X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=metrics.h;h=0371668bd2a1e25c1adaed613071ac8e3c6c0551;hb=1836dccf699779d9092a75755cec96cea1734a2a;hp=a570723dae713f218c9b46c8f0d865ff71e526ad;hpb=c574aef4437253dcf0e6c1fed4c9cab1033b33f9;p=nageru

diff --git a/metrics.h b/metrics.h
index a570723..0371668 100644
--- a/metrics.h
+++ b/metrics.h
@@ -15,6 +15,12 @@
 
 class Histogram;
 
+// 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.
+// Note that this will be wrong if your clock changes, so for non-metric use,
+// you should use std::chrono::steady_clock instead.
+double get_timestamp_for_metrics();
+
 class Metrics {
 public:
 	enum Type {
@@ -45,16 +51,33 @@ public:
 	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,
 	};
-
+	struct MetricKey {
+		MetricKey(const std::string &name, const std::vector<std::pair<std::string, std::string>> labels)
+			: name(name), labels(labels), serialized_labels(serialize_labels(labels))
+		{
+		}
+
+		bool operator< (const MetricKey &other) const
+		{
+			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_labels;
+	};
 	struct Metric {
 		DataType data_type;
-		std::string name;
-		std::vector<std::pair<std::string, std::string>> labels;
 		union {
 			std::atomic<int64_t> *location_int64;
 			std::atomic<double> *location_double;
@@ -63,15 +86,18 @@ private:
 	};
 
 	mutable std::mutex mu;
-	std::map<std::string, Type> types;
-	std::vector<Metric> metrics;
+	std::map<std::string, Type> types;  // Ordered the same as metrics.
+	std::map<MetricKey, Metric> metrics;
 	std::vector<Histogram> histograms;
+
+	friend class Histogram;
 };
 
 class Histogram {
 public:
 	void init(const std::vector<double> &bucket_vals);
 	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;