util.go

package main

import (
	"bytes"
	"encoding/binary"
	"io"
)

func scanZStrings(data []byte, atEOF bool) (int, []byte, error) {
	if atEOF && len(data) == 0 {
		return 0, nil, nil
	} else if i := bytes.IndexByte(data, 0); i >= 0 {
		return i + 1, data[0:i], nil
	} else if atEOF {
		return len(data), data, nil
	} else {
		return 0, nil, nil
	}
}

func readUint16(r io.Reader) (uint16, error) {
	b := [2]byte{}
	if _, err := r.Read(b[:]); err != nil {
		return 0, err
	}
	return binary.LittleEndian.Uint16(b[:]), nil
}

func readUint32(r io.Reader) (uint32, error) {
	b := [4]byte{}
	if _, err := r.Read(b[:]); err != nil {
		return 0, err
	}
	return binary.LittleEndian.Uint32(b[:]), nil
}

func writeUint16(w io.Writer, v uint16) (int, error) {
	b := [2]byte{}
	binary.LittleEndian.PutUint16(b[:], v)
	return w.Write(b[:])
}

func writeUint32(w io.Writer, v uint32) (int, error) {
	b := [4]byte{}
	binary.LittleEndian.PutUint32(b[:], v)
	return w.Write(b[:])
}

func byteswap(b []byte) {
	for i, j := 0, len(b)-1; i < j; i, j = i+1, j-1 {
		b[i], b[j] = b[j], b[i]
	}
}