ceph/src/rocksdb/table/persistent_cache_helper.h

   1 //  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under the BSD-style license found in the
   3 //  LICENSE file in the root directory of this source tree. An additional grant
   4 //  of patent rights can be found in the PATENTS file in the same directory.
   5 #pragma once
   6
   7 #include <string>
   8
   9 #include "monitoring/statistics.h"
  10 #include "table/format.h"
  11 #include "table/persistent_cache_options.h"
  12
  13 namespace rocksdb {
  14
  15 struct BlockContents;
  16
  17 // PersistentCacheHelper
  18 //
  19 // Encapsulates  some of the helper logic for read and writing from the cache
  20 class PersistentCacheHelper {
  21  public:
  22   // insert block into raw page cache
  23   static void InsertRawPage(const PersistentCacheOptions& cache_options,
  24                             const BlockHandle& handle, const char* data,
  25                             const size_t size);
  26
  27   // insert block into uncompressed cache
  28   static void InsertUncompressedPage(
  29       const PersistentCacheOptions& cache_options, const BlockHandle& handle,
  30       const BlockContents& contents);
  31
  32   // lookup block from raw page cacge
  33   static Status LookupRawPage(const PersistentCacheOptions& cache_options,
  34                               const BlockHandle& handle,
  35                               std::unique_ptr<char[]>* raw_data,
  36                               const size_t raw_data_size);
  37
  38   // lookup block from uncompressed cache
  39   static Status LookupUncompressedPage(
  40       const PersistentCacheOptions& cache_options, const BlockHandle& handle,
  41       BlockContents* contents);
  42 };
  43
  44 }  // namespace rocksdb