neoneo-go/_pkg.dev/wire/util/binaryReader.go
Roman Khimov ddd1d92ff1 pkg: hide it by moving to _pkg.dev
The idea here is to preserve the history of `dev` branch development and its
code when merging with the `master`. Later this code could be moved into the
masters code where appropriate.
2019-08-20 18:39:50 +03:00

71 lines
1.5 KiB
Go

package util
import (
"encoding/binary"
"io"
)
//BinReader is a convenient wrapper around a io.Reader and err object
// Used to simplify error handling when reading into a struct with many fields
type BinReader struct {
R io.Reader
Err error
}
// Read reads from the underlying io.Reader
// into the interface v in LE
func (r *BinReader) Read(v interface{}) {
if r.Err != nil {
return
}
r.Err = binary.Read(r.R, binary.LittleEndian, v)
}
// ReadBigEnd reads from the underlying io.Reader
// into the interface v in BE
func (r *BinReader) ReadBigEnd(v interface{}) {
if r.Err != nil {
return
}
r.Err = binary.Read(r.R, binary.BigEndian, v)
}
//VarUint reads a variable integer from the
// underlying reader
func (r *BinReader) VarUint() uint64 {
var b uint8
r.Err = binary.Read(r.R, binary.LittleEndian, &b)
if b == 0xfd {
var v uint16
r.Err = binary.Read(r.R, binary.LittleEndian, &v)
return uint64(v)
}
if b == 0xfe {
var v uint32
r.Err = binary.Read(r.R, binary.LittleEndian, &v)
return uint64(v)
}
if b == 0xff {
var v uint64
r.Err = binary.Read(r.R, binary.LittleEndian, &v)
return v
}
return uint64(b)
}
// VarBytes reads the next set of bytes from the underlying reader.
// VarUInt is used to determine how large that slice is
func (r *BinReader) VarBytes() []byte {
n := r.VarUint()
b := make([]byte, n)
r.Read(b)
return b
}
// VarString calls VarBytes and casts the results as a string
func (r *BinReader) VarString() string {
b := r.VarBytes()
return string(b)
}