Major step towards GPSD-NG support in the client library.

1 files changed, 229 insertions, 0 deletions

diff --git a/gpsd_json.c b/gpsd_json.c
new file mode 100644
index 00000000..aa99786d
--- /dev/null
+++ b/gpsd_json.c
@@ -0,0 +1,229 @@
+/****************************************************************************
+
+NAME
+   gpsd_json.c - move data between in-core and JSON structures
+
+DESCRIPTION
+   This module uses the generic JSON parser to get data from JSON
+representations to gpsd core strctures, and vice_versa.
+
+***************************************************************************/
+
+#include <math.h>
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "gpsd_config.h"
+#include "gpsd.h"
+#include "gps_json.h"
+
+void json_tpv_dump(struct gps_data_t *gpsdata, struct gps_fix_t *fixp, 
+		   char *reply, size_t replylen)
+{
+    assert(replylen > 2);
+    (void)strlcpy(reply, "{\"class\":\"TPV\",", replylen);
+    (void)snprintf(reply+strlen(reply),
+		   replylen-strlen(reply),
+		   "\"tag\":\"%s\",",
+		   gpsdata->tag[0]!='\0' ? gpsdata->tag : "-");
+    (void)snprintf(reply+strlen(reply),
+		   replylen-strlen(reply),
+		   "\"device\":\"%s\",",
+		   gpsdata->gps_device);
+    if (isnan(fixp->time)==0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"time\":%.3f,",
+		       fixp->time);
+    if (isnan(fixp->ept)==0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"ept\":%.3f,",
+		       fixp->ept);
+    if (isnan(fixp->latitude)==0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"lat\":%.9f,",
+		       fixp->latitude);
+    if (isnan(fixp->longitude)==0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"lon\":%.9f,",
+		       fixp->longitude);
+    if (isnan(fixp->altitude)==0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"alt\":%.3f,",
+		       fixp->altitude);
+    if (isnan(fixp->eph)==0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"eph\":%.3f,",
+		       fixp->eph);
+    if (isnan(fixp->epv)==0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"epv\":%.3f,",
+		       fixp->epv);
+    if (isnan(fixp->track)==0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"track\":%.4f,",
+		       fixp->track);
+    if (isnan(fixp->speed)==0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"speed\":%.3f,",
+		       fixp->speed);
+    if (isnan(fixp->climb)==0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"climb\":%.3f,",
+		       fixp->climb);
+    if (isnan(fixp->epd)==0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"epd\":%.4f,",
+		       fixp->epd);
+    if (isnan(fixp->eps)==0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"eps\":%.2f,", fixp->eps);
+    if (isnan(fixp->epc)==0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"epc\":%.2f,", fixp->epc);
+    if (fixp->mode > 0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"mode\":%d,", fixp->mode);
+    if (reply[strlen(reply)-1] == ',')
+	reply[strlen(reply)-1] = '\0';	/* trim trailing comma */
+    (void)strlcat(reply, "}", sizeof(reply)-strlen(reply));
+}
+
+void json_sky_dump(struct gps_data_t *datap, char *reply, size_t replylen)
+{
+    int i, j, used, reported = 0;
+    assert(replylen > 2);
+    (void)strlcpy(reply, "{\"class\":\"SKY\",", replylen);
+    (void)snprintf(reply+strlen(reply),
+		   replylen- strlen(reply),
+		   "\"tag\":\"%s\",",
+		   datap->tag[0]!='\0' ? datap->tag : "-");
+    (void)snprintf(reply+strlen(reply),
+		   replylen-strlen(reply),
+		   "\"device\":\"%s\",",
+		   datap->gps_device);
+    if (isnan(datap->sentence_time)==0)
+	(void)snprintf(reply+strlen(reply),
+		       replylen-strlen(reply),
+		       "\"time\":%.3f ",
+		       datap->sentence_time);
+    /* insurance against flaky drivers */
+    for (i = 0; i < datap->satellites; i++)
+	if (datap->PRN[i])
+	    reported++;
+    (void)snprintf(reply+strlen(reply),
+		   replylen-strlen(reply),
+		   "\"reported\":%d,", reported);
+    if (reported) {
+	(void)strlcat(reply, "\"satellites\":[", replylen);
+	for (i = 0; i < reported; i++) {
+	    used = 0;
+	    for (j = 0; j < datap->satellites_used; j++)
+		if (datap->used[j] == datap->PRN[i]) {
+		    used = 1;
+		    break;
+		}
+	    if (datap->PRN[i]) {
+		(void)snprintf(reply+strlen(reply),
+			       replylen-strlen(reply),
+			       "{\"PRN\":%d,\"el\":%d,\"az\":%d,\"ss\":%.0f,\"used\":%s},",
+			       datap->PRN[i],
+			       datap->elevation[i],datap->azimuth[i],
+			       datap->ss[i],
+			       used ? "true" : "false");
+	    }
+	}
+	reply[strlen(reply)-1] = '\0';	/* trim trailing comma */
+	(void)strlcat(reply, "]", replylen-strlen(reply));
+    }
+    (void)strlcat(reply, "}", replylen-strlen(reply));
+    if (datap->satellites != reported)
+	gpsd_report(LOG_WARN,"Satellite count %d != PRN count %d\n",
+		    datap->satellites, reported);
+}
+
+int json_watch_read(struct policy_t *ccp,
+			 const char *buf, const char **endptr)
+{
+    int intcasoc;
+    struct json_attr_t chanconfig_attrs[] = {
+	{"raw",	           integer,  .addr.integer = &ccp->raw,
+				     .dflt.integer = -1},
+	{"buffer_policy",  integer,  .addr.integer = &intcasoc,
+				     .dflt.integer = -1},
+	{"scaled",         boolean,  .addr.boolean = &ccp->scaled},
+	{NULL},
+    };
+    int status;
+
+    status = json_read_object(buf, chanconfig_attrs, 0, endptr);
+    if (status == 0) {
+	if (intcasoc != -1)
+	    ccp->buffer_policy = intcasoc;
+    }
+    return status;
+}
+
+void json_watch_dump(struct policy_t *ccp, char *reply, size_t replylen)
+{
+    (void)snprintf(reply+strlen(reply), replylen-strlen(reply),
+		   "{\"class\":\"WATCH\",\"raw\":%d,\"buffer_policy\":%d,\"scaled\":%s}",
+		   ccp->raw, 
+		   ccp->buffer_policy,
+		   ccp->scaled ? "true" : "false");
+}
+
+int json_configdev_read(struct devconfig_t *cdp, const char *buf, const char **endptr)
+{
+    struct json_attr_t devconfig_attrs[] = {
+	{"device",	string,   .addr.string.ptr=cdp->device,
+				  .addr.string.len=sizeof(cdp->device)},
+	{"native",	integer,  .addr.integer = &cdp->native,
+				  .dflt.integer = -1},
+	{"bps",		integer,  .addr.integer = &cdp->bps,
+				  .dflt.integer = -1},
+	{"serialmode",	string,	  .addr.string.ptr=cdp->serialmode,
+				  .addr.string.len=sizeof(cdp->serialmode)},
+	{"cycle",	real,     .addr.real = &cdp->cycle,
+				  .dflt.real = NAN},
+	{"mincycle",	real,     .addr.real = &cdp->mincycle,
+				  .dflt.real = NAN},
+	{NULL},
+    };
+
+    return json_read_object(buf, devconfig_attrs, 0, endptr);
+}
+
+void json_configdev_dump(struct gps_device_t *devp, char *reply, size_t replylen)
+{
+    (void)snprintf(reply, replylen,
+		   "{\"class\":\"CONFIGDEV\",\"device\":\"%s\",\"native\":%d,\"bps\":%d,\"serialmode\":\"%u%c%u\",\"cycle\":%2.2f",
+		   devp->gpsdata.gps_device,
+		   devp->gpsdata.driver_mode,
+		   (int)gpsd_get_speed(&devp->ttyset),
+		   9 - devp->gpsdata.stopbits,
+		   (int)devp->gpsdata.parity,
+		   devp->gpsdata.stopbits,
+		   devp->gpsdata.cycle);
+    if (devp->device_type->rate_switcher != NULL)
+	(void)snprintf(reply+strlen(reply), replylen-strlen(reply),
+		       ",\"mincycle\":%2.2f",
+		       devp->device_type->min_cycle);
+    (void)strlcat(reply, "}", replylen);
+}
+
+/* gpsd_json.c ends here */