crowetic/protocol
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Added comments for transaction decoder

Browse Source
This commit is contained in:
Greg Hysen 2019-01-31 14:07:09 -08:00
parent f7b58e7f64
commit 171618d32b
3 changed files with 59 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
packages/contract-wrappers/src/index.ts
View File

@ -37,6 +37,7 @@ export { OrderValidatorWrapper } from './contract_wrappers/order_validator_wrapp
export { DutchAuctionWrapper } from './contract_wrappers/dutch_auction_wrapper';
export { TransactionEncoder } from './utils/transaction_encoder';
export { ZeroExTransactionDecoder } from './utils/zeroex_transaction_decoder';
export {
ContractWrappersError,

31
packages/contract-wrappers/src/utils/zeroex_transaction_decoder.ts
View File

@ -8,29 +8,48 @@ import { DeployedContractInfo, DeployedContractInfoByName, TransactionData, Tran
export class ZeroExTransactionDecoder extends TransactionDecoder {
private static _instance: ZeroExTransactionDecoder;
/**
* Adds a set of ABI definitions, after which transaction data targeting these ABI's can be decoded.
* Additional properties can be included to disambiguate similar ABI's. For example, if two functions
* have the same signature but different parameter names, then their ABI definitions can be disambiguated
* by specifying a contract name.
* @param abiDefinitions ABI definitions for a given contract.
* @param contractName Name of contract that encapsulates the ABI definitions (optional).
* @param deploymentInfos A collection of network/address pairs where this contract is deployed (optional).
*/
public static addABI(
abiArray: AbiDefinition[],
abiDefinitions: AbiDefinition[],
contractName: string,
deploymentInfos?: DeployedContractInfo[],
): void {
const instance = ZeroExTransactionDecoder._getInstance();
instance.addABI(abiArray, contractName, deploymentInfos);
instance.addABI(abiDefinitions, contractName, deploymentInfos);
}
/**
* Decodes transaction data for a known ABI.
* @param txData hex-encoded transaction data.
* @param txProperties Properties about the transaction used to disambiguate similar ABI's (optional).
* @return Decoded transaction data. Includes: function name and signature, along with the decoded arguments.
*/
public static decode(calldata: string, txProperties?: TransactionProperties): TransactionData {
const instance = ZeroExTransactionDecoder._getInstance();
const decodedCalldata = instance.decode(calldata, txProperties);
return decodedCalldata;
}
/**
* Gets instance for singleton.
* @return singleton instance.
*/
private static _getInstance(): ZeroExTransactionDecoder {
if (!ZeroExTransactionDecoder._instance) {
ZeroExTransactionDecoder._instance = new ZeroExTransactionDecoder();
}
return ZeroExTransactionDecoder._instance;
}
/**
* Adds all known contract ABI's defined by the @0x/Artifacts package, along with known 0x
* contract addresses.
*/
private constructor() {
super();
// Load addresses by contract name

46
packages/utils/src/transaction_decoder.ts
View File

@ -6,29 +6,43 @@ import { DeployedContractInfo, FunctionInfoBySelector, TransactionData, Transact
export class TransactionDecoder {
private readonly _functionInfoBySelector: FunctionInfoBySelector = {};
private static _getFunctionSelector(calldata: string): string {
/**
* Retrieves the function selector from tranasction data.
* @param txData hex-encoded transaction data.
* @return hex-encoded function selector.
*/
private static _getFunctionSelector(txData: string): string {
const functionSelectorLength = 10;
if (!calldata.startsWith('0x') || calldata.length < functionSelectorLength) {
if (!txData.startsWith('0x') || txData.length < functionSelectorLength) {
throw new Error(
`Malformed calldata. Must include hex prefix '0x' and 4-byte function selector. Got '${calldata}'`,
`Malformed transaction data. Must include a hex prefix '0x' and 4-byte function selector. Got '${txData}'`,
);
}
const functionSelector = calldata.substr(0, functionSelectorLength);
return functionSelector;
}
public addABI(abiArray: AbiDefinition[], contractName: string, deploymentInfos?: DeployedContractInfo[]): void {
const functionAbis: MethodAbi[] = _.filter(abiArray, abiEntry => {
/**
* Adds a set of ABI definitions, after which transaction data targeting these ABI's can be decoded.
* Additional properties can be included to disambiguate similar ABI's. For example, if two functions
* have the same signature but different parameter names, then their ABI definitions can be disambiguated
* by specifying a contract name.
* @param abiDefinitions ABI definitions for a given contract.
* @param contractName Name of contract that encapsulates the ABI definitions (optional).
* @param deploymentInfos A collection of network/address pairs where this contract is deployed (optional).
*/
public addABI(abiDefinitions: AbiDefinition[], contractName?: string, deploymentInfos?: DeployedContractInfo[]): void {
// Disregard definitions that are not functions
const functionAbis: MethodAbi[] = _.filter(abiDefinitions, abiEntry => {
return abiEntry.type === 'function';
});
// Record function ABI's
_.each(functionAbis, functionAbi => {
const abiEncoder = new AbiEncoder.Method(functionAbi);
const functionSelector = abiEncoder.getSelector();
if (!(functionSelector in this._functionInfoBySelector)) {
this._functionInfoBySelector[functionSelector] = [];
}
// Recored deployed versions of this decoder
// Recored a copy of this ABI for each deployment
const functionSignature = abiEncoder.getSignature();
_.each(deploymentInfos, deploymentInfo => {
this._functionInfoBySelector[functionSelector].push({
@ -39,7 +53,7 @@ export class TransactionDecoder {
networkId: deploymentInfo.networkId,
});
});
// If there isn't a deployed version of this contract, record it without address/network id
// There is no deployment info for this contract; record it without an address/network id
if (_.isEmpty(deploymentInfos)) {
this._functionInfoBySelector[functionSelector].push({
functionSignature,
@ -49,9 +63,15 @@ export class TransactionDecoder {
}
});
}
public decode(calldata: string, txProperties_?: TransactionProperties): TransactionData {
const functionSelector = TransactionDecoder._getFunctionSelector(calldata);
/**
* Decodes transaction data for a known ABI.
* @param txData hex-encoded transaction data.
* @param txProperties Properties about the transaction used to disambiguate similar ABI's (optional).
* @return Decoded transaction data. Includes: function name and signature, along with the decoded arguments.
*/
public decode(txData: string, txProperties_?: TransactionProperties): TransactionData {
// Lookup
const functionSelector = TransactionDecoder._getFunctionSelector(txData);
const txProperties = _.isUndefined(txProperties_) ? {} : txProperties_;
const candidateFunctionInfos = this._functionInfoBySelector[functionSelector];
if (_.isUndefined(candidateFunctionInfos)) {
@ -75,7 +95,7 @@ export class TransactionDecoder {
}
const functionName = functionInfo.abiEncoder.getDataItem().name;
const functionSignature = functionInfo.abiEncoder.getSignatureType();
const functionArguments = functionInfo.abiEncoder.decode(calldata);
const functionArguments = functionInfo.abiEncoder.decode(txData);
const decodedCalldata = {
functionName,
functionSignature,