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|
package binary
import (
"encoding/binary"
"io"
"math"
)
func NewDecoder(input io.Reader) *Decoder {
return &Decoder{
input: input,
}
}
func NewDecoderWithCompress(input io.Reader) *Decoder {
return &Decoder{
input: input,
compressInput: NewCompressReader(input),
}
}
type Decoder struct {
compress bool
input io.Reader
compressInput io.Reader
scratch [binary.MaxVarintLen64]byte
}
func (decoder *Decoder) SelectCompress(compress bool) {
decoder.compress = compress
}
func (decoder *Decoder) Get() io.Reader {
if decoder.compress && decoder.compressInput != nil {
return decoder.compressInput
}
return decoder.input
}
func (decoder *Decoder) Bool() (bool, error) {
v, err := decoder.ReadByte()
if err != nil {
return false, err
}
return v == 1, nil
}
func (decoder *Decoder) Uvarint() (uint64, error) {
return binary.ReadUvarint(decoder)
}
func (decoder *Decoder) Int8() (int8, error) {
v, err := decoder.ReadByte()
if err != nil {
return 0, err
}
return int8(v), nil
}
func (decoder *Decoder) Int16() (int16, error) {
v, err := decoder.UInt16()
if err != nil {
return 0, err
}
return int16(v), nil
}
func (decoder *Decoder) Int32() (int32, error) {
v, err := decoder.UInt32()
if err != nil {
return 0, err
}
return int32(v), nil
}
func (decoder *Decoder) Int64() (int64, error) {
v, err := decoder.UInt64()
if err != nil {
return 0, err
}
return int64(v), nil
}
func (decoder *Decoder) UInt8() (uint8, error) {
v, err := decoder.ReadByte()
if err != nil {
return 0, err
}
return uint8(v), nil
}
func (decoder *Decoder) UInt16() (uint16, error) {
if _, err := decoder.Get().Read(decoder.scratch[:2]); err != nil {
return 0, err
}
return uint16(decoder.scratch[0]) | uint16(decoder.scratch[1])<<8, nil
}
func (decoder *Decoder) UInt32() (uint32, error) {
if _, err := decoder.Get().Read(decoder.scratch[:4]); err != nil {
return 0, err
}
return uint32(decoder.scratch[0]) |
uint32(decoder.scratch[1])<<8 |
uint32(decoder.scratch[2])<<16 |
uint32(decoder.scratch[3])<<24, nil
}
func (decoder *Decoder) UInt64() (uint64, error) {
if _, err := decoder.Get().Read(decoder.scratch[:8]); err != nil {
return 0, err
}
return uint64(decoder.scratch[0]) |
uint64(decoder.scratch[1])<<8 |
uint64(decoder.scratch[2])<<16 |
uint64(decoder.scratch[3])<<24 |
uint64(decoder.scratch[4])<<32 |
uint64(decoder.scratch[5])<<40 |
uint64(decoder.scratch[6])<<48 |
uint64(decoder.scratch[7])<<56, nil
}
func (decoder *Decoder) Float32() (float32, error) {
v, err := decoder.UInt32()
if err != nil {
return 0, err
}
return math.Float32frombits(v), nil
}
func (decoder *Decoder) Float64() (float64, error) {
v, err := decoder.UInt64()
if err != nil {
return 0, err
}
return math.Float64frombits(v), nil
}
func (decoder *Decoder) Fixed(ln int) ([]byte, error) {
if reader, ok := decoder.Get().(FixedReader); ok {
return reader.Fixed(ln)
}
buf := make([]byte, ln)
if _, err := decoder.Get().Read(buf); err != nil {
return nil, err
}
return buf, nil
}
func (decoder *Decoder) String() (string, error) {
strlen, err := decoder.Uvarint()
if err != nil {
return "", err
}
str, err := decoder.Fixed(int(strlen))
if err != nil {
return "", err
}
return string(str), nil
}
func (decoder *Decoder) Decimal128() ([]byte, error) {
bytes := make([]byte, 16)
_, err := decoder.Get().Read(bytes)
return bytes, err
}
func (decoder *Decoder) ReadByte() (byte, error) {
if _, err := decoder.Get().Read(decoder.scratch[:1]); err != nil {
return 0x0, err
}
return decoder.scratch[0], nil
}
type FixedReader interface {
Fixed(ln int) ([]byte, error)
}
|
