Properly display histogram if timestamps are not enabled on server

packet-exchange/src/server.c

@@ -254,27 +254,29 @@ static void print_histograms() {
 
   interval = param->interval / 1000;
 
-  printf("{\"measure_sets\": [{"
-             "\"measure_type\": \"packet_recv_timestamps\","
-             "\"props_names\": [\"user_space\", \"kernel_space\"],"
-             "\"units\": [\"us\", \"us\"],"
-             "\"props_type\": \"histogram\","
-             "\"metadata\": {"
-                "\"i\": \"%dus\", \"duration\": \"%dh%d\""
-                "},"
-             "\"props\": [", interval, duration_hour, duration_minutes);
-
-  max_hist_val = 0;
-  for (int i = 0; i < 2; i++)
-    for (int j = 0; j < MAX_HIST_VAL; j++)
-      if (histograms[i][j])
-        max_hist_val = j > max_hist_val ? j : max_hist_val;
-
-  for (int i = 0; i < 2; i++) {
-    printf("[");
-    for (int j = 0; j < max_hist_val; j++)
-      printf("%" PRIi64 "%s", histograms[i][j], (j + 1 < max_hist_val ? ", " : ""));
-    printf("%s", (i + 1 < 2 ? "], " : "]"));
+  if(enable_timestamps) {
+    printf("{\"measure_sets\": [{"
+               "\"measure_type\": \"packet_recv_timestamps\","
+               "\"props_names\": [\"user_space\", \"kernel_space\"],"
+               "\"units\": [\"us\", \"us\"],"
+               "\"props_type\": \"histogram\","
+               "\"metadata\": {"
+                  "\"i\": \"%dus\", \"duration\": \"%dh%d\""
+                  "},"
+               "\"props\": [", interval, duration_hour, duration_minutes);
+
+    max_hist_val = 0;
+    for (int i = 0; i < 2; i++)
+      for (int j = 0; j < MAX_HIST_VAL; j++)
+        if (histograms[i][j])
+          max_hist_val = j > max_hist_val ? j : max_hist_val;
+
+    for (int i = 0; i < 2; i++) {
+      printf("[");
+      for (int j = 0; j < max_hist_val; j++)
+        printf("%" PRIi64 "%s", histograms[i][j], (j + 1 < max_hist_val ? ", " : ""));
+      printf("%s", (i + 1 < 2 ? "], " : "]"));
+    }
   }
 
   max_hist_val = 0;
@@ -286,8 +288,12 @@ static void print_histograms() {
     if(histograms[2][j])
       min_hist_val = j;
 
-  printf(   "]}, {"
-             "\"measure_type\": \"packet_jitter\","
+  if(!enable_timestamps)
+    printf("{\"measure_sets\": [{");
+  else
+    printf(   "]}, {");
+
+  printf(    "\"measure_type\": \"packet_jitter\","
              "\"props_names\": [\"jitter\"],"
              "\"units\": [\"us\"],"
              "\"props_type\": \"histogram\","