ceph/src/rocksdb/cache/secondary_cache.cc

   1 //  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under both the GPLv2 (found in the
   3 //  COPYING file in the root directory) and Apache 2.0 License
   4 //  (found in the LICENSE.Apache file in the root directory).
   5
   6 #include "rocksdb/secondary_cache.h"
   7
   8 #include "cache/cache_entry_roles.h"
   9
  10 namespace ROCKSDB_NAMESPACE {
  11
  12 namespace {
  13
  14 size_t SliceSize(void* obj) { return static_cast<Slice*>(obj)->size(); }
  15
  16 Status SliceSaveTo(void* from_obj, size_t from_offset, size_t length,
  17                    void* out) {
  18   const Slice& slice = *static_cast<Slice*>(from_obj);
  19   std::memcpy(out, slice.data() + from_offset, length);
  20   return Status::OK();
  21 }
  22
  23 }  // namespace
  24
  25 Status SecondaryCache::InsertSaved(const Slice& key, const Slice& saved) {
  26   static Cache::CacheItemHelper helper{
  27       &SliceSize, &SliceSaveTo, GetNoopDeleterForRole<CacheEntryRole::kMisc>()};
  28   // NOTE: depends on Insert() being synchronous, not keeping pointer `&saved`
  29   return Insert(key, const_cast<Slice*>(&saved), &helper);
  30 }
  31
  32 }  // namespace ROCKSDB_NAMESPACE