A Metamask fork with Infura removed and default networks editable
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ciphermask/app/scripts/controllers/transactions/tx-gas-utils.js

115 lines
3.7 KiB

import EthQuery from 'ethjs-query'
import { hexToBn, BnMultiplyByFraction, bnToHex } from '../../lib/util'
import log from 'loglevel'
import { addHexPrefix } from 'ethereumjs-util'
/**
tx-gas-utils are gas utility methods for Transaction manager
its passed ethquery
and used to do things like calculate gas of a tx.
@param {Object} provider - A network provider.
*/
export default class TxGasUtil {
constructor (provider) {
this.query = new EthQuery(provider)
}
/**
@param {Object} txMeta - the txMeta object
@returns {Object} - the txMeta object with the gas written to the txParams
*/
async analyzeGasUsage (txMeta) {
const block = await this.query.getBlockByNumber('latest', false)
let estimatedGasHex
try {
estimatedGasHex = await this.estimateTxGas(txMeta, block.gasLimit)
} catch (err) {
log.warn(err)
txMeta.simulationFails = {
reason: err.message,
errorKey: err.errorKey,
debug: { blockNumber: block.number, blockGasLimit: block.gasLimit },
}
return txMeta
}
this.setTxGas(txMeta, block.gasLimit, estimatedGasHex)
return txMeta
}
/**
Estimates the tx's gas usage
@param {Object} txMeta - the txMeta object
@param {string} blockGasLimitHex - hex string of the block's gas limit
@returns {string} - the estimated gas limit as a hex string
*/
async estimateTxGas (txMeta, blockGasLimitHex) {
const txParams = txMeta.txParams
// check if gasLimit is already specified
txMeta.gasLimitSpecified = Boolean(txParams.gas)
// if it is, use that value
if (txMeta.gasLimitSpecified) {
return txParams.gas
}
// fallback to block gasLimit
const blockGasLimitBN = hexToBn(blockGasLimitHex)
const saferGasLimitBN = BnMultiplyByFraction(blockGasLimitBN, 19, 20)
txParams.gas = bnToHex(saferGasLimitBN)
// estimate tx gas requirements
return await this.query.estimateGas(txParams)
}
/**
Writes the gas on the txParams in the txMeta
@param {Object} txMeta - the txMeta object to write to
@param {string} blockGasLimitHex - the block gas limit hex
@param {string} estimatedGasHex - the estimated gas hex
*/
setTxGas (txMeta, blockGasLimitHex, estimatedGasHex) {
txMeta.estimatedGas = addHexPrefix(estimatedGasHex)
const txParams = txMeta.txParams
// if gasLimit was specified and doesnt OOG,
// use original specified amount
if (txMeta.gasLimitSpecified) {
txMeta.estimatedGas = txParams.gas
return
}
// if gasLimit not originally specified,
// try adding an additional gas buffer to our estimation for safety
const recommendedGasHex = this.addGasBuffer(txMeta.estimatedGas, blockGasLimitHex)
txParams.gas = recommendedGasHex
return
}
/**
Adds a gas buffer with out exceeding the block gas limit
@param {string} initialGasLimitHex - the initial gas limit to add the buffer too
@param {string} blockGasLimitHex - the block gas limit
@returns {string} - the buffered gas limit as a hex string
*/
addGasBuffer (initialGasLimitHex, blockGasLimitHex) {
const initialGasLimitBn = hexToBn(initialGasLimitHex)
const blockGasLimitBn = hexToBn(blockGasLimitHex)
const upperGasLimitBn = blockGasLimitBn.muln(0.9)
const bufferedGasLimitBn = initialGasLimitBn.muln(1.5)
// if initialGasLimit is above blockGasLimit, dont modify it
if (initialGasLimitBn.gt(upperGasLimitBn)) {
return bnToHex(initialGasLimitBn)
}
// if bufferedGasLimit is below blockGasLimit, use bufferedGasLimit
if (bufferedGasLimitBn.lt(upperGasLimitBn)) {
return bnToHex(bufferedGasLimitBn)
}
// otherwise use blockGasLimit
return bnToHex(upperGasLimitBn)
}
}