Export some metrics from x264 speed control.

[nageru] / metrics.cpp

diff --git a/metrics.cpp b/metrics.cpp
index a60eb6c6a25d1dec85eb79b2f11aa0dfb1f8f84d..2874ad42a8a70260bfb038b7f9320d3aa1880cfb 100644 (file)
--- a/metrics.cpp
+++ b/metrics.cpp
@@ -9,6 +9,26 @@ using namespace std;
 
 Metrics global_metrics;
 
+namespace {
+
+string serialize_name(const string &name, const vector<pair<string, string>> &labels)
+{
+       if (labels.empty()) {
+               return "nageru_" + name;
+       }
+
+       string label_str;
+       for (const pair<string, string> &label : labels) {
+               if (!label_str.empty()) {
+                       label_str += ",";
+               }
+               label_str += label.first + "=\"" + label.second + "\"";
+       }
+       return "nageru_" + name + "{" + label_str + "}";
+}
+
+}  // namespace
+
 void Metrics::add(const string &name, const vector<pair<string, string>> &labels, atomic<int64_t> *location, Metrics::Type type)
 {
        Metric metric;
@@ -37,6 +57,18 @@ void Metrics::add(const string &name, const vector<pair<string, string>> &labels
        types[name] = type;
 }
 
+void Metrics::add_histogram(const string &name, const vector<pair<string, string>> &labels, atomic<int64_t> *location, size_t num_elements)
+{
+       Histogram histogram;
+       histogram.name = name;
+       histogram.labels = labels;
+       histogram.location_int64 = location;
+       histogram.num_elements = num_elements;
+
+       lock_guard<mutex> lock(mu);
+       histograms.push_back(histogram);
+}
+
 string Metrics::serialize() const
 {
        stringstream ss;
@@ -50,21 +82,7 @@ string Metrics::serialize() const
                }
        }
        for (const Metric &metric : metrics) {
-               string name;
-               if (metric.labels.empty()) {
-                       name = "nageru_" + metric.name;
-               } else {
-                       name = "nageru_" + metric.name + "{";
-                       bool first = true;
-                       for (const pair<string, string> &label : metric.labels) {
-                               if (!first) {
-                                       name += ",";
-                               }
-                               first = false;
-                               name += label.first + "=\"" + label.second + "\"";
-                       }
-                       name += "}";
-               }
+               string name = serialize_name(metric.name, metric.labels);
 
                if (metric.data_type == DATA_TYPE_INT64) {
                        ss << name << " " << metric.location_int64->load() << "\n";
@@ -72,6 +90,25 @@ string Metrics::serialize() const
                        ss << name << " " << metric.location_double->load() << "\n";
                }
        }
+       for (const Histogram &histogram : histograms) {
+               ss << "# TYPE nageru_" << histogram.name << " histogram\n";
+
+               int64_t sum = 0, count = 0;
+               for (size_t i = 0; i < histogram.num_elements; ++i) {
+                       char buf[16];
+                       snprintf(buf, sizeof(buf), "%lu", i);
+                       vector<pair<string, string>> labels = histogram.labels;
+                       labels.emplace_back("le", buf);
+
+                       int64_t val = histogram.location_int64[i].load();
+                       sum += i * val;
+                       count += val;
+                       ss << serialize_name(histogram.name + "_bucket", labels) << " " << count << "\n";
+               }
+
+               ss << serialize_name(histogram.name + "_sum", histogram.labels) << " " << sum << "\n";
+               ss << serialize_name(histogram.name + "_count", histogram.labels) << " " << count << "\n";
+       }
 
        return ss.str();
 }