feat: local cache

pkg/localcache/cache.go

@@ -0,0 +1,85 @@
+package localcache
+
+import (
+	"context"
+	"github.com/openimsdk/localcache/link"
+	"github.com/openimsdk/localcache/local"
+	lopt "github.com/openimsdk/localcache/option"
+)
+
+type Cache[V any] interface {
+	Get(ctx context.Context, key string, fetch func(ctx context.Context) (V, error), opts ...*lopt.Option) (V, error)
+	Del(ctx context.Context, key ...string)
+}
+
+func New[V any](opts ...Option) Cache[V] {
+	opt := defaultOption()
+	for _, o := range opts {
+		o(opt)
+	}
+	c := cache[V]{opt: opt}
+	if opt.localSlotNum > 0 && opt.localSlotSize > 0 {
+		c.local = local.NewCache[V](opt.localSlotNum, opt.localSlotSize, opt.localSuccessTTL, opt.localFailedTTL, opt.target, c.onEvict)
+		go func() {
+			c.opt.delCh(c.del)
+		}()
+		if opt.linkSlotNum > 0 {
+			c.link = link.New(opt.linkSlotNum)
+		}
+	}
+	return &c
+}
+
+type cache[V any] struct {
+	opt   *option
+	link  link.Link
+	local local.Cache[V]
+}
+
+func (c *cache[V]) onEvict(key string, value V) {
+	if c.link != nil {
+		lks := c.link.Del(key)
+		for k := range lks {
+			if key != k { // prevent deadlock
+				c.local.Del(k)
+			}
+		}
+	}
+}
+
+func (c *cache[V]) del(key ...string) {
+	for _, k := range key {
+		lks := c.link.Del(k)
+		c.local.Del(k)
+		for k := range lks {
+			c.local.Del(k)
+		}
+	}
+}
+
+func (c *cache[V]) Get(ctx context.Context, key string, fetch func(ctx context.Context) (V, error), opts ...*lopt.Option) (V, error) {
+	if c.local != nil {
+		return c.local.Get(key, func() (V, error) {
+			if c.link != nil {
+				for _, o := range opts {
+					c.link.Link(key, o.Link...)
+				}
+			}
+			return fetch(ctx)
+		})
+	} else {
+		return fetch(ctx)
+	}
+}
+
+func (c *cache[V]) Del(ctx context.Context, key ...string) {
+	if len(key) == 0 {
+		return
+	}
+	for _, fn := range c.opt.delFn {
+		fn(ctx, key...)
+	}
+	if c.local != nil {
+		c.del(key...)
+	}
+}