func()

in pq/buffer.go [205:242]

• 32 lines of code
• 8 McCabe index (conditional complexity)

func (b *buffer) Pages() (start, end *page, n uint) {
	traceln("get buffer active page range")

	if b.head == nil || !b.head.Dirty() {
		traceln("buffer empty")
		return nil, nil, 0
	}

	if b.eventHdrPage == nil {
		traceln("no active page")

		if b.tail.Dirty() {
			traceln("tail is dirty")
			return b.head, nil, b.countPages
		}

		traceln("tail is not dirty")
		for current := b.head; current != nil; current = current.Next {
			if !current.Dirty() {
				return b.head, current, n
			}
			n++
		}

		invariant.Unreachable("tail if list dirty and not dirty?")
	}

	end = b.eventHdrPage
	n = b.countPages
	if end.Dirty() {
		traceln("active page is dirty")
		end = end.Next
	} else {
		traceln("active page is clean")
		n--
	}
	return b.head, end, n
}