mirror of
https://github.com/kremalicious/metamask-extension.git
synced 2024-11-30 08:09:15 +01:00
99 lines
3.3 KiB
JavaScript
99 lines
3.3 KiB
JavaScript
import EthQuery from 'ethjs-query'
|
|
import log from 'loglevel'
|
|
import ethUtil from 'ethereumjs-util'
|
|
import { hexToBn, BnMultiplyByFraction, bnToHex } from '../../lib/util'
|
|
|
|
/**
|
|
* Result of gas analysis, including either a gas estimate for a successful analysis, or
|
|
* debug information for a failed analysis.
|
|
* @typedef {Object} GasAnalysisResult
|
|
* @property {string} blockGasLimit - The gas limit of the block used for the analysis
|
|
* @property {string} estimatedGasHex - The estimated gas, in hexadecimal
|
|
* @property {Object} simulationFails - Debug information about why an analysis failed
|
|
*/
|
|
|
|
/**
|
|
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 {GasAnalysisResult} The result of the gas analysis
|
|
*/
|
|
async analyzeGasUsage (txMeta) {
|
|
const block = await this.query.getBlockByNumber('latest', false)
|
|
|
|
// fallback to block gasLimit
|
|
const blockGasLimitBN = hexToBn(block.gasLimit)
|
|
const saferGasLimitBN = BnMultiplyByFraction(blockGasLimitBN, 19, 20)
|
|
let estimatedGasHex = bnToHex(saferGasLimitBN)
|
|
let simulationFails
|
|
try {
|
|
estimatedGasHex = await this.estimateTxGas(txMeta)
|
|
} catch (error) {
|
|
log.warn(error)
|
|
simulationFails = {
|
|
reason: error.message,
|
|
errorKey: error.errorKey,
|
|
debug: { blockNumber: block.number, blockGasLimit: block.gasLimit },
|
|
}
|
|
}
|
|
|
|
return { blockGasLimit: block.gasLimit, estimatedGasHex, simulationFails }
|
|
}
|
|
|
|
/**
|
|
Estimates the tx's gas usage
|
|
@param {Object} txMeta - the txMeta object
|
|
@returns {string} - the estimated gas limit as a hex string
|
|
*/
|
|
async estimateTxGas (txMeta) {
|
|
const { txParams } = txMeta
|
|
|
|
// estimate tx gas requirements
|
|
return await this.query.estimateGas(txParams)
|
|
}
|
|
|
|
/**
|
|
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, multiplier = 1.5) {
|
|
const initialGasLimitBn = hexToBn(initialGasLimitHex)
|
|
const blockGasLimitBn = hexToBn(blockGasLimitHex)
|
|
const upperGasLimitBn = blockGasLimitBn.muln(0.9)
|
|
const bufferedGasLimitBn = initialGasLimitBn.muln(multiplier)
|
|
|
|
// 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)
|
|
}
|
|
|
|
async getBufferedGasLimit (txMeta, multiplier) {
|
|
const { blockGasLimit, estimatedGasHex, simulationFails } = await this.analyzeGasUsage(txMeta)
|
|
|
|
// add additional gas buffer to our estimation for safety
|
|
const gasLimit = this.addGasBuffer(ethUtil.addHexPrefix(estimatedGasHex), blockGasLimit, multiplier)
|
|
return { gasLimit, simulationFails }
|
|
}
|
|
}
|