static int
readPacket (unsigned char *packet, int size) {
int offset = 0;
int length = 0;
while (1) {
unsigned char byte;
if (!gioReadByte(gioEndpoint, &byte, (offset > 0))) {
if (offset > 0) logPartialPacket(packet, offset);
return 0;
}
if (offset < size) {
if (offset == 0) {
switch (byte) {
case BN_RSP_DISPLAY:
length = 1;
break;
case BN_RSP_CHARACTER:
case BN_RSP_SPACE:
case BN_RSP_BACKSPACE:
case BN_RSP_ENTER:
case BN_RSP_THUMB:
case BN_RSP_ROUTE:
length = 2;
break;
case BN_RSP_DESCRIBE:
length = 3;
break;
default:
logUnknownPacket(byte);
offset = 0;
length = 0;
continue;
}
}
packet[offset] = byte;
} else {
if (offset == size) logTruncatedPacket(packet, offset);
logDiscardedByte(byte);
}
if (++offset == length) {
if (offset > size) {
offset = 0;
length = 0;
continue;
}
logInputPacket(packet, offset);
return length;
}
}
}
static int
readSerialPacket (BrailleDisplay *brl, unsigned char *packet, int size) {
int started = 0;
int escape = 0;
int offset = 0;
int length = 0;
while (1) {
unsigned char byte;
if (!gioReadByte(brl->gioEndpoint, &byte, (started || escape))) {
if (started) logPartialPacket(packet, offset);
return 0;
}
if (byte == ESC) {
if ((escape = !escape)) continue;
} else if (escape) {
escape = 0;
if (offset > 0) {
logShortPacket(packet, offset);
offset = 0;
length = 0;
} else {
started = 1;
}
}
if (!started) {
logIgnoredByte(byte);
continue;
}
if (offset < size) {
if (offset == 0) {
switch (byte) {
case 0X43:
case 0X47:
length = 2;
break;
case 0X4C:
length = 3;
break;
case 0X46:
case 0X48:
length = 5;
break;
case 0X4B:
length = 9;
break;
case 0X53:
length = 10;
break;
default:
logUnknownPacket(byte);
started = 0;
continue;
}
}
packet[offset] = byte;
} else {
if (offset == size) logTruncatedPacket(packet, offset);
logDiscardedByte(byte);
}
if (++offset == length) {
if (offset > size) {
offset = 0;
length = 0;
started = 0;
continue;
}
logInputPacket(packet, offset);
return length;
}
}
}
