diff options
| -rw-r--r-- | eth/gasprice.go | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/eth/gasprice.go b/eth/gasprice.go new file mode 100644 index 000000000..f5b241e2c --- /dev/null +++ b/eth/gasprice.go @@ -0,0 +1,174 @@ +package eth + +import ( + "math/big" + "math/rand" + "sync" + + "github.com/ethereum/go-ethereum/core" + "github.com/ethereum/go-ethereum/core/types" + "github.com/ethereum/go-ethereum/event" + "github.com/ethereum/go-ethereum/logger" + "github.com/ethereum/go-ethereum/logger/glog" +) + +const gpoProcessPastBlocks = 100 + +type blockPriceInfo struct { + baseGasPrice *big.Int +} + +type GasPriceOracle struct { + eth *Ethereum + chain *core.ChainManager + pool *core.TxPool + events event.Subscription + blocks map[uint64]*blockPriceInfo + firstProcessed, lastProcessed uint64 + lastBaseMutex sync.Mutex + lastBase *big.Int +} + +func NewGasPriceOracle(eth *Ethereum) (self *GasPriceOracle) { + self = &GasPriceOracle{} + self.blocks = make(map[uint64]*blockPriceInfo) + self.eth = eth + self.chain = eth.chainManager + self.pool = eth.txPool + self.events = eth.EventMux().Subscribe( + core.ChainEvent{}, + core.ChainSplitEvent{}, + core.TxPreEvent{}, + core.TxPostEvent{}, + ) + self.processPastBlocks() + go self.listenLoop() + return +} + +func (self *GasPriceOracle) processPastBlocks() { + last := self.chain.CurrentBlock().NumberU64() + first := uint64(0) + if last > gpoProcessPastBlocks { + first = last - gpoProcessPastBlocks + } + self.firstProcessed = first + for i := first; i <= last; i++ { + self.processBlock(self.chain.GetBlockByNumber(i)) + } + +} + +func (self *GasPriceOracle) listenLoop() { + for { + ev, isopen := <-self.events.Chan() + if !isopen { + break + } + switch ev := ev.(type) { + case core.ChainEvent: + self.processBlock(ev.Block) + case core.ChainSplitEvent: + self.processBlock(ev.Block) + case core.TxPreEvent: + case core.TxPostEvent: + } + } + self.events.Unsubscribe() +} + +func (self *GasPriceOracle) processBlock(block *types.Block) { + i := block.NumberU64() + if i > self.lastProcessed { + self.lastProcessed = i + } + + lastBase := self.eth.GpoMinGasPrice + bpl := self.blocks[i-1] + if bpl != nil { + lastBase = bpl.baseGasPrice + } + if lastBase == nil { + return + } + + var corr int + lp := self.lowestPrice(block) + if lp == nil { + return + } + + if lastBase.Cmp(lp) < 0 { + corr = self.eth.GpobaseStepUp + } else { + corr = -self.eth.GpobaseStepDown + } + + crand := int64(corr * (900 + rand.Intn(201))) + newBase := new(big.Int).Mul(lastBase, big.NewInt(1000000+crand)) + newBase.Div(newBase, big.NewInt(1000000)) + + bpi := self.blocks[i] + if bpi == nil { + bpi = &blockPriceInfo{} + self.blocks[i] = bpi + } + bpi.baseGasPrice = newBase + self.lastBaseMutex.Lock() + self.lastBase = newBase + self.lastBaseMutex.Unlock() + + glog.V(logger.Detail).Infof("Processed block #%v, base price is %v\n", block.NumberU64(), newBase.Int64()) +} + +// returns the lowers possible price with which a tx was or could have been included +func (self *GasPriceOracle) lowestPrice(block *types.Block) *big.Int { + gasUsed := new(big.Int) + recepits, err := self.eth.BlockProcessor().GetBlockReceipts(block.Hash()) + if err != nil { + return self.eth.GpoMinGasPrice + } + + if len(recepits) > 0 { + gasUsed = recepits[len(recepits)-1].CumulativeGasUsed + } + + if new(big.Int).Mul(gasUsed, big.NewInt(100)).Cmp(new(big.Int).Mul(block.Header().GasLimit, + big.NewInt(int64(self.eth.GpoFullBlockRatio)))) < 0 { + // block is not full, could have posted a tx with MinGasPrice + return self.eth.GpoMinGasPrice + } + + if len(block.Transactions()) < 1 { + return self.eth.GpoMinGasPrice + } + + // block is full, find smallest gasPrice + minPrice := block.Transactions()[0].GasPrice() + for i := 1; i < len(block.Transactions()); i++ { + price := block.Transactions()[i].GasPrice() + if price.Cmp(minPrice) < 0 { + minPrice = price + } + } + return minPrice +} + +func (self *GasPriceOracle) SuggestPrice() *big.Int { + self.lastBaseMutex.Lock() + base := self.lastBase + self.lastBaseMutex.Unlock() + + baseCorr := new(big.Int).Mul(base, big.NewInt(int64(100+self.eth.GpobaseCorrectionFactor))) + baseCorr.Div(baseCorr, big.NewInt(100)) + + if baseCorr.Cmp(self.eth.GpoMinGasPrice) < 0 { + return self.eth.GpoMinGasPrice + } + + if baseCorr.Cmp(self.eth.GpoMaxGasPrice) > 0 { + return self.eth.GpoMaxGasPrice + } + + return baseCorr +} |