VictoriaMetrics/lib/encoding/int.go
Aliaksandr Valialkin 87338633b1
lib/slicesutil: add helper functions for setting slice length and extending its capacity
The added helper functions - SetLength() and ExtendCapacity() - replace error-prone code with simple function calls.
2024-05-12 11:33:49 +02:00

561 lines
16 KiB
Go

package encoding
import (
"encoding/binary"
"fmt"
"sync"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/slicesutil"
)
// MarshalUint16 appends marshaled v to dst and returns the result.
func MarshalUint16(dst []byte, u uint16) []byte {
return append(dst, byte(u>>8), byte(u))
}
// UnmarshalUint16 returns unmarshaled uint16 from src.
//
// the caller must ensure that len(src) >= 2
func UnmarshalUint16(src []byte) uint16 {
// This is faster than the manual conversion.
return binary.BigEndian.Uint16(src)
}
// MarshalUint32 appends marshaled v to dst and returns the result.
func MarshalUint32(dst []byte, u uint32) []byte {
return append(dst, byte(u>>24), byte(u>>16), byte(u>>8), byte(u))
}
// UnmarshalUint32 returns unmarshaled uint32 from src.
//
// The caller must ensure than len(src) >= 4
func UnmarshalUint32(src []byte) uint32 {
// This is faster than the manual conversion.
return binary.BigEndian.Uint32(src)
}
// MarshalUint64 appends marshaled v to dst and returns the result.
func MarshalUint64(dst []byte, u uint64) []byte {
return append(dst, byte(u>>56), byte(u>>48), byte(u>>40), byte(u>>32), byte(u>>24), byte(u>>16), byte(u>>8), byte(u))
}
// UnmarshalUint64 returns unmarshaled uint64 from src.
//
// The caller must ensure that len(src) >= 8
func UnmarshalUint64(src []byte) uint64 {
// This is faster than the manual conversion.
return binary.BigEndian.Uint64(src)
}
// MarshalInt16 appends marshaled v to dst and returns the result.
func MarshalInt16(dst []byte, v int16) []byte {
// Such encoding for negative v must improve compression.
v = (v << 1) ^ (v >> 15) // zig-zag encoding without branching.
u := uint16(v)
return append(dst, byte(u>>8), byte(u))
}
// UnmarshalInt16 returns unmarshaled int16 from src.
//
// The caller must ensure that len(src) >= 2
func UnmarshalInt16(src []byte) int16 {
// This is faster than the manual conversion.
u := binary.BigEndian.Uint16(src)
v := int16(u>>1) ^ (int16(u<<15) >> 15) // zig-zag decoding without branching.
return v
}
// MarshalInt64 appends marshaled v to dst and returns the result.
func MarshalInt64(dst []byte, v int64) []byte {
// Such encoding for negative v must improve compression.
v = (v << 1) ^ (v >> 63) // zig-zag encoding without branching.
u := uint64(v)
return append(dst, byte(u>>56), byte(u>>48), byte(u>>40), byte(u>>32), byte(u>>24), byte(u>>16), byte(u>>8), byte(u))
}
// UnmarshalInt64 returns unmarshaled int64 from src.
//
// The caller must ensure that len(src) >= 8
func UnmarshalInt64(src []byte) int64 {
// This is faster than the manual conversion.
u := binary.BigEndian.Uint64(src)
v := int64(u>>1) ^ (int64(u<<63) >> 63) // zig-zag decoding without branching.
return v
}
// MarshalVarInt64 appends marshalsed v to dst and returns the result.
func MarshalVarInt64(dst []byte, v int64) []byte {
var tmp [1]int64
tmp[0] = v
return MarshalVarInt64s(dst, tmp[:])
}
// MarshalVarInt64s appends marshaled vs to dst and returns the result.
func MarshalVarInt64s(dst []byte, vs []int64) []byte {
dstLen := len(dst)
for _, v := range vs {
if v >= (1<<6) || v <= (-1<<6) {
return marshalVarInt64sSlow(dst[:dstLen], vs)
}
u := uint64((v << 1) ^ (v >> 63))
dst = append(dst, byte(u))
}
return dst
}
func marshalVarInt64sSlow(dst []byte, vs []int64) []byte {
for _, v := range vs {
u := uint64((v << 1) ^ (v >> 63))
// Cases below are sorted in the descending order of frequency on real data
if u < (1 << 7) {
dst = append(dst, byte(u))
continue
}
if u < (1 << (2 * 7)) {
dst = append(dst, byte(u|0x80), byte(u>>7))
continue
}
if u < (1 << (3 * 7)) {
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte(u>>(2*7)))
continue
}
if u >= (1 << (8 * 7)) {
if u < (1 << (9 * 7)) {
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte((u>>(2*7))|0x80), byte((u>>(3*7))|0x80), byte((u>>(4*7))|0x80),
byte((u>>(5*7))|0x80), byte((u>>(6*7))|0x80), byte((u>>(7*7))|0x80), byte(u>>(8*7)))
continue
}
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte((u>>(2*7))|0x80), byte((u>>(3*7))|0x80), byte((u>>(4*7))|0x80),
byte((u>>(5*7))|0x80), byte((u>>(6*7))|0x80), byte((u>>(7*7))|0x80), byte((u>>(8*7))|0x80), 1)
continue
}
if u < (1 << (4 * 7)) {
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte((u>>(2*7))|0x80), byte(u>>(3*7)))
continue
}
if u < (1 << (5 * 7)) {
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte((u>>(2*7))|0x80), byte((u>>(3*7))|0x80), byte(u>>(4*7)))
continue
}
if u < (1 << (6 * 7)) {
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte((u>>(2*7))|0x80), byte((u>>(3*7))|0x80), byte((u>>(4*7))|0x80), byte(u>>(5*7)))
continue
}
if u < (1 << (7 * 7)) {
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte((u>>(2*7))|0x80), byte((u>>(3*7))|0x80), byte((u>>(4*7))|0x80), byte((u>>(5*7))|0x80), byte(u>>(6*7)))
continue
}
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte((u>>(2*7))|0x80), byte((u>>(3*7))|0x80), byte((u>>(4*7))|0x80),
byte((u>>(5*7))|0x80), byte((u>>(6*7))|0x80), byte(u>>(7*7)))
}
return dst
}
// UnmarshalVarInt64 returns unmarshaled int64 from src and returns
// the remaining tail from src.
func UnmarshalVarInt64(src []byte) ([]byte, int64, error) {
var tmp [1]int64
tail, err := UnmarshalVarInt64s(tmp[:], src)
return tail, tmp[0], err
}
// UnmarshalVarInt64s unmarshals len(dst) int64 values from src to dst
// and returns the remaining tail from src.
func UnmarshalVarInt64s(dst []int64, src []byte) ([]byte, error) {
if len(src) < len(dst) {
return src, fmt.Errorf("too small len(src)=%d; it must be bigger or equal to len(dst)=%d", len(src), len(dst))
}
for i := range dst {
c := src[i]
if c >= 0x80 {
return unmarshalVarInt64sSlow(dst, src)
}
dst[i] = int64(int8(c>>1) ^ (int8(c<<7) >> 7))
}
return src[len(dst):], nil
}
func unmarshalVarInt64sSlow(dst []int64, src []byte) ([]byte, error) {
idx := uint(0)
for i := range dst {
if idx >= uint(len(src)) {
return nil, fmt.Errorf("cannot unmarshal varint from empty data")
}
c := src[idx]
idx++
if c < 0x80 {
// Fast path for 1 byte
dst[i] = int64(int8(c>>1) ^ (int8(c<<7) >> 7))
continue
}
if idx >= uint(len(src)) {
return nil, fmt.Errorf("unexpected end of encoded varint at byte 1; src=%x", src[idx-1:])
}
d := src[idx]
idx++
if d < 0x80 {
// Fast path for 2 bytes
u := uint64(c&0x7f) | (uint64(d) << 7)
dst[i] = int64(u>>1) ^ (int64(u<<63) >> 63)
continue
}
if idx >= uint(len(src)) {
return nil, fmt.Errorf("unexpected end of encoded varint at byte 2; src=%x", src[idx-2:])
}
e := src[idx]
idx++
if e < 0x80 {
// Fast path for 3 bytes
u := uint64(c&0x7f) | (uint64(d&0x7f) << 7) | (uint64(e) << (2 * 7))
dst[i] = int64(u>>1) ^ (int64(u<<63) >> 63)
continue
}
u := uint64(c&0x7f) | (uint64(d&0x7f) << 7) | (uint64(e&0x7f) << (2 * 7))
// Slow path
j := idx
for {
if idx >= uint(len(src)) {
return nil, fmt.Errorf("unexpected end of encoded varint; src=%x", src[j-3:])
}
c := src[idx]
idx++
if c < 0x80 {
break
}
}
// These are the most common cases
switch idx - j {
case 1:
u |= (uint64(src[j]) << (3 * 7))
case 2:
b := src[j : j+2 : j+2]
u |= (uint64(b[0]&0x7f) << (3 * 7)) | (uint64(b[1]) << (4 * 7))
case 3:
b := src[j : j+3 : j+3]
u |= (uint64(b[0]&0x7f) << (3 * 7)) | (uint64(b[1]&0x7f) << (4 * 7)) | (uint64(b[2]) << (5 * 7))
case 4:
b := src[j : j+4 : j+4]
u |= (uint64(b[0]&0x7f) << (3 * 7)) | (uint64(b[1]&0x7f) << (4 * 7)) | (uint64(b[2]&0x7f) << (5 * 7)) | (uint64(b[3]) << (6 * 7))
case 5:
b := src[j : j+5 : j+5]
u |= (uint64(b[0]&0x7f) << (3 * 7)) | (uint64(b[1]&0x7f) << (4 * 7)) | (uint64(b[2]&0x7f) << (5 * 7)) | (uint64(b[3]&0x7f) << (6 * 7)) |
(uint64(b[4]) << (7 * 7))
case 6:
b := src[j : j+6 : j+6]
u |= (uint64(b[0]&0x7f) << (3 * 7)) | (uint64(b[1]&0x7f) << (4 * 7)) | (uint64(b[2]&0x7f) << (5 * 7)) | (uint64(b[3]&0x7f) << (6 * 7)) |
(uint64(b[4]&0x7f) << (7 * 7)) | (uint64(b[5]) << (8 * 7))
case 7:
b := src[j : j+7 : j+7]
if b[6] > 1 {
return src[idx:], fmt.Errorf("too big encoded varint; src=%x", src[j-3:])
}
u |= (uint64(b[0]&0x7f) << (3 * 7)) | (uint64(b[1]&0x7f) << (4 * 7)) | (uint64(b[2]&0x7f) << (5 * 7)) | (uint64(b[3]&0x7f) << (6 * 7)) |
(uint64(b[4]&0x7f) << (7 * 7)) | (uint64(b[5]&0x7f) << (8 * 7)) | (1 << (9 * 7))
default:
return src[idx:], fmt.Errorf("too long encoded varint; the maximum allowed length is 10 bytes; got %d bytes; src=%x", idx-j+3, src[j-3:])
}
dst[i] = int64(u>>1) ^ (int64(u<<63) >> 63)
}
return src[idx:], nil
}
// MarshalVarUint64 appends marshaled u to dst and returns the result.
func MarshalVarUint64(dst []byte, u uint64) []byte {
var tmp [1]uint64
tmp[0] = u
return MarshalVarUint64s(dst, tmp[:])
}
// MarshalVarUint64s appends marshaled us to dst and returns the result.
func MarshalVarUint64s(dst []byte, us []uint64) []byte {
dstLen := len(dst)
for _, u := range us {
if u >= (1 << 7) {
return marshalVarUint64sSlow(dst[:dstLen], us)
}
dst = append(dst, byte(u))
}
return dst
}
func marshalVarUint64sSlow(dst []byte, us []uint64) []byte {
for _, u := range us {
// Cases below are sorted in the descending order of frequency on real data
if u < (1 << 7) {
dst = append(dst, byte(u))
continue
}
if u < (1 << (2 * 7)) {
dst = append(dst, byte(u|0x80), byte(u>>7))
continue
}
if u < (1 << (3 * 7)) {
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte(u>>(2*7)))
continue
}
if u >= (1 << (8 * 7)) {
if u < (1 << (9 * 7)) {
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte((u>>(2*7))|0x80), byte((u>>(3*7))|0x80), byte((u>>(4*7))|0x80),
byte((u>>(5*7))|0x80), byte((u>>(6*7))|0x80), byte((u>>(7*7))|0x80), byte(u>>(8*7)))
continue
}
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte((u>>(2*7))|0x80), byte((u>>(3*7))|0x80), byte((u>>(4*7))|0x80),
byte((u>>(5*7))|0x80), byte((u>>(6*7))|0x80), byte((u>>(7*7))|0x80), byte((u>>(8*7))|0x80), 1)
continue
}
if u < (1 << (4 * 7)) {
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte((u>>(2*7))|0x80), byte(u>>(3*7)))
continue
}
if u < (1 << (5 * 7)) {
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte((u>>(2*7))|0x80), byte((u>>(3*7))|0x80), byte(u>>(4*7)))
continue
}
if u < (1 << (6 * 7)) {
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte((u>>(2*7))|0x80), byte((u>>(3*7))|0x80), byte((u>>(4*7))|0x80), byte(u>>(5*7)))
continue
}
if u < (1 << (7 * 7)) {
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte((u>>(2*7))|0x80), byte((u>>(3*7))|0x80), byte((u>>(4*7))|0x80), byte((u>>(5*7))|0x80), byte(u>>(6*7)))
continue
}
dst = append(dst, byte(u|0x80), byte((u>>7)|0x80), byte((u>>(2*7))|0x80), byte((u>>(3*7))|0x80), byte((u>>(4*7))|0x80),
byte((u>>(5*7))|0x80), byte((u>>(6*7))|0x80), byte(u>>(7*7)))
}
return dst
}
// UnmarshalVarUint64 returns unmarshaled uint64 from src and returns
// the remaining tail from src.
func UnmarshalVarUint64(src []byte) ([]byte, uint64, error) {
var tmp [1]uint64
tail, err := UnmarshalVarUint64s(tmp[:], src)
return tail, tmp[0], err
}
// UnmarshalVarUint64s unmarshals len(dst) uint64 values from src to dst
// and returns the remaining tail from src.
func UnmarshalVarUint64s(dst []uint64, src []byte) ([]byte, error) {
if len(src) < len(dst) {
return src, fmt.Errorf("too small len(src)=%d; it must be bigger or equal to len(dst)=%d", len(src), len(dst))
}
for i := range dst {
c := src[i]
if c >= 0x80 {
return unmarshalVarUint64sSlow(dst, src)
}
dst[i] = uint64(c)
}
return src[len(dst):], nil
}
func unmarshalVarUint64sSlow(dst []uint64, src []byte) ([]byte, error) {
idx := uint(0)
for i := range dst {
if idx >= uint(len(src)) {
return nil, fmt.Errorf("cannot unmarshal varuint from empty data")
}
c := src[idx]
idx++
if c < 0x80 {
// Fast path for 1 byte
dst[i] = uint64(c)
continue
}
if idx >= uint(len(src)) {
return nil, fmt.Errorf("unexpected end of encoded varuint at byte 1; src=%x", src[idx-1:])
}
d := src[idx]
idx++
if d < 0x80 {
// Fast path for 2 bytes
dst[i] = uint64(c&0x7f) | (uint64(d) << 7)
continue
}
if idx >= uint(len(src)) {
return nil, fmt.Errorf("unexpected end of encoded varuint at byte 2; src=%x", src[idx-2:])
}
e := src[idx]
idx++
if e < 0x80 {
// Fast path for 3 bytes
dst[i] = uint64(c&0x7f) | (uint64(d&0x7f) << 7) | (uint64(e) << (2 * 7))
continue
}
u := uint64(c&0x7f) | (uint64(d&0x7f) << 7) | (uint64(e&0x7f) << (2 * 7))
// Slow path
j := idx
for {
if idx >= uint(len(src)) {
return nil, fmt.Errorf("unexpected end of encoded varint; src=%x", src[j-3:])
}
c := src[idx]
idx++
if c < 0x80 {
break
}
}
// These are the most common cases
switch idx - j {
case 1:
u |= (uint64(src[j]) << (3 * 7))
case 2:
b := src[j : j+2 : j+2]
u |= (uint64(b[0]&0x7f) << (3 * 7)) | (uint64(b[1]) << (4 * 7))
case 3:
b := src[j : j+3 : j+3]
u |= (uint64(b[0]&0x7f) << (3 * 7)) | (uint64(b[1]&0x7f) << (4 * 7)) | (uint64(b[2]) << (5 * 7))
case 4:
b := src[j : j+4 : j+4]
u |= (uint64(b[0]&0x7f) << (3 * 7)) | (uint64(b[1]&0x7f) << (4 * 7)) | (uint64(b[2]&0x7f) << (5 * 7)) | (uint64(b[3]) << (6 * 7))
case 5:
b := src[j : j+5 : j+5]
u |= (uint64(b[0]&0x7f) << (3 * 7)) | (uint64(b[1]&0x7f) << (4 * 7)) | (uint64(b[2]&0x7f) << (5 * 7)) | (uint64(b[3]&0x7f) << (6 * 7)) |
(uint64(b[4]) << (7 * 7))
case 6:
b := src[j : j+6 : j+6]
u |= (uint64(b[0]&0x7f) << (3 * 7)) | (uint64(b[1]&0x7f) << (4 * 7)) | (uint64(b[2]&0x7f) << (5 * 7)) | (uint64(b[3]&0x7f) << (6 * 7)) |
(uint64(b[4]&0x7f) << (7 * 7)) | (uint64(b[5]) << (8 * 7))
case 7:
b := src[j : j+7 : j+7]
if b[6] > 1 {
return src[idx:], fmt.Errorf("too big encoded varuint; src=%x", src[j-3:])
}
u |= (uint64(b[0]&0x7f) << (3 * 7)) | (uint64(b[1]&0x7f) << (4 * 7)) | (uint64(b[2]&0x7f) << (5 * 7)) | (uint64(b[3]&0x7f) << (6 * 7)) |
(uint64(b[4]&0x7f) << (7 * 7)) | (uint64(b[5]&0x7f) << (8 * 7)) | (1 << (9 * 7))
default:
return src[idx:], fmt.Errorf("too long encoded varuint; the maximum allowed length is 10 bytes; got %d bytes; src=%x", idx-j+3, src[j-3:])
}
dst[i] = u
}
return src[idx:], nil
}
// MarshalBool appends marshaled v to dst and returns the result.
func MarshalBool(dst []byte, v bool) []byte {
x := byte(0)
if v {
x = 1
}
return append(dst, x)
}
// UnmarshalBool unmarshals bool from src.
func UnmarshalBool(src []byte) bool {
return src[0] != 0
}
// MarshalBytes appends marshaled b to dst and returns the result.
func MarshalBytes(dst, b []byte) []byte {
dst = MarshalVarUint64(dst, uint64(len(b)))
dst = append(dst, b...)
return dst
}
// UnmarshalBytes returns unmarshaled bytes from src.
func UnmarshalBytes(src []byte) ([]byte, []byte, error) {
tail, n, err := UnmarshalVarUint64(src)
if err != nil {
return nil, nil, fmt.Errorf("cannot unmarshal string size: %w", err)
}
src = tail
if uint64(len(src)) < n {
return nil, nil, fmt.Errorf("src is too short for reading string with size %d; len(src)=%d", n, len(src))
}
return src[n:], src[:n], nil
}
// GetInt64s returns an int64 slice with the given size.
// The slice contents isn't initialized - it may contain garbage.
func GetInt64s(size int) *Int64s {
v := int64sPool.Get()
if v == nil {
return &Int64s{
A: make([]int64, size),
}
}
is := v.(*Int64s)
is.A = slicesutil.SetLength(is.A, size)
return is
}
// PutInt64s returns is to the pool.
func PutInt64s(is *Int64s) {
int64sPool.Put(is)
}
// Int64s holds an int64 slice
type Int64s struct {
A []int64
}
var int64sPool sync.Pool
// GetUint64s returns an uint64 slice with the given size.
// The slice contents isn't initialized - it may contain garbage.
func GetUint64s(size int) *Uint64s {
v := uint64sPool.Get()
if v == nil {
return &Uint64s{
A: make([]uint64, size),
}
}
is := v.(*Uint64s)
is.A = slicesutil.SetLength(is.A, size)
return is
}
// PutUint64s returns is to the pool.
func PutUint64s(is *Uint64s) {
uint64sPool.Put(is)
}
// Uint64s holds an uint64 slice
type Uint64s struct {
A []uint64
}
var uint64sPool sync.Pool
// GetUint32s returns an uint32 slice with the given size.
// The slize contents isn't initialized - it may contain garbage.
func GetUint32s(size int) *Uint32s {
v := uint32sPool.Get()
if v == nil {
return &Uint32s{
A: make([]uint32, size),
}
}
is := v.(*Uint32s)
is.A = slicesutil.SetLength(is.A, size)
return is
}
// PutUint32s returns is to the pool.
func PutUint32s(is *Uint32s) {
uint32sPool.Put(is)
}
// Uint32s holds an uint32 slice
type Uint32s struct {
A []uint32
}
var uint32sPool sync.Pool