From 9f2efe21f5f09a7a44aecfe11a76bbd0ca091aab Mon Sep 17 00:00:00 2001
From: Vlad <vlad@celestia.org>
Date: Fri, 29 Sep 2023 15:43:16 +0800
Subject: [PATCH] add cache eviction benchmarks

---
 share/eds/store_test.go      | 58 +++++++++++++++++++++++++++++
 share/getters/getter_test.go | 71 ++++++++++++++++++++++++++++++++++++
 2 files changed, 129 insertions(+)

diff --git a/share/eds/store_test.go b/share/eds/store_test.go
index ce42a0e0b9..7052533555 100644
--- a/share/eds/store_test.go
+++ b/share/eds/store_test.go
@@ -18,11 +18,13 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"github.com/celestiaorg/celestia-app/pkg/da"
+	dsbadger "github.com/celestiaorg/go-ds-badger4"
 	"github.com/celestiaorg/rsmt2d"
 
 	"github.com/celestiaorg/celestia-node/share"
 	"github.com/celestiaorg/celestia-node/share/eds/cache"
 	"github.com/celestiaorg/celestia-node/share/eds/edstest"
+	"github.com/celestiaorg/celestia-node/share/ipld"
 )
 
 func TestEDSStore(t *testing.T) {
@@ -465,6 +467,62 @@ func BenchmarkStore(b *testing.B) {
 	})
 }
 
+// BenchmarkCacheEviction benchmarks the time it takes to load a block to the cache, when the
+// cache size is set to 1. This forces cache eviction on every read.
+// BenchmarkCacheEviction-10/128    	     384	   3533586 ns/op (~3ms)
+func BenchmarkCacheEviction(b *testing.B) {
+	const (
+		blocks = 4
+		size   = 128
+	)
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*30)
+	b.Cleanup(cancel)
+
+	dir := b.TempDir()
+	ds, err := dsbadger.NewDatastore(dir, &dsbadger.DefaultOptions)
+	require.NoError(b, err)
+
+	newStore := func(params *Parameters) *Store {
+		edsStore, err := NewStore(params, dir, ds)
+		require.NoError(b, err)
+		err = edsStore.Start(ctx)
+		require.NoError(b, err)
+		return edsStore
+	}
+	edsStore := newStore(DefaultParameters())
+
+	// generate EDSs and store them
+	cids := make([]cid.Cid, blocks)
+	for i := range cids {
+		eds := edstest.RandEDS(b, size)
+		dah, err := da.NewDataAvailabilityHeader(eds)
+		require.NoError(b, err)
+		err = edsStore.Put(ctx, dah.Hash(), eds)
+		require.NoError(b, err)
+
+		// store cids for read loop later
+		cids[i] = ipld.MustCidFromNamespacedSha256(dah.RowRoots[0])
+	}
+
+	// restart store to clear cache
+	require.NoError(b, edsStore.Stop(ctx))
+
+	// set BlockstoreCacheSize to 1 to force eviction on every read
+	params := DefaultParameters()
+	params.BlockstoreCacheSize = 1
+	bstore := newStore(params).Blockstore()
+
+	// start benchmark
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		h := cids[i%blocks]
+		// every read will trigger eviction
+		_, err := bstore.Get(ctx, h)
+		require.NoError(b, err)
+	}
+}
+
 func newStore(t *testing.T) (*Store, error) {
 	t.Helper()
 
diff --git a/share/getters/getter_test.go b/share/getters/getter_test.go
index bacb0a2c39..eda28fac75 100644
--- a/share/getters/getter_test.go
+++ b/share/getters/getter_test.go
@@ -3,6 +3,7 @@ package getters
 import (
 	"context"
 	"os"
+	"sync"
 	"testing"
 	"time"
 
@@ -12,7 +13,9 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
+	"github.com/celestiaorg/celestia-app/pkg/da"
 	"github.com/celestiaorg/celestia-app/pkg/wrapper"
+	dsbadger "github.com/celestiaorg/go-ds-badger4"
 	"github.com/celestiaorg/rsmt2d"
 
 	"github.com/celestiaorg/celestia-node/share"
@@ -217,6 +220,74 @@ func TestIPLDGetter(t *testing.T) {
 	})
 }
 
+// BenchmarkIPLDGetterOverBusyCache benchmarks the performance of the IPLDGetter when the
+// cache size of the underlying blockstore is less than the number of blocks being requested in
+// parallel. This is to ensure performance doesn't degrade when the cache is being frequently
+// evicted.
+// BenchmarkIPLDGetterOverBusyCache-10/128    	       1	12460428417 ns/op (~12s)
+func BenchmarkIPLDGetterOverBusyCache(b *testing.B) {
+	const (
+		blocks = 10
+		size   = 128
+	)
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*30)
+	b.Cleanup(cancel)
+
+	dir := b.TempDir()
+	ds, err := dsbadger.NewDatastore(dir, &dsbadger.DefaultOptions)
+	require.NoError(b, err)
+
+	newStore := func(params *eds.Parameters) *eds.Store {
+		edsStore, err := eds.NewStore(params, dir, ds)
+		require.NoError(b, err)
+		err = edsStore.Start(ctx)
+		require.NoError(b, err)
+		return edsStore
+	}
+	edsStore := newStore(eds.DefaultParameters())
+
+	// generate EDSs and store them
+	hashes := make([]da.DataAvailabilityHeader, blocks)
+	for i := range hashes {
+		eds := edstest.RandEDS(b, size)
+		dah, err := da.NewDataAvailabilityHeader(eds)
+		require.NoError(b, err)
+		err = edsStore.Put(ctx, dah.Hash(), eds)
+		require.NoError(b, err)
+
+		// store cids for read loop later
+		hashes[i] = dah
+	}
+
+	// restart store to clear cache
+	require.NoError(b, edsStore.Stop(ctx))
+
+	// set BlockstoreCacheSize to 1 to force eviction on every read
+	params := eds.DefaultParameters()
+	params.BlockstoreCacheSize = 1
+	edsStore2 := newStore(params)
+	bstore := edsStore2.Blockstore()
+	bserv := ipld.NewBlockservice(bstore, offline.Exchange(bstore))
+
+	// start client
+	getter := NewIPLDGetter(bserv)
+
+	// request blocks in parallel
+	b.ResetTimer()
+	g := sync.WaitGroup{}
+	g.Add(blocks)
+	for _, h := range hashes {
+		h := h
+		go func() {
+			defer g.Done()
+			_, err := getter.GetEDS(ctx, &h)
+			require.NoError(b, err)
+		}()
+	}
+	g.Wait()
+}
+
 func randomEDS(t *testing.T) (*rsmt2d.ExtendedDataSquare, *share.Root) {
 	eds := edstest.RandEDS(t, 4)
 	dah, err := share.NewRoot(eds)