blob: 4bbcdf26093f16fe465768e2468e60b282b8b8f3 [file] [log] [blame]
// Copyright 2016 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package version provides versioning for the agent. A client is expected to
// be able to start and communicate with an agent that supports a compatible
// version.
package version
import (
// TODO(caprita): This mimics the rpc version package at
// v23/rpc/version/version.go. Consider coming up with a common,
// package-independent versioning mechanism that can be reused.
const pkgPath = ""
type T uint32
var (
errNoCompatibleVersion = verror.Register(pkgPath+".errNoCompatibleVersion", verror.NoRetry, "{1:}{2:} There were no compatible versions between ({3},{4}) and ({5},{6})")
errInvalidVersion = verror.Register(pkgPath+".errInvalidVersion", verror.NoRetry, "{1:}{2:} Invalid version {3}{:_}")
// Make T implement flag.Value.
// String returns a string representation of version.
func (v T) String() string {
return fmt.Sprint(uint32(v))
// Set parses the version from the given string. An error is returned if the
// string appears in the wrong syntax or represents an invalid version number.
func (v *T) Set(s string) error {
intV, err := strconv.ParseUint(s, 10, 32)
if err != nil {
return err
*v = T(intV)
return nil
// Range describes a range of versions.
type Range struct {
Min, Max T
// Supported defines the version range supported by the current binary.
var Supported = Range{Min: 0, Max: 0}
// String returns a string representation of the range.
func (r Range) String() string {
return fmt.Sprintf("[%v,%v]", r.Min, r.Max)
// Common returns the highest common version between the provided ranges.
// Returns an error if no such version exists.
func Common(ctx *context.T, l, r Range) (T, error) {
minMax := l.Max
if r.Max < minMax {
minMax = r.Max
if l.Min > minMax || r.Min > minMax {
return 0, verror.New(errNoCompatibleVersion, ctx,
uint64(l.Min), uint64(l.Max), uint64(r.Min), uint64(r.Max))
return minMax, nil
// Contains returns whether the given version is in the given range.
func (r Range) Contains(v T) bool {
return r.Max >= v && r.Min <= v
// RangeFromString parses a Range from the given string min, max values.
func RangeFromString(ctx *context.T, min, max string) (Range, error) {
var vMin, vMax T
if err := vMin.Set(min); err != nil {
return Range{}, verror.New(errInvalidVersion, ctx, min, err)
if err := vMax.Set(max); err != nil {
return Range{}, verror.New(errInvalidVersion, ctx, max, err)
return Range{vMin, vMax}, nil