Merge bitcoin/bitcoin#25290: [kernel 3a/n] Decouple `CTxMemPool` from `ArgsManager`

d1684beabe5b738c2cc83de83e1aaef11a761b69 fees: Pass in a filepath instead of referencing gArgs (Carl Dong)
9a3d825c30e8e6118d74a4e568744cb9d03f7f5d init: Remove redundant -*mempool*, -limit* queries (Carl Dong)
6c5c60c4124293d948735756f84efc85262ea66f mempool: Use m_limit for UpdateTransactionsFromBlock (Carl Dong)
9e93b1030182eff92ef91181e17c7dd498c7e164 node/ifaces: Use existing MemPoolLimits (Carl Dong)
38af2bcf358a72b9457d370282e57f4be1c5c849 mempoolaccept: Use limits from mempool in constructor (Carl Dong)
9333427014695ac235c96d48791098168dfdc9db mempool: Introduce (still-unused) MemPoolLimits (Carl Dong)
716bb5fbd31077bbe99d11a54d6c2c250afc8085 scripted-diff: Rename anc/desc size limit vars to indicate SI unit (Carl Dong)
1ecc77321deb61b9f6888e4e10752b9d972fd26e scripted-diff: Rename DEFAULT_MEMPOOL_EXPIRY to indicate time unit (Carl Dong)
aa9141cd8185cb7ad532bc16feb9d302b05d9697 mempool: Pass in -mempoolexpiry instead of referencing gArgs (Carl Dong)
51c7a41a5eb6fcb60333812c770d80227cf7b64d init: Only determine maxmempool once (Carl Dong)
386c9472c8764738282e6d163b42e15a8feda7ea mempool: Make GetMinFee() with custom size protected (Carl Dong)
82f00de7a6a60cbc9ad0c6e1d0ffb1bc70c49af5 mempool: Pass in -maxmempool instead of referencing gArgs (Carl Dong)
f1941e8bfd2eecc478c7660434b1ebf6a64095a0 pool: Add and use MemPoolOptions, ApplyArgsManOptions (Carl Dong)
0199bd35bb44e32ee0db9b51c9d1bd7518c26f19 fuzz/rbf: Add missing TestingSetup (Carl Dong)
ccbaf546a68d6cda8ed3efd0598c0e4121b366bb scripted-diff: Rename DEFAULT_MAX_MEMPOOL_SIZE to indicate SI unit (Carl Dong)
fc02f77ca604f0221171bfde3059b34f5d0fb1cd ArgsMan: Add Get*Arg functions returning optional (Carl Dong)

Pull request description:

  This is part of the `libbitcoinkernel` project: #24303, https://github.com/bitcoin/bitcoin/projects/18

  -----

  As mentioned in the Stage 1 Step 2 description of [the `libbitcoinkernel` project](https://github.com/bitcoin/bitcoin/issues/24303), `ArgsManager` will not be part of `libbitcoinkernel`. Therefore, it is important that we remove any dependence on `ArgsManager` by code that will be part of `libbitcoinkernel`. This is the first in a series of PRs aiming to achieve this.

  This PR removes `CTxMemPool+MempoolAccept`'s dependency on `ArgsManager` by introducing a `CTxMemPool::Options` struct, which is used to specify `CTxMemPool`'s various options at construction time.

  These options are:
  - `-maxmempool` -> `CTxMemPool::Options::max_size`
  - `-mempoolexpiry` -> `CTxMemPool::Options::expiry`
  - `-limitancestorcount` -> `CTxMemPool::Options::limits::ancestor_count`
  - `-limitancestorsize` -> `CTxMemPool::Options::limits::ancestor_size`
  - `-limitdescendantcount` -> `CTxMemPool::Options::limits::descendant_count`
  - `-limitdescendantsize` -> `CTxMemPool::Options::limits::descendant_size`

  More context can be gleaned from the commit messages. The important commits are:

  - 56eb479ded8bfb2ef635bb6f3b484f9d5952c70d "pool: Add and use MemPoolOptions, ApplyArgsManOptions"
  - a1e08b70f3068f4e8def1c630d8f50cd54da7832 "mempool: Pass in -maxmempool instead of referencing gArgs"
  - 6f4bf3ede5812b374828f08fc728ceded2f10024 "mempool: Pass in -mempoolexpiry instead of referencing gArgs"
  - 5958a7fe4806599fc620ee8c1a881ca10fa2dd16 "mempool: Introduce (still-unused) MemPoolLimits"

  Reviewers: Help needed in the following commits (see commit messages):
  - a1e08b70f3068f4e8def1c630d8f50cd54da7832 "mempool: Pass in -maxmempool instead of referencing gArgs"
  - 0695081a797e9a5d7787b78b0f8289dafcc6bff7 "node/ifaces: Use existing MemPoolLimits"

  Note to Reviewers: There are perhaps an infinite number of ways to architect `CTxMemPool::Options`, the current one tries to keep it simple, usable, and flexible. I hope we don't spend too much time arguing over the design here since that's not the point. In the case that you're 100% certain that a different design is strictly better than this one in every regard, please show us a fully-implemented branch.

  -----

  TODO:
  - [x] Use the more ergonomic `CTxMemPool::Options` where appropriate
  - [x] Doxygen comments for `ApplyArgsManOptions`, `MemPoolOptions`

  -----

  Questions for Reviewers:
  1. Should we use `std::chrono::seconds` for `CTxMemPool::Options::expiry` and `CTxMemPool::m_expiry` instead of an `int64_t`? Something else? (`std::chrono::hours`?)
  2. Should I merge `CTxMemPool::Limits` inside `CTxMemPool::Options`?

ACKs for top commit:
  MarcoFalke:
    ACK d1684beabe5b738c2cc83de83e1aaef11a761b69 🍜
  ryanofsky:
    Code review ACK d1684beabe5b738c2cc83de83e1aaef11a761b69. Just minor cleanups since last review, mostly switching to brace initialization

Tree-SHA512: 2c138e52d69f61c263f1c3648f01c801338a8f576762c815f478ef5148b8b2f51e91ded5c1be915e678c0b14f6cfba894b82afec58d999d39a7bb7c914736e0b

1 files changed, 20 insertions, 17 deletions

diff --git a/src/txmempool.h b/src/txmempool.h
index 6320378c04..f44e78fde5 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -14,6 +14,9 @@
 #include <utility>
 #include <vector>
 
+#include <kernel/mempool_limits.h>
+#include <kernel/mempool_options.h>
+
 #include <coins.h>
 #include <consensus/amount.h>
 #include <indirectmap.h>
@@ -450,6 +453,8 @@ protected:
 
     bool m_is_loaded GUARDED_BY(cs){false};
 
+    CFeeRate GetMinFee(size_t sizelimit) const;
+
 public:
 
     static const int ROLLING_FEE_HALFLIFE = 60 * 60 * 12; // public only for testing
@@ -559,15 +564,21 @@ public:
     indirectmap<COutPoint, const CTransaction*> mapNextTx GUARDED_BY(cs);
     std::map<uint256, CAmount> mapDeltas GUARDED_BY(cs);
 
+    using Options = kernel::MemPoolOptions;
+
+    const int64_t m_max_size_bytes;
+    const std::chrono::seconds m_expiry;
+
+    using Limits = kernel::MemPoolLimits;
+
+    const Limits m_limits;
+
     /** Create a new CTxMemPool.
      * Sanity checks will be off by default for performance, because otherwise
      * accepting transactions becomes O(N^2) where N is the number of transactions
      * in the pool.
-     *
-     * @param[in] estimator is used to estimate appropriate transaction fees.
-     * @param[in] check_ratio is the ratio used to determine how often sanity checks will run.
      */
-    explicit CTxMemPool(CBlockPolicyEstimator* estimator = nullptr, int check_ratio = 0);
+    explicit CTxMemPool(const Options& opts);
 
     /**
      * If sanity-checking is turned on, check makes sure the pool is
@@ -647,13 +658,8 @@ public:
      *
      * @param[in] vHashesToUpdate          The set of txids from the
      *     disconnected block that have been accepted back into the mempool.
-     * @param[in] ancestor_size_limit      The maximum allowed size in virtual
-     *     bytes of an entry and its ancestors
-     * @param[in] ancestor_count_limit     The maximum allowed number of
-     *     transactions including the entry and its ancestors.
      */
-    void UpdateTransactionsFromBlock(const std::vector<uint256>& vHashesToUpdate,
-            uint64_t ancestor_size_limit, uint64_t ancestor_count_limit) EXCLUSIVE_LOCKS_REQUIRED(cs, cs_main) LOCKS_EXCLUDED(m_epoch);
+    void UpdateTransactionsFromBlock(const std::vector<uint256>& vHashesToUpdate) EXCLUSIVE_LOCKS_REQUIRED(cs, cs_main) LOCKS_EXCLUDED(m_epoch);
 
     /** Try to calculate all in-mempool ancestors of entry.
      *  (these are all calculated including the tx itself)
@@ -700,7 +706,9 @@ public:
       *  takes the fee rate to go back down all the way to 0. When the feerate
       *  would otherwise be half of this, it is set to 0 instead.
       */
-    CFeeRate GetMinFee(size_t sizelimit) const;
+    CFeeRate GetMinFee() const {
+        return GetMinFee(m_max_size_bytes);
+    }
 
     /** Remove transactions from the mempool until its dynamic size is <= sizelimit.
       *  pvNoSpendsRemaining, if set, will be populated with the list of outpoints
@@ -826,14 +834,9 @@ private:
      * @param[out] descendants_to_remove Populated with the txids of entries that
      *     exceed ancestor limits. It's the responsibility of the caller to
      *     removeRecursive them.
-     * @param[in] ancestor_size_limit the max number of ancestral bytes allowed
-     *     for any descendant
-     * @param[in] ancestor_count_limit the max number of ancestor transactions
-     *     allowed for any descendant
      */
     void UpdateForDescendants(txiter updateIt, cacheMap& cachedDescendants,
-                              const std::set<uint256>& setExclude, std::set<uint256>& descendants_to_remove,
-                              uint64_t ancestor_size_limit, uint64_t ancestor_count_limit) EXCLUSIVE_LOCKS_REQUIRED(cs);
+                              const std::set<uint256>& setExclude, std::set<uint256>& descendants_to_remove) EXCLUSIVE_LOCKS_REQUIRED(cs);
     /** Update ancestors of hash to add/remove it as a descendant transaction. */
     void UpdateAncestorsOf(bool add, txiter hash, setEntries &setAncestors) EXCLUSIVE_LOCKS_REQUIRED(cs);
     /** Set ancestor state for an entry */