Clean up histogram printing and fix missing bracket

packet-exchange/src/client.c

@@ -310,17 +310,12 @@ static void print_histograms() {
            "\"props_names\": [\"user_space\", \"kernel_space\"],"
            "\"units\": [\"us\", \"us\"],"
            "\"props_type\": \"histogram\","
-           "\"metadata\": {"
-           "\"i\": \"%dus\", \"duration\": \"%dh%d\", \"etf_offset\": \"%dus\","
-           "},"
-           "\"props\": [",
+           "\"metadata\": {\"i\": \"%dus\", \"duration\": \"%dh%d\", \"etf_offset\": \"%dus\",},"
+           "\"props\": [[",
            interval, duration_hour, duration_minutes, thread_params.etf_offset);
-    histogram = kernel_latency_hist;
 
-    max_hist_val = 0;
-    for (int j = 0; j < MAX_KERNEL_LATENCY; j++)
-      if (histogram[j])
-        max_hist_val = j > max_hist_val ? j : max_hist_val;
+    histogram = kernel_latency_hist;
+    max_hist_val = histogram_max(histogram, MAX_KERNEL_LATENCY - 1);
 
   } else {
     printf("{\"measure_sets\": [{"
@@ -328,25 +323,17 @@ static void print_histograms() {
            "\"props_names\": [\"rtt\"],"
            "\"units\": [\"us\"],"
            "\"props_type\": \"histogram\","
-           "\"metadata\": {"
-           "\"i\": \"%dus\", \"duration\": \"%dh%d\", \"etf_offset\": \"%dus\","
-           "},"
-           "\"props\": [",
+           "\"metadata\": {\"i\": \"%dus\", \"duration\": \"%dh%d\", \"etf_offset\": \"%dus\",},"
+           "\"props\": [[",
            interval, duration_hour, duration_minutes, thread_params.etf_offset);
-    histogram = rtt_hist;
 
-    max_hist_val = 0;
-    for (int j = 0; j < MAX_RTT; j++)
-      if (histogram[j])
-        max_hist_val = j > max_hist_val ? j : max_hist_val;
+    histogram = rtt_hist;
+    max_hist_val = histogram_max(histogram, MAX_RTT - 1);
   }
 
-  printf("[");
   for (int j = 0; j < max_hist_val; j++)
     printf("%" PRIi64 "%s", histogram[j], (j + 1 < max_hist_val ? ", " : ""));
-  printf("]");
-
-  printf("]}]}\n");
+  printf("]]}]}\n");
 }
 
 static void sighand(int sig_num) {

packet-exchange/src/common.c

@@ -35,6 +35,20 @@ uint64_t calcdiff_ns(struct timespec t1, struct timespec t2) {
 int max(int a, int b) { return a > b ? a : b; }
 int min(int a, int b) { return a < b ? a : b; }
 
+int histogram_min(uint64_t * histogram, int max_value) {
+  int ret = max_value;
+  for (int i = max_value; i >= 0; i--)
+    ret = histogram[i] ? i : ret;
+  return ret;
+}
+int histogram_max(uint64_t * histogram, int max_value) {
+  int ret = 0;
+  for (int i = 0; i <= max_value; i++)
+    ret = histogram[i] ? i : ret;
+  return ret;
+}
+
+
 static void sighand_wrapper(int sig) {
 
   // If we get un unexpected signal, report it, if not print the histogram

packet-exchange/src/common.h

@@ -29,6 +29,9 @@ void init_signals(void (*_sighand)(int), int enable_histograms);
 int min(int a, int b);
 int max(int a, int b);
 
+int histogram_min(uint64_t * histogram, int max_value);
+int histogram_max(uint64_t * histogram, int max_value);
+
 extern void (*previous_handlers[NSIG])(int);
 
 #endif

packet-exchange/src/server.c

@@ -271,58 +271,36 @@ static void print_histograms() {
   if (enable_timestamps) {
     printf("{\"measure_sets\": [{"
            "\"measure_type\": \"packet_recv_timestamps\","
-           "\"props_names\": [\"user_space\", \"kernel_space\"],"
-           "\"units\": [\"us\", \"us\"],"
+           "\"props_names\": [\"kernel_space\"],"
+           "\"units\": [\"us\"],"
            "\"props_type\": \"histogram\","
-           "\"metadata\": {"
-           "\"i\": \"%dus\", \"duration\": \"%dh%d\""
-           "},"
-           "\"props\": [",
+           "\"metadata\": \"i\": \"%dus\", \"duration\": \"%dh%d\"},"
+           "\"props\": [[",
            interval, duration_hour, duration_minutes);
 
-    max_latency = 0;
-    for (int j = 0; j < MAX_KERNEL_LATENCY; j++)
-      if (kernel_latency_hist[j])
-        max_latency = j;
+    max_latency = histogram_max(kernel_latency_hist, MAX_KERNEL_LATENCY - 1);
 
-    printf("[");
     for (int j = 0; j < max_latency; j++)
       printf("%" PRIi64 "%s", kernel_latency_hist[j], (j + 1 < max_latency ? ", " : ""));
-    printf("]");
+    printf("]]");
   }
 
-  max_jitter = 0;
-  for (int j = 0; j < MAX_JITTER; j++)
-    if (jitter_hist[j])
-      max_jitter = j;
+  max_jitter = histogram_max(jitter_hist, MAX_JITTER - 1);
+  min_jitter = histogram_min(jitter_hist, MAX_JITTER - 1);
 
-  min_jitter = MAX_JITTER - 1;
-  for (int j = MAX_JITTER - 1; j >= 0; j--)
-    if (jitter_hist[j])
-      min_jitter = j;
-
-  if (!enable_timestamps)
-    printf("{\"measure_sets\": [{");
-  else
-    printf("]}, {");
+  printf("%s", enable_timestamps ? "]}, {" : "{\"measure_sets\": [{");
 
   printf("\"measure_type\": \"packet_jitter\","
          "\"props_names\": [\"jitter\"],"
          "\"units\": [\"us\"],"
          "\"props_type\": \"histogram\","
          "\"middle\": \"%d\","
-         "\"metadata\": {"
-         "\"i\": \"%dus\", \"duration\": \"%dh%d\""
-         "},"
+         "\"metadata\": {\"i\": \"%dus\", \"duration\": \"%dh%d\"},"
          "\"props\": [[",
-         MAX_JITTER / 2 - min_jitter,
-         interval,
-         duration_hour,
-         duration_minutes);
+         MAX_JITTER / 2 - min_jitter, interval, duration_hour, duration_minutes);
 
   for (int j = min_jitter; j < max_jitter; j++)
     printf("%" PRIi64 "%s", jitter_hist[j], (j + 1 < max_jitter ? ", " : ""));
-
   printf("]]}]}\n");
 }