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/*
* Copyright (C) 2017 Konsulko Group
* Author: Matt Ranostay <matt.ranostay@konsulko.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define _GNU_SOURCE
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <gps.h>
#include <pthread.h>
#include <json-c/json.h>
#define AFB_BINDING_VERSION 2
#include <afb/afb-binding.h>
static struct gps_data_t data;
static struct afb_event location_event;
static pthread_t thread;
static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
#define MSECS_TO_USECS(x) (x * 1000)
// struct dop_t item order
static const char *dop_names[] = {
"xdop",
"ydop",
"pdop",
"hdop",
"vdop",
"tdop",
"gdop",
NULL
};
static json_object *populate_json_dop_data(json_object *jresp, struct dop_t *dop)
{
char **names = (char **) dop_names;
double *tmp = (double *) dop;
json_object *value = NULL;
while (*names) {
double val = *tmp++;
if (val != 0) {
value = json_object_new_double(val);
json_object_object_add(jresp, *names, value);
}
names++;
}
return jresp;
}
static json_object *populate_json_data(json_object *jresp)
{
json_object *value = NULL;
if (data.fix.mode != MODE_3D) {
json_object_put(jresp);
return NULL;
}
if (data.set & ALTITUDE_SET) {
value = json_object_new_double(data.fix.altitude);
json_object_object_add(jresp, "altitude", value);
}
if (data.set & LATLON_SET) {
value = json_object_new_double(data.fix.latitude);
json_object_object_add(jresp, "latitude", value);
value = json_object_new_double(data.fix.longitude);
json_object_object_add(jresp, "longitude", value);
}
if (data.set & SPEED_SET) {
value = json_object_new_double(data.fix.speed);
json_object_object_add(jresp, "speed", value);
}
jresp = populate_json_dop_data(jresp, &data.dop);
return jresp;
}
static void get_data(struct afb_req request)
{
json_object *jresp = NULL;
pthread_mutex_lock(&mutex);
jresp = populate_json_data(json_object_new_object());
if (jresp != NULL) {
afb_req_success(request, jresp, "GNSS location data");
} else {
afb_req_fail(request, "failed", "No 3D GNSS fix");
}
pthread_mutex_unlock(&mutex);
}
static void subscribe(struct afb_req request)
{
const char *value = afb_req_value(request, "value");
if (value && !strcasecmp(value, "location")) {
afb_req_subscribe(request, location_event);
afb_req_success(request, NULL, NULL);
return;
}
afb_req_fail(request, "failed", "Invalid event");
}
static void unsubscribe(struct afb_req request)
{
const char *value = afb_req_value(request, "value");
if (value && !strcasecmp(value, "location")) {
afb_req_unsubscribe(request, location_event);
afb_req_success(request, NULL, NULL);
return;
}
afb_req_fail(request, "failed", "Invalid event");
}
static void *data_poll(void *ptr)
{
/*
* keep reading till an error condition happens
*/
while (gps_waiting(&data, MSECS_TO_USECS(2000)) && !errno)
{
json_object *jresp = NULL;
pthread_mutex_lock(&mutex);
if (gps_read(&data) == -1) {
AFB_ERROR("Cannot read from GPS daemon.\n");
pthread_mutex_unlock(&mutex);
break;
}
jresp = populate_json_data(json_object_new_object());
if (jresp != NULL)
afb_event_push(location_event, jresp);
pthread_mutex_unlock(&mutex);
}
AFB_INFO("Closing GPS daemon connection.\n");
gps_stream(&data, WATCH_DISABLE, NULL);
gps_close(&data);
abort();
return NULL;
}
static int init()
{
const char *host, *port;
int ret;
location_event = afb_daemon_make_event("location");
host = getenv("AFBGPS_HOST") ? : "localhost";
port = getenv("AFBGPS_SERVICE") ? : "2947";
ret = gps_open(host, port, &data);
if (ret < 0)
return ret;
gps_stream(&data, WATCH_ENABLE | WATCH_JSON, NULL);
return pthread_create(&thread, NULL, &data_poll, NULL);
}
static const struct afb_verb_v2 binding_verbs[] = {
{ .verb = "location", .callback = get_data, .info = "Get GNSS data" },
{ .verb = "subscribe", .callback = subscribe, .info = "Subscribe to GNSS events" },
{ .verb = "unsubscribe", .callback = unsubscribe, .info = "Unsubscribe to GNSS events" },
{ }
};
/*
* binder API description
*/
const struct afb_binding_v2 afbBindingV2 = {
.api = "gps",
.specification = "GNSS/GPS API",
.verbs = binding_verbs,
.init = init,
};
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