caches.cpp raw
1 // Copyright (c) 2021-present The Bitcoin Core developers
2 // Distributed under the MIT software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4
5 #include <node/caches.h>
6
7 #include <common/args.h>
8 #include <common/system.h>
9 #include <index/txindex.h>
10 #include <index/txospenderindex.h>
11 #include <kernel/caches.h>
12 #include <node/interface_ui.h>
13 #include <tinyformat.h>
14 #include <util/byte_units.h>
15 #include <util/log.h>
16 #include <util/overflow.h>
17 #include <util/translation.h>
18
19 #include <algorithm>
20 #include <cstdint>
21 #include <limits>
22 #include <string>
23
24 // Unlike for the UTXO database, for the txindex scenario the leveldb cache make
25 // a meaningful difference: https://github.com/bitcoin/bitcoin/pull/8273#issuecomment-229601991
26 //! Max memory allocated to tx index DB specific cache in bytes.
27 static constexpr uint64_t MAX_TX_INDEX_CACHE{1_GiB};
28 //! Max memory allocated to all block filter index caches combined in bytes.
29 static constexpr uint64_t MAX_FILTER_INDEX_CACHE{1_GiB};
30 //! Max memory allocated to tx spenderindex DB specific cache in bytes.
31 static constexpr uint64_t MAX_TXOSPENDER_INDEX_CACHE{1_GiB};
32 //! Maximum dbcache size on 32-bit systems.
33 static constexpr uint64_t MAX_32BIT_DBCACHE{1_GiB};
34 //! Larger default dbcache on 64-bit systems with enough RAM.
35 static constexpr uint64_t HIGH_DEFAULT_DBCACHE{1_GiB};
36 //! Minimum detected RAM required for HIGH_DEFAULT_DBCACHE.
37 static constexpr uint64_t HIGH_DEFAULT_DBCACHE_MIN_TOTAL_RAM{4_GiB};
38
39 namespace node {
40 uint64_t GetDefaultDBCache()
41 {
42 if constexpr (sizeof(void*) >= 8) {
43 if (GetTotalRAM().value_or(0) >= HIGH_DEFAULT_DBCACHE_MIN_TOTAL_RAM) {
44 return HIGH_DEFAULT_DBCACHE;
45 }
46 }
47 return DEFAULT_DB_CACHE;
48 }
49
50 uint64_t CalculateDbCacheBytes(const ArgsManager& args)
51 {
52 if (auto db_cache{args.GetIntArg("-dbcache")}) {
53 if (*db_cache < 0) db_cache = 0;
54 const uint64_t db_cache_bytes{SaturatingLeftShift<uint64_t>(*db_cache, 20)};
55 constexpr uint64_t max_db_cache{sizeof(void*) == 4 ? MAX_32BIT_DBCACHE : std::numeric_limits<uint64_t>::max()};
56 return std::max<uint64_t>(MIN_DB_CACHE, std::min<uint64_t>(db_cache_bytes, max_db_cache));
57 }
58 return GetDefaultDBCache();
59 }
60
61 CacheSizes CalculateCacheSizes(const ArgsManager& args, size_t n_indexes)
62 {
63 uint64_t total_cache{CalculateDbCacheBytes(args)};
64
65 // Allocate proportional to usage pattern benefit:
66 // - txindex (10%): serves getrawtransaction RPCs with mostly unique,
67 // non-repetitive lookups across the entire blockchain.
68 // - blockfilterindex (5%): serves BIP 157 light clients that repeatedly
69 // query recent blocks, benefiting from LevelDB cache, but the
70 // working set for a typical 2-week offline gap is ~200kiB, well within 5%
71 // of the total cache.
72 // - txospenderindex (5%): serves gettxspendingprevout RPCs with very
73 // specific, rarely repeated outpoint queries.
74 // - coinstatsindex: intentionally not included here, since usage pattern
75 // does not seem to suggest it would be necessary to cache.
76 IndexCacheSizes index_sizes;
77 index_sizes.tx_index = std::min(total_cache * 10 / 100, args.GetBoolArg("-txindex", DEFAULT_TXINDEX) ? MAX_TX_INDEX_CACHE : 0);
78 index_sizes.txospender_index = std::min(total_cache * 5 / 100, args.GetBoolArg("-txospenderindex", DEFAULT_TXOSPENDERINDEX) ? MAX_TXOSPENDER_INDEX_CACHE : 0);
79 if (n_indexes > 0) {
80 uint64_t max_cache = std::min(total_cache * 5 / 100, MAX_FILTER_INDEX_CACHE);
81 index_sizes.filter_index = max_cache / n_indexes;
82 total_cache -= index_sizes.filter_index * n_indexes;
83 }
84 total_cache -= index_sizes.tx_index;
85 total_cache -= index_sizes.txospender_index;
86 return {index_sizes, kernel::CacheSizes{total_cache}};
87 }
88
89 void LogOversizedDbCache(const ArgsManager& args) noexcept
90 {
91 if (const auto total_ram{GetTotalRAM()}) {
92 const uint64_t db_cache{CalculateDbCacheBytes(args)};
93 if (ShouldWarnOversizedDbCache(db_cache, *total_ram)) {
94 InitWarning(bilingual_str{tfm::format(_("A %zu MiB dbcache may be too large for a system memory of only %zu MiB."),
95 db_cache >> 20, *total_ram >> 20)});
96 }
97 }
98 }
99 } // namespace node
100