// Copyright 2017 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 ethash
import (
"bytes"
"errors"
"fmt"
"math/big"
"runtime"
"time"
"github.com/ava-labs/coreth/consensus"
"github.com/ava-labs/coreth/consensus/misc"
"github.com/ava-labs/coreth/core/state"
"github.com/ava-labs/coreth/core/types"
"github.com/ava-labs/coreth/params"
mapset "github.com/deckarep/golang-set"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/math"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/trie"
"golang.org/x/crypto/sha3"
)
// Ethash proof-of-work protocol constants.
var (
FrontierBlockReward = big.NewInt(5e+18) // Block reward in wei for successfully mining a block
ByzantiumBlockReward = big.NewInt(3e+18) // Block reward in wei for successfully mining a block upward from Byzantium
ConstantinopleBlockReward = big.NewInt(2e+18) // Block reward in wei for successfully mining a block upward from Constantinople
maxUncles = 2 // Maximum number of uncles allowed in a single block
allowedFutureBlockTime = 15 * time.Second // Max time from current time allowed for blocks, before they're considered future blocks
// calcDifficultyEip2384 is the difficulty adjustment algorithm as specified by EIP 2384.
// It offsets the bomb 4M blocks from Constantinople, so in total 9M blocks.
// Specification EIP-2384: https://eips.ethereum.org/EIPS/eip-2384
calcDifficultyEip2384 = makeDifficultyCalculator(big.NewInt(9000000))
// calcDifficultyConstantinople is the difficulty adjustment algorithm for Constantinople.
// It returns the difficulty that a new block should have when created at time given the
// parent block's time and difficulty. The calculation uses the Byzantium rules, but with
// bomb offset 5M.
// Specification EIP-1234: https://eips.ethereum.org/EIPS/eip-1234
calcDifficultyConstantinople = makeDifficultyCalculator(big.NewInt(5000000))
// calcDifficultyByzantium is the difficulty adjustment algorithm. It returns
// the difficulty that a new block should have when created at time given the
// parent block's time and difficulty. The calculation uses the Byzantium rules.
// Specification EIP-649: https://eips.ethereum.org/EIPS/eip-649
calcDifficultyByzantium = makeDifficultyCalculator(big.NewInt(3000000))
)
// Various error messages to mark blocks invalid. These should be private to
// prevent engine specific errors from being referenced in the remainder of the
// codebase, inherently breaking if the engine is swapped out. Please put common
// error types into the consensus package.
var (
errOlderBlockTime = errors.New("timestamp older than parent")
errTooManyUncles = errors.New("too many uncles")
errDuplicateUncle = errors.New("duplicate uncle")
errUncleIsAncestor = errors.New("uncle is ancestor")
errDanglingUncle = errors.New("uncle's parent is not ancestor")
errInvalidDifficulty = errors.New("non-positive difficulty")
errInvalidMixDigest = errors.New("invalid mix digest")
errInvalidPoW = errors.New("invalid proof-of-work")
)
// Author implements consensus.Engine, returning the header's coinbase as the
// proof-of-work verified author of the block.
func (ethash *Ethash) Author(header *types.Header) (common.Address, error) {
return header.Coinbase, nil
}
// VerifyHeader checks whether a header conforms to the consensus rules of the
// stock Ethereum ethash engine.
func (ethash *Ethash) VerifyHeader(chain consensus.ChainHeaderReader, header *types.Header, seal bool) error {
// If we're running a full engine faking, accept any input as valid
if ethash.config.PowMode == ModeFullFake {
return nil
}
// Short circuit if the header is known, or its parent not
number := header.Number.Uint64()
if chain.GetHeader(header.Hash(), number) != nil {
return nil
}
parent := chain.GetHeader(header.ParentHash, number-1)
if parent == nil {
return consensus.ErrUnknownAncestor
}
// Sanity checks passed, do a proper verification
return ethash