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package protoscan
import (
"encoding/binary"
"io"
"math"
)
// Fixed32 reads a fixed 4 byte value as a uint32. This proto type is
// more efficient than uint32 if values are often greater than 2^28.
func (b *base) Fixed32() (uint32, error) {
if len(b.Data) < b.Index+4 {
return 0, io.ErrUnexpectedEOF
}
v := binary.LittleEndian.Uint32(b.Data[b.Index:])
b.Index += 4
return v, nil
}
// Fixed64 reads a fixed 8 byte value as an uint64. This proto type is
// more efficient than uint64 if values are often greater than 2^56.
func (b *base) Fixed64() (uint64, error) {
if len(b.Data) < b.Index+8 {
return 0, io.ErrUnexpectedEOF
}
v := binary.LittleEndian.Uint64(b.Data[b.Index:])
b.Index += 8
return v, nil
}
// Sfixed32 reads a fixed 4 byte value signed value.
func (b *base) Sfixed32() (int32, error) {
v, err := b.Fixed32()
return int32(v), err
}
// Sfixed64 reads a fixed 8 byte signed value.
func (b *base) Sfixed64() (int64, error) {
v, err := b.Fixed64()
return int64(v), err
}
// Varint32 reads up to 32-bits of variable-length encoded data.
// Note that negative int32 values could still be encoded
// as 64-bit varints due to their leading 1s.
func (b *base) Varint32() (uint32, error) {
var v uint32
var err error
b.Index, v, err = varint32(b.Data, b.Index)
return v, err
}
func varint32(data []byte, index int) (int, uint32, error) {
var val uint32
// go versions at least <= 1.15 will not inline functions with
// for loops. https://github.com/golang/go/issues/14768
// for shift := uint(0); ; shift += 7 {
shift := uint(0)
loop:
if shift >= 32 {
return index, 0, ErrIntOverflow
}
if len(data) <= index {
return index, 0, io.ErrUnexpectedEOF
}
d := data[index]
index++
val |= uint32(d&0x7F) << shift
if d >= 0x80 {
shift += 7
goto loop
}
return index, val, nil
}
// Varint64 reads up to 64-bits of variable-length encoded data.
func (b *base) Varint64() (uint64, error) {
var v uint64
var err error
b.Index, v, err = varint64(b.Data, b.Index)
return v, err
}
func varint64(data []byte, index int) (int, uint64, error) {
var val uint64
// go versions at least <= 1.15 will not inline functions with
// for loops. https://github.com/golang/go/issues/14768
// for shift := uint(0); ; shift += 7 {
shift := uint(0)
loop:
if shift >= 64 {
return 0, 0, ErrIntOverflow
}
if len(data) <= index {
return 0, 0, io.ErrUnexpectedEOF
}
d := data[index]
index++
val |= uint64(d&0x7F) << shift
if d >= 0x80 {
shift += 7
goto loop
}
return index, val, nil
}
// Double values are encoded as a fixed length of 8 bytes in their IEEE-754 format.
func (b *base) Double() (float64, error) {
v, err := b.Fixed64()
return math.Float64frombits(v), err
}
// Float values are encoded as a fixed length of 4 bytes in their IEEE-754 format.
func (b *base) Float() (float32, error) {
v, err := b.Fixed32()
return math.Float32frombits(v), err
}
// Int32 reads a variable-length encoding of up to 4 bytes. This field type is
// best used if the field only has positive numbers, otherwise use sint32.
// Note, this field can also by read as an Int64.
func (b *base) Int32() (int32, error) {
var v uint64
var err error
b.Index, v, err = varint64(b.Data, b.Index)
return int32(v), err
}
// Int64 reads a variable-length encoding of up to 8 bytes. This field type is
// best used if the field only has positive numbers, otherwise use sint64.
func (b *base) Int64() (int64, error) {
var v uint64
var err error
b.Index, v, err = varint64(b.Data, b.Index)
return int64(v), err
}
// Uint32 reads a variable-length encoding of up to 4 bytes.
func (b *base) Uint32() (uint32, error) {
var v uint32
var err error
b.Index, v, err = varint32(b.Data, b.Index)
return v, err
}
// Uint64 reads a variable-length encoding of up to 8 bytes.
func (b *base) Uint64() (uint64, error) {
var v uint64
var err error
b.Index, v, err = varint64(b.Data, b.Index)
return v, err
}
// Sint32 uses variable-length encoding with zig-zag encoding for signed values.
// This field type more efficiently encodes negative numbers than regular int32s.
func (b *base) Sint32() (int32, error) {
var v uint64
var err error
b.Index, v, err = varint64(b.Data, b.Index)
return int32(unZig64(v)), err
}
// Sint64 uses variable-length encoding with zig-zag encoding for signed values.
// This field type more efficiently encodes negative numbers than regular int64s.
func (b *base) Sint64() (int64, error) {
var v uint64
var err error
b.Index, v, err = varint64(b.Data, b.Index)
return unZig64(v), err
}
// Bool is encoded as 0x01 or 0x00 plus the field+type prefix byte. 2 bytes total.
func (b *base) Bool() (bool, error) {
if len(b.Data) <= b.Index {
return false, io.ErrUnexpectedEOF
}
if d := b.Data[b.Index]; d&0x80 == 0 {
b.Index++
return d == 1, nil
}
var v uint64
var err error
b.Index, v, err = varint64(b.Data, b.Index)
return v == 1, err
}
// String reads a string type. This data will always contain UTF-8 encoded or
// 7-bit ASCII text.
func (m *Message) String() (string, error) {
b, err := m.Bytes()
return string(b), err
}
// Bytes returns the encode sequence of bytes.
// NOTE: this value is NOT copied.
func (m *Message) Bytes() ([]byte, error) {
l, err := m.packedLength()
if err != nil {
return nil, err
}
b := m.Data[m.Index : m.Index+l]
m.Index += l
return b, nil
}
func unZig64(v uint64) int64 {
return int64((v >> 1) ^ uint64((int64(v&1)<<63)>>63))
}
|
