forked from cerc-io/plugeth
ethash: less copy-paste for EIP 1234
This commit is contained in:
Martin Holst Swende
parent
0732617b65
commit
3df7df0386
@ -43,6 +43,16 @@ var (
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ConstantinopleBlockReward = big.NewInt(2e+18) // Block reward in wei for successfully mining a block upward from Constantinople
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maxUncles = 2 // Maximum number of uncles allowed in a single block
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allowedFutureBlockTime = 15 * time.Second // Max time from current time allowed for blocks, before they're considered future blocks
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// calcDifficultyConstantinople is the difficulty adjustment algorithm for Constantinople.
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// It returns the difficulty that a new block should have when created at time given the
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// parent block's time and difficulty. The calculation uses the Byzantium rules, but with bomb offset 5M.
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calcDifficultyConstantinople = makeDifficultyCalculator(big.NewInt(4999999))
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// calcDifficultyByzantium is the difficulty adjustment algorithm. It returns
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// the difficulty that a new block should have when created at time given the
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// parent block's time and difficulty. The calculation uses the Byzantium rules.
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calcDifficultyByzantium = makeDifficultyCalculator(big.NewInt(2999999))
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)
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// Various error messages to mark blocks invalid. These should be private to
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@ -319,126 +329,67 @@ var (
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big9 = big.NewInt(9)
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big10 = big.NewInt(10)
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bigMinus99 = big.NewInt(-99)
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big2999999 = big.NewInt(2999999)
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big4999999 = big.NewInt(4999999)
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)
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// calcDifficultyConstantinople is the difficulty adjustment algorithm. It returns
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// the difficulty that a new block should have when created at time given the
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// parent block's time and difficulty. The calculation uses the Constantinople rules.
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func calcDifficultyConstantinople(time uint64, parent *types.Header) *big.Int {
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// https://github.com/ethereum/EIPs/issues/100.
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// algorithm:
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// diff = (parent_diff +
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// (parent_diff / 2048 * max((2 if len(parent.uncles) else 1) - ((timestamp - parent.timestamp) // 9), -99))
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// ) + 2^(periodCount - 2)
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// makeDifficultyCalculator creates a difficultyCalculator with the given bomb-delay.
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// the difficulty is calculated with Byzantium rules, which differs from Homestead in
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// how uncles affect the calculation
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func makeDifficultyCalculator(bombDelay *big.Int) func(time uint64, parent *types.Header) *big.Int {
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return func(time uint64, parent *types.Header) *big.Int {
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// https://github.com/ethereum/EIPs/issues/100.
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// algorithm:
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// diff = (parent_diff +
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// (parent_diff / 2048 * max((2 if len(parent.uncles) else 1) - ((timestamp - parent.timestamp) // 9), -99))
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// ) + 2^(periodCount - 2)
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bigTime := new(big.Int).SetUint64(time)
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bigParentTime := new(big.Int).Set(parent.Time)
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bigTime := new(big.Int).SetUint64(time)
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bigParentTime := new(big.Int).Set(parent.Time)
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// holds intermediate values to make the algo easier to read & audit
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x := new(big.Int)
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y := new(big.Int)
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// holds intermediate values to make the algo easier to read & audit
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x := new(big.Int)
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y := new(big.Int)
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// (2 if len(parent_uncles) else 1) - (block_timestamp - parent_timestamp) // 9
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x.Sub(bigTime, bigParentTime)
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x.Div(x, big9)
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if parent.UncleHash == types.EmptyUncleHash {
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x.Sub(big1, x)
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} else {
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x.Sub(big2, x)
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// (2 if len(parent_uncles) else 1) - (block_timestamp - parent_timestamp) // 9
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x.Sub(bigTime, bigParentTime)
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x.Div(x, big9)
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if parent.UncleHash == types.EmptyUncleHash {
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x.Sub(big1, x)
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} else {
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x.Sub(big2, x)
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}
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// max((2 if len(parent_uncles) else 1) - (block_timestamp - parent_timestamp) // 9, -99)
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if x.Cmp(bigMinus99) < 0 {
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x.Set(bigMinus99)
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}
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// parent_diff + (parent_diff / 2048 * max((2 if len(parent.uncles) else 1) - ((timestamp - parent.timestamp) // 9), -99))
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y.Div(parent.Difficulty, params.DifficultyBoundDivisor)
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x.Mul(y, x)
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x.Add(parent.Difficulty, x)
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// minimum difficulty can ever be (before exponential factor)
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if x.Cmp(params.MinimumDifficulty) < 0 {
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x.Set(params.MinimumDifficulty)
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}
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// calculate a fake block number for the ice-age delay:
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// https://github.com/ethereum/EIPs/pull/669
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// fake_block_number = max(0, block.number - 3_000_000)
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fakeBlockNumber := new(big.Int)
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if parent.Number.Cmp(bombDelay) >= 0 {
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fakeBlockNumber = fakeBlockNumber.Sub(parent.Number, bombDelay) // Note, parent is 1 less than the actual block number
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}
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// for the exponential factor
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periodCount := fakeBlockNumber
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periodCount.Div(periodCount, expDiffPeriod)
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// the exponential factor, commonly referred to as "the bomb"
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// diff = diff + 2^(periodCount - 2)
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if periodCount.Cmp(big1) > 0 {
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y.Sub(periodCount, big2)
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y.Exp(big2, y, nil)
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x.Add(x, y)
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}
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return x
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}
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// max((2 if len(parent_uncles) else 1) - (block_timestamp - parent_timestamp) // 9, -99)
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if x.Cmp(bigMinus99) < 0 {
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x.Set(bigMinus99)
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}
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// parent_diff + (parent_diff / 2048 * max((2 if len(parent.uncles) else 1) - ((timestamp - parent.timestamp) // 9), -99))
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y.Div(parent.Difficulty, params.DifficultyBoundDivisor)
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x.Mul(y, x)
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x.Add(parent.Difficulty, x)
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// minimum difficulty can ever be (before exponential factor)
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if x.Cmp(params.MinimumDifficulty) < 0 {
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x.Set(params.MinimumDifficulty)
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}
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// calculate a fake block number for the ice-age delay:
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// https://github.com/ethereum/EIPs/pull/1234
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// fake_block_number = max(0, block.number - 5_000_000)
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fakeBlockNumber := new(big.Int)
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if parent.Number.Cmp(big4999999) >= 0 {
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fakeBlockNumber = fakeBlockNumber.Sub(parent.Number, big4999999) // Note, parent is 1 less than the actual block number
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}
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// for the exponential factor
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periodCount := fakeBlockNumber
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periodCount.Div(periodCount, expDiffPeriod)
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// the exponential factor, commonly referred to as "the bomb"
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// diff = diff + 2^(periodCount - 2)
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if periodCount.Cmp(big1) > 0 {
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y.Sub(periodCount, big2)
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y.Exp(big2, y, nil)
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x.Add(x, y)
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}
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return x
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}
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// calcDifficultyByzantium is the difficulty adjustment algorithm. It returns
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// the difficulty that a new block should have when created at time given the
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// parent block's time and difficulty. The calculation uses the Byzantium rules.
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func calcDifficultyByzantium(time uint64, parent *types.Header) *big.Int {
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// https://github.com/ethereum/EIPs/issues/100.
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// algorithm:
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// diff = (parent_diff +
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// (parent_diff / 2048 * max((2 if len(parent.uncles) else 1) - ((timestamp - parent.timestamp) // 9), -99))
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// ) + 2^(periodCount - 2)
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bigTime := new(big.Int).SetUint64(time)
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bigParentTime := new(big.Int).Set(parent.Time)
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// holds intermediate values to make the algo easier to read & audit
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x := new(big.Int)
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y := new(big.Int)
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// (2 if len(parent_uncles) else 1) - (block_timestamp - parent_timestamp) // 9
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x.Sub(bigTime, bigParentTime)
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x.Div(x, big9)
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if parent.UncleHash == types.EmptyUncleHash {
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x.Sub(big1, x)
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} else {
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x.Sub(big2, x)
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}
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// max((2 if len(parent_uncles) else 1) - (block_timestamp - parent_timestamp) // 9, -99)
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if x.Cmp(bigMinus99) < 0 {
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x.Set(bigMinus99)
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}
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// parent_diff + (parent_diff / 2048 * max((2 if len(parent.uncles) else 1) - ((timestamp - parent.timestamp) // 9), -99))
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y.Div(parent.Difficulty, params.DifficultyBoundDivisor)
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x.Mul(y, x)
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x.Add(parent.Difficulty, x)
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// minimum difficulty can ever be (before exponential factor)
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if x.Cmp(params.MinimumDifficulty) < 0 {
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x.Set(params.MinimumDifficulty)
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}
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// calculate a fake block number for the ice-age delay:
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// https://github.com/ethereum/EIPs/pull/669
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// fake_block_number = max(0, block.number - 3_000_000)
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fakeBlockNumber := new(big.Int)
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if parent.Number.Cmp(big2999999) >= 0 {
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fakeBlockNumber = fakeBlockNumber.Sub(parent.Number, big2999999) // Note, parent is 1 less than the actual block number
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}
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// for the exponential factor
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periodCount := fakeBlockNumber
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periodCount.Div(periodCount, expDiffPeriod)
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// the exponential factor, commonly referred to as "the bomb"
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// diff = diff + 2^(periodCount - 2)
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if periodCount.Cmp(big1) > 0 {
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y.Sub(periodCount, big2)
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y.Exp(big2, y, nil)
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x.Add(x, y)
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}
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return x
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}
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// calcDifficultyHomestead is the difficulty adjustment algorithm. It returns
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