chore: benchmark pub randomness commit (#190)

For numPubRand ≤ 1000, the growth appears roughly linear, with execution
time increasing by similar factors as numPubRand

---
Benchmark ran on M3 Pro.
numPubRand | Iterations (b.N) | Time per Iteration (ns/op) | Approx.
Time (ms) | Approx. Time (s)
-- | -- | -- | -- | --
10 | 38 | 29,210,366 | ~29.2 ms | ~0.03 s
50 | 16 | 68,297,312 | ~68.3 ms | ~0.07 s
100 | 9 | 120,456,028 | ~120.5 ms | ~0.12 s
200 | 5 | 224,715,767 | ~224.7 ms | ~0.22 s
500 | 2 | 536,105,584 | ~536.1 ms | ~0.54 s
1,000 | 1 | 1,056,664,416 | ~1.1 s | ~1.1 s
5,000 | 1 | 5,159,288,750 | ~5.2 s | ~5.2 s
10,000 | 1 | 10,353,431,958 | ~10.4 s | ~10.4 s
25,000 | 1 | 26,828,946,167 | ~26.8 s | ~26.8 s
50,000 | 1 | 53,123,792,875 | ~53.1 s | ~53.1 s
75,000 | 1 | 156,188,836,166 | ~156.2 s | ~2.6 m
100,000 | 1 | 211,468,613,458 | ~211.5 s | ~3.5 m

---

![image](https://github.com/user-attachments/assets/dad4f1cc-b197-46ae-80e9-37902db8b6c4)

---
References
[issue](#68)

CHANGELOG.md

@@ -43,6 +43,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 * [#179](https://github.com/babylonlabs-io/finality-provider/pull/179) Change `btc_pk` text to `eots_pk` in CLI
 * [#182](https://github.com/babylonlabs-io/finality-provider/pull/182) Remove fp manager
 * [#184](https://github.com/babylonlabs-io/finality-provider/pull/184) eots manager sign record store
+* [#190](https://github.com/babylonlabs-io/finality-provider/pull/190) Benchmark pub rand
 
 ### Bug Fixes
 

finality-provider/service/fp_instance_test.go

@@ -1,15 +1,15 @@
 package service_test
 
 import (
-	"math/rand"
-	"os"
-	"path/filepath"
-	"testing"
-
+	"fmt"
 	bbntypes "github.com/babylonlabs-io/babylon/types"
 	"github.com/golang/mock/gomock"
 	"github.com/stretchr/testify/require"
 	"go.uber.org/zap"
+	"math/rand"
+	"os"
+	"path/filepath"
+	"testing"
 
 	"github.com/babylonlabs-io/babylon/testutil/datagen"
 	ftypes "github.com/babylonlabs-io/babylon/x/finality/types"
@@ -36,7 +36,7 @@ func FuzzCommitPubRandList(f *testing.F) {
 		mockClientController := testutil.PrepareMockedClientController(t, r, randomStartingHeight, currentHeight, 0)
 		mockClientController.EXPECT().QueryFinalityProviderVotingPower(gomock.Any(), gomock.Any()).
 			Return(uint64(0), nil).AnyTimes()
-		_, fpIns, cleanUp := startFinalityProviderAppWithRegisteredFp(t, r, mockClientController, true, randomStartingHeight)
+		_, fpIns, cleanUp := startFinalityProviderAppWithRegisteredFp(t, r, mockClientController, true, randomStartingHeight, testutil.TestPubRandNum)
 		defer cleanUp()
 
 		expectedTxHash := testutil.GenRandomHexStr(r, 32)
@@ -60,7 +60,7 @@ func FuzzSubmitFinalitySigs(f *testing.F) {
 		startingBlock := &types.BlockInfo{Height: randomStartingHeight, Hash: testutil.GenRandomByteArray(r, 32)}
 		mockClientController := testutil.PrepareMockedClientController(t, r, randomStartingHeight, currentHeight, 0)
 		mockClientController.EXPECT().QueryLatestFinalizedBlocks(gomock.Any()).Return(nil, nil).AnyTimes()
-		_, fpIns, cleanUp := startFinalityProviderAppWithRegisteredFp(t, r, mockClientController, true, randomStartingHeight)
+		_, fpIns, cleanUp := startFinalityProviderAppWithRegisteredFp(t, r, mockClientController, true, randomStartingHeight, testutil.TestPubRandNum)
 		defer cleanUp()
 
 		// commit pub rand
@@ -124,7 +124,7 @@ func FuzzDetermineStartHeight(f *testing.F) {
 		}}
 		mockClientController.EXPECT().QueryLatestFinalizedBlocks(uint64(1)).Return(finalizedBlocks, nil).AnyTimes()
 
-		_, fpIns, cleanUp := startFinalityProviderAppWithRegisteredFp(t, r, mockClientController, false, randomStartingHeight)
+		_, fpIns, cleanUp := startFinalityProviderAppWithRegisteredFp(t, r, mockClientController, false, randomStartingHeight, testutil.TestPubRandNum)
 		defer cleanUp()
 		fpIns.MustUpdateStateAfterFinalitySigSubmission(lastVotedHeight)
 
@@ -139,7 +139,14 @@ func FuzzDetermineStartHeight(f *testing.F) {
 	})
 }
 
-func startFinalityProviderAppWithRegisteredFp(t *testing.T, r *rand.Rand, cc clientcontroller.ClientController, isStaticStartHeight bool, startingHeight uint64) (*service.FinalityProviderApp, *service.FinalityProviderInstance, func()) {
+func startFinalityProviderAppWithRegisteredFp(
+	t *testing.T,
+	r *rand.Rand,
+	cc clientcontroller.ClientController,
+	isStaticStartHeight bool,
+	startingHeight uint64,
+	numPubRand uint32,
+) (*service.FinalityProviderApp, *service.FinalityProviderInstance, func()) {
 	logger := zap.NewNop()
 	// create an EOTS manager
 	eotsHomeDir := filepath.Join(t.TempDir(), "eots-home")
@@ -152,7 +159,7 @@ func startFinalityProviderAppWithRegisteredFp(t *testing.T, r *rand.Rand, cc cli
 	// create finality-provider app with randomized config
 	fpHomeDir := filepath.Join(t.TempDir(), "fp-home")
 	fpCfg := config.DefaultConfigWithHome(fpHomeDir)
-	fpCfg.NumPubRand = testutil.TestPubRandNum
+	fpCfg.NumPubRand = numPubRand
 	fpCfg.PollerConfig.AutoChainScanningMode = !isStaticStartHeight
 	fpCfg.PollerConfig.StaticChainScanningStartHeight = startingHeight
 	db, err := fpCfg.DatabaseConfig.GetDBBackend()
@@ -194,3 +201,54 @@ func startFinalityProviderAppWithRegisteredFp(t *testing.T, r *rand.Rand, cc cli
 
 	return app, fpIns, cleanUp
 }
+
+func setupBenchmarkEnvironment(t *testing.T, seed int64, numPubRand uint32) (*types.BlockInfo, *service.FinalityProviderInstance, func()) {
+	r := rand.New(rand.NewSource(seed))
+
+	randomStartingHeight := uint64(r.Int63n(100) + 1)
+	currentHeight := randomStartingHeight + uint64(r.Int63n(10)+2)
+	startingBlock := &types.BlockInfo{
+		Height: randomStartingHeight,
+		Hash:   testutil.GenRandomByteArray(r, 32),
+	}
+
+	// Mock client controller setup
+	mockClientController := testutil.PrepareMockedClientController(t, r, randomStartingHeight, currentHeight, 0)
+	mockClientController.EXPECT().QueryFinalityProviderVotingPower(gomock.Any(), gomock.Any()).
+		Return(uint64(0), nil).AnyTimes()
+
+	// Set up finality provider app
+	_, fpIns, cleanUp := startFinalityProviderAppWithRegisteredFp(t, r, mockClientController, true, randomStartingHeight, numPubRand)
+
+	// Configure additional mocks
+	expectedTxHash := testutil.GenRandomHexStr(r, 32)
+	mockClientController.EXPECT().
+		CommitPubRandList(fpIns.GetBtcPk(), startingBlock.Height+1, gomock.Any(), gomock.Any(), gomock.Any()).
+		Return(&types.TxResponse{TxHash: expectedTxHash}, nil).AnyTimes()
+	mockClientController.EXPECT().QueryLastCommittedPublicRand(gomock.Any(), uint64(1)).Return(nil, nil).AnyTimes()
+
+	return startingBlock, fpIns, cleanUp
+}
+func BenchmarkCommitPubRand(b *testing.B) {
+	for _, numPubRand := range []uint32{10, 50, 100, 200, 500, 1000, 5000, 10000, 25000, 50000, 75000, 100000} {
+		b.Run(fmt.Sprintf("numPubRand=%d", numPubRand), func(b *testing.B) {
+			t := &testing.T{}
+			startingBlock, fpIns, cleanUp := setupBenchmarkEnvironment(t, 42, numPubRand)
+			defer cleanUp()
+
+			// exclude setup time
+			b.ResetTimer()
+
+			for i := 0; i < b.N; i++ {
+				res, err := fpIns.CommitPubRand(startingBlock.Height)
+				if err != nil {
+					b.Fatalf("unexpected error: %v", err)
+				}
+
+				if res == nil {
+					b.Fatalf("unexpected result")
+				}
+			}
+		})
+	}
+}