bitcoin-bitcoin-core/src/kernel/mempool_options.h

// Copyright (c) 2022 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#ifndef BITCOIN_KERNEL_MEMPOOL_OPTIONS_H
#define BITCOIN_KERNEL_MEMPOOL_OPTIONS_H

class CBlockPolicyEstimator;

namespace kernel {
/**
 * Options struct containing options for constructing a CTxMemPool. Default
 * constructor populates the struct with sane default values which can be
 * modified.
 *
 * Most of the time, this struct should be referenced as CTxMemPool::Options.
 */
struct MemPoolOptions {
    /* Used to estimate appropriate transaction fees. */
    CBlockPolicyEstimator* estimator{nullptr};
    /* The ratio used to determine how often sanity checks will run.  */
    int check_ratio{0};
};
} // namespace kernel

#endif // BITCOIN_KERNEL_MEMPOOL_OPTIONS_H
pool: Add and use MemPoolOptions, ApplyArgsManOptions Reviewers: Note that CTxMemPool now requires a non-defaulted CTxMemPool::Options for its constructor. Meaning that there's no need to worry about a stray CTxMemPool constructor somewhere defaulting to something incorrect. All instances of CTxMemPool construction are addressed here in this commit. We set options for CTxMemPool and construct it in many different ways. A good example can be seen in how we determine CTxMemPool's check_ratio in AppInitMain(...). 1. We first set the default based on chainparams's DefaultConsistencyChecks() 2. Then, we apply the ArgsManager option on top of that default 3. Finally, we clamp the result of that between 0 and 1 Million With this patch, most CTxMemPool construction are along the lines of: MemPoolOptions mempool_opts{...default overrides...}; ApplyArgsManOptions(argsman, mempool_opts); ...hard overrides... CTxMemPool pool{mempool_opts}; This "compositional" style of building options means that we can omit unnecessary/irrelevant steps wherever we want but also maintain full customizability. For example: - For users of libbitcoinkernel, where we eventually want to remove ArgsManager, they simply won't call (or even know about) ApplyArgsManOptions. - See src/init.cpp to see how the check_ratio CTxMemPool option works after this change. A MemPoolOptionsForTest helper was also added and used by tests/fuzz tests where a local CTxMemPool needed to be created. The change in src/test/fuzz/tx_pool.cpp seemingly changes behaviour by applying ArgsManager options on top of the CTxMemPool::Options defaults. However, in future commits where we introduce flags like -maxmempool, the call to ApplyArgsManOptions is actually what preserves the existing behaviour. Previously, although it wasn't obvious, our CTxMemPool would consult gArgs for flags like -maxmempool when it needed it, so it already relied on ArgsManager information. This patchset just laid bare the obfuscatory perils of globals. [META] As this patchset progresses, we will move more and more CTxMemPool-relevant options into MemPoolOptions and add their ArgsMan-related logic to ApplyArgsManOptions. 2022-03-18 13:51:37 -04:00			`// Copyright (c) 2022 The Bitcoin Core developers`
			`// Distributed under the MIT software license, see the accompanying`
			`// file COPYING or http://www.opensource.org/licenses/mit-license.php.`
			`#ifndef BITCOIN_KERNEL_MEMPOOL_OPTIONS_H`
			`#define BITCOIN_KERNEL_MEMPOOL_OPTIONS_H`

			`class CBlockPolicyEstimator;`

			`namespace kernel {`
			`/**`
			`* Options struct containing options for constructing a CTxMemPool. Default`
			`* constructor populates the struct with sane default values which can be`
			`* modified.`
			`*`
			`* Most of the time, this struct should be referenced as CTxMemPool::Options.`
			`*/`
			`struct MemPoolOptions {`
			`/* Used to estimate appropriate transaction fees. */`
			`CBlockPolicyEstimator* estimator{nullptr};`
			`/* The ratio used to determine how often sanity checks will run. */`
			`int check_ratio{0};`
			`};`
			`} // namespace kernel`

			`#endif // BITCOIN_KERNEL_MEMPOOL_OPTIONS_H`