Sha256: 3f0c824968eb73808db15403e6f9c0a1a2696d5943f5a8323bdd9127513f6855
Contents?: true
Size: 1.84 KB
Versions: 122
Compression:
Stored size: 1.84 KB
Contents
package variablelengthquantity
import "errors"
var ErrUnterminatedSequence = errors.New("unterminated sequence")
// encodeInt returns the varint encoding of x.
func encodeInt(x uint32) []byte {
if x>>7 == 0 {
return []byte{
byte(x),
}
}
if x>>14 == 0 {
return []byte{
byte(0x80 | x>>7),
byte(127 & x),
}
}
if x>>21 == 0 {
return []byte{
byte(0x80 | x>>14),
byte(0x80 | x>>7),
byte(127 & x),
}
}
if x>>28 == 0 {
return []byte{
byte(0x80 | x>>21),
byte(0x80 | x>>14),
byte(0x80 | x>>6),
byte(127 & x),
}
}
return []byte{
byte(0x80 | x>>28),
byte(0x80 | x>>21),
byte(0x80 | x>>14),
byte(0x80 | x>>7),
byte(127 & x),
}
}
// decodeInt reads a varint-encoded integer from the slice.
// It returns the integer and the number of bytes consumed, or
// zero if there is not enough.
func decodeInt(buf []byte) (x uint32, n int, err error) {
if len(buf) < 1 {
return 0, 0, nil
}
if buf[0] < 0x80 {
return uint32(buf[0]), 1, nil
}
var b byte
for n, b = range buf {
x = x << 7
x |= uint32(b) & 0x7f
if (b & 0x80) == 0 {
return x, n + 1, nil
}
}
return x, 0, ErrUnterminatedSequence
}
// EncodeVarint encodes a slice of uint32 into a var-int encoded bytes.
func EncodeVarint(xa []uint32) []byte {
result := make([]byte, 0)
for _, x := range xa {
result = append(result, encodeInt(x)...)
}
return result
}
// DecodeVarint decodes a buffer of var-int encoded values into
// a slice of uint32 values; an error is returned if buf doesn't
// decode var-int successfully.
func DecodeVarint(buf []byte) (ra []uint32, err error) {
if len(buf) == 0 {
return []uint32{0}, nil
}
usedBytes := 0
ra = make([]uint32, 0)
for usedBytes < len(buf) {
r, nUsed, err := decodeInt(buf[usedBytes:])
if err != nil {
return nil, err
}
ra = append(ra, r)
usedBytes += nUsed
}
return ra, nil
}
Version data entries
122 entries across 122 versions & 1 rubygems