// 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 core
import (
"errors"
"fmt"
"math"
"math/big"
"sort"
"sync"
"time"
"github.com/ava-labs/go-ethereum/common"
"github.com/ava-labs/go-ethereum/common/prque"
"github.com/ava-labs/go-ethereum/core/state"
"github.com/ava-labs/go-ethereum/core/types"
"github.com/ava-labs/go-ethereum/event"
"github.com/ava-labs/go-ethereum/log"
"github.com/ava-labs/go-ethereum/metrics"
"github.com/ava-labs/go-ethereum/params"
)
const (
// chainHeadChanSize is the size of channel listening to ChainHeadEvent.
chainHeadChanSize = 10
)
var (
// ErrInvalidSender is returned if the transaction contains an invalid signature.