chore: Add ability to capture sampler metrics (#374)

* chore: Add ability to capture sampler metrics

* Added block number metrics

packages/asset-swapper/CHANGELOG.json

@@ -1,4 +1,13 @@
 [
+    {
+        "version": "16.38.0",
+        "changes": [
+            {
+                "note": "Capture sampler metrics",
+                "pr": 374
+            }
+        ]
+    },
     {
         "version": "16.37.0",
         "changes": [

packages/asset-swapper/contracts/src/UtilitySampler.sol

@@ -77,4 +77,19 @@ contract UtilitySampler {
         assembly { size := extcodesize(account) }
         return size > 0;
     }
+
+    function getGasLeft()
+        public
+        returns (uint256)
+    {
+        return gasleft();
+    }
+
+    function getBlockNumber()
+        public
+        view
+        returns (uint256)
+    {
+        return block.number;
+    }
 }

packages/asset-swapper/src/index.ts

@@ -113,6 +113,7 @@ export {
     SwapQuoterError,
     SwapQuoterOpts,
     SwapQuoterRfqOpts,
+    SamplerMetrics,
 } from './types';
 export { affiliateFeeUtils } from './utils/affiliate_fee_utils';
 export {

packages/asset-swapper/src/types.ts

@@ -19,6 +19,7 @@ import {
     OptimizedMarketOrder,
     TokenAdjacencyGraph,
 } from './utils/market_operation_utils/types';
+export { SamplerMetrics } from './utils/market_operation_utils/types';
 import { ExtendedQuoteReportSources, PriceComparisonsReport, QuoteReport } from './utils/quote_report_generator';
 import { MetricsProxy } from './utils/quote_requestor';
 

packages/asset-swapper/src/utils/market_operation_utils/index.ts

@@ -158,6 +158,8 @@ export class MarketOperationUtils {
 
         // Call the sampler contract.
         const samplerPromise = this._sampler.executeAsync(
+            this._sampler.getBlockNumber(),
+            this._sampler.getGasLeft(),
             this._sampler.getTokenDecimals([makerToken, takerToken]),
             // Get native order fillable amounts.
             this._sampler.getLimitOrderFillableTakerAmounts(nativeOrders, this.contractAddresses.exchangeProxy),
@@ -184,6 +186,7 @@ export class MarketOperationUtils {
                 takerAmount,
             ),
             this._sampler.isAddressContract(txOrigin),
+            this._sampler.getGasLeft(),
         );
 
         // Refresh the cached pools asynchronously if required
@@ -191,6 +194,8 @@ export class MarketOperationUtils {
 
         const [
             [
+                blockNumber,
+                gasBefore,
                 tokenDecimals,
                 orderFillableTakerAmounts,
                 outputAmountPerEth,
@@ -198,9 +203,14 @@ export class MarketOperationUtils {
                 dexQuotes,
                 rawTwoHopQuotes,
                 isTxOriginContract,
+                gasAfter,
             ],
         ] = await Promise.all([samplerPromise]);
 
+        // Log the gas metrics
+        _opts.samplerMetrics?.logGasDetails({ gasBefore, gasAfter });
+        _opts.samplerMetrics?.logBlockNumber(blockNumber);
+
         // Filter out any invalid two hop quotes where we couldn't find a route
         const twoHopQuotes = rawTwoHopQuotes.filter(
             q => q && q.fillData && q.fillData.firstHopSource && q.fillData.secondHopSource,

packages/asset-swapper/src/utils/market_operation_utils/sampler.ts

@@ -130,6 +130,37 @@ export class DexOrderSampler extends SamplerOperations {
         BatchedOperationResult<T8>
     ]>;
 
+    // prettier-ignore
+    public async executeAsync<
+        T1, T2, T3, T4, T5, T6, T7, T8, T9
+    >(...ops: [T1, T2, T3, T4, T5, T6, T7, T8, T9]): Promise<[
+        BatchedOperationResult<T1>,
+        BatchedOperationResult<T2>,
+        BatchedOperationResult<T3>,
+        BatchedOperationResult<T4>,
+        BatchedOperationResult<T5>,
+        BatchedOperationResult<T6>,
+        BatchedOperationResult<T7>,
+        BatchedOperationResult<T8>,
+        BatchedOperationResult<T9>
+    ]>;
+
+    // prettier-ignore
+    public async executeAsync<
+        T1, T2, T3, T4, T5, T6, T7, T8, T9, T10
+    >(...ops: [T1, T2, T3, T4, T5, T6, T7, T8, T9, T10]): Promise<[
+        BatchedOperationResult<T1>,
+        BatchedOperationResult<T2>,
+        BatchedOperationResult<T3>,
+        BatchedOperationResult<T4>,
+        BatchedOperationResult<T5>,
+        BatchedOperationResult<T6>,
+        BatchedOperationResult<T7>,
+        BatchedOperationResult<T8>,
+        BatchedOperationResult<T9>,
+        BatchedOperationResult<T10>,
+    ]>;
+
     /**
      * Run a series of operations from `DexOrderSampler.ops` in a single transaction.
      */

packages/asset-swapper/src/utils/market_operation_utils/sampler_operations.ts

@@ -158,6 +158,30 @@ export class SamplerOperations {
         };
     }
 
+    public getGasLeft(): BatchedOperation<BigNumber> {
+        return {
+            encodeCall: () => this._samplerContract.getGasLeft().getABIEncodedTransactionData(),
+            handleCallResults: (callResults: string) =>
+                this._samplerContract.getABIDecodedReturnData<BigNumber>('getGasLeft', callResults),
+            handleRevert: () => {
+                /* should never happen */
+                throw new Error('Invalid result for getGasLeft');
+            },
+        };
+    }
+
+    public getBlockNumber(): BatchedOperation<BigNumber> {
+        return {
+            encodeCall: () => this._samplerContract.getBlockNumber().getABIEncodedTransactionData(),
+            handleCallResults: (callResults: string) =>
+                this._samplerContract.getABIDecodedReturnData<BigNumber>('getBlockNumber', callResults),
+            handleRevert: () => {
+                /* should never happen */
+                throw new Error('Invalid result for getBlockNumber');
+            },
+        };
+    }
+
     public getLimitOrderFillableTakerAmounts(
         orders: SignedNativeOrder[],
         exchangeAddress: string,

packages/asset-swapper/src/utils/market_operation_utils/types.ts

@@ -469,6 +469,28 @@ export interface GetMarketOrdersOpts {
      * Gas price to use for quote
      */
     gasPrice: BigNumber;
+
+    /**
+     * Sampler metrics for recording data on the sampler service and operations
+     */
+    samplerMetrics?: SamplerMetrics;
+}
+
+export interface SamplerMetrics {
+    /**
+     * Logs the gas information performed during a sampler call.
+     *
+     * @param data.gasBefore The gas remaining measured before any operations have been performed
+     * @param data.gasAfter The gas remaining measured after all operations have been performed
+     */
+    logGasDetails(data: { gasBefore: BigNumber; gasAfter: BigNumber }): void;
+
+    /**
+     * Logs the block number
+     *
+     * @param blockNumber block number of the sampler call
+     */
+    logBlockNumber(blockNumber: BigNumber): void;
 }
 
 /**

packages/asset-swapper/test/market_operation_utils_test.ts

@@ -23,6 +23,7 @@ import {
     POSITIVE_INF,
     SELL_SOURCE_FILTER_BY_CHAIN_ID,
     SOURCE_FLAGS,
+    ZERO_AMOUNT,
 } from '../src/utils/market_operation_utils/constants';
 import { createFills } from '../src/utils/market_operation_utils/fills';
 import { PoolsCache } from '../src/utils/market_operation_utils/pools_cache';
@@ -427,6 +428,8 @@ describe('MarketOperationUtils tests', () => {
         getTwoHopSellQuotes: (..._params: any[]) => [],
         getTwoHopBuyQuotes: (..._params: any[]) => [],
         isAddressContract: (..._params: any[]) => false,
+        getGasLeft: () => ZERO_AMOUNT,
+        getBlockNumber: () => ZERO_AMOUNT,
     };
 
     const MOCK_SAMPLER = ({