new metadata resolver api

src/Libraries/Microsoft.Extensions.Http.Diagnostics/Http/DefaultHttpDependencyMetadataResolver.cs

@@ -0,0 +1,22 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Generic;
+
+namespace Microsoft.Extensions.Http.Diagnostics;
+
+/// <summary>
+/// Default implementation of <see cref="HttpDependencyMetadataResolver"/> that uses the base
+/// trie-based lookup algorithm.
+/// </summary>
+public sealed class DefaultHttpDependencyMetadataResolver : HttpDependencyMetadataResolver
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="DefaultHttpDependencyMetadataResolver"/> class.
+    /// </summary>
+    /// <param name="dependencyMetadata">A collection of HTTP dependency metadata used for request resolution.</param>
+    public DefaultHttpDependencyMetadataResolver(IEnumerable<IDownstreamDependencyMetadata> dependencyMetadata)
+        : base(dependencyMetadata)
+    {
+    }
+}

src/Libraries/Microsoft.Extensions.Http.Diagnostics/Http/DownstreamDependencyMetadataManager.cs → src/Libraries/Microsoft.Extensions.Http.Diagnostics/Http/HttpDependencyMetadataResolver.cs

@@ -6,13 +6,21 @@
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Net;
 using System.Net.Http;
 using System.Text.RegularExpressions;
-using Microsoft.Extensions.Telemetry.Internal;
+using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Extensions.Http.Diagnostics;
 
-internal sealed class DownstreamDependencyMetadataManager : IDownstreamDependencyMetadataManager
+/// <summary>
+/// Resolves metadata for HTTP requests based on hostname, path, and method patterns.
+/// </summary>
+/// <remarks>
+/// This class provides a high-performance way to identify HTTP requests by mapping them to previously
+/// configured metadata using specialized trie-based data structures. This enables efficient lookup
+/// of service information, operation names, and other metadata for telemetry and policy application.
+/// </remarks>
+public abstract class HttpDependencyMetadataResolver
 {
     internal readonly struct ProcessedMetadata
     {
@@ -27,22 +35,35 @@
     private readonly HostSuffixTrieNode _hostSuffixTrieRoot = new();
     private readonly FrozenDictionary<string, ProcessedMetadata> _frozenProcessedMetadataMap;
 
-    public DownstreamDependencyMetadataManager(IEnumerable<IDownstreamDependencyMetadata> downstreamDependencyMetadata)
+    /// <summary>
+    /// Initializes a new instance of the <see cref="HttpDependencyMetadataResolver"/> class.
+    /// </summary>
+    /// <param name="dependencyMetadata">A collection of HTTP dependency metadata used for request resolution.</param>
+    /// <exception cref="ArgumentNullException"><paramref name="dependencyMetadata"/> is <see langword="null"/>.</exception>
+    protected HttpDependencyMetadataResolver(IEnumerable<IDownstreamDependencyMetadata> dependencyMetadata)
     {
+        _ = Throw.IfNull(dependencyMetadata);
+
         Dictionary<string, RequestMetadataTrieNode> dependencyTrieMap = [];
-        foreach (var dependency in downstreamDependencyMetadata)
+        foreach (var dependency in dependencyMetadata)
         {
             AddDependency(dependency, dependencyTrieMap);
         }
 
-        _frozenProcessedMetadataMap = ProcessDownstreamDependencyMetadata(dependencyTrieMap).ToFrozenDictionary(StringComparer.Ordinal);
+        _frozenProcessedMetadataMap = ProcessDependencyMetadata(dependencyTrieMap).ToFrozenDictionary(StringComparer.Ordinal);
     }
 
-    public RequestMetadata? GetRequestMetadata(HttpRequestMessage requestMessage)
+#if !NET462 
+    /// <summary>
+    /// Gets request metadata for the specified HTTP request message.
+    /// </summary>
+    /// <param name="requestMessage">The HTTP request message.</param>
+    /// <returns>The resolved <see cref="RequestMetadata"/> if found; otherwise, <see langword="null"/>.</returns>
+    public virtual RequestMetadata? GetRequestMetadata(HttpRequestMessage requestMessage)
     {
         try
         {
-            if (requestMessage.RequestUri == null)
+            if (requestMessage?.RequestUri == null)
             {
                 return null;
             }
@@ -56,8 +77,13 @@
             return null;
         }
     }
-
-    public RequestMetadata? GetRequestMetadata(HttpWebRequest requestMessage)
+#else
+    /// <summary>
+    /// Gets request metadata for the specified HTTP web request.
+    /// </summary>
+    /// <param name="requestMessage">The HTTP web request.</param>
+    /// <returns>The resolved <see cref="RequestMetadata"/> if found; otherwise, <see langword="null"/>.</returns>
+    public virtual RequestMetadata? GetRequestMetadata(HttpWebRequest requestMessage)
     {
         try
         {
@@ -70,12 +96,12 @@
             return null;
         }
     }
+#endif
 
     private static char[] MakeToUpperArray()
     {
         // Initialize the _toUpper array for quick conversion of any ascii char to upper
         // without incurring cost of checking whether the character requires conversion.
-
         var a = new char[Constants.ASCIICharCount];
         for (int i = 0; i < Constants.ASCIICharCount; i++)
         {
@@ -173,12 +199,12 @@
         trieCurrent.RequestMetadata = routeMetadata;
     }
 
-    private static Dictionary<string, ProcessedMetadata> ProcessDownstreamDependencyMetadata(Dictionary<string, RequestMetadataTrieNode> dependencyTrieMap)
+    private static Dictionary<string, ProcessedMetadata> ProcessDependencyMetadata(Dictionary<string, RequestMetadataTrieNode> dependencyTrieMap)
     {
         Dictionary<string, ProcessedMetadata> finalArrayDict = [];
         foreach (var dep in dependencyTrieMap)
         {
-            var finalArray = ProcessDownstreamDependencyMetadataInternal(dep.Value);
+            var finalArray = ProcessDependencyMetadataInternal(dep.Value);
             finalArrayDict.Add(dep.Key, finalArray);
         }
 
@@ -190,7 +216,7 @@
     // remove the ExlcudeCodeCoverage attribute and ensure it's covered fully using local runs and enable it back before
     // pushing the change to PR.
     [ExcludeFromCodeCoverage]
-    private static ProcessedMetadata ProcessDownstreamDependencyMetadataInternal(RequestMetadataTrieNode requestMetadataTrieRoot)
+    private static ProcessedMetadata ProcessDependencyMetadataInternal(RequestMetadataTrieNode requestMetadataTrieRoot)
     {
         Queue<RequestMetadataTrieNode> queue = new();
         queue.Enqueue(requestMetadataTrieRoot);
@@ -278,17 +304,17 @@
         return null;
     }
 
-    private void AddDependency(IDownstreamDependencyMetadata downstreamDependencyMetadata, Dictionary<string, RequestMetadataTrieNode> dependencyTrieMap)
+    private void AddDependency(IDownstreamDependencyMetadata dependencyMetadata, Dictionary<string, RequestMetadataTrieNode> dependencyTrieMap)
     {
-        foreach (var hostNameSuffix in downstreamDependencyMetadata.UniqueHostNameSuffixes)
+        foreach (var hostNameSuffix in dependencyMetadata.UniqueHostNameSuffixes)
         {
             // Add hostname to hostname suffix trie
-            AddHostnameToTrie(hostNameSuffix, downstreamDependencyMetadata.DependencyName);
+            AddHostnameToTrie(hostNameSuffix, dependencyMetadata.DependencyName);
         }
 
-        foreach (var routeMetadata in downstreamDependencyMetadata.RequestMetadata)
+        foreach (var routeMetadata in dependencyMetadata.RequestMetadata)
         {
-            routeMetadata.DependencyName = downstreamDependencyMetadata.DependencyName;
+            routeMetadata.DependencyName = dependencyMetadata.DependencyName;
 
             // Add route metadata to the route per dependency trie
             AddRouteToTrie(routeMetadata, dependencyTrieMap);
@@ -445,4 +471,4 @@
             hostMetadata.RequestMetadata : // Return the default request metadata for this host if no matching route is found.
             routeMetadataTrieRoot.RequestMetadatas[trieCurrent.RequestMetadataEntryIndex];
     }
-}
+}

src/Libraries/Microsoft.Extensions.Http.Diagnostics/Http/HttpDiagnosticsServiceCollectionExtensions.cs

@@ -4,7 +4,6 @@
 using System.Diagnostics.CodeAnalysis;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Http.Diagnostics;
-using Microsoft.Extensions.Telemetry.Internal;
 using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Extensions.DependencyInjection;
@@ -23,9 +22,10 @@
     public static IServiceCollection AddDownstreamDependencyMetadata(this IServiceCollection services, IDownstreamDependencyMetadata downstreamDependencyMetadata)
     {
         _ = Throw.IfNull(services);
-        services.TryAddSingleton<IDownstreamDependencyMetadataManager, DownstreamDependencyMetadataManager>();
-        _ = services.AddSingleton(downstreamDependencyMetadata);
+        _ = Throw.IfNull(downstreamDependencyMetadata);
 
+        services.TryAddEnumerable(ServiceDescriptor.Singleton<IDownstreamDependencyMetadata>(downstreamDependencyMetadata));
+        services.TryAddSingleton<HttpDependencyMetadataResolver, DefaultHttpDependencyMetadataResolver>();
         return services;
     }
 
@@ -39,9 +39,40 @@
         where T : class, IDownstreamDependencyMetadata
     {
         _ = Throw.IfNull(services);
-        services.TryAddSingleton<IDownstreamDependencyMetadataManager, DownstreamDependencyMetadataManager>();
-        _ = services.AddSingleton<IDownstreamDependencyMetadata, T>();
+        services.TryAddEnumerable(ServiceDescriptor.Singleton<IDownstreamDependencyMetadata, T>());
+        services.TryAddSingleton<HttpDependencyMetadataResolver, DefaultHttpDependencyMetadataResolver>();
+        return services;
+    }
+
+    /// <summary>
+    /// Adds services required for HTTP dependency metadata resolution.
+    /// </summary>
+    /// <param name="services">The <see cref="IServiceCollection"/> to add the services to.</param>
+    /// <returns>The <see cref="IServiceCollection"/> so that additional calls can be chained.</returns>
+    public static IServiceCollection AddHttpDependencyMetadataResolver(this IServiceCollection services)
+    {
+        services.TryAddSingleton<HttpDependencyMetadataResolver, DefaultHttpDependencyMetadataResolver>();
+        return services;
+    }
+
+    /// <summary>
+    /// Adds services required for HTTP dependency metadata resolution with the specified metadata providers.
+    /// </summary>
+    /// <param name="services">The <see cref="IServiceCollection"/> to add the services to.</param>
+    /// <param name="providers">The HTTP dependency metadata providers to register.</param>
+    /// <returns>The <see cref="IServiceCollection"/> so that additional calls can be chained.</returns>
+    public static IServiceCollection AddHttpDependencyMetadataResolver(
+        this IServiceCollection services,
+        params IDownstreamDependencyMetadata[] providers)
+    {
+        _ = Throw.IfNull(services);
+
+        foreach (var provider in providers)
+        {
+            services.TryAddEnumerable(ServiceDescriptor.Singleton<IDownstreamDependencyMetadata>(provider));
+        }
 
+        services.TryAddSingleton<HttpDependencyMetadataResolver, DefaultHttpDependencyMetadataResolver>();
         return services;
     }
 }

src/Libraries/Microsoft.Extensions.Http.Diagnostics/Logging/Internal/HttpRequestReader.cs

@@ -12,7 +12,6 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Http.Diagnostics;
 using Microsoft.Extensions.Options;
-using Microsoft.Extensions.Telemetry.Internal;
 using Microsoft.Shared.Diagnostics;
 using Microsoft.Shared.Pools;
 
@@ -43,23 +42,23 @@
 
     private readonly OutgoingPathLoggingMode _outgoingPathLogMode;
     private readonly IOutgoingRequestContext _requestMetadataContext;
-    private readonly IDownstreamDependencyMetadataManager? _downstreamDependencyMetadataManager;
+    private readonly HttpDependencyMetadataResolver? _dependencyMetadataResolver;
 
     public HttpRequestReader(
         IServiceProvider serviceProvider,
         IOptionsMonitor<LoggingOptions> optionsMonitor,
         IHttpRouteFormatter routeFormatter,
         IHttpRouteParser httpRouteParser,
         IOutgoingRequestContext requestMetadataContext,
-        IDownstreamDependencyMetadataManager? downstreamDependencyMetadataManager = null,
+        HttpDependencyMetadataResolver? dependencyMetadataResolver = null,
         [ServiceKey] string? serviceKey = null)
         : this(
               optionsMonitor.GetKeyedOrCurrent(serviceKey),
               routeFormatter,
               httpRouteParser,
               serviceProvider.GetRequiredOrKeyedRequiredService<IHttpHeadersReader>(serviceKey),
               requestMetadataContext,
-              downstreamDependencyMetadataManager)
+              dependencyMetadataResolver)
     {
     }
 
@@ -69,15 +68,15 @@
         IHttpRouteParser httpRouteParser,
         IHttpHeadersReader httpHeadersReader,
         IOutgoingRequestContext requestMetadataContext,
-        IDownstreamDependencyMetadataManager? downstreamDependencyMetadataManager = null)
+        HttpDependencyMetadataResolver? dependencyMetadataResolver = null)
     {
         _outgoingPathLogMode = Throw.IfOutOfRange(options.RequestPathLoggingMode);
         _httpHeadersReader = httpHeadersReader;
 
         _routeFormatter = routeFormatter;
         _httpRouteParser = httpRouteParser;
         _requestMetadataContext = requestMetadataContext;
-        _downstreamDependencyMetadataManager = downstreamDependencyMetadataManager;
+        _dependencyMetadataResolver = dependencyMetadataResolver;
 
         _defaultSensitiveParameters = options.RouteParameterDataClasses.ToFrozenDictionary(StringComparer.Ordinal);
         _queryParameterDataClasses = options.RequestQueryParametersDataClasses.ToFrozenDictionary(StringComparer.Ordinal);
@@ -234,7 +233,7 @@
 
         var requestMetadata = request.GetRequestMetadata() ??
             _requestMetadataContext.RequestMetadata ??
-            _downstreamDependencyMetadataManager?.GetRequestMetadata(request);
+            _dependencyMetadataResolver?.GetRequestMetadata(request);
 
         if (requestMetadata == null)
         {

src/Libraries/Microsoft.Extensions.Http.Diagnostics/Logging/Internal/IDownstreamDependencyMetadataManager.cs

@@ -1,15 +1,17 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System;
 using System.Net;
 using System.Net.Http;
 using Microsoft.Extensions.Http.Diagnostics;
 
 namespace Microsoft.Extensions.Telemetry.Internal;
 
 /// <summary>
-/// Interface to manage dependency metadata.
+/// (Obsolete) Use <see cref="HttpDependencyMetadataResolver"/>.
 /// </summary>
+[Obsolete("Use HttpDependencyMetadataResolver instead. This internal interface will be removed.")]
 internal interface IDownstreamDependencyMetadataManager
 {
     /// <summary>

test/Libraries/Microsoft.Extensions.Http.Diagnostics.Tests/Telemetry/DownstreamDependencyMetadataManagerTests.cs

@@ -4,14 +4,14 @@
 using System;
 using System.Net.Http;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Telemetry.Internal;
+using Microsoft.Extensions.Http.Diagnostics;
 using Xunit;
 
 namespace Microsoft.Extensions.Telemetry.Telemetry;
 
 public class DownstreamDependencyMetadataManagerTests : IDisposable
 {
-    private readonly IDownstreamDependencyMetadataManager _depMetadataManager;
+    private readonly HttpDependencyMetadataResolver _metadataResolver;
     private readonly ServiceProvider _sp;
 
     public DownstreamDependencyMetadataManagerTests()
@@ -20,7 +20,7 @@ public DownstreamDependencyMetadataManagerTests()
             .AddDownstreamDependencyMetadata(new BackslashDownstreamDependencyMetadata())
             .AddDownstreamDependencyMetadata(new EmptyRouteDependencyMetadata())
             .BuildServiceProvider();
-        _depMetadataManager = _sp.GetRequiredService<IDownstreamDependencyMetadataManager>();
+        _metadataResolver = _sp.GetRequiredService<HttpDependencyMetadataResolver>();
     }
 
     [Theory]
@@ -51,7 +51,7 @@ public void GetRequestMetadata_RoutesRegisteredWithBackslashes_ShouldReturnHostM
             RequestUri = new Uri(uriString: urlString)
         };
 
-        var requestMetadata = _depMetadataManager.GetRequestMetadata(requestMessage);
+        var requestMetadata = _metadataResolver.GetRequestMetadata(requestMessage);
         Assert.NotNull(requestMetadata);
         Assert.Equal(new BackslashDownstreamDependencyMetadata().DependencyName, requestMetadata.DependencyName);
         Assert.Equal(expectedRequestName, requestMetadata.RequestName);
@@ -71,7 +71,7 @@ public void GetRequestMetadata_EmptyRouteRegisteredForDependency_ShouldReturnMet
             RequestUri = new Uri(uriString: urlString)
         };
 
-        var requestMetadata = _depMetadataManager.GetRequestMetadata(requestMessage);
+        var requestMetadata = _metadataResolver.GetRequestMetadata(requestMessage);
 
         Assert.NotNull(requestMetadata);
         Assert.Equal("EmptyRouteService", requestMetadata.DependencyName);