add option to configure continuous state writing interval

help.h

@@ -96,6 +96,7 @@ static struct argp_option optionsReadsb[] = {
     {"write-prom", OptPromFile, "<filepath>", 0, "Periodically write prometheus output to <filepath>", 1},
     {"write-globe-history", OptGlobeHistoryDir, "<dir>", 0, "Extended Globe History", 1},
     {"write-state", OptStateDir, "<dir>", 0, "Write state to disk to have traces after a restart", 1},
+    {"write-state-every", OptStateInterval, "<seconds>", 0, "Continuously write state to disk every X seconds (default: 3600)", 1},
     {"write-state-only-on-exit", OptStateOnlyOnExit, 0, 0, "Don't continously update state.", 1},
     {"heatmap-dir", OptHeatmapDir, "<dir>", 0, "Change the directory where heatmaps are saved (default is in globe history dir)", 1},
     {"heatmap", OptHeatmap, "<interval in seconds>", 0, "Make Heatmap, each aircraft at most every interval seconds (creates historydir/heatmap.bin and exit after that)", 1},

readsb.c

@@ -153,6 +153,7 @@ static void configSetDefaults(void) {
     Modes.netIngest = 0;
     Modes.uuidFile = strdup("/usr/local/share/adsbexchange/adsbx-uuid");
     Modes.json_trace_interval = 20 * 1000;
+    Modes.state_write_interval = 1 * HOURS;
     Modes.heatmap_current_interval = -15;
     Modes.heatmap_interval = 60 * SECONDS;
     Modes.json_reliable = -13;
@@ -1555,6 +1556,14 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state) {
         case OptStateOnlyOnExit:
             Modes.state_only_on_exit = 1;
             break;
+        case OptStateInterval:
+            Modes.state_write_interval = (int64_t) (atof(arg) * 1.0 * SECONDS);
+            if (Modes.state_write_interval < 59 * SECONDS) {
+                fprintf(stderr, "ERROR: --write-state-every less than 60 seconds (specified: %s)\n", arg);
+                exit(1);
+                Modes.state_write_interval = 1 * HOURS;
+            }
+            break;
         case OptStateDir:
             sfree(Modes.state_parent_dir);
             Modes.state_parent_dir = strdup(arg);
@@ -2337,8 +2346,7 @@ static void miscStuff(int64_t now) {
             //fprintf(stderr, "save_blob: %02x\n", blob);
             notask_save_blob(blob);
             blob = (blob + 1) % STATE_BLOBS;
-            next_blob = now + 60 * MINUTES / STATE_BLOBS;
-
+            next_blob = now + Modes.state_write_interval / STATE_BLOBS;
             return;
         }
     }

readsb.h

@@ -782,6 +782,7 @@ struct _Modes
     int8_t dump_reduce; // only dump beast that would be sent out according to reduce_interval
     int8_t state_only_on_exit;
     int8_t free_aircraft;
+    int64_t state_write_interval;
     char *prom_file;
     int64_t heatmap_current_interval;
     int64_t heatmap_interval; // don't change data type
@@ -1168,6 +1169,7 @@ enum {
     OptPromFile,
     OptGlobeHistoryDir,
     OptStateDir,
+    OptStateInterval,
     OptStateOnlyOnExit,
     OptHeatmap,
     OptHeatmapDir,