Utility class for read line

ReadLine.kt

class ReadLine {

    private val EOL = listOf(
        13.toByte(), // CR
        10.toByte()  // LR
    )
    private val EOL_SIZE = EOL.size
    private val MSG_MAX_LENGTH = 99

    private var line = byteArrayOf()
    private var reset = false

    fun feed (data: ByteArray): ByteArray? {
        // require reset
        if (reset) {
            line = byteArrayOf()
            reset = false
        }

        // append data
        line += data

        // end with newline, return data
        if (endWithNewLine(line)) {
            reset = true
            return line
        }
        // reset if data too long
        else if (line.size > MSG_MAX_LENGTH) {
            line = byteArrayOf()
        }
        return null
    }

    private fun endWithNewLine (data: ByteArray): Boolean {
        if (data.size <= EOL_SIZE) return false
        return data.takeLast(EOL_SIZE) == EOL
    }

}