Method grow

hashmap.go:296–333

(newSize uintptr, loop bool)

}

func (m *Map[Key, Value]) grow(newSize uintptr, loop bool) {
	defer m.resizing.CompareAndSwap(1, 0)

	for {
		currentStore := m.store.Load()
		if newSize == 0 {
			newSize = uintptr(len(currentStore.index)) << 1
		} else {
			newSize = roundUpPower2(newSize)
		}

		index := make([]*ListElement[Key, Value], newSize)
		header := (*reflect.SliceHeader)(unsafe.Pointer(&index))

		newStore := &store[Key, Value]{
			keyShifts: strconv.IntSize - log2(newSize),
			array:     unsafe.Pointer(header.Data), // use address of slice data storage
			index:     index,
		}

		m.fillIndexItems(newStore) // initialize new index slice with longer keys

		m.store.Store(newStore)

		m.fillIndexItems(newStore) // make sure that the new index is up-to-date with the current state of the linked list

		if !loop {
			return
		}

		// check if a new resize needs to be done already
		count := uintptr(m.Len())
		if !m.isResizeNeeded(newStore, count) {
			return
		}
		newSize = 0 // 0 means double the current size
	}
}

func (m *Map[Key, Value]) fillIndexItems(store *store[Key, Value]) {
	first := m.linkedList.First()