diff options
| -rw-r--r-- | src/af-gps-binding.c | 186 |
1 files changed, 131 insertions, 55 deletions
diff --git a/src/af-gps-binding.c b/src/af-gps-binding.c index c96ccf0..668a10f 100644 --- a/src/af-gps-binding.c +++ b/src/af-gps-binding.c @@ -40,6 +40,8 @@ #define METER_PER_SECOND_TO_KILOMETER_PER_HOUR 3.6 /* 3600 / 1000 */ #define METER_PER_SECOND_TO_MILE_PER_HOUR 2.236936292 /* 3600 / 1609.344 */ +#define DEFAULT_PERIOD 2000 /* 2 seconds */ + /* * references: * @@ -47,6 +49,7 @@ * http://www.gpsinformation.org/dale/nmea.htm */ +/* flags for recording what field is set */ struct flags { unsigned time: 1; unsigned latitude: 1; @@ -56,6 +59,7 @@ struct flags { unsigned track: 1; }; +/* the gps data converted */ struct gps { struct flags set; @@ -67,36 +71,47 @@ struct gps { double track; }; +/* + * the type of position expected + * + * here, this type is mainly the selection of units + */ enum type { - type_wgs84, - type_dms_kmh, - type_dms_mph, - type_dms_kn, + type_wgs84, /* longitude, latitude, track: degre, altitude: m, speed: m/s */ + type_dms_kmh, /* longitude, latitude: degre°minute'second.xxx"X, track: degre, altitude: m, speed: km/h */ + type_dms_mph, /* longitude, latitude: degre°minute'second.xxx"X, track: degre, altitude: m, speed: mph */ + type_dms_kn, /* longitude, latitude: degre°minute'second.xxx"X, track: degre, altitude: m, speed: kn */ type_COUNT, type_DEFAULT = type_wgs84, type_INVALID = -1 }; struct event; -struct period; +/* + * for each expected period + */ struct period { - struct period *next; - struct event *events; - uint32_t period; - uint32_t last; + struct period *next; /* link to the next other period */ + struct event *events; /* events for the period */ + uint32_t period; /* value of the period in ms */ + uint32_t last; /* last update of the period */ }; +/* + * each generated event + */ struct event { - struct event *next; - struct event *byid; - struct period *period; - const char *name; - struct afb_event event; - enum type type; - int id; + struct event *next; /* link for the same period */ + const char *name; /* name of the event */ + struct afb_event event; /* the event for the binder */ + enum type type; /* the type of data expected */ + int id; /* id of the event for unsubscribe */ }; +/* + * names of the types + */ static const char * const type_NAMES[type_COUNT] = { "WGS84", "DMS.km/h", @@ -109,30 +124,45 @@ static const char * const type_NAMES[type_COUNT] = { */ const struct afb_binding_interface *afbitf; -static struct gps frames[10]; -static int frameidx; -static int newframes; - -static struct json_object *time_ms; -static struct json_object *latitude_wgs; -static struct json_object *longitude_wgs; -static struct json_object *latitude_dms; -static struct json_object *longitude_dms; -static struct json_object *altitude_m; -static struct json_object *speed_ms; -static struct json_object *speed_kmh; -static struct json_object *speed_mph; -static struct json_object *speed_kn; -static struct json_object *track_d; - -static struct json_object *positions[type_COUNT]; +/* + * records the raw frames + */ +static struct gps frames[10]; /* a short memory for further computation if needed */ +static int frameidx; /* index of the last frame (frames are in the reverse order) */ +static int newframes; /* boolean indication of wether new frames are availables */ -static struct period *periods; -static struct event *events; +/* + * records the JSON object for sending positions + */ +static struct json_object *time_ms; /* time as double in millisecond */ +static struct json_object *latitude_wgs; /* latitude as double in degree */ +static struct json_object *longitude_wgs; /* longitude as double in degree */ +static struct json_object *latitude_dms; /* latitude as string in d°m's.s"X */ +static struct json_object *longitude_dms; /* longitude as string in d°m's.s"X */ +static struct json_object *altitude_m; /* altitude as double in meter */ +static struct json_object *speed_ms; /* speed as double in m/s */ +static struct json_object *speed_kmh; /* speed as double in km/h */ +static struct json_object *speed_mph; /* speed as double in mph */ +static struct json_object *speed_kn; /* speed as double in kn */ +static struct json_object *track_d; /* heading track as double in degree */ + +static struct json_object *positions[type_COUNT]; /* computed positions by type */ + +/* head of the list of periods */ +static struct period *list_of_periods; /* declare the connection routine */ static int nmea_connect(); +/***************************************************************************************/ +/***************************************************************************************/ +/** **/ +/** **/ +/** SECTION: FORMATING JSON POSITIONS **/ +/** **/ +/** **/ +/***************************************************************************************/ +/***************************************************************************************/ /* * Creates the JSON representation for Degree Minute Second representation of coordinates */ @@ -288,15 +318,34 @@ static struct json_object *position(enum type type) return json_object_get(result); } +/***************************************************************************************/ +/***************************************************************************************/ +/** **/ +/** **/ +/** SECTION: MANAGING EVENTS **/ +/** **/ +/** **/ +/***************************************************************************************/ +/***************************************************************************************/ /* * get the event handler of given id */ static struct event *event_of_id(int id) { - struct event *r = events; - while(r && r->id != id) - r = r->byid; - return r; + struct period *p; + struct event *e; + + p = list_of_periods; + while(p != NULL) { + e = p->events; + p = p->next; + while(e != NULL) { + if (e->id == id) + return e; + e = e->next; + } + } + return NULL; } /* @@ -305,20 +354,20 @@ static struct event *event_of_id(int id) static struct event *event_get(enum type type, int period) { static int id; - int mask; + int shift; uint32_t perio; struct period *p, **pp, *np; struct event *e; /* normalize the period */ period = period <= 100 ? 1 : period > 60000 ? 600 : (period / 100); - mask = 31; - while(period > (period & mask)) - mask <<= 1; - perio = (uint32_t)(100 * (period & mask)); + shift = 0; + while((period >> shift) > 31) + shift++; + perio = (uint32_t)(100 * (((period >> shift) & 31) << shift)); /* search for the period */ - pp = &periods; + pp = &list_of_periods; p = *pp; while(p != NULL && p->period < perio) { pp = &p->next; @@ -355,8 +404,6 @@ static struct event *event_get(enum type type, int period) } e->next = p->events; - e->byid = events; - e->period = p; e->type = type; do { id++; @@ -365,16 +412,18 @@ static struct event *event_get(enum type type, int period) } while(event_of_id(id) != NULL); e->id = id; p->events = e; - events = e; } return e; } +/* + * Sends the events if needed + */ static void event_send() { struct period *p, **pp; - struct event *e, **pe, **peid; + struct event *e, **pe; struct timeval tv; uint32_t now; @@ -387,7 +436,7 @@ static void event_send() now = (uint32_t)(tv.tv_sec * 1000) + (uint32_t)(tv.tv_usec / 1000); /* iterates over the periods */ - pp = &periods; + pp = &list_of_periods; p = *pp; while (p != NULL) { if (p->events == NULL) { @@ -407,10 +456,6 @@ static void event_send() else { /* no more listeners, free the event */ *pe = e->next; - peid = &events; - while (*peid != e) - peid = &(*peid)->byid; - *peid = e->byid; afb_event_drop(e->event); free(e); } @@ -423,6 +468,18 @@ static void event_send() } } +/***************************************************************************************/ +/***************************************************************************************/ +/** **/ +/** **/ +/** SECTION: HANDLING NMEA SENTENCES **/ +/** **/ +/** **/ +/***************************************************************************************/ +/***************************************************************************************/ +/* + * interprets a nmea time + */ static int nmea_time(const char *text, uint32_t *result) { uint32_t x; @@ -466,6 +523,9 @@ static int nmea_time(const char *text, uint32_t *result) return 1; } +/* + * interprets a nmea angle having minutes + */ static int nmea_angle(const char *text, double *result) { uint32_t x = 0; @@ -503,6 +563,10 @@ static int nmea_angle(const char *text, double *result) return 1; } +/* + * creates a new position for the given optionnal fields + * returns 1 if correct or 0 if a format error exists + */ static int nmea_set( const char *tim, const char *lat, const char *latu, @@ -596,6 +660,9 @@ static int nmea_set( return 1; } +/* + * Splits the nmea sentences in its fields + */ static int nmea_split(char *s, char *fields[], int count) { int index = 0; @@ -789,6 +856,15 @@ static int nmea_connect() return rc; } +/***************************************************************************************/ +/***************************************************************************************/ +/** **/ +/** **/ +/** SECTION: BINDING VERBS IMPLEMENTATION **/ +/** **/ +/** **/ +/***************************************************************************************/ +/***************************************************************************************/ /* * Returns the type corresponding to the given name */ @@ -836,7 +912,7 @@ static void subscribe(struct afb_req req) if (get_type_for_req(req, &type)) { period = afb_req_value(req, "period"); - event = event_get(type, period == NULL ? 2000 : atoi(period)); + event = event_get(type, period == NULL ? DEFAULT_PERIOD : atoi(period)); if (event == NULL) afb_req_fail(req, "out-of-memory", NULL); else if (afb_req_subscribe(req, event->event) != 0) |