github.com/bigzoro/my_simplechain@v0.0.0-20240315012955-8ad0a2a29bb9/p2p/util.go (about) 1 // Copyright 2019 The go-simplechain Authors 2 // This file is part of the go-simplechain library. 3 // 4 // The go-simplechain library is free software: you can redistribute it and/or modify 5 // it under the terms of the GNU Lesser General Public License as published by 6 // the Free Software Foundation, either version 3 of the License, or 7 // (at your option) any later version. 8 // 9 // The go-simplechain library is distributed in the hope that it will be useful, 10 // but WITHOUT ANY WARRANTY; without even the implied warranty of 11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 // GNU Lesser General Public License for more details. 13 // 14 // You should have received a copy of the GNU Lesser General Public License 15 // along with the go-simplechain library. If not, see <http://www.gnu.org/licenses/>. 16 17 package p2p 18 19 import ( 20 "container/heap" 21 "time" 22 ) 23 24 // expHeap tracks strings and their expiry time. 25 type expHeap []expItem 26 27 // expItem is an entry in addrHistory. 28 type expItem struct { 29 item string 30 exp time.Time 31 } 32 33 // nextExpiry returns the next expiry time. 34 func (h *expHeap) nextExpiry() time.Time { 35 return (*h)[0].exp 36 } 37 38 // add adds an item and sets its expiry time. 39 func (h *expHeap) add(item string, exp time.Time) { 40 heap.Push(h, expItem{item, exp}) 41 } 42 43 // contains checks whether an item is present. 44 func (h expHeap) contains(item string) bool { 45 for _, v := range h { 46 if v.item == item { 47 return true 48 } 49 } 50 return false 51 } 52 53 // expire removes items with expiry time before 'now'. 54 func (h *expHeap) expire(now time.Time) { 55 for h.Len() > 0 && h.nextExpiry().Before(now) { 56 heap.Pop(h) 57 } 58 } 59 60 // heap.Interface boilerplate 61 func (h expHeap) Len() int { return len(h) } 62 func (h expHeap) Less(i, j int) bool { return h[i].exp.Before(h[j].exp) } 63 func (h expHeap) Swap(i, j int) { h[i], h[j] = h[j], h[i] } 64 func (h *expHeap) Push(x interface{}) { *h = append(*h, x.(expItem)) } 65 func (h *expHeap) Pop() interface{} { 66 old := *h 67 n := len(old) 68 x := old[n-1] 69 *h = old[0 : n-1] 70 return x 71 }