vikarti.anatra/safing-portbase
1
0
Fork 0
mirror of https://github.com/safing/portbase synced 2025-04-17 16:09:08 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

Improve varint errors, add helper for getting encoded size

Browse source
This commit is contained in:
Daniel 2021-09-17 22:01:50 +02:00
parent a01df19cd0
commit 17fcefb403
2 changed files with 34 additions and 5 deletions
formats/varint
helpers.govarint.go

26
formats/varint/helpers.go
View file

@ -20,3 +20,29 @@ func GetNextBlock(data []byte) ([]byte, int, error) {
}
return data[n:totalLength], totalLength, nil
}
// EncodedSize returns the size required to varint-encode an uint.
func EncodedSize(n uint64) (size int) {
switch {
case n < 128:
return 1
case n < 16384:
return 2
case n < 2097152:
return 3
case n < 268435456:
return 4
case n < 34359738368:
return 5
case n < 4398046511104:
return 6
case n < 562949953421312:
return 7
case n < 72057594037927936:
return 8
case n < 9223372036854775808:
return 9
default:
return 10
}
}

13
formats/varint/varint.go
View file

@ -5,6 +5,9 @@ import (
"errors"
)
// ErrBufTooSmall is returned when there is not enough data for parsing a varint.
var ErrBufTooSmall = errors.New("varint: buf too small")
// Pack8 packs a uint8 into a VarInt.
func Pack8(n uint8) []byte {
if n < 128 {
@ -37,13 +40,13 @@ func Pack64(n uint64) []byte {
// Unpack8 unpacks a VarInt into a uint8. It returns the extracted int, how many bytes were used and an error.
func Unpack8(blob []byte) (uint8, int, error) {
if len(blob) < 1 {
return 0, 0, errors.New("varint: buf has zero length")
return 0, 0, ErrBufTooSmall
}
if blob[0] < 128 {
return blob[0], 1, nil
}
if len(blob) < 2 {
return 0, 0, errors.New("varint: buf too small")
return 0, 0, ErrBufTooSmall
}
if blob[1] != 0x01 {
return 0, 0, errors.New("varint: encoded integer greater than 255 (uint8)")
@ -55,7 +58,7 @@ func Unpack8(blob []byte) (uint8, int, error) {
func Unpack16(blob []byte) (uint16, int, error) {
n, r := binary.Uvarint(blob)
if r == 0 {
return 0, 0, errors.New("varint: buf too small")
return 0, 0, ErrBufTooSmall
}
if r < 0 {
return 0, 0, errors.New("varint: encoded integer greater than 18446744073709551615 (uint64)")
@ -70,7 +73,7 @@ func Unpack16(blob []byte) (uint16, int, error) {
func Unpack32(blob []byte) (uint32, int, error) {
n, r := binary.Uvarint(blob)
if r == 0 {
return 0, 0, errors.New("varint: buf too small")
return 0, 0, ErrBufTooSmall
}
if r < 0 {
return 0, 0, errors.New("varint: encoded integer greater than 18446744073709551615 (uint64)")
@ -85,7 +88,7 @@ func Unpack32(blob []byte) (uint32, int, error) {
func Unpack64(blob []byte) (uint64, int, error) {
n, r := binary.Uvarint(blob)
if r == 0 {
return 0, 0, errors.New("varint: buf too small")
return 0, 0, ErrBufTooSmall
}
if r < 0 {
return 0, 0, errors.New("varint: encoded integer greater than 18446744073709551615 (uint64)")