scripted-diff: Move mempool_args to src/node

It is part of the node library. Also, it won't be moved to the kernel
lib, as it will be pruned of ArgsManager.

-BEGIN VERIFY SCRIPT-
 # Move module
 git mv src/mempool_args.cpp src/node/
 git mv src/mempool_args.h   src/node/
 # Replacements
 sed -i 's:mempool_args\.h:node/mempool_args.h:g'     $(git grep -l mempool_args)
 sed -i 's:mempool_args\.cpp:node/mempool_args.cpp:g' $(git grep -l mempool_args)
 sed -i 's:MEMPOOL_ARGS_H:NODE_MEMPOOL_ARGS_H:g'      $(git grep -l MEMPOOL_ARGS_H)
-END VERIFY SCRIPT-

src/node/mempool_args.cpp

@@ -0,0 +1,99 @@
+// 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.
+
+#include <node/mempool_args.h>
+
+#include <kernel/mempool_limits.h>
+#include <kernel/mempool_options.h>
+
+#include <chainparams.h>
+#include <consensus/amount.h>
+#include <logging.h>
+#include <policy/feerate.h>
+#include <policy/policy.h>
+#include <tinyformat.h>
+#include <util/error.h>
+#include <util/moneystr.h>
+#include <util/system.h>
+#include <util/translation.h>
+
+#include <chrono>
+#include <memory>
+
+using kernel::MemPoolLimits;
+using kernel::MemPoolOptions;
+
+namespace {
+void ApplyArgsManOptions(const ArgsManager& argsman, MemPoolLimits& mempool_limits)
+{
+    mempool_limits.ancestor_count = argsman.GetIntArg("-limitancestorcount", mempool_limits.ancestor_count);
+
+    if (auto vkb = argsman.GetIntArg("-limitancestorsize")) mempool_limits.ancestor_size_vbytes = *vkb * 1'000;
+
+    mempool_limits.descendant_count = argsman.GetIntArg("-limitdescendantcount", mempool_limits.descendant_count);
+
+    if (auto vkb = argsman.GetIntArg("-limitdescendantsize")) mempool_limits.descendant_size_vbytes = *vkb * 1'000;
+}
+}
+
+std::optional<bilingual_str> ApplyArgsManOptions(const ArgsManager& argsman, const CChainParams& chainparams, MemPoolOptions& mempool_opts)
+{
+    mempool_opts.check_ratio = argsman.GetIntArg("-checkmempool", mempool_opts.check_ratio);
+
+    if (auto mb = argsman.GetIntArg("-maxmempool")) mempool_opts.max_size_bytes = *mb * 1'000'000;
+
+    if (auto hours = argsman.GetIntArg("-mempoolexpiry")) mempool_opts.expiry = std::chrono::hours{*hours};
+
+    // incremental relay fee sets the minimum feerate increase necessary for BIP 125 replacement in the mempool
+    // and the amount the mempool min fee increases above the feerate of txs evicted due to mempool limiting.
+    if (argsman.IsArgSet("-incrementalrelayfee")) {
+        if (std::optional<CAmount> inc_relay_fee = ParseMoney(argsman.GetArg("-incrementalrelayfee", ""))) {
+            mempool_opts.incremental_relay_feerate = CFeeRate{inc_relay_fee.value()};
+        } else {
+            return AmountErrMsg("incrementalrelayfee", argsman.GetArg("-incrementalrelayfee", ""));
+        }
+    }
+
+    if (argsman.IsArgSet("-minrelaytxfee")) {
+        if (std::optional<CAmount> min_relay_feerate = ParseMoney(argsman.GetArg("-minrelaytxfee", ""))) {
+            // High fee check is done afterward in CWallet::Create()
+            mempool_opts.min_relay_feerate = CFeeRate{min_relay_feerate.value()};
+        } else {
+            return AmountErrMsg("minrelaytxfee", argsman.GetArg("-minrelaytxfee", ""));
+        }
+    } else if (mempool_opts.incremental_relay_feerate > mempool_opts.min_relay_feerate) {
+        // Allow only setting incremental fee to control both
+        mempool_opts.min_relay_feerate = mempool_opts.incremental_relay_feerate;
+        LogPrintf("Increasing minrelaytxfee to %s to match incrementalrelayfee\n", mempool_opts.min_relay_feerate.ToString());
+    }
+
+    // Feerate used to define dust.  Shouldn't be changed lightly as old
+    // implementations may inadvertently create non-standard transactions
+    if (argsman.IsArgSet("-dustrelayfee")) {
+        if (std::optional<CAmount> parsed = ParseMoney(argsman.GetArg("-dustrelayfee", ""))) {
+            mempool_opts.dust_relay_feerate = CFeeRate{parsed.value()};
+        } else {
+            return AmountErrMsg("dustrelayfee", argsman.GetArg("-dustrelayfee", ""));
+        }
+    }
+
+    mempool_opts.permit_bare_multisig = argsman.GetBoolArg("-permitbaremultisig", DEFAULT_PERMIT_BAREMULTISIG);
+
+    if (argsman.GetBoolArg("-datacarrier", DEFAULT_ACCEPT_DATACARRIER)) {
+        mempool_opts.max_datacarrier_bytes = argsman.GetIntArg("-datacarriersize", MAX_OP_RETURN_RELAY);
+    } else {
+        mempool_opts.max_datacarrier_bytes = std::nullopt;
+    }
+
+    mempool_opts.require_standard = !argsman.GetBoolArg("-acceptnonstdtxn", !chainparams.RequireStandard());
+    if (!chainparams.IsTestChain() && !mempool_opts.require_standard) {
+        return strprintf(Untranslated("acceptnonstdtxn is not currently supported for %s chain"), chainparams.NetworkIDString());
+    }
+
+    mempool_opts.full_rbf = argsman.GetBoolArg("-mempoolfullrbf", mempool_opts.full_rbf);
+
+    ApplyArgsManOptions(argsman, mempool_opts.limits);
+
+    return std::nullopt;
+}