Memory, expiry and standardness options for the mempool

1// Copyright (c) 2022-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#ifndef BITCOIN_KERNEL_MEMPOOL_OPTIONS_H
5#define BITCOIN_KERNEL_MEMPOOL_OPTIONS_H
6
7#include <kernel/mempool_limits.h>
8
9#include <policy/feerate.h>
10#include <policy/policy.h>
11#include <util/time.h>
12
13#include <cstdint>
14#include <optional>
15
16class ValidationSignals;
17
18/** Default for -maxmempool, maximum megabytes of mempool memory usage */
19inline constexpr unsigned int DEFAULT_MAX_MEMPOOL_SIZE_MB{300};
20/** Default for -maxmempool when blocksonly is set */
21inline constexpr unsigned int DEFAULT_BLOCKSONLY_MAX_MEMPOOL_SIZE_MB{5};
22/** Default for -mempoolexpiry, expiration time for mempool transactions in hours */
23inline constexpr unsigned int DEFAULT_MEMPOOL_EXPIRY_HOURS{336};
24/** Whether to fall back to legacy V1 serialization when writing mempool.dat */
25inline constexpr bool DEFAULT_PERSIST_V1_DAT{false};
26/** Default for -acceptnonstdtxn */
27inline constexpr bool DEFAULT_ACCEPT_NON_STD_TXN{false};
28
29namespace kernel {
30/**
31 * Options struct containing options for constructing a CTxMemPool. Default
32 * constructor populates the struct with sane default values which can be
33 * modified.
34 *
35 * Most of the time, this struct should be referenced as CTxMemPool::Options.
36 */
37struct MemPoolOptions {
38    /* The ratio used to determine how often sanity checks will run.  */
39    int check_ratio{0};
40    int64_t max_size_bytes{DEFAULT_MAX_MEMPOOL_SIZE_MB * 1'000'000};
41    std::chrono::seconds expiry{std::chrono::hours{DEFAULT_MEMPOOL_EXPIRY_HOURS}};
42    CFeeRate incremental_relay_feerate{DEFAULT_INCREMENTAL_RELAY_FEE};
43    /** A fee rate smaller than this is considered zero fee (for relaying, mining and transaction creation) */
44    CFeeRate min_relay_feerate{DEFAULT_MIN_RELAY_TX_FEE};
45    CFeeRate dust_relay_feerate{DUST_RELAY_TX_FEE};
46    /**
47     * A data carrying output is an unspendable output containing data. The script
48     * type is designated as TxoutType::NULL_DATA.
49     *
50     * Maximum size of TxoutType::NULL_DATA scripts that this node considers standard.
51     * If nullopt, any size is nonstandard.
52     */
53    std::optional<unsigned> max_datacarrier_bytes{DEFAULT_ACCEPT_DATACARRIER ? std::optional{MAX_OP_RETURN_RELAY} : std::nullopt};
54    bool permit_bare_multisig{DEFAULT_PERMIT_BAREMULTISIG};
55    bool require_standard{true};
56    bool persist_v1_dat{DEFAULT_PERSIST_V1_DAT};
57    MemPoolLimits limits{};
58
59    ValidationSignals* signals{nullptr};
60};
61} // namespace kernel
62
63#endif // BITCOIN_KERNEL_MEMPOOL_OPTIONS_H
64