util.go

package go_engine_io_parser

import (
	"bytes"
)

func writeBinaryLen(l int64, w *bytes.Buffer) error {
	if l <= 0 {
		if err := w.WriteByte(StartByte); err != nil {
			return err
		}
		if err := w.WriteByte(TerminateByte); err != nil {
			return err
		}
		return nil
	}
	max := int64(1)
	for n := l / 10; n > 0; n /= 10 {
		max *= 10
	}
	for max > 0 {
		n := l / max
		if err := w.WriteByte(byte(n)); err != nil {
			return err
		}
		l -= n * max
		max /= 10
	}
	return w.WriteByte(0xff)
}

func writeTextLen(l int64, w *bytes.Buffer) error {
	if l <= 0 {
		if err := w.WriteByte(TerminateSymbol); err != nil {
			return err
		}
		if err := w.WriteByte(SeparateSymbol); err != nil {
			return err
		}
		return nil
	}
	max := int64(1)
	for n := l / 10; n > 0; n /= 10 {
		max *= 10
	}
	for max > 0 {
		n := l / max
		if err := w.WriteByte(byte(n) + TerminateSymbol); err != nil {
			return err
		}
		l -= n * max
		max /= 10
	}
	return w.WriteByte(SeparateSymbol)
}

func readBinaryLen(r byteReader) (int64, error) {
	ret := int64(0)
	for {
		b, err := r.ReadByte()
		if err != nil {
			return 0, err
		}
		if b == 0xff {
			break
		}
		if b > 9 {
			return 0, errInvalidPayload
		}
		ret = ret*10 + int64(b)
	}
	return ret, nil
}

func readTextLen(r byteReader) (int64, error) {
	ret := int64(0)
	for {
		b, err := r.ReadByte()
		if err != nil {
			return 0, err
		}
		if b == SeparateSymbol {
			break
		}
		if b < '0' || b > '9' {
			return 0, errInvalidPayload
		}
		ret = ret*10 + int64(b-TerminateSymbol)
	}
	return ret, nil
}

func byteToPacketType(b byte, typ FrameType) Type {
	if typ == FrameString {
		b -= TerminateSymbol
	}
	return Type(b)
}

func byteToFrameType(b byte) FrameType {
	return FrameType(b)
}