summaryrefslogtreecommitdiffstats
path: root/src/kv/rocksdb_cache/ShardedCache.cc
blob: 7d160f9c7b427bd084e51143c2ce34bb98fe3009 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
// Copyright (c) 2018-Present Red Hat Inc.  All rights reserved.
//
// Copyright (c) 2011-2018, Facebook, Inc.  All rights reserved.
// This source code is licensed under both the GPLv2 and Apache 2.0 License
//
// 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.

#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif

#include "ShardedCache.h"

#include <string>

namespace rocksdb_cache {

ShardedCache::ShardedCache(size_t capacity, int num_shard_bits,
                           bool strict_capacity_limit)
    : num_shard_bits_(num_shard_bits),
      capacity_(capacity),
      strict_capacity_limit_(strict_capacity_limit),
      last_id_(1) {}

void ShardedCache::SetCapacity(size_t capacity) {
  int num_shards = 1 << num_shard_bits_;
  const size_t per_shard = (capacity + (num_shards - 1)) / num_shards;
  std::lock_guard<std::mutex> l(capacity_mutex_);
  for (int s = 0; s < num_shards; s++) {
    GetShard(s)->SetCapacity(per_shard);
  }
  capacity_ = capacity;
}

void ShardedCache::SetStrictCapacityLimit(bool strict_capacity_limit) {
  int num_shards = 1 << num_shard_bits_;
  std::lock_guard<std::mutex> l(capacity_mutex_);
  for (int s = 0; s < num_shards; s++) {
    GetShard(s)->SetStrictCapacityLimit(strict_capacity_limit);
  }
  strict_capacity_limit_ = strict_capacity_limit;
}

rocksdb::Status ShardedCache::Insert(const rocksdb::Slice& key, void* value, size_t charge,
                            DeleterFn deleter,
                            rocksdb::Cache::Handle** handle, Priority priority) {
  uint32_t hash = HashSlice(key);
  return GetShard(Shard(hash))
      ->Insert(key, hash, value, charge, deleter, handle, priority);
}

rocksdb::Cache::Handle* ShardedCache::Lookup(const rocksdb::Slice& key, rocksdb::Statistics* /*stats*/) {
  uint32_t hash = HashSlice(key);
  return GetShard(Shard(hash))->Lookup(key, hash);
}

bool ShardedCache::Ref(rocksdb::Cache::Handle* handle) {
  uint32_t hash = GetHash(handle);
  return GetShard(Shard(hash))->Ref(handle);
}

bool ShardedCache::Release(rocksdb::Cache::Handle* handle, bool force_erase) {
  uint32_t hash = GetHash(handle);
  return GetShard(Shard(hash))->Release(handle, force_erase);
}

void ShardedCache::Erase(const rocksdb::Slice& key) {
  uint32_t hash = HashSlice(key);
  GetShard(Shard(hash))->Erase(key, hash);
}

uint64_t ShardedCache::NewId() {
  return last_id_.fetch_add(1, std::memory_order_relaxed);
}

size_t ShardedCache::GetCapacity() const {
  std::lock_guard<std::mutex> l(capacity_mutex_);
  return capacity_;
}

bool ShardedCache::HasStrictCapacityLimit() const {
  std::lock_guard<std::mutex> l(capacity_mutex_);
  return strict_capacity_limit_;
}

size_t ShardedCache::GetUsage() const {
  // We will not lock the cache when getting the usage from shards.
  int num_shards = 1 << num_shard_bits_;
  size_t usage = 0;
  for (int s = 0; s < num_shards; s++) {
    usage += GetShard(s)->GetUsage();
  }
  return usage;
}

size_t ShardedCache::GetUsage(rocksdb::Cache::Handle* handle) const {
  return GetCharge(handle);
}

size_t ShardedCache::GetPinnedUsage() const {
  // We will not lock the cache when getting the usage from shards.
  int num_shards = 1 << num_shard_bits_;
  size_t usage = 0;
  for (int s = 0; s < num_shards; s++) {
    usage += GetShard(s)->GetPinnedUsage();
  }
  return usage;
}

#if (ROCKSDB_MAJOR >= 7 || (ROCKSDB_MAJOR == 6 && ROCKSDB_MINOR >= 22))
DeleterFn ShardedCache::GetDeleter(Handle* handle) const
{
  uint32_t hash = GetHash(handle);
  return GetShard(Shard(hash))->GetDeleter(handle);
}

void ShardedCache::ApplyToAllEntries(
    const std::function<void(const rocksdb::Slice& key, void* value, size_t charge,
                             DeleterFn deleter)>& callback,
    const ApplyToAllEntriesOptions& opts)
{
  int num_shards = 1 << num_shard_bits_;
  for (int s = 0; s < num_shards; s++) {
    GetShard(s)->ApplyToAllCacheEntries(callback, true /* thread_safe */);
  }
}
#else
void ShardedCache::ApplyToAllCacheEntries(void (*callback)(void*, size_t),
                                          bool thread_safe) {
  int num_shards = 1 << num_shard_bits_;
  for (int s = 0; s < num_shards; s++) {
    GetShard(s)->ApplyToAllCacheEntries(
      [callback](const rocksdb::Slice&, void* value, size_t charge, DeleterFn) {
        callback(value, charge);
      },
      thread_safe);
  }
}
#endif

void ShardedCache::EraseUnRefEntries() {
  int num_shards = 1 << num_shard_bits_;
  for (int s = 0; s < num_shards; s++) {
    GetShard(s)->EraseUnRefEntries();
  }
}

std::string ShardedCache::GetPrintableOptions() const {
  std::string ret;
  ret.reserve(20000);
  const int kBufferSize = 200;
  char buffer[kBufferSize];
  {
    std::lock_guard<std::mutex> l(capacity_mutex_);
    snprintf(buffer, kBufferSize, "    capacity : %zu\n",
             capacity_);
    ret.append(buffer);
    snprintf(buffer, kBufferSize, "    num_shard_bits : %d\n", num_shard_bits_);
    ret.append(buffer);
    snprintf(buffer, kBufferSize, "    strict_capacity_limit : %d\n",
             strict_capacity_limit_);
    ret.append(buffer);
  }
  ret.append(GetShard(0)->GetPrintableOptions());
  return ret;
}
int GetDefaultCacheShardBits(size_t capacity) {
  int num_shard_bits = 0;
  size_t min_shard_size = 512L * 1024L;  // Every shard is at least 512KB.
  size_t num_shards = capacity / min_shard_size;
  while (num_shards >>= 1) {
    if (++num_shard_bits >= 6) {
      // No more than 6.
      return num_shard_bits;
    }
  }
  return num_shard_bits;
}

}  // namespace rocksdb_cache