Limit the number of buckets in verifiedTransactionCache to 3

data/transactions/verify/verifiedTxnCache.go

@@ -26,7 +26,6 @@ import (
 	"github.com/algorand/go-algorand/protocol"
 )
 
-const entriesPerBucket = 8179 // the default bucket size; a prime number could promote a lower hash collisions in case the hash function isn't perfect.
 const maxPinnedEntries = 500000
 
 // VerifiedTxnCacheError helps to identify the errors of a cache error and diffrenciate these from a general verification errors.
@@ -72,6 +71,8 @@ type VerifiedTransactionCache interface {
 
 // verifiedTransactionCache provides an implementation of the VerifiedTransactionCache interface
 type verifiedTransactionCache struct {
+	// Number of entries in each map (bucket).
+	entriesPerBucket int
 	// bucketsLock is the lock for syncornizing the access to the cache
 	bucketsLock deadlock.Mutex
 	// buckets is the circular cache buckets buffer
@@ -84,14 +85,14 @@ type verifiedTransactionCache struct {
 
 // MakeVerifiedTransactionCache creates an instance of verifiedTransactionCache and returns it.
 func MakeVerifiedTransactionCache(cacheSize int) VerifiedTransactionCache {
-	bucketsCount := 1 + (cacheSize / entriesPerBucket)
 	impl := &verifiedTransactionCache{
-		buckets: make([]map[transactions.Txid]*GroupContext, bucketsCount),
-		pinned:  make(map[transactions.Txid]*GroupContext, cacheSize),
-		base:    0,
+		entriesPerBucket: (cacheSize + 1) / 2,
+		buckets:          make([]map[transactions.Txid]*GroupContext, 3),
+		pinned:           make(map[transactions.Txid]*GroupContext, cacheSize),
+		base:             0,
 	}
-	for i := 0; i < bucketsCount; i++ {
-		impl.buckets[i] = make(map[transactions.Txid]*GroupContext, entriesPerBucket)
+	for i := 0; i < len(impl.buckets); i++ {
+		impl.buckets[i] = make(map[transactions.Txid]*GroupContext, impl.entriesPerBucket)
 	}
 	return impl
 }
@@ -245,10 +246,10 @@ func (v *verifiedTransactionCache) Pin(txgroup []transactions.SignedTxn) (err er
 
 // add is the internal implementation of Add/AddPayset which adds a transaction group to the buffer.
 func (v *verifiedTransactionCache) add(txgroup []transactions.SignedTxn, groupCtx *GroupContext) {
-	if len(v.buckets[v.base])+len(txgroup) > entriesPerBucket {
+	if len(v.buckets[v.base])+len(txgroup) > v.entriesPerBucket {
 		// move to the next bucket while deleting the content of the next bucket.
 		v.base = (v.base + 1) % len(v.buckets)
-		v.buckets[v.base] = make(map[transactions.Txid]*GroupContext, entriesPerBucket)
+		v.buckets[v.base] = make(map[transactions.Txid]*GroupContext, v.entriesPerBucket)
 	}
 	currentBucket := v.buckets[v.base]
 	for _, txn := range txgroup {

data/transactions/verify/verifiedTxnCache_test.go

@@ -49,7 +49,8 @@ func TestBucketCycling(t *testing.T) {
 	partitiontest.PartitionTest(t)
 
 	bucketCount := 3
-	icache := MakeVerifiedTransactionCache(entriesPerBucket * bucketCount)
+	entriesPerBucket := 100
+	icache := MakeVerifiedTransactionCache(entriesPerBucket * (bucketCount - 1))
 	impl := icache.(*verifiedTransactionCache)
 	_, signedTxn, _, _ := generateTestObjects(entriesPerBucket*bucketCount*2, bucketCount, 0)
 
@@ -58,7 +59,7 @@ func TestBucketCycling(t *testing.T) {
 	require.NoError(t, err)
 
 	// fill up the cache with entries.
-	for i := 0; i < entriesPerBucket*(bucketCount+1); i++ {
+	for i := 0; i < entriesPerBucket*bucketCount; i++ {
 		impl.Add([]transactions.SignedTxn{signedTxn[i]}, groupCtx)
 		// test to see that the base is sliding when bucket get filled up.
 		require.Equal(t, i/entriesPerBucket, impl.base)
@@ -136,13 +137,13 @@ func BenchmarkGetUnverifiedTranscationGroups50(b *testing.B) {
 func TestUpdatePinned(t *testing.T) {
 	partitiontest.PartitionTest(t)
 
-	size := entriesPerBucket
+	size := 100
 	icache := MakeVerifiedTransactionCache(size * 10)
 	impl := icache.(*verifiedTransactionCache)
 	_, signedTxn, secrets, addrs := generateTestObjects(size*2, 10, 0)
 	txnGroups := generateTransactionGroups(signedTxn, secrets, addrs)
 
-	// insert half of the entries.
+	// insert some entries.
 	for i := 0; i < len(txnGroups); i++ {
 		groupCtx, _ := PrepareGroupContext(txnGroups[i], blockHeader)
 		impl.Add(txnGroups[i], groupCtx)
@@ -165,7 +166,7 @@ func TestUpdatePinned(t *testing.T) {
 func TestPinningTransactions(t *testing.T) {
 	partitiontest.PartitionTest(t)
 
-	size := entriesPerBucket
+	size := 100
 	icache := MakeVerifiedTransactionCache(size)
 	impl := icache.(*verifiedTransactionCache)
 	_, signedTxn, secrets, addrs := generateTestObjects(size*2, 10, 0)
@@ -182,5 +183,4 @@ func TestPinningTransactions(t *testing.T) {
 
 	// try to pin an entry that was not added.
 	require.Error(t, impl.Pin(txnGroups[len(txnGroups)-1]))
-
 }