Workable code, that needs cleaning up

Author: MrLotU

Sources/Prometheus/MetricTypes/Histogram.swift

@@ -19,9 +19,9 @@ public class Histogram<NumType: DoubleRepresentable, Labels: HistogramLabels>: M
 
     private var buckets: [Counter<NumType, EmptyCodable>] = []
 
-    private var upperBounds: [Double]
+    internal let upperBounds: [Double]
 
-    private var labels: Labels
+    internal private(set) var labels: Labels
 
     private let total: Counter<NumType, EmptyCodable>
 
@@ -45,10 +45,13 @@ public class Histogram<NumType: DoubleRepresentable, Labels: HistogramLabels>: M
     public func getMetric() -> String {
         var output = [String]()
 
-        if let help = help {
-            output.append("# HELP \(name) \(help)")
+        
+        if self.labels == Labels() {
+            if let help = help {
+                output.append("# HELP \(name) \(help)")
+            }
+            output.append("# TYPE \(name) histogram")
         }
-        output.append("# TYPE \(name) histogram")
 
         var acc: NumType = 0
         for (i, bound) in self.upperBounds.enumerated() {
@@ -66,7 +69,12 @@ public class Histogram<NumType: DoubleRepresentable, Labels: HistogramLabels>: M
         return output.joined(separator: "\n")
     }
 
-    public func observe(_ value: NumType) {
+    public func observe(_ value: NumType, _ labels: Labels? = nil) {
+        if let labels = labels {
+            let his = prometheus.getOrCreateHistogram(with: labels, for: self)
+            his.observe(value)
+            return
+        }
         self.total.inc(value)
 
         for (i, bound) in self.upperBounds.enumerated() {
@@ -77,3 +85,21 @@ public class Histogram<NumType: DoubleRepresentable, Labels: HistogramLabels>: M
         }
     }
 }
+
+extension Prometheus {
+    fileprivate func getOrCreateHistogram<T: Numeric, U: HistogramLabels>(with labels: U, for his: Histogram<T, U>) -> Histogram<T, U> {
+        let summaries = metrics.filter { (metric) -> Bool in
+            guard let metric = metric as? Histogram<T, U> else { return false }
+            guard metric.name == his.name, metric.help == his.help, metric.labels == labels else { return false }
+            return true
+            } as? [Histogram<T, U>] ?? []
+        if summaries.count > 2 { fatalError("Somehow got 2 summaries with the same data type") }
+        if let summary = summaries.first {
+            return summary
+        } else {
+            let histogram = Histogram<T, U>(his.name, his.help, labels, his.upperBounds, self)
+            self.metrics.append(histogram)
+            return histogram
+        }
+    }
+}

Sources/Prometheus/MetricTypes/Summary.swift

@@ -27,7 +27,7 @@ public class Summary<NumType: DoubleRepresentable, Labels: SummaryLabels>: Metri
 
     internal let quantiles: [Double]
 
-    internal init(_ name: String, _ help: String? = nil, _ quantiles: [Double] = defaultQuantiles, _ labels: Labels = Labels(), _ p: Prometheus) {
+    internal init(_ name: String, _ help: String? = nil, _ labels: Labels = Labels(), _ quantiles: [Double] = defaultQuantiles, _ p: Prometheus) {
         self.name = name
         self.help = help
 
@@ -82,16 +82,18 @@ public class Summary<NumType: DoubleRepresentable, Labels: SummaryLabels>: Metri
 
 extension Prometheus {
     fileprivate func getOrCreateSummary<T: Numeric, U: SummaryLabels>(withLabels labels: U, forSummary sum: Summary<T, U>) -> Summary<T, U> {
-        let summary = metrics.filter { (metric) -> Bool in
+        let summaries = metrics.filter { (metric) -> Bool in
             guard let metric = metric as? Summary<T, U> else { return false }
             guard metric.name == sum.name, metric.help == sum.help, metric.labels == labels else { return false }
             return true
         } as? [Summary<T, U>] ?? []
-        if summary.count > 2 { fatalError("Somehow got 2 summaries with the same data type") }
-        if let summary = summary.first {
+        if summaries.count > 2 { fatalError("Somehow got 2 summaries with the same data type") }
+        if let summary = summaries.first {
             return summary
         } else {
-            return createSummary(forType: T.self, named: sum.name, helpText: sum.help, quantiles: sum.quantiles, labels: labels)
+            let summary = Summary<T, U>(sum.name, sum.help, labels, sum.quantiles, self)
+            self.metrics.append(summary)
+            return summary
         }
     }
 }

Sources/Prometheus/Prometheus.swift

@@ -109,9 +109,9 @@ public class Prometheus {
         named name: String,
         helpText: String? = nil,
         buckets: [Double] = defaultBuckets,
-        labels: U) -> Histogram<T, U>
+        labels: U.Type) -> Histogram<T, U>
     {
-        let histogram = Histogram<T, U>(name, helpText, labels, buckets, self)
+        let histogram = Histogram<T, U>(name, helpText, U(), buckets, self)
         self.metrics.append(histogram)
         return histogram
     }
@@ -131,7 +131,7 @@ public class Prometheus {
         helpText: String? = nil,
         buckets: [Double] = defaultBuckets) -> Histogram<T, EmptyHistogramCodable>
     {
-        return self.createHistogram(forType: type, named: name, helpText: helpText, buckets: buckets, labels: EmptyHistogramCodable())
+        return self.createHistogram(forType: type, named: name, helpText: helpText, buckets: buckets, labels: EmptyHistogramCodable.self)
     }
 
     // MARK: - Summary
@@ -141,9 +141,9 @@ public class Prometheus {
         named name: String,
         helpText: String? = nil,
         quantiles: [Double] = defaultQuantiles,
-        labels: U) -> Summary<T, U>
+        labels: U.Type) -> Summary<T, U>
     {
-        let summary = Summary<T, U>(name, helpText, quantiles, labels, self)
+        let summary = Summary<T, U>(name, helpText, U(), quantiles, self)
         metrics.append(summary)
         return summary
     }
@@ -154,13 +154,13 @@ public class Prometheus {
         helpText: String? = nil,
         quantiles: [Double] = defaultQuantiles) -> Summary<T, EmptySummaryCodable>
     {
-        return self.createSummary(forType: type, named: name, helpText: helpText, quantiles: quantiles, labels: EmptySummaryCodable())
+        return self.createSummary(forType: type, named: name, helpText: helpText, quantiles: quantiles, labels: EmptySummaryCodable.self)
     }
 
     /// Creates prometheus formatted metrics
     ///
     /// - Returns: Newline seperated string with metrics for all Metric Trackers of this Prometheus instance
     public func getMetrics() -> String {
-        return metrics.map { $0.getMetric() }.joined(separator: "\n\n")
+        return metrics.map { $0.getMetric() }.joined(separator: "\n")
     }
 }

Sources/PrometheusExample/main.swift

@@ -7,34 +7,51 @@ struct MyCodable: MetricLabels {
 let codable1 = MyCodable(thing: "Thing1")
 let codable2 = MyCodable(thing: "Thing2")
 
-let counter = Prometheus.shared.createCounter(forType: Int.self, named: "my_counter", helpText: "Just a counter", initialValue: 12)
+//let counter = Prometheus.shared.createCounter(forType: Int.self, named: "my_counter", helpText: "Just a counter", initialValue: 12)
+//
+//counter.inc(5)
+//
+//let gauge = Prometheus.shared.createGauge(forType: Int.self, named: "my_gauge", helpText: "Just a gauge", initialValue: 0)
+//
+//gauge.set(123)
 
-counter.inc(5)
-
-let gauge = Prometheus.shared.createGauge(forType: Int.self, named: "my_gauge", helpText: "Just a gauge", initialValue: 0)
-
-gauge.set(123)
+struct HistogramThing: HistogramLabels {
+    var le: String = ""
+    let route: String
+    
+    init() {
+        self.route = "*"
+    }
+    
+    init(_ route: String) {
+        self.route = route
+    }
+}
 
-let histogram = Prometheus.shared.createHistogram(forType: Double.self, named: "my_histogram", helpText: "Just a histogram")
+let histogram = Prometheus.shared.createHistogram(forType: Double.self, named: "my_histogram", helpText: "Just a histogram", labels: HistogramThing.self)
 
 for _ in 0...Int.random(in: 10...50) {
     histogram.observe(Double.random(in: 0...1))
 }
 
+for _ in 0...Int.random(in: 10...50) {
+    histogram.observe(Double.random(in: 0...1), HistogramThing("/test"))
+}
+
 struct SummaryThing: SummaryLabels {
     var quantile: String = ""
     let route: String
 
     init() {
         self.route = "*"
     }
-    
+
     init(_ route: String) {
         self.route = route
     }
 }
 
-let summary = Prometheus.shared.createSummary(forType: Double.self, named: "my_summary", helpText: "Just a summary", labels: SummaryThing())
+let summary = Prometheus.shared.createSummary(forType: Double.self, named: "my_summary", helpText: "Just a summary", labels: SummaryThing.self)
 
 for _ in 0...Int.random(in: 100...1000) {
     summary.observe(Double.random(in: 0...10000))