protocol/contracts/extensions/src/max_gas_price_utils.ts
2020-03-03 17:30:53 -08:00

45 lines
1.7 KiB
TypeScript

import { constants } from '@0x/contracts-test-utils';
import { assetDataUtils } from '@0x/order-utils';
import { StaticCallAssetData } from '@0x/types';
import { AbiEncoder, BigNumber } from '@0x/utils';
const maxGasPriceEncoder = AbiEncoder.create([{ name: 'maxGasPrice', type: 'uint256' }]);
const customGasPriceEncoder = AbiEncoder.createMethod('checkGasPrice', [{ name: 'data', type: 'bytes' }]);
const defaultGasPriceEncoder = AbiEncoder.createMethod('checkGasPrice', []);
const ONE_GWEI = new BigNumber(10 ** 9);
export const TWENTY_GWEI = ONE_GWEI.times(20);
/**
* Encodes the given stop limit data parameters into StaticCall asset data so that it can be used
* in a 0x order.
*/
export function encodeMaxGasPriceStaticCallData(maxGasPriceContractAddress: string, maxGasPrice?: BigNumber): string {
const staticCallData =
maxGasPrice === undefined
? defaultGasPriceEncoder.encode({})
: customGasPriceEncoder.encode({
data: maxGasPriceEncoder.encode({ maxGasPrice }),
});
return assetDataUtils.encodeStaticCallAssetData(
maxGasPriceContractAddress,
staticCallData,
constants.KECCAK256_NULL,
);
}
/**
* Decodes the maxGasPrice StaticCall asset data.
*/
export function decodeMaxGasPriceStaticCallData(assetData: string): BigNumber {
// tslint:disable-next-line:no-unnecessary-type-assertion
const { staticCallData } = assetDataUtils.decodeAssetDataOrThrow(assetData) as StaticCallAssetData;
try {
const { maxGasPrice } = maxGasPriceEncoder.decode(customGasPriceEncoder.strictDecode<string>(staticCallData));
return maxGasPrice;
} catch (e) {
defaultGasPriceEncoder.strictDecode(staticCallData);
return TWENTY_GWEI;
}
}