add: dict add lazy eviction

Makefile

@@ -18,6 +18,9 @@ heap:
 build-docker:
 	docker build -t rotom .
 
+bench:
+	go test -bench . -benchmem
+
 clean:
 	rm -f *.aof
 	rm -f coverage.html

dict/bench_test.go

@@ -107,14 +107,14 @@ func BenchmarkRemove(b *testing.B) {
 
 func BenchmarkMigrate(b *testing.B) {
 	b.Run("stdmap", func(b *testing.B) {
-		m := getStdmap(100000)
+		m := getStdmap(10000)
 		b.ResetTimer()
 		for i := 0; i < b.N; i++ {
 			maps.Clone(m)
 		}
 	})
 	b.Run("dict", func(b *testing.B) {
-		m := getDict(100000)
+		m := getDict(10000)
 		b.ResetTimer()
 		for i := 0; i < b.N; i++ {
 			m.Migrate()

dict/benchmark/main.go

@@ -31,7 +31,7 @@ func main() {
 	c := ""
 	entries := 0
 	flag.StringVar(&c, "cache", "dict", "map to bench.")
-	flag.IntVar(&entries, "entries", 2000*10000, "number of entries to test.")
+	flag.IntVar(&entries, "entries", 1000*10000, "number of entries to test.")
 	flag.Parse()
 
 	fmt.Println(c)
@@ -51,7 +51,7 @@ func main() {
 			val []byte
 			ts  int64
 		}
-		m := make(map[string]Item)
+		m := make(map[string]Item, entries)
 		for i := 0; i < entries; i++ {
 			k, v := genKV(i)
 			m[string(k)] = Item{val: v, ts: 0}
@@ -62,7 +62,7 @@ func main() {
 			val []byte
 			ts  int64
 		}
-		m := swiss.New[string, Item](8)
+		m := swiss.New[string, Item](entries)
 		for i := 0; i < entries; i++ {
 			k, v := genKV(i)
 			m.Put(string(k), Item{val: v, ts: 0})

dict/dict.go

@@ -49,11 +49,15 @@ func (dict *Dict) getShard(key string) *shard {
 func (dict *Dict) Get(key string) ([]byte, int64, bool) {
 	shard := dict.getShard(key)
 	idx, ok := shard.index.Get(key)
-	if ok && !idx.expired() {
-		_, val := shard.findEntry(idx)
-		return val, idx.lo, ok
+	if !ok {
+		return nil, 0, false
 	}
-	return nil, 0, false
+	if idx.expired() {
+		shard.removeEntry(key, idx)
+		return nil, 0, false
+	}
+	_, val := shard.findEntry(idx)
+	return val, idx.lo, ok
 }
 
 func (dict *Dict) SetTx(key string, val []byte, expiration int64) bool {
@@ -85,29 +89,32 @@ func (dict *Dict) SetEx(kstr string, value []byte, duration time.Duration) bool
 func (dict *Dict) Remove(key string) bool {
 	shard := dict.getShard(key)
 	idx, ok := shard.index.Get(key)
-	if ok {
-		shard.removeEntry(key, idx)
-		return !idx.expired()
+	if !ok {
+		return false
 	}
-	return false
+	shard.removeEntry(key, idx)
+	return !idx.expired()
 }
 
 func (dict *Dict) SetTTL(key string, expiration int64) bool {
 	shard := dict.getShard(key)
 	idx, ok := shard.index.Get(key)
-	if ok && !idx.expired() {
-		shard.index.Put(key, idx.setTTL(expiration))
-		return true
+	if !ok {
+		return false
+	}
+	if idx.expired() {
+		shard.removeEntry(key, idx)
+		return false
 	}
-	return false
+	shard.index.Put(key, idx.setTTL(expiration))
+	return true
 }
 
 type Walker func(key string, value []byte, ttl int64) (next bool)
 
 func (dict *Dict) Scan(callback Walker) {
 	for _, shard := range dict.shards {
-		next := shard.scan(callback)
-		if !next {
+		if !shard.scan(callback) {
 			return
 		}
 	}
@@ -121,8 +128,7 @@ func (dict *Dict) Migrate() {
 
 func (dict *Dict) EvictExpired() {
 	id := rand.IntN(len(dict.shards))
-	shard := dict.shards[id]
-	shard.evictExpired()
+	dict.shards[id].evictExpired()
 }
 
 // Stats represents the runtime statistics of Dict.

dict/dict_test.go

@@ -5,6 +5,6 @@ import (
 )
 
 func genKV(i int) (string, []byte) {
-	k := fmt.Sprintf("%08x", i)
+	k := fmt.Sprintf("%09x", i)
 	return k, []byte(k)
 }

dict/utils.go

@@ -43,9 +43,10 @@ type Options struct {
 }
 
 var DefaultOptions = Options{
-	ShardCount: 1024,
-	IndexSize:  1024,
-	BufferSize: 64 * KB,
+	ShardCount:   1024,
+	IndexSize:    1024,
+	BufferSize:   64 * KB,
+	MigrateRatio: 0.4,
 }
 
 func validateOptions(options Options) error {