1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
|
/*
* 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)
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);
}
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,
};
|
