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