blob: 0d8854453a88d0f9b01b32617c4e1ac48654b2b2 [file] [log] [blame]
// 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).
#pragma once
#include <unordered_map>
namespace rocksdb {
// Helper methods to estimate memroy usage by std containers.
template <class Key, class Value, class Hash>
size_t ApproximateMemoryUsage(
const std::unordered_map<Key, Value, Hash>& umap) {
typedef std::unordered_map<Key, Value, Hash> Map;
return sizeof(umap) +
// Size of all items plus a next pointer for each item.
(sizeof(typename Map::value_type) + sizeof(void*)) * umap.size() +
// Size of hash buckets.
umap.bucket_count() * sizeof(void*);
} // namespace rocksdb