go-ethereum/beacon/light/range.go
Felföldi Zsolt fff843cfaf
beacon/light: add CommitteeChain (#27766)
This change implements CommitteeChain which is a key component of the beacon light client. It is a passive data structure that can validate, hold and update a chain of beacon light sync committees and updates, starting from a checkpoint that proves the starting committee through a beacon block hash, header and corresponding state. Once synced to the current sync period, CommitteeChain can also validate signed beacon headers.
2023-12-08 13:38:00 +01:00

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)
}
}