
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+//  Copyright (c) 2011-present, Facebook, Inc.  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).
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+//
+// Thread-safe (provides internal synchronization)
+
+#pragma once
+#include <string>
+#include <vector>
+#include <stdint.h>
+
+#include "db/dbformat.h"
+#include "db/range_del_aggregator.h"
+#include "options/cf_options.h"
+#include "port/port.h"
+#include "rocksdb/cache.h"
+#include "rocksdb/env.h"
+#include "rocksdb/options.h"
+#include "rocksdb/table.h"
+#include "table/table_reader.h"
+#include "trace_replay/block_cache_tracer.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class Env;
+class Arena;
+struct FileDescriptor;
+class GetContext;
+class HistogramImpl;
+
+// Manages caching for TableReader objects for a column family. The actual
+// cache is allocated separately and passed to the constructor. TableCache
+// wraps around the underlying SST file readers by providing Get(),
+// MultiGet() and NewIterator() methods that hide the instantiation,
+// caching and access to the TableReader. The main purpose of this is
+// performance - by caching the TableReader, it avoids unnecessary file opens
+// and object allocation and instantiation. One exception is compaction, where
+// a new TableReader may be instantiated - see NewIterator() comments
+//
+// Another service provided by TableCache is managing the row cache - if the
+// DB is configured with a row cache, and the lookup key is present in the row
+// cache, lookup is very fast. The row cache is obtained from
+// ioptions.row_cache
+class TableCache {
+ public:
+  TableCache(const ImmutableCFOptions& ioptions,
+             const FileOptions& storage_options, Cache* cache,
+             BlockCacheTracer* const block_cache_tracer);
+  ~TableCache();
+
+  // Return an iterator for the specified file number (the corresponding
+  // file length must be exactly "file_size" bytes).  If "table_reader_ptr"
+  // is non-nullptr, also sets "*table_reader_ptr" to point to the Table object
+  // underlying the returned iterator, or nullptr if no Table object underlies
+  // the returned iterator.  The returned "*table_reader_ptr" object is owned
+  // by the cache and should not be deleted, and is valid for as long as the
+  // returned iterator is live.
+  // @param range_del_agg If non-nullptr, adds range deletions to the
+  //    aggregator. If an error occurs, returns it in a NewErrorInternalIterator
+  // @param for_compaction If true, a new TableReader may be allocated (but
+  //                       not cached), depending on the CF options
+  // @param skip_filters Disables loading/accessing the filter block
+  // @param level The level this table is at, -1 for "not set / don't know"
+  InternalIterator* NewIterator(
+      const ReadOptions& options, const FileOptions& toptions,
+      const InternalKeyComparator& internal_comparator,
+      const FileMetaData& file_meta, RangeDelAggregator* range_del_agg,
+      const SliceTransform* prefix_extractor, TableReader** table_reader_ptr,
+      HistogramImpl* file_read_hist, TableReaderCaller caller, Arena* arena,
+      bool skip_filters, int level, const InternalKey* smallest_compaction_key,
+      const InternalKey* largest_compaction_key);
+
+  // If a seek to internal key "k" in specified file finds an entry,
+  // call get_context->SaveValue() repeatedly until
+  // it returns false. As a side effect, it will insert the TableReader
+  // into the cache and potentially evict another entry
+  // @param get_context Context for get operation. The result of the lookup
+  //                    can be retrieved by calling get_context->State()
+  // @param file_read_hist If non-nullptr, the file reader statistics are
+  //                       recorded
+  // @param skip_filters Disables loading/accessing the filter block
+  // @param level The level this table is at, -1 for "not set / don't know"
+  Status Get(const ReadOptions& options,
+             const InternalKeyComparator& internal_comparator,
+             const FileMetaData& file_meta, const Slice& k,
+             GetContext* get_context,
+             const SliceTransform* prefix_extractor = nullptr,
+             HistogramImpl* file_read_hist = nullptr, bool skip_filters = false,
+             int level = -1);
+
+  // Return the range delete tombstone iterator of the file specified by
+  // `file_meta`.
+  Status GetRangeTombstoneIterator(
+      const ReadOptions& options,
+      const InternalKeyComparator& internal_comparator,
+      const FileMetaData& file_meta,
+      std::unique_ptr<FragmentedRangeTombstoneIterator>* out_iter);
+
+  // If a seek to internal key "k" in specified file finds an entry,
+  // call get_context->SaveValue() repeatedly until
+  // it returns false. As a side effect, it will insert the TableReader
+  // into the cache and potentially evict another entry
+  // @param mget_range Pointer to the structure describing a batch of keys to
+  //                   be looked up in this table file. The result is stored
+  //                   in the embedded GetContext
+  // @param skip_filters Disables loading/accessing the filter block
+  // @param level The level this table is at, -1 for "not set / don't know"
+  Status MultiGet(const ReadOptions& options,
+                  const InternalKeyComparator& internal_comparator,
+                  const FileMetaData& file_meta,
+                  const MultiGetContext::Range* mget_range,
+                  const SliceTransform* prefix_extractor = nullptr,
+                  HistogramImpl* file_read_hist = nullptr,
+                  bool skip_filters = false, int level = -1);
+
+  // Evict any entry for the specified file number
+  static void Evict(Cache* cache, uint64_t file_number);
+
+  // Clean table handle and erase it from the table cache
+  // Used in DB close, or the file is not live anymore.
+  void EraseHandle(const FileDescriptor& fd, Cache::Handle* handle);
+
+  // Find table reader
+  // @param skip_filters Disables loading/accessing the filter block
+  // @param level == -1 means not specified
+  Status FindTable(const FileOptions& toptions,
+                   const InternalKeyComparator& internal_comparator,
+                   const FileDescriptor& file_fd, Cache::Handle**,
+                   const SliceTransform* prefix_extractor = nullptr,
+                   const bool no_io = false, bool record_read_stats = true,
+                   HistogramImpl* file_read_hist = nullptr,
+                   bool skip_filters = false, int level = -1,
+                   bool prefetch_index_and_filter_in_cache = true);
+
+  // Get TableReader from a cache handle.
+  TableReader* GetTableReaderFromHandle(Cache::Handle* handle);
+
+  // Get the table properties of a given table.
+  // @no_io: indicates if we should load table to the cache if it is not present
+  //         in table cache yet.
+  // @returns: `properties` will be reset on success. Please note that we will
+  //            return Status::Incomplete() if table is not present in cache and
+  //            we set `no_io` to be true.
+  Status GetTableProperties(const FileOptions& toptions,
+                            const InternalKeyComparator& internal_comparator,
+                            const FileDescriptor& file_meta,
+                            std::shared_ptr<const TableProperties>* properties,
+                            const SliceTransform* prefix_extractor = nullptr,
+                            bool no_io = false);
+
+  // Return total memory usage of the table reader of the file.
+  // 0 if table reader of the file is not loaded.
+  size_t GetMemoryUsageByTableReader(
+      const FileOptions& toptions,
+      const InternalKeyComparator& internal_comparator,
+      const FileDescriptor& fd,
+      const SliceTransform* prefix_extractor = nullptr);
+
+  // Returns approximated offset of a key in a file represented by fd.
+  uint64_t ApproximateOffsetOf(
+      const Slice& key, const FileDescriptor& fd, TableReaderCaller caller,
+      const InternalKeyComparator& internal_comparator,
+      const SliceTransform* prefix_extractor = nullptr);
+
+  // Returns approximated data size between start and end keys in a file
+  // represented by fd (the start key must not be greater than the end key).
+  uint64_t ApproximateSize(const Slice& start, const Slice& end,
+                           const FileDescriptor& fd, TableReaderCaller caller,
+                           const InternalKeyComparator& internal_comparator,
+                           const SliceTransform* prefix_extractor = nullptr);
+
+  // Release the handle from a cache
+  void ReleaseHandle(Cache::Handle* handle);
+
+  Cache* get_cache() const { return cache_; }
+
+  // Capacity of the backing Cache that indicates inifinite TableCache capacity.
+  // For example when max_open_files is -1 we set the backing Cache to this.
+  static const int kInfiniteCapacity = 0x400000;
+
+  // The tables opened with this TableCache will be immortal, i.e., their
+  // lifetime is as long as that of the DB.
+  void SetTablesAreImmortal() {
+    if (cache_->GetCapacity() >= kInfiniteCapacity) {
+      immortal_tables_ = true;
+    }
+  }
+
+ private:
+  // Build a table reader
+  Status GetTableReader(const FileOptions& file_options,
+                        const InternalKeyComparator& internal_comparator,
+                        const FileDescriptor& fd, bool sequential_mode,
+                        bool record_read_stats, HistogramImpl* file_read_hist,
+                        std::unique_ptr<TableReader>* table_reader,
+                        const SliceTransform* prefix_extractor = nullptr,
+                        bool skip_filters = false, int level = -1,
+                        bool prefetch_index_and_filter_in_cache = true);
+
+  // Create a key prefix for looking up the row cache. The prefix is of the
+  // format row_cache_id + fd_number + seq_no. Later, the user key can be
+  // appended to form the full key
+  void CreateRowCacheKeyPrefix(const ReadOptions& options,
+                               const FileDescriptor& fd,
+                               const Slice& internal_key,
+                               GetContext* get_context, IterKey& row_cache_key);
+
+  // Helper function to lookup the row cache for a key. It appends the
+  // user key to row_cache_key at offset prefix_size
+  bool GetFromRowCache(const Slice& user_key, IterKey& row_cache_key,
+                       size_t prefix_size, GetContext* get_context);
+
+  const ImmutableCFOptions& ioptions_;
+  const FileOptions& file_options_;
+  Cache* const cache_;
+  std::string row_cache_id_;
+  bool immortal_tables_;
+  BlockCacheTracer* const block_cache_tracer_;
+};
+
+}  // namespace ROCKSDB_NAMESPACE