Merge pull request ethereum#5 from expanse-project/test-difficulty-ad…

…justment

merge difficulty adjustment branch

core/chain_util.go

@@ -40,7 +40,14 @@ var (
 // given the parent block's time and difficulty.
 func CalcDifficulty(time, parentTime uint64, parentNumber, parentDiff *big.Int) *big.Int {
  diff := new(big.Int)
- adjust := new(big.Int).Div(parentDiff, params.DifficultyBoundDivisor)
+ adjust := new(big.Int)
+
+ if parentNumber.Cmp(params.HardFork1) < 0 {
+ adjust = new(big.Int).Div(parentDiff, params.DifficultyBoundDivisor)
+ } else {
+ adjust = new(big.Int).Div(parentDiff, params.DifficultyBoundDivisor2)
+ }
+
  bigTime := new(big.Int)
  bigParentTime := new(big.Int)
 

params/protocol_params.go

@@ -30,6 +30,8 @@ var (
  TxGas = big.NewInt(21000) // Per transaction. NOTE: Not payable on data of calls between transactions.
  TxDataZeroGas = big.NewInt(4) // Per byte of data attached to a transaction that equals zero. NOTE: Not payable on data of calls between transactions.
  DifficultyBoundDivisor = big.NewInt(2048) // The bound divisor of the difficulty, used in the update calculations.
+ DifficultyBoundDivisor2 = big.NewInt(512) // Difficulty should adjust faster.
+ HardFork1 = big.NewInt(23000) // fork at this block number
  QuadCoeffDiv = big.NewInt(512) // Divisor for the quadratic particle of the memory cost equation.
  GenesisDifficulty = big.NewInt(131072) // Difficulty of the Genesis block.
  DurationLimit = big.NewInt(60) // The decision boundary on the blocktime duration used to determine whether difficulty should go up or not.