/**
* Erzeugt einen neuen HDB3Sender.
*
* @param medium Die Signalcodierung, anbhaengig vom Uebertragungsmedium.
*/
public HDB3Sender(AMI.Medium medium) {
this.dc = 0;
this.last = medium.minus();
this.state = HDB3Sender.State.START;
this.medium = medium;
this.zeroBuffer = new ZeroBuffer();
}
/**
* Beendet die Uebertragung und codiert alle noch unbehandelten bits.
*
* @return Die resultierende Signalfolge.
*/
public String flush() {
CharSequence tmp = zeroBuffer.read();
zeroBuffer.clear();
state = HDB3Sender.State.START;
dc = 0;
last = medium.minus();
return tmp.toString();
}
/**
* Codiert eine bit-Folge durch das AMI-Verfahren.
*
* @param toSend Die zu codierende bit-Folge, als boolesches Array.
* @return Die resultierende Signalfolge.
*/
public String send(boolean[] toSend) {
StringBuilder output = new StringBuilder();
for (int i = 0; i < toSend.length; i++) {
boolean b = toSend[i];
if (!b) {
if (state != HDB3Sender.State.THREE_ZEROS) {
state = state.next();
zeroBuffer.buffer(medium.zero());
} else {
if (dc == 0 && last == medium.plus()) {
output.append(zeroBuffer.read());
output.append(medium.plus());
dc += 1;
last = medium.plus();
} else if (dc == 0 && last == medium.minus()) {
output.append(zeroBuffer.read());
output.append(medium.minus());
dc -= 1;
last = medium.minus();
} else if (dc == 1) {
output.append("-==-");
dc -= 2;
last = medium.minus();
} else if (dc == -1) {
output.append("+==+");
dc += 2;
last = medium.plus();
}
state = HDB3Sender.State.START;
zeroBuffer.clear();
}
} else {
if (dc == 0 && last == medium.plus()) {
output.append(zeroBuffer.read());
output.append(medium.minus());
dc -= 1;
last = medium.minus();
} else if (dc == 0 && last == medium.minus()) {
output.append(zeroBuffer.read());
output.append(medium.plus());
dc += 1;
last = medium.plus();
} else if (dc == 1) {
output.append(zeroBuffer.read());
output.append(medium.minus());
dc -= 1;
last = medium.minus();
} else if (dc == -1) {
output.append(zeroBuffer.read());
output.append(medium.plus());
dc += 1;
last = medium.plus();
}
state = HDB3Sender.State.START;
zeroBuffer.clear();
}
}
return output.toString();
}
