gas price

.env.example

@@ -11,3 +11,6 @@ INSERT_BATCH_SIZE=60
 # should not be more often than CONFIRMATION_BLOCKS time. e.g every 3 minutes
 CRON_EXPRESSION="0 */3 * * * *"
 CONFIRMATION_BLOCKS=3
+
+# one of "low", "standard", "fast", "instant" or a number in Gwei
+GAS_PRICE=fast

package.json

@@ -16,11 +16,12 @@
     "dotenv": "^8.2.0",
     "eth-ens-namehash": "^2.0.8",
     "fixed-merkle-tree": "^0.3.4",
+    "gas-price-oracle": "^0.2.2",
     "ioredis": "^4.17.3",
     "snarkjs": "git+https://github.com/tornadocash/snarkjs.git#869181cfaf7526fe8972073d31655493a04326d5",
+    "torn-token": "^1.0.0",
     "tx-manager": "^0.2.9",
-    "web3": "^1.2.11",
-    "torn-token": "^1.0.0"
+    "web3": "^1.2.11"
   },
   "devDependencies": {
     "babel-eslint": "^10.1.0",

src/index.js

@@ -1,8 +1,10 @@
 require('dotenv').config()
 const cron = require('cron')
-const { web3, redis, getTornadoTrees, txManager } = require('./singletons')
+const { web3, redis, getTornadoTrees, txManager, gasOracle } = require('./singletons')
 const config = require('torn-token')
 const { getTornadoEvents, getRegisteredEvents } = require('./events')
+const GAS_PRICE_VALUES = ['low', 'standard', 'fast', 'instant']
+const { toWei, toHex } = require('web3-utils')
 
 const STARTING_BLOCK = process.env.STARTING_BLOCK || 0
 const prefix = {
@@ -47,10 +49,19 @@ async function main(isRetry = false) {
     console.log(
       `Submitting tree update with ${chunks['deposit'].length} deposits and ${chunks['withdrawal'].length} withdrawals`,
     )
+    let gasPrice
+    if (GAS_PRICE_VALUES.includes(process.env.GAS_PRICE)) {
+      const gasPrices = await gasOracle.gasPrices()
+      gasPrice = gasPrices[process.env.GAS_PRICE]
+    } else {
+      gasPrice = Number(process.env.GAS_PRICE)
+    }
+
     const data = tornadoTrees.methods.updateRoots(chunks['deposit'], chunks['withdrawal']).encodeABI()
     const tx = txManager.createTx({
       to: tornadoTrees._address,
       data,
+      gasPrice: toHex(toWei(gasPrice.toString(), 'Gwei')),
     })
 
     try {

src/singletons.js

@@ -5,6 +5,8 @@ const tornadoTreesAbi = require('../abi/tornadoTrees.json')
 const Redis = require('ioredis')
 const ENSResolver = require('./resolver')
 const resolver = new ENSResolver()
+const { GasPriceOracle } = require('gas-price-oracle')
+const gasOracle = new GasPriceOracle({ defaultRpc: process.env.RPC_URL })
 const redis = new Redis(process.env.REDIS_URL)
 const config = require('torn-token')
 let tornadoTrees
@@ -34,4 +36,5 @@ module.exports = {
   redis,
   getTornadoTrees,
   txManager,
+  gasOracle,
 }

yarn.lock

@@ -2133,6 +2133,14 @@ gas-price-oracle@^0.2.0:
     axios "^0.19.2"
     bignumber.js "^9.0.0"
 
+gas-price-oracle@^0.2.2:
+  version "0.2.2"
+  resolved "https://registry.yarnpkg.com/gas-price-oracle/-/gas-price-oracle-0.2.2.tgz#32c57a9aa6bc69152be96812880232efebfecbc6"
+  integrity sha512-I4+rLbc7C1vgYXV+cYY0MKeqdZVna2hXpNfD2fcIvf/wIgvtIYmG9gsmhiaYGSgOE2RSPUs2xf/W4K2nJOoNuQ==
+  dependencies:
+    axios "^0.19.2"
+    bignumber.js "^9.0.0"
+
 get-caller-file@^1.0.1:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/get-caller-file/-/get-caller-file-1.0.3.tgz#f978fa4c90d1dfe7ff2d6beda2a515e713bdcf4a"