core/txpool: abstraction prep work for secondary pools (blob pool)

cmd/geth/main.go

@@ -419,7 +419,7 @@ func startNode(ctx *cli.Context, stack *node.Node, backend ethapi.Backend, isCon
 		}
 		// Set the gas price to the limits from the CLI and start mining
 		gasprice := flags.GlobalBig(ctx, utils.MinerGasPriceFlag.Name)
-		ethBackend.TxPool().SetGasPrice(gasprice)
+		ethBackend.TxPool().SetGasTip(gasprice)
 		if err := ethBackend.StartMining(); err != nil {
 			utils.Fatalf("Failed to start mining: %v", err)
 		}

core/txpool/subpool.go

@@ -0,0 +1,38 @@
+// Copyright 2023 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package txpool
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+// SubPool represents a specialized transaction pool that lives on its own (e.g.
+// blob pool). Since independent of how many specialized pools we have, they do
+// need to be updated in lockstep and assemble into one coherent view for block
+// production, this interface defines the common methods that allow the primary
+// transaction pool to manage the subpools.
+type SubPool interface {
+	// Reset retrieves the current state of the blockchain and ensures the content
+	// of the transaction pool is valid with regard to the chain state.
+	Reset(oldHead, newHead *types.Header)
+
+	// SetGasTip updates the minimum price required by the subpool for a new
+	// transaction, and drops all transactions below this threshold.
+	SetGasTip(tip *big.Int)
+}