79 lines
2.5 KiB
Go
79 lines
2.5 KiB
Go
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// Copyright 2023 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 light
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// periodRange represents a (possibly zero-length) range of integers (sync periods).
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type periodRange struct {
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Start, End uint64
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}
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// isEmpty returns true if the length of the range is zero.
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func (a periodRange) isEmpty() bool {
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return a.End == a.Start
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}
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// contains returns true if the range includes the given period.
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func (a periodRange) contains(period uint64) bool {
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return period >= a.Start && period < a.End
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}
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// canExpand returns true if the range includes or can be expanded with the given
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// period (either the range is empty or the given period is inside, right before or
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// right after the range).
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func (a periodRange) canExpand(period uint64) bool {
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return a.isEmpty() || (period+1 >= a.Start && period <= a.End)
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}
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// expand expands the range with the given period.
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// This method assumes that canExpand returned true: otherwise this is a no-op.
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func (a *periodRange) expand(period uint64) {
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if a.isEmpty() {
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a.Start, a.End = period, period+1
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return
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}
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if a.Start == period+1 {
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a.Start--
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}
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if a.End == period {
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a.End++
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}
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}
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// split splits the range into two ranges. The 'fromPeriod' will be the first
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// element in the second range (if present).
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// The original range is unchanged by this operation
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func (a *periodRange) split(fromPeriod uint64) (periodRange, periodRange) {
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if fromPeriod <= a.Start {
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// First range empty, everything in second range,
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return periodRange{}, *a
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}
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if fromPeriod >= a.End {
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// Second range empty, everything in first range,
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return *a, periodRange{}
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}
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x := periodRange{a.Start, fromPeriod}
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y := periodRange{fromPeriod, a.End}
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return x, y
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}
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// each invokes the supplied function fn once per period in range
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func (a *periodRange) each(fn func(uint64)) {
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for p := a.Start; p < a.End; p++ {
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fn(p)
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}
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}
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