/* recv_fsm
*
* Attempt to process some data from the buffer located at 'data'.
*
* If a command is succcessfully read, then this returns the number of bytes
* consumed from the buffer. If a partial command is present in the buffer,
* but not enough to process yet, then this will return 0; the invoking
* function should call it later when more data is available. If an error
* occurs such that no further data can be handled from the connection, then
* this will call close_conn on the connection and return -1.
*/
static int recv_fsm(struct tcp_pcb *pcb, uint8_t * data, int len) {
uint8_t cmd = *data;
int npoints;
switch (ps_state) {
case MAIN:
switch (cmd) {
case 'p':
/* Prepare stream. */
if (dac_prepare() < 0) {
return send_resp(pcb, RESP_NAK_INVL, cmd, 1);
} else {
return send_resp(pcb, RESP_ACK, cmd, 1);
}
case 'b':
/* Make sure we have all of this packet... */
if (len < sizeof(struct begin_command))
return 0;
struct begin_command *bc = (struct begin_command *)data;
if (bc->point_rate > DAC_MAX_POINT_RATE)
return send_resp(pcb, RESP_NAK_INVL, cmd, 1);
// XXX set_low_water_mark(bc->low_water_mark);
dac_set_rate(bc->point_rate);
dac_start();
return send_resp(pcb, RESP_ACK, cmd,
sizeof(struct begin_command));
case 'u':
/* Update and Begin use the same packet format */
if (len < sizeof(struct begin_command))
return 0;
struct begin_command *uc = (struct begin_command *)data;
if (uc->point_rate > DAC_MAX_POINT_RATE)
return send_resp(pcb, RESP_NAK_INVL, cmd, 1);
dac_set_rate(uc->point_rate);
// XXX set_low_water_mark(uc->low_water_mark);
return send_resp(pcb, RESP_ACK, cmd,
sizeof(struct begin_command));
case 'q':
if (len < sizeof(struct queue_command))
return 0;
struct queue_command *qc = (struct queue_command *)data;
if (qc->point_rate > DAC_MAX_POINT_RATE)
return send_resp(pcb, RESP_NAK_INVL, cmd, 1);
dac_rate_queue(qc->point_rate);
return send_resp(pcb, RESP_ACK, cmd,
sizeof(struct queue_command));
case 'd':
/* Data: switch into the DATA state to start reading
* points into the buffer. */
if (len < sizeof(struct data_command))
return 0;
struct data_command *h = (struct data_command *) data;
if (h->npoints) {
ps_state = DATA;
ps_pointsleft = h->npoints;
/* We'll send a response once we've read all
* of the data. */
return sizeof(struct data_command);
} else {
/* 0-length data packets are legit. */
return send_resp(pcb, RESP_ACK, cmd,
sizeof(struct data_command));
}
case 's':
/* Stop */
if (dac_get_state() == DAC_IDLE) {
return send_resp(pcb, RESP_NAK_INVL, cmd, 1);
} else {
dac_stop(0);
return send_resp(pcb, RESP_ACK, cmd, 1);
}
case 0:
case 0xFF:
/* Emergency-stop. */
le_estop(ESTOP_PACKET);
return send_resp(pcb, RESP_ACK, cmd, 1);
case 'c':
/* Clear e-stop. */
le_estop_clear(ESTOP_CLEAR_ALL);
if (le_get_state() == LIGHTENGINE_READY)
return send_resp(pcb, RESP_ACK, cmd, 1);
else
return send_resp(pcb, RESP_NAK_ESTOP, cmd, 1);
case '?':
/* Ping */
return send_resp(pcb, RESP_ACK, cmd, 1);
default:
outputf("unknown cmd 0x%02x", cmd);
return close_conn(pcb, CONNCLOSED_UNKNOWNCMD, -1);
}
return -1;
case DATA:
ASSERT_NOT_EQUAL(ps_pointsleft, 0);
/* We can only write a complete point at a time. */
if (len < sizeof(struct dac_point))
return 0;
/* How many bytes of data is it our business to write? */
npoints = len / sizeof(struct dac_point);
if (npoints > ps_pointsleft)
npoints = ps_pointsleft;
/* How much do we have room for now? Note that dac_prepare
* is a ring buffer, so it's OK if it returns less than the
* number of points we have ready for it. We'll just have
* the FSM invoke us again. */
int nready = dac_request();
packed_point_t *addr = dac_request_addr();
/* On the other hand, if the DAC isn't ready for *any* data,
* then ignore the rest of this write command and NAK when
* it's over. The FSM will take care of us... */
if (nready <= 0) {
if (nready == 0) {
outputf("overflow: wanted to write %d", npoints);
} else {
outputf("underflow: pl %d np %d r %d", ps_pointsleft, npoints, nready);
}
ps_state = DATA_ABORTING;
/* Danger: goto. This could probably be structured
* better... */
goto handle_aborted_data;
}
if (npoints > nready)
npoints = nready;
dac_point_t *pdata = (dac_point_t *)data;
int i;
for (i = 0; i < npoints; i++) {
dac_pack_point(addr + i, pdata + i);
}
/* Let the DAC know we've given it more data */
dac_advance(npoints);
ps_pointsleft -= npoints;
if (!ps_pointsleft) {
ps_state = MAIN;
return send_resp(pcb, RESP_ACK, 'd',
npoints * sizeof(struct dac_point));
} else {
return (npoints * sizeof(struct dac_point));
}
case DATA_ABORTING:
ASSERT_NOT_EQUAL(ps_pointsleft, 0);
/* We can only consume a complete point at a time. */
if (len < sizeof(struct dac_point))
return 0;
/* How many points do we have? */
npoints = len / sizeof(struct dac_point);
if (npoints > ps_pointsleft)
npoints = ps_pointsleft;
handle_aborted_data:
ps_pointsleft -= npoints;
if (!ps_pointsleft) {
ps_state = MAIN;
return send_resp(pcb, RESP_NAK_INVL, 'd',
npoints * sizeof(struct dac_point));
} else {
return (npoints * sizeof(struct dac_point));
}
default:
break;
}
panic("invalid state in recv_dfa");
return -1;
}
void playback_refill() {
dac_point_t *ptr = 0;
int i;
int dlen = dac_request(&ptr);
/* Have we underflowed? */
if (dlen < 0) {
if (le_get_state() != LIGHTENGINE_READY)
return;
outputf("*U*");
dac_prepare();
return;
}
/* If we don't have any more room... */
if (dlen == 0) {
if (dac_get_state() == DAC_PREPARED)
dac_start();
return;
}
switch (playback_src) {
case SRC_ILDAPLAYER:
if (!(playback_source_flags & ILDA_PLAYER_PLAYING))
break;
outputf("%d", dlen);
i = ilda_read_points(dlen, ptr);
if (i < 0) {
outputf("err: %d", i);
playback_source_flags &= ~ILDA_PLAYER_PLAYING;
} else if (i == 0) {
ilda_reset_file();
if (playback_source_flags & ILDA_PLAYER_REPEAT) {
outputf("rep");
} else {
outputf("done");
/* If the whole file didn't fit in the
* buffer, we may have to start it now. */
dlen = 0;
playback_source_flags &= ~ILDA_PLAYER_PLAYING;
}
} else {
dac_advance(i);
}
break;
default:
panic("bad playback source");
}
/* If the buffer is nearly full, start it up */
if (dlen < 100 && dac_get_state() == DAC_PREPARED)
dac_start();
}
