hexfile.go

package tcmrc

import (
	"bufio"
	"bytes"
	"fmt"
	"os"
)

type HexFile struct {
	os.File
	dataBytesWritten int
	writeBuffer      *bufio.Writer
}

type DataRecord struct {
	Reclen     uint8
	LoadOffset uint16
	Data       []byte
}

func (r *DataRecord) Checksum() int {
	var sum uint8 = 0

	sum += r.Reclen
	sum += uint8(r.LoadOffset / 256)
	sum += uint8(r.LoadOffset % 256)

	for _, d := range r.Data {
		sum += uint8(d)
	}

	return int((^sum) + 1)
}

func (r *DataRecord) Format() string {
	var buffer bytes.Buffer

	buffer.WriteString(":")
	buffer.WriteString(fmt.Sprintf("%02X", r.Reclen))
	buffer.WriteString(fmt.Sprintf("%04X", r.LoadOffset))
	buffer.WriteString("00")

	for _, d := range r.Data {
		buffer.WriteString(fmt.Sprintf("%02X", d))
	}

	buffer.WriteString(fmt.Sprintf("%02X", r.Checksum()))

	return buffer.String()
}

func (h *HexFile) WriteEOFRecord() {
	h.writeLine(":00000001FF")
}

func (h *HexFile) WriteDataBytes(data []byte) {
	r := new(DataRecord)
	r.Data = data
	r.Reclen = uint8(len(data))
	h.WriteDataRecord(r)
}

func (h *HexFile) WriteDataRecord(r *DataRecord) {
	r.LoadOffset = uint16(h.dataBytesWritten)
	h.writeLine(r.Format())
	h.dataBytesWritten += int(r.Reclen)
}

func (h *HexFile) Close() error {
	h.WriteEOFRecord()
	h.writeBuffer.Flush()
	return h.File.Close()
}

func (h *HexFile) writeLine(str string) {
	h.writeBuffer.WriteString(fmt.Sprintf("%s\n", str))
}

func NewHexFile(fileName string) (*HexFile, error) {
	file, err := os.Create(fileName)

	if err != nil {
		return nil, err
	}

	hex := &HexFile{
		File:             *file,
		dataBytesWritten: 0,
		writeBuffer:      bufio.NewWriter(file),
	}

	return hex, nil
}