72 lines
2.0 KiB
Go
72 lines
2.0 KiB
Go
// Copyright 2019 The go-ethereum Authors
|
|
// This file is part of the go-ethereum library.
|
|
//
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// The go-ethereum library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package p2p
|
|
|
|
import (
|
|
"container/heap"
|
|
"time"
|
|
)
|
|
|
|
// expHeap tracks strings and their expiry time.
|
|
type expHeap []expItem
|
|
|
|
// expItem is an entry in addrHistory.
|
|
type expItem struct {
|
|
item string
|
|
exp time.Time
|
|
}
|
|
|
|
// nextExpiry returns the next expiry time.
|
|
func (h *expHeap) nextExpiry() time.Time {
|
|
return (*h)[0].exp
|
|
}
|
|
|
|
// add adds an item and sets its expiry time.
|
|
func (h *expHeap) add(item string, exp time.Time) {
|
|
heap.Push(h, expItem{item, exp})
|
|
}
|
|
|
|
// contains checks whether an item is present.
|
|
func (h expHeap) contains(item string) bool {
|
|
for _, v := range h {
|
|
if v.item == item {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
// expire removes items with expiry time before 'now'.
|
|
func (h *expHeap) expire(now time.Time) {
|
|
for h.Len() > 0 && h.nextExpiry().Before(now) {
|
|
heap.Pop(h)
|
|
}
|
|
}
|
|
|
|
// heap.Interface boilerplate
|
|
func (h expHeap) Len() int { return len(h) }
|
|
func (h expHeap) Less(i, j int) bool { return h[i].exp.Before(h[j].exp) }
|
|
func (h expHeap) Swap(i, j int) { h[i], h[j] = h[j], h[i] }
|
|
func (h *expHeap) Push(x interface{}) { *h = append(*h, x.(expItem)) }
|
|
func (h *expHeap) Pop() interface{} {
|
|
old := *h
|
|
n := len(old)
|
|
x := old[n-1]
|
|
*h = old[0 : n-1]
|
|
return x
|
|
}
|