Merge pull request swift-server#2 from Yasumoto/master

Fixup tests since we're now all async

Author: MrLotU

.travis.yml

@@ -1,6 +1,6 @@
 language: generic
 os: osx
-osx_image: xcode10.1
+osx_image: xcode10.2
 script:
   - swift build
-  - swift test
+  - swift test -Xswiftc -DDEBUG

README.md

@@ -1,4 +1,4 @@
-[![Build Status](https://travis-ci.com/MrLotU/SwiftPrometheus.svg?branch=master)](https://travis-ci.com/MrLotU/SwiftPrometheus) [![Swift 4.2](https://img.shields.io/badge/swift-4.2-orange.svg?style=flat)](http://swift.org)
+[![Build Status](https://travis-ci.com/MrLotU/SwiftPrometheus.svg?branch=master)](https://travis-ci.com/MrLotU/SwiftPrometheus) [![Swift 5.0](https://img.shields.io/badge/swift-5.0-orange.svg?style=flat)](http://swift.org)
 
 # SwiftPrometheus, Prometheus client for Swift
 
@@ -13,7 +13,9 @@ For examples, see [main.swift](./Sources/PrometheusExample/main.swift)
 Counters go up, and reset when the process restarts.
 
 ```swift
-let counter = Prometheus.shared.createCounter(forType: Int.self, named: "my_counter")
+let prom = PrometheusClient()
+
+let counter = prom.createCounter(forType: Int.self, named: "my_counter")
 counter.inc() // Increment by 1
 counter.inc(12) // Increment by given value 
 ```
@@ -23,7 +25,9 @@ counter.inc(12) // Increment by given value
 Gauges can go up and down
 
 ```swift
-let gauge = Prometheus.shared.createGauge(forType: Int.self, named: "my_gauge")
+let prom = PrometheusClient()
+
+let gauge = prom.createGauge(forType: Int.self, named: "my_gauge")
 gauge.inc() // Increment by 1
 gauge.dec(19) // Decrement by given value
 gauge.set(12) // Set to a given value
@@ -34,7 +38,9 @@ gauge.set(12) // Set to a given value
 Histograms track the size and number of events in buckets. This allows for aggregatable calculation of quantiles.
 
 ```swift
-let histogram = Prometheus.shared.createHistogram(forType: Double.self, named: "my_histogram")
+let prom = PrometheusClient()
+
+let histogram = prom.createHistogram(forType: Double.self, named: "my_histogram")
 histogram.observe(4.7) // Observe the given value
 ```
 
@@ -43,7 +49,9 @@ histogram.observe(4.7) // Observe the given value
 Summaries track the size and number of events
 
 ```swift
-let summary = Prometheus.shared.createSummary(forType: Double.self, named: "my_summary")
+let prom = PrometheusClient()
+
+let summary = prom.createSummary(forType: Double.self, named: "my_summary")
 summary.observe(4.7) // Observe the given value
 ```
 
@@ -64,7 +72,9 @@ struct MyInfoStruct: MetricLabels {
    }
 }
 
-let info = Prometheus.shared.createInfo(named: "my_info", helpText: "Just some info", labelType: MyInfoStruct.self)
+let prom = PrometheusClient()
+
+let info = prom.createInfo(named: "my_info", helpText: "Just some info", labelType: MyInfoStruct.self)
 
 info.info(MyInfoStruct("def"))
 ```
@@ -78,19 +88,25 @@ struct RouteLabels: MetricLabels {
    var route: String = "*"
 }
 
-let counter = Prometheus.shared.createCounter(forType: Int.self, named: "my_counter", helpText: "Just a counter", withLabelType: RouteLabels.self)
+let prom = PrometheusClient()
+
+let counter = prom.createCounter(forType: Int.self, named: "my_counter", helpText: "Just a counter", withLabelType: RouteLabels.self)
 
 counter.inc(12, .init(route: "/"))
 ```
 
 # Exporting
 
-To keep SwiftPrometheus as clean and leight weitght as possible, there is no way of exporting metrics to Prometheus. All you can do is get a formatted string that Prometheus can use, so you can integrate it in your own Serverside Swift application
+To keep SwiftPrometheus as clean and lightweight as possible, there is no way of exporting metrics directly to Prometheus. Instead, retrieve a formatted string that Prometheus can use, so you can integrate it in your own Serverside Swift application
 
 This could look something like this:
 ```swift
-router.get("/metrics") { request -> String in
-    return Prometheus.shared.getMetrics()
+router.get("/metrics") { request -> Future<String> in
+    let promise = req.eventLoop.newPromise(String.self)
+    prom.getMetrics {
+        promise.succeed(result: $0)
+    }
+    return promise.futureResult
 }
 ```
 Here, I used [Vapor](https://github.com/vapor/vapor) syntax, but this will work with any web framework, since it's just returning a plain String.
@@ -99,6 +115,6 @@ Here, I used [Vapor](https://github.com/vapor/vapor) syntax, but this will work
 
 All contributions are most welcome!
 
-If you think of some crazy cool new feature that should be included, please [create an issue](https://github.com/MrLotU/SwiftPrometheus/issues/new/choose). Or, if you want to implement it yourself, [fork this repo](https://github.com/MrLotU/SwiftPrometheus/fork) and submit a PR!
+If you think of some cool new feature that should be included, please [create an issue](https://github.com/MrLotU/SwiftPrometheus/issues/new/choose). Or, if you want to implement it yourself, [fork this repo](https://github.com/MrLotU/SwiftPrometheus/fork) and submit a PR!
 
 If you find a bug or have issues, please [create an issue](https://github.com/MrLotU/SwiftPrometheus/issues/new/choose) explaining your problems. Please include as much information as possible, so it's easier for me to reproduce (Framework, OS, Swift version, terminal output, etc.)

Sources/Prometheus/MetricTypes/Gauge.swift

@@ -29,6 +29,7 @@ public class Gauge<NumType: Numeric, Labels: MetricLabels>: Metric, PrometheusHa
     ///     - help: Helpt text of the Gauge
     ///     - initialValue: Initial value to set the Gauge to
     ///     - p: Prometheus instance that created this Gauge
+    ///
     internal init(_ name: String, _ help: String? = nil, _ initialValue: NumType = 0, _ p: PrometheusClient) {
         self.name = name
         self.help = help
@@ -39,8 +40,9 @@ public class Gauge<NumType: Numeric, Labels: MetricLabels>: Metric, PrometheusHa
 
     /// Gets the metric string for this Gauge
     ///
-    /// - Returns:
-    ///     Newline seperated Prometheus formatted metric string
+    /// - Parameters:
+    ///     - done: Callback passing a newline separated Prometheus-formatted metric string
+    ///
     public func getMetric(_ done: @escaping (String) -> Void) {
         prometheusQueue.async(flags: .barrier) {
             var output = [String]()
@@ -49,7 +51,7 @@ public class Gauge<NumType: Numeric, Labels: MetricLabels>: Metric, PrometheusHa
                 output.append("# HELP \(self.name) \(help)")
             }
             output.append("# TYPE \(self.name) \(self._type)")
-
+            
             output.append("\(self.name) \(self.value)")
 
             self.metrics.forEach { (labels, value) in
@@ -67,15 +69,15 @@ public class Gauge<NumType: Numeric, Labels: MetricLabels>: Metric, PrometheusHa
     ///     - amount: Amount to set the gauge to
     ///     - labels: Labels to attach to the value
     ///
-    public func set(_ amount: NumType, _ labels: Labels? = nil, _ done: @escaping (NumType) -> Void = { _ in }) {
+    public func set(_ amount: NumType, _ labels: Labels? = nil, _ done: @escaping () -> Void = { }) {
         prometheusQueue.async(flags: .barrier) {
-        if let labels = labels {
-            self.metrics[labels] = amount
-            done(amount)
-        } else {
-            self.value = amount
-            done(self.value)
-        }
+            if let labels = labels {
+                self.metrics[labels] = amount
+                done()
+            } else {
+                self.value = amount
+                done()
+            }
         }
     }
 
@@ -84,49 +86,50 @@ public class Gauge<NumType: Numeric, Labels: MetricLabels>: Metric, PrometheusHa
     /// - Parameters:
     ///     - amount: Amount to increment the Gauge with
     ///     - labels: Labels to attach to the value
+    ///     - done: Completion handler
     ///
     public func inc(_ amount: NumType, _ labels: Labels? = nil, _ done: @escaping (NumType) -> Void = { _ in }) {
         prometheusQueue.async(flags: .barrier) {
-        if let labels = labels {
-            var val = self.metrics[labels] ?? self.initialValue
-            val += amount
-            self.metrics[labels] = val
-            done(val)
-        } else {
-            self.value += amount
-            done(self.value)
-        }
+            if let labels = labels {
+                var val = self.metrics[labels] ?? self.initialValue
+                val += amount
+                self.metrics[labels] = val
+                done(val)
+            } else {
+                self.value += amount
+                done(self.value)
+            }
         }
     }
 
     /// Increments the Gauge
     ///
     /// - Parameters:
     ///     - labels: Labels to attach to the value
+    ///     - done: Completion handler
     ///
     public func inc(_ labels: Labels? = nil, _ done: @escaping (NumType) -> Void = { _ in }) {
-        self.inc(1, labels) {
-            done($0)
-        }
+        self.inc(1, labels, done)
     }
 
     /// Decrements the Gauge
     ///
     /// - Parameters:
     ///     - amount: Amount to decrement the Gauge with
     ///     - labels: Labels to attach to the value
+    ///     - done: Completion handler
     ///
     public func dec(_ amount: NumType, _ labels: Labels? = nil, _ done: @escaping (NumType) -> Void = { _ in }) {
         prometheusQueue.async(flags: .barrier) {
-        if let labels = labels {
-            var val = self.metrics[labels] ?? self.initialValue
-            val -= amount
-            self.metrics[labels] = val
-            done(val)
-        } else {
-            self.value -= amount
-            done(self.value)
-        }
+            if let labels = labels {
+                var val = self.metrics[labels] ?? self.initialValue
+                val -= amount
+                self.metrics[labels] = val
+                done(val)
+            } else {
+                self.value -= amount
+                done(self.value)
+            }
         }
     }
 
@@ -136,9 +139,7 @@ public class Gauge<NumType: Numeric, Labels: MetricLabels>: Metric, PrometheusHa
     ///     - labels: Labels to attach to the value
     ///
     public func dec(_ labels: Labels? = nil, _ done: @escaping (NumType) -> Void = { _ in }) {
-        self.dec(1, labels) {
-            done($0)
-        }
+        self.dec(1, labels, done)
     }
 
     /// Gets the value of the Gauge
@@ -147,6 +148,7 @@ public class Gauge<NumType: Numeric, Labels: MetricLabels>: Metric, PrometheusHa
     ///     - labels: Labels to get the value for
     ///
     /// - Returns: The value of the Gauge attached to the provided labels
+    ///
     public func get(_ labels: Labels? = nil) -> NumType {
         if let labels = labels {
             return self.metrics[labels] ?? initialValue

Sources/Prometheus/MetricTypes/Histogram.swift

@@ -14,7 +14,7 @@ extension HistogramLabels {
     }
 }
 
-/// Prometheus Counter metric
+/// Prometheus Histogram metric
 ///
 /// See https://prometheus.io/docs/concepts/metric_types/#Histogram
 public class Histogram<NumType: DoubleRepresentable, Labels: HistogramLabels>: Metric, PrometheusHandled {
@@ -71,8 +71,8 @@ public class Histogram<NumType: DoubleRepresentable, Labels: HistogramLabels>: M
 
     /// Gets the metric string for this Histogram
     ///
-    /// - Returns:
-    ///     Newline seperated Prometheus formatted metric string
+    /// - Parameters:
+    ///     - done: Newline separated Prometheus-formatted metric string
     public func getMetric(_ done: @escaping (String) -> Void) {
         prometheusQueue.async(flags: .barrier) {
             var output = [String]()
@@ -123,20 +123,26 @@ public class Histogram<NumType: DoubleRepresentable, Labels: HistogramLabels>: M
     /// - Parameters:
     ///     - value: Value to observe
     ///     - labels: Labels to attach to the observed value
-    public func observe(_ value: NumType, _ labels: Labels? = nil) {
+    ///     - done: Completion handler
+    public func observe(_ value: NumType, _ labels: Labels? = nil, _ done: @escaping () -> Void = { }) {
         prometheusQueue.async(flags: .barrier) {
-            if let labels = labels, type(of: labels) != type(of: EmptySummaryLabels()) {
-                let his = self.prometheus.getOrCreateHistogram(with: labels, for: self)
-                his.observe(value)
+            let completion: () -> Void = {
+                self.total.inc(value)
+
+                for (i, bound) in self.upperBounds.enumerated() {
+                    if bound >= value.doubleValue {
+                        self.buckets[i].inc()
+                        break
+                    }
+                }
+                done()
             }
-            self.total.inc(value)
 
-            for (i, bound) in self.upperBounds.enumerated() {
-                if bound >= value.doubleValue {
-                    self.buckets[i].inc()
-                    return
-                }
+            if let labels = labels, type(of: labels) != type(of: EmptySummaryLabels()) {
+                let his = self.prometheus.getOrCreateHistogram(with: labels, for: self)
+                return his.observe(value, nil, completion)
             }
+            return completion()
         }
     }
 }

Sources/Prometheus/MetricTypes/Info.swift

@@ -39,8 +39,9 @@ public class Info<Labels: MetricLabels>: Metric, PrometheusHandled {
 
     /// Gets the metric string for this Info
     ///
-    /// - Returns:
-    ///     Newline seperated Prometheus formatted metric string
+    /// - Parameters:
+    ///     - done: Callback passing a newline separated Prometheus-formatted metric string
+    ///
     public func getMetric(_ done: @escaping (String) -> Void) {
         prometheusQueue.async(flags: .barrier) {
             var output = [String]()

Sources/Prometheus/MetricTypes/Summary.swift

@@ -72,9 +72,11 @@ public class Summary<NumType: DoubleRepresentable, Labels: SummaryLabels>: Metri
 
     /// Gets the metric string for this Summary
     ///
-    /// - Returns:
-    ///     Newline seperated Prometheus formatted metric string
-    public func getMetric(_ done: @escaping (String) -> Void) {
+    /// - Parameters:
+    ///     - done: Completion handler
+    ///     - metric: String value in prom-format
+    ///
+    public func getMetric(_ done: @escaping (_ metric: String) -> Void) {
         prometheusQueue.async(flags: .barrier) {
             var output = [String]()
 
@@ -109,7 +111,7 @@ public class Summary<NumType: DoubleRepresentable, Labels: SummaryLabels>: Metri
             }
 
             self.labels.quantile = ""
-            
+
             done(output.joined(separator: "\n"))
         }
     }
@@ -119,15 +121,25 @@ public class Summary<NumType: DoubleRepresentable, Labels: SummaryLabels>: Metri
     /// - Parameters:
     ///     - value: Value to observe
     ///     - labels: Labels to attach to the observed value
-    public func observe(_ value: NumType, _ labels: Labels? = nil) {
+    ///     - done: Completion handler
+    ///
+    public func observe(_ value: NumType, _ labels: Labels? = nil, _ done: @escaping () -> Void = { }) {
         prometheusQueue.async(flags: .barrier) {
+            func completion() {
+                self.count.inc(1)
+                self.sum.inc(value)
+                self.values.append(value)
+                done()
+            }
+            
             if let labels = labels, type(of: labels) != type(of: EmptySummaryLabels()) {
                 let sum = self.prometheus.getOrCreateSummary(withLabels: labels, forSummary: self)
-                sum.observe(value)
+                sum.observe(value) {
+                    completion()
+                }
+            } else {
+                completion()
             }
-            self.count.inc(1)
-            self.sum.inc(value)
-            self.values.append(value)
         }
     }
 }

Sources/Prometheus/Utils.swift

@@ -62,9 +62,9 @@ public protocol DoubleRepresentable: Numeric {
 /// Numbers that convert to other types
 public protocol ConvertibleNumberType: DoubleRepresentable {}
 public extension ConvertibleNumberType {
-    public var floatValue: Float {get {return Float(doubleValue)}}
-    public var intValue: Int {get {return lrint(doubleValue)}}
-    public var CGFloatValue: CGFloat {get {return CGFloat(doubleValue)}}
+    var floatValue: Float {get {return Float(doubleValue)}}
+    var intValue: Int {get {return lrint(doubleValue)}}
+    var CGFloatValue: CGFloat {get {return CGFloat(doubleValue)}}
 }
 
 /// Double Representable Conformance