add performance enhancements

Author: BenjaminAbt

.github/copilot-instructions.md

@@ -0,0 +1 @@
+- @azure Rule - Use Azure Best Practices: When generating code for Azure, running terminal commands for Azure, or performing operations related to Azure, invoke your `get_azure_best_practices` tool if available.

Directory.Build.props

@@ -25,11 +25,11 @@
     </PropertyGroup>
 
     <PropertyGroup Label="Project Defaults">
-        <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
+        <TargetFrameworks>net8.0;net9.0;net10.0</TargetFrameworks>
     </PropertyGroup>
 
     <PropertyGroup Label="C#">
-        <LangVersion>12.0</LangVersion>
+        <LangVersion>preview</LangVersion>
         <Nullable>enable</Nullable>
         <ImplicitUsings>enable</ImplicitUsings>
         <TreatWarningsAsErrors>true</TreatWarningsAsErrors>

global.json

@@ -1,5 +1,5 @@
 {
-    "sdk": {
-        "version": "9.0.100"
-    }
+  "sdk": {
+    "version": "10.0.100-preview.2.25164.34"
+  }
 }

src/MyCSharp.HttpClientHints.AspNetCore/HttpClientHintsHttpContextExtensions.cs

@@ -1,6 +1,7 @@
 // Copyright © myCSharp.de - all rights reserved
 
 using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Primitives;
 
 namespace MyCSharp.HttpClientHints.AspNetCore;
 
@@ -9,15 +10,28 @@ namespace MyCSharp.HttpClientHints.AspNetCore;
 /// </summary>
 public static class HttpClientHintsHttpContextExtensions
 {
+    /// <summary>
+    /// The cache key used to store the client hints in the HttpContext.Items dictionary.
+    /// </summary>
+    private const string ClientHintsCacheKey = "__HttpClientHints";
+
     /// <summary>
     /// Retrieves the <see cref="HttpClientHints"/> from the current HTTP context.
     /// </summary>
     /// <param name="context">The HTTP context containing the request headers.</param>
     /// <returns>An instance of <see cref="HttpClientHints"/> populated with the relevant header values.</returns>
     public static HttpClientHints GetClientHints(this HttpContext context)
     {
-        IHeaderDictionary headers = context.Request.Headers;
-        return headers.GetClientHints();
+        // Check if client hints are already cached for this request
+        if (context.Items.TryGetValue(ClientHintsCacheKey, out var cached) && cached is HttpClientHints hints)
+        {
+            return hints;
+        }
+        
+        // Create and cache new client hints
+        var newHints = context.Request.Headers.GetClientHints();
+        context.Items[ClientHintsCacheKey] = newHints;
+        return newHints;
     }
 
     /// <summary>
@@ -27,25 +41,36 @@ public static HttpClientHints GetClientHints(this HttpContext context)
     /// <returns>An instance of <see cref="HttpClientHints"/> populated with the relevant header values.</returns>
     public static HttpClientHints GetClientHints(this IHeaderDictionary headers)
     {
-        // user agent
-        string? userAgent = headers["User-Agent"].FirstOrDefault();
-        string? ua = headers["Sec-CH-UA"].FirstOrDefault();
+        // User Agent
+        headers.TryGetValue("User-Agent", out StringValues userAgentValues);
+        string? userAgent = userAgentValues.Count > 0 ? userAgentValues[0] : null;
+        
+        headers.TryGetValue("Sec-CH-UA", out StringValues uaValues);
+        string? ua = uaValues.Count > 0 ? uaValues[0] : null;
 
-        // platform
-        string? platform = headers["Sec-CH-UA-Platform"].FirstOrDefault();
-        string? platformVersion = headers["Sec-CH-UA-Platform-Version"].FirstOrDefault();
+        // Platform
+        headers.TryGetValue("Sec-CH-UA-Platform", out StringValues platformValues);
+        string? platform = platformValues.Count > 0 ? platformValues[0] : null;
+        
+        headers.TryGetValue("Sec-CH-UA-Platform-Version", out StringValues platformVersionValues);
+        string? platformVersion = platformVersionValues.Count > 0 ? platformVersionValues[0] : null;
 
-        // architecture
-        string? architecture = headers["Sec-CH-UA-Arch"].FirstOrDefault();
+        // Architecture
+        headers.TryGetValue("Sec-CH-UA-Arch", out StringValues architectureValues);
+        string? architecture = architectureValues.Count > 0 ? architectureValues[0] : null;
 
-        // other
-        string? fullVersionList = headers["Sec-CH-UA-Full-Version-List"].FirstOrDefault();
+        // Other
+        headers.TryGetValue("Sec-CH-UA-Full-Version-List", out StringValues fullVersionListValues);
+        string? fullVersionList = fullVersionListValues.Count > 0 ? fullVersionListValues[0] : null;
 
-        // device
-        string? model = headers["Sec-CH-UA-Model"].FirstOrDefault();
-        bool? mobile = HttpClientHintsInterpreter.IsMobile(headers["Sec-CH-UA-Mobile"].FirstOrDefault());
+        // Device
+        headers.TryGetValue("Sec-CH-UA-Model", out StringValues modelValues);
+        string? model = modelValues.Count > 0 ? modelValues[0] : null;
+        
+        headers.TryGetValue("Sec-CH-UA-Mobile", out StringValues mobileValues);
+        bool? mobile = HttpClientHintsInterpreter.IsMobile(mobileValues.Count > 0 ? mobileValues[0] : null);
 
-        // return the HttpClientHints record
+        // Return the HttpClientHints record
         return new(userAgent, platform, platformVersion, architecture, model, fullVersionList, ua, mobile, headers);
     }
 }

src/MyCSharp.HttpClientHints.AspNetCore/HttpClientHintsMiddlewareConfig.cs

@@ -12,12 +12,32 @@ public class HttpClientHintsMiddlewareConfig
     /// </summary>
     /// <value>The name of the response header as a <see cref="string"/>.</value>
     /// <remarks>These settings are set by <see cref="HttpClientHintsRegistration"/>. Do not set these values manually.</remarks>
-    public required string ResponseHeader { get; set; }
+    public required string ResponseHeader
+    {
+        get;
+        set
+        {
+            field = value;
+            HasResponseHeaders = string.IsNullOrEmpty(value) is false;
+        }
+    }
+
+    public bool HasResponseHeaders { get; internal set; }
 
     /// <summary>
     /// Gets or sets the lifetime of the client hints in seconds.
     /// </summary>
     /// <value>A <see cref="string"/> containing an <see cref="int"/> representing the lifetime in seconds, or <c>null</c> if unspecified.</value>
     /// <remarks>These settings are set by <see cref="HttpClientHintsRegistration"/>. Do not set these values manually.</remarks>
-    public string? LifeTime { get; set; }
+    public string? LifeTime
+    {
+        get;
+        set
+        {
+            field = value;
+            HasLifetime = string.IsNullOrEmpty(value) is false;
+        }
+    }
+
+    public bool HasLifetime { get; internal set; }
 }

src/MyCSharp.HttpClientHints.AspNetCore/HttpClientHintsRequestMiddleware.cs

@@ -1,18 +1,11 @@
-// Copyright © myCSharp.de - all rights reserved
-
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Options;
 
 namespace MyCSharp.HttpClientHints.AspNetCore;
 
-/// <summary>
-/// Middleware for adding HTTP Client Hints headers to the response.
-/// Initializes a new instance of the <see cref="HttpClientHintsRequestMiddleware"/> class.
-/// </summary>
-/// <param name="next">The next middleware in the request pipeline.</param>
-/// <param name="options">The options for configuring the middleware.</param>
 public class HttpClientHintsRequestMiddleware(RequestDelegate next, IOptions<HttpClientHintsMiddlewareConfig> options)
 {
+    // Cache the options value and pre-compute conditions to avoid repeated checks
     private readonly HttpClientHintsMiddlewareConfig _options = options.Value;
 
     /// <summary>
@@ -22,12 +15,12 @@ public class HttpClientHintsRequestMiddleware(RequestDelegate next, IOptions<Htt
     /// <returns>A <see cref="Task"/> that represents the asynchronous operation.</returns>
     public async Task InvokeAsync(HttpContext context)
     {
-        // Add Client Hints headers to the response
-        if (string.IsNullOrEmpty(_options.ResponseHeader) is false)
+        if (_options.HasResponseHeaders)
         {
+            // Set headers directly without additional checks
             context.Response.Headers["Accept-CH"] = _options.ResponseHeader;
 
-            if (_options.LifeTime is not null)
+            if (_options.HasLifetime)
             {
                 context.Response.Headers["Accept-CH-Lifetime"] = _options.LifeTime;
             }

src/MyCSharp.HttpClientHints/HttpClientHintsInterpreter.cs

@@ -21,12 +21,12 @@ public static class HttpClientHintsInterpreter
     /// </returns>
     public static bool? IsMobile(string? mobileHeaderValue)
     {
-        if (mobileHeaderValue is "?1")
+        if (string.Equals(mobileHeaderValue, "?1", StringComparison.Ordinal))
         {
             return true;
         }
 
-        if (mobileHeaderValue is "?0")
+        if (string.Equals(mobileHeaderValue, "?0", StringComparison.Ordinal))
         {
             return false;
         }