Include tx compression level in calldata units cache

core/types/transaction.go

@@ -64,15 +64,54 @@ type Transaction struct {
 	inner TxData    // Consensus contents of a transaction
 	time  time.Time // Time first seen locally (spam avoidance)
 
-	// Arbitrum cache: must be atomically accessed
-	CalldataUnits uint64
+	// Arbitrum cache of the calldata units at a brotli compression level.
+	// The top 8 bits are the brotli compression level last used to compute this,
+	// and the remaining 56 bits are the calldata units at that compression level.
+	calldataUnitsForBrotliCompressionLevel atomic.Uint64
 
 	// caches
 	hash atomic.Pointer[common.Hash]
 	size atomic.Uint64
 	from atomic.Pointer[sigCache]
 }
 
+// GetRawCachedCalldataUnits returns the cached brotli compression level and corresponding calldata units,
+// or (0, 0) if the cache is empty.
+func (tx *Transaction) GetRawCachedCalldataUnits() (uint64, uint64) {
+	repr := tx.calldataUnitsForBrotliCompressionLevel.Load()
+	cachedCompressionLevel := repr >> 56
+	calldataUnits := repr & ((1 << 56) - 1)
+	return cachedCompressionLevel, calldataUnits
+}
+
+// GetCachedCalldataUnits returns the cached calldata units for a given brotli compression level,
+// returning nil if no cache is present or the cache is for a different compression level.
+func (tx *Transaction) GetCachedCalldataUnits(requestedCompressionLevel uint64) *uint64 {
+	cachedCompressionLevel, cachedUnits := tx.GetRawCachedCalldataUnits()
+	if cachedUnits == 0 {
+		// empty cache
+		return nil
+	}
+	if cachedCompressionLevel != requestedCompressionLevel {
+		// wrong compression level
+		return nil
+	}
+	return &cachedUnits
+}
+
+// SetCachedCalldataUnits sets the cached brotli compression level and corresponding calldata units,
+// or clears the cache if the values are too large to fit (at least 2**8 and 2**56 respectively).
+// Note that a zero calldataUnits is also treated as an empty cache.
+func (tx *Transaction) SetCachedCalldataUnits(compressionLevel uint64, calldataUnits uint64) {
+	var repr uint64
+	// Ensure the compressionLevel and calldataUnits will fit.
+	// Otherwise, just clear the cache.
+	if compressionLevel < 1<<8 && calldataUnits < 1<<56 {
+		repr = compressionLevel<<56 | calldataUnits
+	}
+	tx.calldataUnitsForBrotliCompressionLevel.Store(repr)
+}
+
 // NewTx creates a new transaction.
 func NewTx(inner TxData) *Transaction {
 	tx := new(Transaction)

core/types/transaction_arbitrum_test.go

@@ -0,0 +1,49 @@
+// Copyright 2014 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 types
+
+import "testing"
+
+func TestTxCalldataUnitsCache(t *testing.T) {
+	tx := &Transaction{}
+	units := tx.GetCachedCalldataUnits(0)
+	if units != nil {
+		t.Errorf("unexpected initial cache present %v for compression 0", units)
+	}
+	units = tx.GetCachedCalldataUnits(1)
+	if units != nil {
+		t.Errorf("unexpected initial cache present %v for compression 1", units)
+	}
+	tx.SetCachedCalldataUnits(200, 1000)
+	units = tx.GetCachedCalldataUnits(100)
+	if units != nil {
+		t.Errorf("unexpected cached units %v present for incorrect compression 100", units)
+	}
+	units = tx.GetCachedCalldataUnits(0)
+	if units != nil {
+		t.Errorf("unexpected cached units %v present for incorrect compression 0", units)
+	}
+	units = tx.GetCachedCalldataUnits(200)
+	if units == nil || *units != 1000 {
+		t.Errorf("unexpected cached units %v for correct compression 200", units)
+	}
+	tx.SetCachedCalldataUnits(1, 1<<60)
+	units = tx.GetCachedCalldataUnits(1)
+	if units != nil {
+		t.Errorf("unexpected cache value %v present after reset", units)
+	}
+}