add gas and proof time benchmark calculation to VAnchor

metrics/gas-metrics.json

@@ -0,0 +1 @@
+{"gasValues":[661286,661286,686895,661248,686847,1130005,699731,661250,724066,678023],"meanGas":725063.7,"medianGas":682435,"maxGas":1130005,"minGas":661248}

metrics/proof-time-metrics.json

@@ -0,0 +1 @@
+{"proofTimeBenchmark":[0.40818073800206184,0.32580487800017,0.3070519740022719,0.29866049300134184,0.31581392799690367,0.3105338900014758,0.3413618200011551,0.31213331399857996,0.3210563869997859,0.31590337700024246,0.3266429139971733,1.4795384709984065,0.4170037260018289,0.32156791399791834,0.32067060899734495,0.33638264499977233,0.3212308249995112,0.31559075000137093,0.3192889959998429,0.3091612539999187,0.3159814720004797,0.3263165629990399,0.31113440499827266,0.31878438099846246,0.32332615699991585,0.33013279699906706],"meanTime":0.37112517992278116,"medianTime":0.3208634979985654,"maxTime":1.4795384709984065,"minTime":0.29866049300134184}

packages/anchors/src/VAnchor.ts

@@ -1,6 +1,7 @@
 import { BigNumber, BigNumberish, ethers } from 'ethers';
+import { performance } from 'perf_hooks';
 import { VAnchor as VAnchorContract, VAnchor__factory, VAnchorEncodeInputs__factory } from '@webb-tools/contracts';
-import { p256, toHex, RootInfo, Keypair, FIELD_SIZE, getExtDataHash, toFixedHex, Utxo, getChainIdType } from '@webb-tools/utils';
+import { p256, toHex, RootInfo, Keypair, FIELD_SIZE, getExtDataHash, toFixedHex, Utxo, getChainIdType, median, mean, max, min } from '@webb-tools/utils';
 import { IAnchorDeposit, IAnchor, IExtData, IMerkleProofData, IUTXOInput, IVariableAnchorPublicInputs, IWitnessInput } from '@webb-tools/interfaces';
 import { MerkleTree } from '@webb-tools/merkle-tree';
 
@@ -14,6 +15,8 @@ function checkNativeAddress(tokenAddress: string): boolean {
   return false;
 }
 
+export var gasBenchmark = [];
+export var proofTimeBenchmark = [];
 // This convenience wrapper class is used in tests -
 // It represents a deployed contract throughout its life (e.g. maintains merkle tree state)
 // Functionality relevant to anchors in general (proving, verifying) is implemented in static methods
@@ -479,10 +482,15 @@ export class VAnchor implements IAnchor {
   }
 
   public async proveAndVerify(wtns: any, small: boolean) {
+    let start = performance.now();
     let res = await snarkjs.groth16.prove(small
       ? this.smallCircuitZkeyPath
       : this.largeCircuitZkeyPath, wtns
     );
+    let proof_time = (performance.now() - start)/1000;
+
+    proofTimeBenchmark.push(proof_time)
+    // console.log("Proof gen took: ", proof_time, "s");
     let proof = res.proof;
     let publicSignals = res.publicSignals;
 
@@ -495,6 +503,35 @@ export class VAnchor implements IAnchor {
     return proofEncoded;
   }
 
+  public async getGasBenchmark() {
+    const gasValues = gasBenchmark.map(Number)
+    const meanGas = mean(gasValues);
+    const medianGas = median(gasValues);
+    const maxGas = max(gasValues);
+    const minGas = min(gasValues);
+    return {
+        gasValues,
+        meanGas,
+        medianGas,
+        maxGas,
+        minGas,
+    };
+    // return gasBenchmark;
+  }
+  public async getProofTimeBenchmark() {
+    const meanTime = mean(proofTimeBenchmark);
+    const medianTime = median(proofTimeBenchmark);
+    const maxTime = max(proofTimeBenchmark);
+    const minTime = min(proofTimeBenchmark);
+    return {
+        proofTimeBenchmark,
+        meanTime,
+        medianTime,
+        maxTime,
+        minTime,
+      }
+  }
+
   public async setupTransaction(
     inputs: Utxo[], 
     outputs: Utxo[], 
@@ -602,6 +639,9 @@ export class VAnchor implements IAnchor {
     );
     const receipt = await tx.wait();
     //console.log(`updated root (transact, contract) is ${toFixedHex(await this.contract.getLastRoot())}`);
+    // console.log("gas used: ", receipt.gasUsed.toString());
+    gasBenchmark.push(receipt.gasUsed.toString());
+
     return receipt;
   }
 

packages/utils/src/utils.ts

@@ -18,6 +18,16 @@ export const FIELD_SIZE = BigNumber.from(
   '21888242871839275222246405745257275088548364400416034343698204186575808495617',
 )
 
+export const median = (arr: number[]): number => {
+  if (!arr.length) return undefined;
+  const s = [...arr].sort((a, b) => a - b);
+  const mid = Math.floor(s.length / 2);
+  return s.length % 2 === 0 ? ((s[mid - 1] + s[mid]) / 2) : s[mid];
+};
+export const mean = arr => arr.reduce( ( p, c ) => p + c, 0 )  / arr.length;
+export const max = arr => arr.reduce((a,b)=>a>b?a:b);
+export const min = arr => arr.reduce((a,b)=> a<=b?a:b);
+
 /** Generate random number of specified byte length */
 export const randomBN = (nbytes = 31) => BigNumber.from(crypto.randomBytes(nbytes))
 

test/vanchor/vanchor.test.ts

@@ -29,6 +29,7 @@ import { MerkleTree } from '../../packages/merkle-tree/src';
 import { Utxo, poseidonHash, poseidonHash2 } from '../../packages/utils/src';
 import { VAnchor } from '../../packages/anchors/src';
 import { Verifier } from "../../packages/vbridge"
+import { writeFileSync } from "fs";
 
 const { NATIVE_AMOUNT } = process.env
 const BN = require('bn.js');
@@ -1099,6 +1100,15 @@ describe('VAnchor for 2 max edges', () => {
         wrappedToken.setFee(wrapFee, (await wrappedToken.proposalNonce()).add(1))
       );
     });
+    it('should print/save benchmarks', async () => {
+      // Alice deposits into tornado pool
+      const gasBenchmark = await anchor.getGasBenchmark()
+      const proofTimeBenchmark = await anchor.getProofTimeBenchmark()
+      console.log("Gas benchmark:\n", gasBenchmark);
+      console.log("Proof time benchmark:\n", proofTimeBenchmark);
+      writeFileSync("./metrics/gas-metrics.json", JSON.stringify(gasBenchmark));
+      writeFileSync("./metrics/proof-time-metrics.json", JSON.stringify(proofTimeBenchmark));
+    })
   }) 
 });