refactor

rq/internal/hashchange.go

@@ -0,0 +1,39 @@
+package internal
+
+import (
+	"math/rand"
+
+	"zero/core/hash"
+)
+
+type HashChange struct {
+	id      int64
+	oldHash *hash.ConsistentHash
+	newHash *hash.ConsistentHash
+}
+
+func NewHashChange(oldHash, newHash *hash.ConsistentHash) HashChange {
+	return HashChange{
+		id:      rand.Int63(),
+		oldHash: oldHash,
+		newHash: newHash,
+	}
+}
+
+func (hc HashChange) GetId() int64 {
+	return hc.id
+}
+
+func (hc HashChange) ShallEvict(key interface{}) bool {
+	oldTarget, oldOk := hc.oldHash.Get(key)
+	if !oldOk {
+		return false
+	}
+
+	newTarget, newOk := hc.newHash.Get(key)
+	if !newOk {
+		return false
+	}
+
+	return oldTarget != newTarget
+}