sdk taking shape.

sdk/cache/interface.go

@@ -0,0 +1,10 @@
+package cache
+
+import "time"
+
+type Cache32[V any] interface {
+	Get(k string) (v V, ok bool)
+	Delete(k string)
+	Set(k string, v V) bool
+	SetWithTTL(k string, v V, d time.Duration) bool
+}

sdk/cache/memory/cache.go

@@ -0,0 +1,48 @@
+package cache_memory
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+	"time"
+
+	"github.com/dgraph-io/ristretto"
+)
+
+type RistrettoCache[V any] struct {
+	Cache *ristretto.Cache[string, V]
+}
+
+func New32[V any](max int64) *RistrettoCache[V] {
+	cache, _ := ristretto.NewCache(&ristretto.Config[string, V]{
+		NumCounters: max * 10,
+		MaxCost:     max,
+		BufferItems: 64,
+		KeyToHash:   func(key string) (uint64, uint64) { return h32(key), 0 },
+	})
+	return &RistrettoCache[V]{Cache: cache}
+}
+
+func (s RistrettoCache[V]) Get(k string) (v V, ok bool) { return s.Cache.Get(k) }
+func (s RistrettoCache[V]) Delete(k string)             { s.Cache.Del(k) }
+func (s RistrettoCache[V]) Set(k string, v V) bool      { return s.Cache.Set(k, v, 1) }
+func (s RistrettoCache[V]) SetWithTTL(k string, v V, d time.Duration) bool {
+	return s.Cache.SetWithTTL(k, v, 1, d)
+}
+
+func h32(key string) uint64 {
+	// we get an event id or pubkey as hex,
+	// so just extract the last 8 bytes from it and turn them into a uint64
+	return shortUint64(key)
+}
+
+func shortUint64(idOrPubkey string) uint64 {
+	length := len(idOrPubkey)
+	if length < 8 {
+		return 0
+	}
+	b, err := hex.DecodeString(idOrPubkey[length-8:])
+	if err != nil {
+		return 0
+	}
+	return uint64(binary.BigEndian.Uint32(b))
+}