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