1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
|
// Copyright 2015 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 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/logger"
"github.com/ethereum/go-ethereum/logger/glog"
)
const (
gpoProcessPastBlocks = 100
// for testing
gpoDefaultBaseCorrectionFactor = 110
gpoDefaultMinGasPrice = 10000000000000
)
type blockPriceInfo struct {
baseGasPrice *big.Int
}
// GasPriceOracle recommends gas prices based on the content of recent
// blocks.
type GasPriceOracle struct {
eth *Ethereum
initOnce sync.Once
minPrice *big.Int
lastBaseMutex sync.Mutex
lastBase *big.Int
// state of listenLoop
blocks map[uint64]*blockPriceInfo
firstProcessed, lastProcessed uint64
minBase *big.Int
}
// NewGasPriceOracle returns a new oracle.
func NewGasPriceOracle(eth *Ethereum) *GasPriceOracle {
minprice := eth.GpoMinGasPrice
if minprice == nil {
minprice = big.NewInt(gpoDefaultMinGasPrice)
}
minbase := new(big.Int).Mul(minprice, big.NewInt(100))
if eth.GpobaseCorrectionFactor > 0 {
minbase = minbase.Div(minbase, big.NewInt(int64(eth.GpobaseCorrectionFactor)))
}
return &GasPriceOracle{
eth: eth,
blocks: make(map[uint64]*blockPriceInfo),
minBase: minbase,
minPrice: minprice,
lastBase: minprice,
}
}
func (gpo *GasPriceOracle) init() {
gpo.initOnce.Do(func() {
gpo.processPastBlocks(gpo.eth.BlockChain())
go gpo.listenLoop()
})
}
func (self *GasPriceOracle) processPastBlocks(chain *core.BlockChain) {
last := int64(-1)
cblock := chain.CurrentBlock()
if cblock != nil {
last = int64(cblock.NumberU64())
}
first := int64(0)
if last > gpoProcessPastBlocks {
first = last - gpoProcessPastBlocks
}
self.firstProcessed = uint64(first)
for i := first; i <= last; i++ {
block := chain.GetBlockByNumber(uint64(i))
if block != nil {
self.processBlock(block)
}
}
}
func (self *GasPriceOracle) listenLoop() {
events := self.eth.EventMux().Subscribe(core.ChainEvent{}, core.ChainSplitEvent{})
defer events.Unsubscribe()
for event := range events.Chan() {
switch event := event.Data.(type) {
case core.ChainEvent:
self.processBlock(event.Block)
case core.ChainSplitEvent:
self.processBlock(event.Block)
}
}
}
func (self *GasPriceOracle) processBlock(block *types.Block) {
i := block.NumberU64()
if i > self.lastProcessed {
self.lastProcessed = i
}
lastBase := self.minPrice
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))
if newBase.Cmp(self.minBase) < 0 {
newBase = self.minBase
}
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 := big.NewInt(0)
receipts := self.eth.BlockProcessor().GetBlockReceipts(block.Hash())
if len(receipts) > 0 {
if cgu := receipts[len(receipts)-1].CumulativeGasUsed; cgu != nil {
gasUsed = receipts[len(receipts)-1].CumulativeGasUsed
}
}
if new(big.Int).Mul(gasUsed, big.NewInt(100)).Cmp(new(big.Int).Mul(block.GasLimit(),
big.NewInt(int64(self.eth.GpoFullBlockRatio)))) < 0 {
// block is not full, could have posted a tx with MinGasPrice
return big.NewInt(0)
}
txs := block.Transactions()
if len(txs) == 0 {
return big.NewInt(0)
}
// block is full, find smallest gasPrice
minPrice := txs[0].GasPrice()
for i := 1; i < len(txs); i++ {
price := txs[i].GasPrice()
if price.Cmp(minPrice) < 0 {
minPrice = price
}
}
return minPrice
}
// SuggestPrice returns the recommended gas price.
func (self *GasPriceOracle) SuggestPrice() *big.Int {
self.init()
self.lastBaseMutex.Lock()
price := new(big.Int).Set(self.lastBase)
self.lastBaseMutex.Unlock()
price.Mul(price, big.NewInt(int64(self.eth.GpobaseCorrectionFactor)))
price.Div(price, big.NewInt(100))
if price.Cmp(self.minPrice) < 0 {
price.Set(self.minPrice)
} else if self.eth.GpoMaxGasPrice != nil && price.Cmp(self.eth.GpoMaxGasPrice) > 0 {
price.Set(self.eth.GpoMaxGasPrice)
}
return price
}
|
