Add the GPU memory metrics to the Grafana dashboard.

[nageru] / metrics.h

diff --git a/metrics.h b/metrics.h
index 40aa8f7bf387159c6b31a40688e9e7b06b1fa37f..e2e1e74f5ac9bb818f5bbdb8e6798ec27cadf869 100644 (file)
--- a/metrics.h
+++ b/metrics.h
@@ -7,13 +7,17 @@
 // which makes it quite unwieldy. Thus, we'll package our own for the time being.
 
 #include <atomic>
+#include <chrono>
+#include <deque>
 #include <map>
 #include <memory>
 #include <mutex>
 #include <string>
+#include <utility>
 #include <vector>
 
 class Histogram;
+class Summary;
 
 // Prometheus recommends the use of timestamps instead of “time since event”,
 // so you can use this to get the number of seconds since the epoch.
@@ -27,6 +31,11 @@ public:
                TYPE_COUNTER,
                TYPE_GAUGE,
                TYPE_HISTOGRAM,  // Internal use only.
+               TYPE_SUMMARY,  // Internal use only.
+       };
+       enum Laziness {
+               PRINT_ALWAYS,
+               PRINT_WHEN_NONEMPTY,
        };
 
        void add(const std::string &name, std::atomic<int64_t> *location, Type type = TYPE_COUNTER)
@@ -44,50 +53,69 @@ public:
                add(name, {}, location);
        }
 
+       void add(const std::string &name, Summary *location)
+       {
+               add(name, {}, location);
+       }
+
        void add(const std::string &name, const std::vector<std::pair<std::string, std::string>> &labels, std::atomic<int64_t> *location, Type type = TYPE_COUNTER);
        void add(const std::string &name, const std::vector<std::pair<std::string, std::string>> &labels, std::atomic<double> *location, Type type = TYPE_COUNTER);
-       void add(const std::string &name, const std::vector<std::pair<std::string, std::string>> &labels, Histogram *location);
+       void add(const std::string &name, const std::vector<std::pair<std::string, std::string>> &labels, Histogram *location, Laziness laziness = PRINT_ALWAYS);
+       void add(const std::string &name, const std::vector<std::pair<std::string, std::string>> &labels, Summary *location, Laziness laziness = PRINT_ALWAYS);
+
+       void remove(const std::string &name)
+       {
+               remove(name, {});
+       }
+
+       void remove(const std::string &name, const std::vector<std::pair<std::string, std::string>> &labels);
 
        std::string serialize() const;
 
 private:
        static std::string serialize_name(const std::string &name, const std::vector<std::pair<std::string, std::string>> &labels);
+       static std::string serialize_labels(const std::vector<std::pair<std::string, std::string>> &labels);
 
        enum DataType {
                DATA_TYPE_INT64,
                DATA_TYPE_DOUBLE,
                DATA_TYPE_HISTOGRAM,
+               DATA_TYPE_SUMMARY,
        };
        struct MetricKey {
                MetricKey(const std::string &name, const std::vector<std::pair<std::string, std::string>> labels)
-                       : name(name), labels(labels), serialized(serialize_name(name, labels))
+                       : name(name), labels(labels), serialized_labels(serialize_labels(labels))
                {
                }
 
                bool operator< (const MetricKey &other) const
                {
-                       return serialized < other.serialized;
+                       if (name != other.name)
+                               return name < other.name;
+                       return serialized_labels < other.serialized_labels;
                }
 
                const std::string name;
                const std::vector<std::pair<std::string, std::string>> labels;
-               const std::string serialized;
+               const std::string serialized_labels;
        };
        struct Metric {
                DataType data_type;
+               Laziness laziness;  // Only for TYPE_HISTOGRAM.
                union {
                        std::atomic<int64_t> *location_int64;
                        std::atomic<double> *location_double;
                        Histogram *location_histogram;
+                       Summary *location_summary;
                };
        };
 
        mutable std::mutex mu;
-       std::map<std::string, Type> types;  // Ordered the same as metrics, assuming no { signs in names (which are illegal).
+       std::map<std::string, Type> types;  // Ordered the same as metrics.
        std::map<MetricKey, Metric> metrics;
-       std::vector<Histogram> histograms;
 
        friend class Histogram;
+       friend class Summary;
 };
 
 class Histogram {
@@ -96,7 +124,7 @@ public:
        void init_uniform(size_t num_buckets);  // Sets up buckets 0..(N-1).
        void init_geometric(double min, double max, size_t num_buckets);
        void count_event(double val);
-       std::string serialize(const std::string &name, const std::vector<std::pair<std::string, std::string>> &labels) const;
+       std::string serialize(Metrics::Laziness laziness, const std::string &name, const std::vector<std::pair<std::string, std::string>> &labels) const;
 
 private:
        // Bucket <i> counts number of events where val[i - 1] < x <= val[i].
@@ -112,6 +140,25 @@ private:
        std::atomic<int64_t> count_after_last_bucket{0};
 };
 
+// This is a pretty dumb streaming quantile class, but it's exact, and we don't have
+// too many values (typically one per frame, and one-minute interval), so we don't
+// need anything fancy.
+class Summary {
+public:
+       void init(const std::vector<double> &quantiles, double window_seconds);
+       void count_event(double val);
+       std::string serialize(Metrics::Laziness laziness, const std::string &name, const std::vector<std::pair<std::string, std::string>> &labels);
+
+private:
+       std::vector<double> quantiles;
+       std::chrono::duration<double> window;
+
+       mutable std::mutex mu;
+       std::deque<std::pair<std::chrono::steady_clock::time_point, double>> values;
+       std::atomic<double> sum{0.0};
+       std::atomic<int64_t> count{0};
+};
+
 extern Metrics global_metrics;
 
 #endif  // !defined(_METRICS_H)