add shard map for arc

arc_shard.go

@@ -0,0 +1,108 @@
+package gcache
+
+import (
+	"time"
+	_ "unsafe"
+)
+
+type ARCShard struct {
+	shard []*ARC
+	baseCache
+}
+
+//var _ ARCShard = *Cache()
+
+var _ Cache = (*ARCShard)(nil)
+
+func newARCShard(cb *CacheBuilder) *ARCShard {
+	c := &ARCShard{}
+	buildCache(&c.baseCache, cb)
+	c.init(cb)
+	//c.loadGroup.cache = c
+
+	return c
+}
+
+func (c *ARCShard) init(cb *CacheBuilder) {
+	c.shard = make([]*ARC, cb.shardCount)
+	for i := 0; i < c.shardCount; i++ {
+		c.shard[i] = newARC(cb)
+	}
+}
+
+// GetShard returns shard under given key
+func (c *ARCShard) getShard(key interface{}) *ARC {
+	hash := efaceHash(key, 1)
+	return c.shard[uint(hash)%uint(c.shardCount)]
+}
+
+func (c *ARCShard) Set(key, value interface{}) error {
+	arc := c.getShard(key)
+	_, err := arc.set(key, value)
+	return err
+}
+
+func (c *ARCShard) SetWithExpire(key, value interface{}, expiration time.Duration) error {
+	arc := c.getShard(key)
+	return arc.SetWithExpire(key, value, expiration)
+}
+
+func (c *ARCShard) Get(key interface{}) (interface{}, error) {
+	arc := c.getShard(key)
+	v, err := arc.Get(key)
+	return v, err
+}
+
+func (c *ARCShard) GetIFPresent(key interface{}) (interface{}, error) {
+	arc := c.getShard(key)
+	return arc.GetIFPresent(key)
+}
+
+func (c *ARCShard) GetALL(checkExpired bool) map[interface{}]interface{} {
+	//todo
+	//return arc.GetALL(checkExpired)
+	return map[interface{}]interface{}{}
+}
+
+func (c *ARCShard) get(key interface{}, onLoad bool) (interface{}, error) {
+	arc := c.getShard(key)
+	return arc.get(key, onLoad)
+}
+
+func (c *ARCShard) Remove(key interface{}) bool {
+	arc := c.getShard(key)
+	return arc.Remove(key)
+}
+
+func (c *ARCShard) Purge() {
+	for _, arc := range c.shard {
+		arc.Purge()
+	}
+	return
+}
+
+func (c *ARCShard) Keys(checkExpired bool) []interface{} {
+	allKeys := make([]interface{}, 0)
+	for _, arc := range c.shard {
+		keys := arc.Keys(checkExpired)
+		allKeys = append(allKeys, keys)
+	}
+	return allKeys
+}
+
+func (c *ARCShard) Len(checkExpired bool) int {
+	len := 0
+	for _, arc := range c.shard {
+		l := arc.Len(checkExpired)
+		len += l
+	}
+	return len
+}
+
+func (c *ARCShard) Has(key interface{}) bool {
+	arc := c.getShard(key)
+	return arc.Has(key)
+}
+
+//go:linkname efaceHash runtime.efaceHash
+func efaceHash(i interface{}, seed uintptr) uintptr

arc_shard_test.go

@@ -0,0 +1,125 @@
+package gcache
+
+import (
+	"fmt"
+	"testing"
+	"time"
+)
+
+func TestARCShardGet(t *testing.T) {
+	size := 10
+	gc := buildTest(t, TYPE_ARC, size).ShardCount(3).Build()
+	//gc.Set("k1", "v1")
+
+	testSetCache(t, gc, size)
+	testGetCache(t, gc, size)
+}
+
+//func TestLoadingARCShardGet(t *testing.T) {
+//	size := 1000
+//	numbers := 1000
+//	testGetCache(t, buildTestLoadingCache(t, TYPE_ARC, size, loader), numbers)
+//}
+
+func TestARCShardLength(t *testing.T) {
+	shardCount := 3
+	gc := buildTestLoadingWithExpiration(t, TYPE_ARC, 2, time.Millisecond).ShardCount(shardCount).Build()
+	gc.Get("test1")
+	gc.Get("test2")
+	gc.Get("test3")
+	length := gc.Len(true)
+	expectedLength := 2
+	if length < shardCount || length > shardCount*expectedLength {
+		t.Errorf("Expected length is %v, not %v", expectedLength, length)
+	}
+	time.Sleep(time.Millisecond)
+	gc.Get("test4")
+	length = gc.Len(true)
+	expectedLength = 1
+	if length != expectedLength {
+		t.Errorf("Expected length is %v, not %v", expectedLength, length)
+	}
+}
+
+func TestARCShardEvictItem(t *testing.T) {
+	cacheSize := 10
+	numbers := cacheSize + 1
+	gc := buildTestLoadingCache(t, TYPE_ARC, cacheSize, loader)
+
+	for i := 0; i < numbers; i++ {
+		_, err := gc.Get(fmt.Sprintf("Key-%d", i))
+		if err != nil {
+			t.Errorf("Unexpected error: %v", err)
+		}
+	}
+}
+
+func TestARCShardPurgeCache(t *testing.T) {
+	cacheSize := 10
+	purgeCount := 0
+	gc := New(cacheSize).
+		ARC().
+		LoaderFunc(loader).
+		PurgeVisitorFunc(func(k, v interface{}) {
+			purgeCount++
+		}).
+		ShardCount(3).
+		Build()
+
+	for i := 0; i < cacheSize; i++ {
+		_, err := gc.Get(fmt.Sprintf("Key-%d", i))
+		if err != nil {
+			t.Errorf("Unexpected error: %v", err)
+		}
+	}
+
+	gc.Purge()
+
+	if purgeCount != cacheSize {
+		t.Errorf("failed to purge everything")
+	}
+}
+
+//
+//func TestARCShardGetIFPresent(t *testing.T) {
+//	testGetIFPresent(t, TYPE_ARC)
+//}
+//
+func TestARCShardHas(t *testing.T) {
+	gc := buildTestLoadingWithExpiration(t, TYPE_ARC, 2, 10*time.Millisecond).ShardCount(3).Build()
+
+	for i := 0; i < 10; i++ {
+		t.Run(fmt.Sprint(i), func(t *testing.T) {
+			gc.Get("test1")
+			gc.Get("test2")
+
+			if gc.Has("test0") {
+				t.Fatal("should not have test0")
+			}
+			if !gc.Has("test1") {
+				t.Fatal("should have test1")
+			}
+			if !gc.Has("test2") {
+				t.Fatal("should have test2")
+			}
+
+			time.Sleep(20 * time.Millisecond)
+
+			if gc.Has("test0") {
+				t.Fatal("should not have test0")
+			}
+			if gc.Has("test1") {
+				t.Fatal("should not have test1")
+			}
+			if gc.Has("test2") {
+				t.Fatal("should not have test2")
+			}
+		})
+	}
+}
+
+func TestKey(t *testing.T) {
+	key := "bbb"
+	h := efaceHash(key, 1)
+	t.Log(h)
+}

cache.go

@@ -51,6 +51,7 @@ type Cache interface {
 type baseCache struct {
 	clock            Clock
 	size             int
+	shardCount       int
 	loaderExpireFunc LoaderExpireFunc
 	evictedFunc      EvictedFunc
 	purgeVisitorFunc PurgeVisitorFunc
@@ -77,6 +78,7 @@ type CacheBuilder struct {
 	clock            Clock
 	tp               string
 	size             int
+	shardCount       int
 	loaderExpireFunc LoaderExpireFunc
 	evictedFunc      EvictedFunc
 	purgeVisitorFunc PurgeVisitorFunc
@@ -173,9 +175,18 @@ func (cb *CacheBuilder) Build() Cache {
 		panic("gcache: Cache size <= 0")
 	}
 
+	if cb.shardCount <= 0 {
+		panic("gcache: Shard Count <= 0")
+	}
+
 	return cb.build()
 }
 
+func (cb *CacheBuilder) ShardCount(cnt int) *CacheBuilder {
+	cb.shardCount = cnt
+	return cb
+}
+
 func (cb *CacheBuilder) build() Cache {
 	switch cb.tp {
 	case TYPE_SIMPLE:
@@ -185,6 +196,9 @@ func (cb *CacheBuilder) build() Cache {
 	case TYPE_LFU:
 		return newLFUCache(cb)
 	case TYPE_ARC:
+		if cb.shardCount > 0 {
+			return newARCShard(cb)
+		}
 		return newARC(cb)
 	default:
 		panic("gcache: Unknown type " + cb.tp)
@@ -194,6 +208,7 @@ func (cb *CacheBuilder) build() Cache {
 func buildCache(c *baseCache, cb *CacheBuilder) {
 	c.clock = cb.clock
 	c.size = cb.size
+	c.shardCount = cb.shardCount
 	c.loaderExpireFunc = cb.loaderExpireFunc
 	c.expiration = cb.expiration
 	c.addedFunc = cb.addedFunc

helpers_test.go

@@ -161,3 +161,17 @@ func buildTestLoadingCacheWithExpiration(t *testing.T, tp string, size int, ep t
 		EvictedFunc(getSimpleEvictedFunc(t)).
 		Build()
 }
+
+func buildTest(t *testing.T, tp string, size int) *CacheBuilder {
+	return New(size).
+		EvictType(tp).
+		EvictedFunc(getSimpleEvictedFunc(t))
+}
+
+func buildTestLoadingWithExpiration(t *testing.T, tp string, size int, ep time.Duration) *CacheBuilder {
+	return New(size).
+		EvictType(tp).
+		Expiration(ep).
+		LoaderFunc(loader).
+		EvictedFunc(getSimpleEvictedFunc(t))
+}