turboezh/heapcache

package heapcache
 
type (
    itemsHeap struct {
        less Less
        Heap []*wrapper
    }
)
 
func newHeap(capacity int, less Less) *itemsHeap {
    return &itemsHeap{
        less: less,
        Heap: make([]*wrapper, 0, capacity),
    }
}
 
func (h *itemsHeap) Len() int {
    return len(h.Heap)
}
 
func (h *itemsHeap) Less(i, j int) bool {
    return h.less(h.Heap[i].value, h.Heap[j].value)
}
 
func (h *itemsHeap) Swap(i, j int) {
    h.Heap[i], h.Heap[j] = h.Heap[j], h.Heap[i]
    h.Heap[i].index = i
    h.Heap[j].index = j
}
 
func (h *itemsHeap) Push(value interface{}) {
    item := value.(*wrapper)
    item.index = len(h.Heap)
    h.Heap = append(h.Heap, item)
}
 
func (h *itemsHeap) Pop() interface{} {
    n := len(h.Heap)
    item := h.Heap[n-1]
    item.index = -1 // for safety
    h.Heap = h.Heap[0 : n-1]
    return item
}