99 lines
2.9 KiB
Go
99 lines
2.9 KiB
Go
package core
|
|
|
|
import (
|
|
"bytes"
|
|
"math/big"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
"github.com/ethereum/go-ethereum/core/types"
|
|
"github.com/ethereum/go-ethereum/logger"
|
|
"github.com/ethereum/go-ethereum/logger/glog"
|
|
"github.com/ethereum/go-ethereum/params"
|
|
"github.com/ethereum/go-ethereum/rlp"
|
|
)
|
|
|
|
// CalcDifficulty is the difficulty adjustment algorithm. It returns
|
|
// the difficulty that a new block b should have when created at time
|
|
// given the parent block's time and difficulty.
|
|
func CalcDifficulty(time int64, parentTime int64, parentDiff *big.Int) *big.Int {
|
|
diff := new(big.Int)
|
|
adjust := new(big.Int).Div(parentDiff, params.DifficultyBoundDivisor)
|
|
if big.NewInt(time-parentTime).Cmp(params.DurationLimit) < 0 {
|
|
diff.Add(parentDiff, adjust)
|
|
} else {
|
|
diff.Sub(parentDiff, adjust)
|
|
}
|
|
if diff.Cmp(params.MinimumDifficulty) < 0 {
|
|
return params.MinimumDifficulty
|
|
}
|
|
return diff
|
|
}
|
|
|
|
// CalcTD computes the total difficulty of block.
|
|
func CalcTD(block, parent *types.Block) *big.Int {
|
|
if parent == nil {
|
|
return block.Difficulty()
|
|
}
|
|
d := block.Difficulty()
|
|
d.Add(d, parent.Td)
|
|
return d
|
|
}
|
|
|
|
// CalcGasLimit computes the gas limit of the next block after parent.
|
|
// The result may be modified by the caller.
|
|
func CalcGasLimit(parent *types.Block) *big.Int {
|
|
decay := new(big.Int).Div(parent.GasLimit(), params.GasLimitBoundDivisor)
|
|
contrib := new(big.Int).Mul(parent.GasUsed(), big.NewInt(3))
|
|
contrib = contrib.Div(contrib, big.NewInt(2))
|
|
contrib = contrib.Div(contrib, params.GasLimitBoundDivisor)
|
|
|
|
gl := new(big.Int).Sub(parent.GasLimit(), decay)
|
|
gl = gl.Add(gl, contrib)
|
|
gl = gl.Add(gl, big.NewInt(1))
|
|
gl.Set(common.BigMax(gl, params.MinGasLimit))
|
|
|
|
if gl.Cmp(params.GenesisGasLimit) < 0 {
|
|
gl.Add(parent.GasLimit(), decay)
|
|
gl.Set(common.BigMin(gl, params.GenesisGasLimit))
|
|
}
|
|
return gl
|
|
}
|
|
|
|
// GetBlockByHash returns the block corresponding to the hash or nil if not found
|
|
func GetBlockByHash(db common.Database, hash common.Hash) *types.Block {
|
|
data, _ := db.Get(append(blockHashPre, hash[:]...))
|
|
if len(data) == 0 {
|
|
return nil
|
|
}
|
|
var block types.StorageBlock
|
|
if err := rlp.Decode(bytes.NewReader(data), &block); err != nil {
|
|
glog.V(logger.Error).Infof("invalid block RLP for hash %x: %v", hash, err)
|
|
return nil
|
|
}
|
|
return (*types.Block)(&block)
|
|
}
|
|
|
|
// GetBlockByHash returns the canonical block by number or nil if not found
|
|
func GetBlockByNumber(db common.Database, number uint64) *types.Block {
|
|
key, _ := db.Get(append(blockNumPre, big.NewInt(int64(number)).Bytes()...))
|
|
if len(key) == 0 {
|
|
return nil
|
|
}
|
|
|
|
return GetBlockByHash(db, common.BytesToHash(key))
|
|
}
|
|
|
|
// WriteHead force writes the current head
|
|
func WriteHead(db common.Database, block *types.Block) error {
|
|
key := append(blockNumPre, block.Number().Bytes()...)
|
|
err := db.Put(key, block.Hash().Bytes())
|
|
if err != nil {
|
|
return err
|
|
}
|
|
err = db.Put([]byte("LastBlock"), block.Hash().Bytes())
|
|
if err != nil {
|
|
return err
|
|
}
|
|
return nil
|
|
}
|