Timer units (#17)

* package.resolved

* WIP: Implement Time Units

* Wrap tests & Up NIO version

* Apply suggestions from code review

Co-Authored-By: Joe Smith <[email protected]>

* Update linux tests

Author: MrLotU

Package.swift

@@ -13,7 +13,7 @@ let package = Package(
             targets: ["PrometheusExample"]),
     ],
     dependencies: [
-        .package(url: "https://github.com/apple/swift-metrics.git", from: "1.0.0"),
+        .package(url: "https://github.com/apple/swift-metrics.git", from: "1.2.0"),
         .package(url: "https://github.com/apple/swift-nio.git", from: "2.0.0"),
     ],
     targets: [

Sources/Prometheus/MetricTypes/Summary.swift

@@ -1,4 +1,5 @@
 import NIOConcurrencyHelpers
+import enum CoreMetrics.TimeUnit
 
 /// Label type Summaries can use
 public protocol SummaryLabels: MetricLabels {
@@ -29,6 +30,8 @@ public class PromSummary<NumType: DoubleRepresentable, Labels: SummaryLabels>: P
     /// Type of the metric, used for formatting
     public let _type: PromMetricType = .summary
 
+    private var displayUnit: TimeUnit?
+    
     /// Labels for this Summary
     internal private(set) var labels: Labels
 
@@ -64,6 +67,8 @@ public class PromSummary<NumType: DoubleRepresentable, Labels: SummaryLabels>: P
 
         self.prometheus = p
 
+        self.displayUnit = nil
+        
         self.sum = .init("\(self.name)_sum", nil, 0, p)
 
         self.count = .init("\(self.name)_count", nil, 0, p)
@@ -92,24 +97,24 @@ public class PromSummary<NumType: DoubleRepresentable, Labels: SummaryLabels>: P
                 let (q, v) = arg
                 self.labels.quantile = "\(q)"
                 let labelsString = encodeLabels(self.labels)
-                output.append("\(self.name)\(labelsString) \(v)")
+                output.append("\(self.name)\(labelsString) \(format(v))")
             }
 
             let labelsString = encodeLabels(self.labels, ["quantile"])
             output.append("\(self.name)_count\(labelsString) \(self.count.get())")
-            output.append("\(self.name)_sum\(labelsString) \(self.sum.get())")
+            output.append("\(self.name)_sum\(labelsString) \(format(self.sum.get().doubleValue))")
 
             self.subSummaries.forEach { subSum in
                 calculateQuantiles(quantiles: self.quantiles, values: subSum.values.map { $0.doubleValue }).sorted { $0.key < $1.key }.forEach { (arg) in
                     let (q, v) = arg
                     subSum.labels.quantile = "\(q)"
                     let labelsString = encodeLabels(subSum.labels)
-                    output.append("\(subSum.name)\(labelsString) \(v)")
+                    output.append("\(subSum.name)\(labelsString) \(format(v))")
                 }
 
                 let labelsString = encodeLabels(subSum.labels, ["quantile"])
                 output.append("\(subSum.name)_count\(labelsString) \(subSum.count.get())")
-                output.append("\(subSum.name)_sum\(labelsString) \(subSum.sum.get())")
+                output.append("\(subSum.name)_sum\(labelsString) \(format(subSum.sum.get().doubleValue))")
                 subSum.labels.quantile = ""
             }
 
@@ -119,6 +124,24 @@ public class PromSummary<NumType: DoubleRepresentable, Labels: SummaryLabels>: P
         }
     }
 
+    private func format(_ v: Double) -> Double {
+        guard let displayUnit = self.displayUnit else { return v }
+        switch displayUnit {
+        case .days: return (v / 1_000_000_000) * 60 * 60 * 24
+        case .hours: return (v / 1_000_000_000) * 60 * 60
+        case .minutes: return (v / 1_000_000_000) * 60
+        case .seconds: return v / 1_000_000_000
+        case .milliseconds: return v / 1_000_000
+        case .nanoseconds: return v
+        }
+    }
+    
+    internal func preferDisplayUnit(_ unit: TimeUnit) {
+        self.lock.withLock {
+            self.displayUnit = unit
+        }
+    }
+    
     /// Record a value
     ///
     /// - Parameters:

Sources/Prometheus/PrometheusMetrics.swift

@@ -68,6 +68,10 @@ private class MetricsSummary: TimerHandler {
     let summary: PromSummary<Int64, DimensionSummaryLabels>
     let labels: DimensionSummaryLabels?
 
+    func preferDisplayUnit(_ unit: TimeUnit) {
+        self.summary.preferDisplayUnit(unit)
+    }
+    
     internal init(summary: PromSummary<Int64, DimensionSummaryLabels>, dimensions: [(String, String)]) {
         self.summary = summary
         guard !dimensions.isEmpty else {

Tests/SwiftPrometheusTests/PrometheusMetricsTests.swift

@@ -133,7 +133,7 @@ final class PrometheusMetricsTests: XCTestCase {
         my_summary{quantile="0.99"} 10000.0
         my_summary{quantile="0.999"} 10000.0
         my_summary_count 5
-        my_summary_sum 10130
+        my_summary_sum 10130.0
         my_summary{quantile="0.01", myValue="labels"} 123.0
         my_summary{quantile="0.05", myValue="labels"} 123.0
         my_summary{quantile="0.5", myValue="labels"} 123.0
@@ -142,7 +142,32 @@ final class PrometheusMetricsTests: XCTestCase {
         my_summary{quantile="0.99", myValue="labels"} 123.0
         my_summary{quantile="0.999", myValue="labels"} 123.0
         my_summary_count{myValue="labels"} 1
-        my_summary_sum{myValue="labels"} 123
+        my_summary_sum{myValue="labels"} 123.0
+        """)
+    }
+    
+    func testSummaryWithPreferredDisplayUnit() {
+        let summary = Timer(label: "my_summary", preferredDisplayUnit: .seconds)
+        
+        summary.recordSeconds(1)
+        summary.recordMilliseconds(2 * 1_000)
+        summary.recordNanoseconds(4 * 1_000_000_000)
+        summary.recordSeconds(10000)
+
+        let promise = self.eventLoop.makePromise(of: String.self)
+        prom.collect(promise.succeed)
+        
+        XCTAssertEqual(try! promise.futureResult.wait(), """
+        # TYPE my_summary summary
+        my_summary{quantile="0.01"} 1.0
+        my_summary{quantile="0.05"} 1.0
+        my_summary{quantile="0.5"} 3.0
+        my_summary{quantile="0.9"} 10000.0
+        my_summary{quantile="0.95"} 10000.0
+        my_summary{quantile="0.99"} 10000.0
+        my_summary{quantile="0.999"} 10000.0
+        my_summary_count 4
+        my_summary_sum 10007.0
         """)
     }
 

Tests/SwiftPrometheusTests/XCTestManifests.swift

@@ -14,6 +14,7 @@ extension PrometheusMetricsTests {
         ("testHistogram", testHistogram),
         ("testMetricDestroying", testMetricDestroying),
         ("testSummary", testSummary),
+        ("testSummaryWithPreferredDisplayUnit", testSummaryWithPreferredDisplayUnit),
     ]
 }
 
@@ -25,6 +26,7 @@ extension SwiftPrometheusTests {
         ("testCounter", testCounter),
         ("testGauge", testGauge),
         ("testHistogram", testHistogram),
+        ("testMultipleCounter", testMultipleCounter),
         ("testSummary", testSummary),
     ]
 }