[feature] Read + Write tombstones for deleted Actors (#1005)

* [feature] Read + Write tombstones for deleted Actors

* copyTombstone

* update to use resultcache instead of old ttl cache

Signed-off-by: kim <grufwub@gmail.com>

* update go-cache library to fix result cache capacity / ordering bugs

Signed-off-by: kim <grufwub@gmail.com>

* bump go-cache/v3 to v3.1.6 to fix bugs

Signed-off-by: kim <grufwub@gmail.com>

* switch on status code

* better explain ErrGone reasoning

Signed-off-by: kim <grufwub@gmail.com>
Co-authored-by: kim <grufwub@gmail.com>

vendor/codeberg.org/gruf/go-maps/list.go

@@ -0,0 +1,154 @@
+package maps
+
+// list is a doubly-linked list containing elemnts with key-value pairs of given generic parameter types.
+type list[K comparable, V any] struct {
+	head *elem[K, V]
+	tail *elem[K, V]
+	len  int
+}
+
+// Index returns the element at index from list.
+func (l *list[K, V]) Index(idx int) *elem[K, V] {
+	switch {
+	// Idx in first half
+	case idx < l.len/2:
+		elem := l.head
+		for i := 0; i < idx; i++ {
+			elem = elem.next
+		}
+		return elem
+
+	// Index in last half
+	default:
+		elem := l.tail
+		for i := l.len - 1; i > idx; i-- {
+			elem = elem.prev
+		}
+		return elem
+	}
+}
+
+// PushFront will push the given element to the front of the list.
+func (l *list[K, V]) PushFront(elem *elem[K, V]) {
+	if l.len == 0 {
+		// Set new tail + head
+		l.head = elem
+		l.tail = elem
+
+		// Link elem to itself
+		elem.next = elem
+		elem.prev = elem
+	} else {
+		oldHead := l.head
+
+		// Link to old head
+		elem.next = oldHead
+		oldHead.prev = elem
+
+		// Link up to tail
+		elem.prev = l.tail
+		l.tail.next = elem
+
+		// Set new head
+		l.head = elem
+	}
+
+	// Incr count
+	l.len++
+}
+
+// PushBack will push the given element to the back of the list.
+func (l *list[K, V]) PushBack(elem *elem[K, V]) {
+	if l.len == 0 {
+		// Set new tail + head
+		l.head = elem
+		l.tail = elem
+
+		// Link elem to itself
+		elem.next = elem
+		elem.prev = elem
+	} else {
+		oldTail := l.tail
+
+		// Link up to head
+		elem.next = l.head
+		l.head.prev = elem
+
+		// Link to old tail
+		elem.prev = oldTail
+		oldTail.next = elem
+
+		// Set new tail
+		l.tail = elem
+	}
+
+	// Incr count
+	l.len++
+}
+
+// PopTail will pop the current tail of the list, returns nil if empty.
+func (l *list[K, V]) PopTail() *elem[K, V] {
+	if l.len == 0 {
+		return nil
+	}
+	elem := l.tail
+	l.Unlink(elem)
+	return elem
+}
+
+// Unlink will unlink the given element from the doubly-linked list chain.
+func (l *list[K, V]) Unlink(elem *elem[K, V]) {
+	if l.len <= 1 {
+		// Drop elem's links
+		elem.next = nil
+		elem.prev = nil
+
+		// Only elem in list
+		l.head = nil
+		l.tail = nil
+		l.len = 0
+		return
+	}
+
+	// Get surrounding elems
+	next := elem.next
+	prev := elem.prev
+
+	// Relink chain
+	next.prev = prev
+	prev.next = next
+
+	switch elem {
+	// Set new head
+	case l.head:
+		l.head = next
+
+	// Set new tail
+	case l.tail:
+		l.tail = prev
+	}
+
+	// Drop elem's links
+	elem.next = nil
+	elem.prev = nil
+
+	// Decr count
+	l.len--
+}
+
+// elem represents an element in a doubly-linked list.
+type elem[K comparable, V any] struct {
+	next *elem[K, V]
+	prev *elem[K, V]
+	K    K
+	V    V
+}
+
+// allocElems will allocate a slice of empty elements of length.
+func allocElems[K comparable, V any](i int) []*elem[K, V] {
+	s := make([]*elem[K, V], i)
+	for i := range s {
+		s[i] = &elem[K, V]{}
+	}
+	return s
+}