status-im/status-go

package peers

import (
    "container/heap"
)

type peerInfoItem struct {
    *peerInfo
    index int
}

type peerPriorityQueue []*peerInfoItem

var _ heap.Interface = (*peerPriorityQueue)(nil)

func (q peerPriorityQueue) Len() int { return len(q) }

func (q peerPriorityQueue) Less(i, j int) bool {
    return q[i].discoveredTime.After(q[j].discoveredTime)
}

func (q peerPriorityQueue) Swap(i, j int) {
    q[i], q[j] = q[j], q[i]
    q[i].index = i
    q[j].index = j
}

func (q *peerPriorityQueue) Push(x interface{}) {
    item := x.(*peerInfoItem)
    item.index = len(*q)
    *q = append(*q, item)
}

func (q *peerPriorityQueue) Pop() interface{} {
    old := *q
    n := len(old)
    item := old[n-1]
    item.index = -1
    *q = old[0 : n-1]
    return item
}