cache

cache/cache.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/charlienet/go-mixed/bytesconv"
+	"github.com/charlienet/go-mixed/json"
 	"github.com/charlienet/go-mixed/locker"
 	"github.com/charlienet/go-mixed/logx"
 )
@@ -22,6 +23,7 @@ type Cache struct {
 	distributdCache  DistributdCache   // 分布式缓存
 	publishSubscribe PublishSubscribe  // 发布订阅
 	lock             locker.ChanLocker // 资源锁
+	stats            *Stats            // 缓存命中计数
 	qps              *qps              // 访问计数
 	logger           logx.Logger       // 日志记录
 }
@@ -148,3 +150,39 @@ func (c *Cache) getFromSource(ctx context.Context, key string, fn LoadFunc) erro
 		return c.getFromSource(ctx, key, fn)
 	}
 }
+
+func (c *Cache) marshal(value any) ([]byte, error) {
+	switch value := value.(type) {
+	case nil:
+		return nil, nil
+	case []byte:
+		return value, nil
+	case string:
+		return []byte(value), nil
+	}
+
+	b, err := json.Marshal(value)
+	return b, err
+}
+
+func (c *Cache) unmarshal(b []byte, value any) error {
+	if len(b) == 0 {
+		return nil
+	}
+
+	switch value := value.(type) {
+	case nil:
+		return nil
+	case *[]byte:
+		clone := make([]byte, len(b))
+		copy(clone, b)
+		*value = clone
+		return nil
+	case *string:
+		*value = string(b)
+		return nil
+	}
+
+	err := json.Unmarshal(b, value)
+	return err
+}

cache/local_cache.go

@@ -0,0 +1,7 @@
+package cache
+
+type LocalCache interface {
+	Set(key string, data []byte)
+	Get(key string) ([]byte, bool)
+	Del(key string)
+}

cache/stats.go

@@ -0,0 +1,20 @@
+package cache
+
+import "sync/atomic"
+
+type Stats struct {
+	Hits   uint64
+	Misses uint64
+}
+
+func (s *Stats) AddHits() {
+	atomic.AddUint64(&s.Hits, 1)
+}
+
+func (s *Stats) AddMisses() {
+	atomic.AddUint64(&s.Misses, 1)
+}
+
+func (c *Cache) Stats() *Stats {
+	return c.stats
+}

cache/tiny_lfu.go

@@ -0,0 +1,52 @@
+package cache
+
+import (
+	"time"
+
+	"github.com/charlienet/go-mixed/locker"
+	"github.com/vmihailenco/go-tinylfu"
+)
+
+type TinyLFU struct {
+	mu  locker.Locker
+	lfu *tinylfu.T
+	ttl time.Duration
+}
+
+func NewTinyLFU(size int, ttl time.Duration) *TinyLFU {
+	return &TinyLFU{
+		mu:  locker.NewLocker(),
+		lfu: tinylfu.New(size, 100000),
+		ttl: ttl,
+	}
+}
+
+func (c *TinyLFU) Set(key string, b []byte, expire time.Duration) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.lfu.Set(&tinylfu.Item{
+		Key:   key,
+		Value: b,
+		ExpireAt: time.Now().Add(c.ttl),
+	})
+}
+
+func (c *TinyLFU) Get(key string) ([]byte, bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	val, ok := c.lfu.Get(key)
+	if !ok {
+		return nil, false
+	}
+
+	return val.([]byte), true
+}
+
+func (c *TinyLFU) Del(key string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.lfu.Del(key)
+}

cache/tiny_lfu_test.go

@@ -0,0 +1,57 @@
+package cache_test
+
+import (
+	"context"
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/charlienet/go-mixed/cache"
+	"github.com/charlienet/go-mixed/rand"
+)
+
+func TestTinyGet(t *testing.T) {
+	strFor := func(i int) string {
+		return fmt.Sprintf("a string %d", i)
+	}
+	keyName := func(i int) string {
+		return fmt.Sprintf("key-%00000d", i)
+	}
+
+	mycache := cache.NewTinyLFU(1000, 1*time.Second)
+	size := 50000
+	// Put a bunch of stuff in the cache with a TTL of 1 second
+	for i := 0; i < size; i++ {
+		key := keyName(i)
+		mycache.Set(key, []byte(strFor(i)), time.Second*2)
+	}
+
+	// Read stuff for a bit longer than the TTL - that's when the corruption occurs
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+
+	done := ctx.Done()
+
+loop:
+	for {
+		select {
+		case <-done:
+			// this is expected
+			break loop
+		default:
+			i := rand.Intn(size)
+			key := keyName(i)
+
+			b, ok := mycache.Get(key)
+			if !ok {
+				continue loop
+			}
+
+			got := string(b)
+			expected := strFor(i)
+			if got != expected {
+				t.Fatalf("expected=%q got=%q key=%q", expected, got, key)
+			}
+		}
+	}
+}