Update the queue length metric after trimming, not before.

[nageru] / metrics.h

diff --git a/metrics.h b/metrics.h
index 603abb09630623c163d155952346d0fdb6a6865f..d515720ade805b8c4d43eeea23fe23955e7aa819 100644 (file)
--- a/metrics.h
+++ b/metrics.h
@@ -28,6 +28,10 @@ public:
                TYPE_GAUGE,
                TYPE_HISTOGRAM,  // 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)
        {
@@ -46,7 +50,7 @@ public:
 
        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 remove(const std::string &name)
        {
@@ -85,6 +89,7 @@ private:
        };
        struct Metric {
                DataType data_type;
+               Laziness laziness;  // Only for TYPE_HISTOGRAM.
                union {
                        std::atomic<int64_t> *location_int64;
                        std::atomic<double> *location_double;
@@ -106,7 +111,7 @@ 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].