faup1090 changes to consume commands via stdin (#107)

* Create a network service and connection faup's stdin. Create a Modes.faup_rate_multiplier attribute and set from faup command input

* Use faup_rate_multiplier to adjust the minAge for emitting messages

* Convert upload_rate_multiplier to a double and adjust minAge with it

* Cleanup

* Var name change

* MODES_NOTUSED define for unused modes client object

* Sanity check on faup multiplier field

dump1090.h

@@ -256,6 +256,9 @@ typedef enum {
 #define MAX_AMPLITUDE 65535.0
 #define MAX_POWER (MAX_AMPLITUDE * MAX_AMPLITUDE)
 
+#define FAUP_DEFAULT_RATE_MULTIPLIER    1.0                  // FA Upload rate multiplier
+
+
 // Include subheaders after all the #defines are in place
 
 #include "util.h"
@@ -357,6 +360,7 @@ struct _Modes {                             // Internal state
     uint64_t json_interval;          // Interval between rewriting the json aircraft file, in milliseconds; also the advertised map refresh interval
     uint64_t json_stats_interval;    // Interval between rewriting the json stats file, in milliseconds
     int   json_location_accuracy;    // Accuracy of location metadata: 0=none, 1=approx, 2=exact
+    double faup_rate_multiplier;     // Multiplier to adjust rate of faup1090 messages emitted
 
     int   json_aircraft_history_next;
     struct {

faup1090.c

@@ -77,6 +77,7 @@ static void faupInitConfig(void) {
     Modes.quiet                   = 1;
     Modes.net_output_flush_size   = MODES_OUT_FLUSH_SIZE;
     Modes.net_output_flush_interval = 200; // milliseconds
+    Modes.faup_rate_multiplier    = FAUP_DEFAULT_RATE_MULTIPLIER;
 }
 
 //
@@ -149,7 +150,7 @@ int main(int argc, char **argv) {
     char *bo_connect_ipaddr = "127.0.0.1";
     int bo_connect_port = 30005;
     struct client *c;
-    struct net_service *beast_input, *fatsv_output;
+    struct net_service *beast_input, *fatsv_output, *fa_cmd_input;
 
     // Set sane defaults
     faupInitConfig();
@@ -207,6 +208,9 @@ int main(int argc, char **argv) {
     fatsv_output = makeFatsvOutputService();
     createGenericClient(fatsv_output, STDOUT_FILENO);
 
+    fa_cmd_input = makeFaCmdInputService();
+    createGenericClient(fa_cmd_input, STDIN_FILENO);
+
     // Run it until we've lost either connection
     while (!Modes.exit && beast_input->connections && fatsv_output->connections) {
         struct timespec r = { 0, 100 * 1000 * 1000};

net_io.c

@@ -71,6 +71,7 @@
 static int handleBeastCommand(struct client *c, char *p);
 static int decodeBinMessage(struct client *c, char *p);
 static int decodeHexMessage(struct client *c, char *hex);
+static int handleFaupCommand(struct client *c, char *hex);
 
 static void moveNetClient(struct client *c, struct net_service *new_service);
 
@@ -250,6 +251,11 @@ struct net_service *makeFatsvOutputService(void)
     return serviceInit("FATSV TCP output", &Modes.fatsv_out, NULL, READ_MODE_IGNORE, NULL, NULL);
 }
 
+struct net_service *makeFaCmdInputService(void)
+{
+    return serviceInit("faup Command input", NULL, NULL, READ_MODE_ASCII, "\n", handleFaupCommand);
+}
+
 void modesInitNet(void) {
     struct net_service *s;
 
@@ -1109,6 +1115,37 @@ static void moveNetClient(struct client *c, struct net_service *new_service)
     c->service = new_service;
 }
 
+static int handleFaupCommand(struct client *c, char *p) {
+    if (p == NULL)
+        return 0;
+
+    MODES_NOTUSED(c);
+    char* msg_field;
+    double multiplier;
+    msg_field = strtok (p, "\t");
+
+    // Traverse through message for commands
+    while (msg_field != NULL) {
+        if (strcmp(msg_field, "upload_rate_multiplier") == 0) {
+            msg_field = strtok (NULL, "\t");
+            multiplier = atof(msg_field);
+
+            // Sanity check on multiplier value
+            if (!(multiplier > 0 && multiplier <= 100)) {
+                fprintf(stderr, "handleFaupCommand(): upload_rate_multiplier (%0.2f) out of range\n", multiplier);
+                return 0;
+            }
+
+            fprintf(stderr, "handleFaupCommand(): Adjusting message rate to FlightAware by %0.2fx\n", multiplier);
+            Modes.faup_rate_multiplier = multiplier;
+            break;
+        }
+        msg_field = strtok (NULL, "\t");
+    }
+
+    return 0;
+}
+
 //
 // Handle a Beast command message.
 // Currently, we just look for the Mode A/C command message
@@ -2466,6 +2503,7 @@ static void writeFATSV()
             (trackDataValid(&a->emergency_valid) && a->emergency != a->fatsv_emitted_emergency);
 
         uint64_t minAge;
+        double adjustedMinAge;
         if (immediate) {
             // a change we want to emit right away
             minAge = 0;
@@ -2485,8 +2523,12 @@ static void writeFATSV()
             minAge = (changed ? 10000 : 30000);
         }
 
-        if ((now - a->fatsv_last_emitted) < minAge)
+        // Adjust rate for multiplier
+        adjustedMinAge = minAge / Modes.faup_rate_multiplier;
+
+        if ((now - a->fatsv_last_emitted) < adjustedMinAge) {
             continue;
+        }
 
         char *p = prepareWrite(&Modes.fatsv_out, TSV_MAX_PACKET_SIZE);
         if (!p)

net_io.h

@@ -80,6 +80,7 @@ struct client *createGenericClient(struct net_service *service, int fd);
 // view1090 / faup1090 want to create these themselves:
 struct net_service *makeBeastInputService(void);
 struct net_service *makeFatsvOutputService(void);
+struct net_service *makeFaCmdInputService(void);
 
 void sendBeastSettings(struct client *c, const char *settings);