types/logid: simplify implementation (#7415)

Share the same underlying implementation for both PrivateID and PublicID.
For the shared methods, declare them in the same order.
Only keep documentation on methods without obvious meaning.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
pull/7432/head
Joe Tsai 2 years ago committed by GitHub
parent e1530cdfcc
commit 283a84724f
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23

@ -15,7 +15,6 @@ import (
"time"
"tailscale.com/tstest"
"tailscale.com/types/logid"
)
func TestFastShutdown(t *testing.T) {
@ -296,28 +295,6 @@ func TestParseAndRemoveLogLevel(t *testing.T) {
}
}
func TestPublicIDUnmarshalText(t *testing.T) {
const hexStr = "6c60a9e0e7af57170bb1347b2d477e4cbc27d4571a4923b21651456f931e3d55"
x := []byte(hexStr)
var id logid.PublicID
if err := id.UnmarshalText(x); err != nil {
t.Fatal(err)
}
if id.String() != hexStr {
t.Errorf("String = %q; want %q", id.String(), hexStr)
}
err := tstest.MinAllocsPerRun(t, 0, func() {
var id logid.PublicID
if err := id.UnmarshalText(x); err != nil {
t.Fatal(err)
}
})
if err != nil {
t.Fatal(err)
}
}
func unmarshalOne(t *testing.T, body []byte) map[string]any {
t.Helper()
var entries []map[string]any

@ -1,27 +1,30 @@
// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
// Package logid contains ID types for interacting with the log service.
package logid
import (
"bytes"
"crypto/rand"
"crypto/sha256"
"encoding/binary"
"encoding/hex"
"errors"
"fmt"
"unicode/utf8"
"golang.org/x/exp/slices"
)
// PrivateID represents an instance that write logs.
// PrivateID represents a log steam for writing.
// Private IDs are only shared with the server when writing logs.
type PrivateID [32]byte
// Safely generate a new PrivateId for use in Config objects.
// You should persist this across runs of an instance of your app, so that
// it can append to the same log file on each run.
// NewPrivateID generates a new random PrivateID.
// This should persist across runs of an instance of the application,
// so that it can append to the same log stream for each invocation.
func NewPrivateID() (id PrivateID, err error) {
_, err = rand.Read(id[:])
if err != nil {
if _, err := rand.Read(id[:]); err != nil {
return PrivateID{}, err
}
// Clamping, for future use.
@ -30,137 +33,58 @@ func NewPrivateID() (id PrivateID, err error) {
return id, nil
}
func (id PrivateID) MarshalText() ([]byte, error) {
b := make([]byte, hex.EncodedLen(len(id)))
if i := hex.Encode(b, id[:]); i != len(b) {
return nil, fmt.Errorf("logid.PrivateID.MarshalText: i=%d", i)
}
return b, nil
// ParsePrivateID returns a PrivateID from its hex representation.
func ParsePrivateID(in string) (out PrivateID, err error) {
err = parseID("logid.ParsePublicID", (*[32]byte)(&out), in)
return out, err
}
// ParsePrivateID returns a PrivateID from its hex (String) representation.
func ParsePrivateID(s string) (PrivateID, error) {
if len(s) != 64 {
return PrivateID{}, errors.New("invalid length")
}
var p PrivateID
for i := range p {
a, ok1 := fromHexChar(s[i*2+0])
b, ok2 := fromHexChar(s[i*2+1])
if !ok1 || !ok2 {
return PrivateID{}, errors.New("invalid hex character")
}
p[i] = (a << 4) | b
}
return p, nil
func (id PrivateID) MarshalText() ([]byte, error) {
return formatID(id), nil
}
// IsZero reports whether id is the zero value.
func (id PrivateID) IsZero() bool { return id == PrivateID{} }
func (id *PrivateID) UnmarshalText(s []byte) error {
b, err := hex.DecodeString(string(s))
if err != nil {
return fmt.Errorf("logid.PrivateID.UnmarshalText: %v", err)
}
if len(b) != len(id) {
return fmt.Errorf("logid.PrivateID.UnmarshalText: invalid hex length: %d", len(b))
}
copy(id[:], b)
return nil
func (id *PrivateID) UnmarshalText(in []byte) error {
return parseID("logid.PrivateID", (*[32]byte)(id), in)
}
func (id PrivateID) String() string {
b, err := id.MarshalText()
if err != nil {
panic(err)
}
return string(b)
return string(formatID(id))
}
func (id PrivateID) IsZero() bool {
return id == PrivateID{}
}
// Public returns the public ID of the private ID,
// which is the SHA-256 hash of the private ID.
func (id PrivateID) Public() (pub PublicID) {
h := sha256.New()
h.Write(id[:])
if n := copy(pub[:], h.Sum(pub[:0])); n != len(pub) {
panic(fmt.Sprintf("public id short copy: %d", n))
}
return pub
return PublicID(sha256.Sum256(id[:]))
}
// PublicID represents an instance in the logs service for reading and adoption.
// The public ID value is a SHA-256 hash of a private ID.
// PublicID represents a log stream for reading.
// The PrivateID cannot be feasibly reversed from the PublicID.
type PublicID [sha256.Size]byte
// ParsePublicID returns a PublicID from its hex (String) representation.
func ParsePublicID(s string) (PublicID, error) {
if len(s) != sha256.Size*2 {
return PublicID{}, errors.New("invalid length")
}
var p PublicID
for i := range p {
a, ok1 := fromHexChar(s[i*2+0])
b, ok2 := fromHexChar(s[i*2+1])
if !ok1 || !ok2 {
return PublicID{}, errors.New("invalid hex character")
}
p[i] = (a << 4) | b
}
return p, nil
// ParsePublicID returns a PublicID from its hex representation.
func ParsePublicID(in string) (out PublicID, err error) {
err = parseID("logid.ParsePublicID", (*[32]byte)(&out), in)
return out, err
}
func (id PublicID) MarshalText() ([]byte, error) {
b := make([]byte, hex.EncodedLen(len(id)))
if i := hex.Encode(b, id[:]); i != len(b) {
return nil, fmt.Errorf("logid.PublicID.MarshalText: i=%d", i)
}
return b, nil
return formatID(id), nil
}
func (id *PublicID) UnmarshalText(s []byte) error {
if len(s) != len(id)*2 {
return fmt.Errorf("logid.PublicID.UnmarshalText: invalid hex length: %d", len(s))
}
for i := range id {
a, ok1 := fromHexChar(s[i*2+0])
b, ok2 := fromHexChar(s[i*2+1])
if !ok1 || !ok2 {
return errors.New("invalid hex character")
}
id[i] = (a << 4) | b
}
return nil
func (id *PublicID) UnmarshalText(in []byte) error {
return parseID("logid.ParsePublicID", (*[32]byte)(id), in)
}
func (id PublicID) String() string {
b, err := id.MarshalText()
if err != nil {
panic(err)
}
return string(b)
}
// fromHexChar converts a hex character into its value and a success flag.
func fromHexChar(c byte) (byte, bool) {
switch {
case '0' <= c && c <= '9':
return c - '0', true
case 'a' <= c && c <= 'f':
return c - 'a' + 10, true
case 'A' <= c && c <= 'F':
return c - 'A' + 10, true
}
return 0, false
return string(formatID(id))
}
func (id1 PublicID) Less(id2 PublicID) bool {
for i, c1 := range id1[:] {
c2 := id2[i]
if c1 != c2 {
return c1 < c2
}
}
return false // equal
return slices.Compare(id1[:], id2[:]) < 0
}
func (id PublicID) IsZero() bool {
@ -170,3 +94,22 @@ func (id PublicID) IsZero() bool {
func (id PublicID) Prefix64() uint64 {
return binary.BigEndian.Uint64(id[:8])
}
func formatID(in [32]byte) []byte {
var hexArr [2 * len(in)]byte
hex.Encode(hexArr[:], in[:])
return hexArr[:]
}
func parseID[Bytes []byte | string](funcName string, out *[32]byte, in Bytes) (err error) {
if len(in) != 2*len(out) {
return fmt.Errorf("%s: invalid hex length: %d", funcName, len(in))
}
var hexArr [2 * len(out)]byte
copy(hexArr[:], in)
if _, err := hex.Decode(out[:], hexArr[:]); err != nil {
r, _ := utf8.DecodeRune(bytes.TrimLeft([]byte(in), "0123456789abcdefABCDEF"))
return fmt.Errorf("%s: invalid hex character: %c", funcName, r)
}
return nil
}

@ -5,6 +5,8 @@ package logid
import (
"testing"
"tailscale.com/tstest"
)
func TestIDs(t *testing.T) {
@ -63,4 +65,15 @@ func TestIDs(t *testing.T) {
if id1 != id4 {
t.Fatalf("ParsePrivateID returned different id")
}
hexString := "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
hexBytes := []byte(hexString)
if err := tstest.MinAllocsPerRun(t, 0, func() {
ParsePrivateID(hexString)
new(PrivateID).UnmarshalText(hexBytes)
ParsePublicID(hexString)
new(PublicID).UnmarshalText(hexBytes)
}); err != nil {
t.Fatal(err)
}
}

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