Merge branch 'main' into benchmark

Author: freef4ll

.github/workflows/main.yml

@@ -16,3 +16,7 @@ jobs:
       linux_6_0_arguments_override: "-Xswiftc -warnings-as-errors --explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"
       linux_nightly_6_0_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"
       linux_nightly_main_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"
+
+  release-builds:
+    name: Release builds
+    uses: apple/swift-nio/.github/workflows/release_builds.yml@main

.github/workflows/pull_request.yml

@@ -28,3 +28,7 @@ jobs:
   cxx-interop:
     name: Cxx interop
     uses: apple/swift-nio/.github/workflows/cxx_interop.yml@main
+
+  release-builds:
+    name: Release builds
+    uses: apple/swift-nio/.github/workflows/release_builds.yml@main

Sources/Prometheus/Docs.docc/index.md

@@ -60,7 +60,7 @@ text representation:
 ```swift
 var buffer = [UInt8]()
 buffer.reserveCapacity(1024) // potentially smart moves to reduce the number of reallocations
-registry.emit(into: buffer)
+registry.emit(into: &buffer)
 
 print(String(decoding: buffer, as: Unicode.UTF8.self))
 ```

Sources/Prometheus/Histogram.swift

@@ -56,6 +56,7 @@ public final class Histogram<Value: Bucketable>: Sendable {
         self.box = .init(.init(buckets: buckets))
     }
 
+    @inlinable
     public func record(_ value: Value) {
         self.box.withLockedValue { state in
             for i in state.buckets.startIndex..<state.buckets.endIndex {

Sources/Prometheus/MetricDescriptor.swift

@@ -0,0 +1,66 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftPrometheus open source project
+//
+// Copyright (c) 2018-2025 SwiftPrometheus project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftPrometheus project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+/// A descriptor that defines the components of a fully qualified Prometheus metric name.
+///
+/// The final, underscore-separated metric name is generated by the ``name`` computed property. The ``helpText``
+/// is used to generate the corresponding `# HELP` line in the Prometheus exposition format.
+/// - Warning: This initializer will trigger a `preconditionFailure` if ``metricName`` is an empty string.
+public struct MetricNameDescriptor {
+    /// An optional top-level namespace for the metric.
+    public let namespace: String?
+
+    /// An optional subsystem to group related metrics.
+    public let subsystem: String?
+
+    /// The required, descriptive base name of the metric.
+    public let metricName: String
+
+    /// An optional suffix describing the metric's unit (e.g., `total`).
+    public let unitName: String?
+
+    /// Optional help text for the metric. If a non-empty string is provided, it will be emitted as a `# HELP` line in the exposition format.
+    /// If the parameter is omitted or an empty string is passed, the `# HELP` line will not be generated for this metric.
+    public let helpText: String?
+
+    /// Creates a new ``MetricNameDescriptor`` that defines the components of a fully qualified Prometheus metric name.
+    ///
+    /// - Parameter namespace: An optional top-level namespace for the metric.
+    /// - Parameter subsystem: An optional subsystem to group related metrics within a namespace.
+    /// - Parameter metricName: The required, descriptive base name of the metric.
+    /// - Parameter unitName: An optional suffix describing the metric's unit (e.g., `total`).
+    /// - Parameter helpText: Optional help text for the metric. If a non-empty string is provided, it will be emitted as a `# HELP` line in the exposition format.
+    ///                       If the parameter is omitted or an empty string is passed, the `# HELP` line will not be generated for this metric.
+    public init(
+        namespace: String? = nil,
+        subsystem: String? = nil,
+        metricName: String,
+        unitName: String? = nil,
+        helpText: String? = nil
+    ) {
+        precondition(!metricName.isEmpty, "metricName must not be empty")
+        self.namespace = namespace
+        self.subsystem = subsystem
+        self.metricName = metricName
+        self.unitName = unitName
+        self.helpText = helpText
+    }
+
+    /// The fully qualified metric name, joining non-empty components with underscores (e.g. `namespace_subsytem_metricName_unitName`).
+    public var name: String {
+        [namespace, subsystem, metricName, unitName]
+            .compactMap { $0?.isEmpty == false ? $0 : nil }
+            .joined(separator: "_")
+    }
+}