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Diffstat (limited to 'packages/sol-cov/src/trace_collection_subprovider.ts')
| -rw-r--r-- | packages/sol-cov/src/trace_collection_subprovider.ts | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/packages/sol-cov/src/trace_collection_subprovider.ts b/packages/sol-cov/src/trace_collection_subprovider.ts new file mode 100644 index 000000000..9866472b9 --- /dev/null +++ b/packages/sol-cov/src/trace_collection_subprovider.ts @@ -0,0 +1,185 @@ +import { BlockchainLifecycle } from '@0xproject/dev-utils'; +import { Callback, ErrorCallback, NextCallback, Subprovider } from '@0xproject/subproviders'; +import { Web3Wrapper } from '@0xproject/web3-wrapper'; +import { CallData, JSONRPCRequestPayload, Provider, TxData } from 'ethereum-types'; +import * as _ from 'lodash'; +import { Lock } from 'semaphore-async-await'; + +import { constants } from './constants'; +import { BlockParamLiteral } from './types'; + +interface MaybeFakeTxData extends TxData { + isFakeTransaction?: boolean; +} + +const BLOCK_GAS_LIMIT = 6000000; + +export interface TraceCollectionSubproviderConfig { + shouldCollectTransactionTraces: boolean; + shouldCollectCallTraces: boolean; + shouldCollectGasEstimateTraces: boolean; +} + +// Because there is no notion of a call trace in the Ethereum rpc - we collect them in a rather non-obvious/hacky way. +// On each call - we create a snapshot, execute the call as a transaction, get the trace, revert the snapshot. +// That allows us to avoid influencing test behaviour. + +/** + * This class implements the [web3-provider-engine](https://github.com/MetaMask/provider-engine) subprovider interface. + * It collects traces of all transactions that were sent and all calls that were executed through JSON RPC. It must + * be extended by implementing the _recordTxTraceAsync method which is called for every transaction. + */ +export abstract class TraceCollectionSubprovider extends Subprovider { + protected _web3Wrapper!: Web3Wrapper; + // Lock is used to not accept normal transactions while doing call/snapshot magic because they'll be reverted later otherwise + private _lock = new Lock(); + private _defaultFromAddress: string; + private _isEnabled = true; + private _config: TraceCollectionSubproviderConfig; + /** + * Instantiates a TraceCollectionSubprovider instance + * @param defaultFromAddress default from address to use when sending transactions + */ + constructor(defaultFromAddress: string, config: TraceCollectionSubproviderConfig) { + super(); + this._defaultFromAddress = defaultFromAddress; + this._config = config; + } + /** + * Starts trace collection + */ + public start(): void { + this._isEnabled = true; + } + /** + * Stops trace collection + */ + public stop(): void { + this._isEnabled = false; + } + /** + * This method conforms to the web3-provider-engine interface. + * It is called internally by the ProviderEngine when it is this subproviders + * turn to handle a JSON RPC request. + * @param payload JSON RPC payload + * @param next Callback to call if this subprovider decides not to handle the request + * @param end Callback to call if subprovider handled the request and wants to pass back the request. + */ + // tslint:disable-next-line:prefer-function-over-method async-suffix + public async handleRequest(payload: JSONRPCRequestPayload, next: NextCallback, _end: ErrorCallback): Promise<void> { + if (this._isEnabled) { + switch (payload.method) { + case 'eth_sendTransaction': + if (!this._config.shouldCollectTransactionTraces) { + next(); + } else { + const txData = payload.params[0]; + next(this._onTransactionSentAsync.bind(this, txData)); + } + return; + + case 'eth_call': + if (!this._config.shouldCollectCallTraces) { + next(); + } else { + const callData = payload.params[0]; + next(this._onCallOrGasEstimateExecutedAsync.bind(this, callData)); + } + return; + + case 'eth_estimateGas': + if (!this._config.shouldCollectGasEstimateTraces) { + next(); + } else { + const estimateGasData = payload.params[0]; + next(this._onCallOrGasEstimateExecutedAsync.bind(this, estimateGasData)); + } + return; + + default: + next(); + return; + } + } else { + next(); + return; + } + } + /** + * Set's the subprovider's engine to the ProviderEngine it is added to. + * This is only called within the ProviderEngine source code, do not call + * directly. + */ + public setEngine(engine: Provider): void { + super.setEngine(engine); + this._web3Wrapper = new Web3Wrapper(engine); + } + protected abstract async _recordTxTraceAsync( + address: string, + data: string | undefined, + txHash: string, + ): Promise<void>; + private async _onTransactionSentAsync( + txData: MaybeFakeTxData, + err: Error | null, + txHash: string | undefined, + cb: Callback, + ): Promise<void> { + if (!txData.isFakeTransaction) { + // This transaction is a usual transaction. Not a call executed as one. + // And we don't want it to be executed within a snapshotting period + await this._lock.acquire(); + } + const NULL_ADDRESS = '0x0'; + if (_.isNull(err)) { + const toAddress = + _.isUndefined(txData.to) || txData.to === NULL_ADDRESS ? constants.NEW_CONTRACT : txData.to; + await this._recordTxTraceAsync(toAddress, txData.data, txHash as string); + } else { + const latestBlock = await this._web3Wrapper.getBlockWithTransactionDataAsync(BlockParamLiteral.Latest); + const transactions = latestBlock.transactions; + for (const transaction of transactions) { + const toAddress = + _.isUndefined(txData.to) || txData.to === NULL_ADDRESS ? constants.NEW_CONTRACT : txData.to; + await this._recordTxTraceAsync(toAddress, transaction.input, transaction.hash); + } + } + if (!txData.isFakeTransaction) { + // This transaction is a usual transaction. Not a call executed as one. + // And we don't want it to be executed within a snapshotting period + this._lock.release(); + } + cb(); + } + private async _onCallOrGasEstimateExecutedAsync( + callData: Partial<CallData>, + _err: Error | null, + _callResult: string, + cb: Callback, + ): Promise<void> { + await this._recordCallOrGasEstimateTraceAsync(callData); + cb(); + } + private async _recordCallOrGasEstimateTraceAsync(callData: Partial<CallData>): Promise<void> { + // We don't want other transactions to be exeucted during snashotting period, that's why we lock the + // transaction execution for all transactions except our fake ones. + await this._lock.acquire(); + const blockchainLifecycle = new BlockchainLifecycle(this._web3Wrapper); + await blockchainLifecycle.startAsync(); + const fakeTxData: MaybeFakeTxData = { + gas: BLOCK_GAS_LIMIT, + isFakeTransaction: true, // This transaction (and only it) is allowed to come through when the lock is locked + ...callData, + from: callData.from || this._defaultFromAddress, + }; + try { + const txHash = await this._web3Wrapper.sendTransactionAsync(fakeTxData); + await this._web3Wrapper.awaitTransactionMinedAsync(txHash, 0); + } catch (err) { + // Even if this transaction failed - we've already recorded it's trace. + _.noop(); + } + await blockchainLifecycle.revertAsync(); + this._lock.release(); + } +} |