Remove duplicate GetCacheKey methods (#5651)

* Remove duplicate GetCacheKey methods

Consolidate to only the `ReadOnlySpan<object>`-based method.

* Update XML comments to say that the values are serialized

src/Libraries/Microsoft.Extensions.AI/ChatCompletion/CachingChatClient.cs

@@ -1,6 +1,7 @@
 // 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.Collections.Generic;
 using System.Runtime.CompilerServices;
 using System.Threading;
@@ -16,6 +17,12 @@ namespace Microsoft.Extensions.AI;
 /// </summary>
 public abstract class CachingChatClient : DelegatingChatClient
 {
+    /// <summary>A boxed <see langword="true"/> value.</summary>
+    private static readonly object _boxedTrue = true;
+
+    /// <summary>A boxed <see langword="false"/> value.</summary>
+    private static readonly object _boxedFalse = false;
+
     /// <summary>Initializes a new instance of the <see cref="CachingChatClient"/> class.</summary>
     /// <param name="innerClient">The underlying <see cref="IChatClient"/>.</param>
     protected CachingChatClient(IChatClient innerClient)
@@ -45,7 +52,7 @@ public override async Task<ChatCompletion> CompleteAsync(IList<ChatMessage> chat
         // We're only storing the final result, not the in-flight task, so that we can avoid caching failures
         // or having problems when one of the callers cancels but others don't. This has the drawback that
         // concurrent callers might trigger duplicate requests, but that's acceptable.
-        var cacheKey = GetCacheKey(false, chatMessages, options);
+        var cacheKey = GetCacheKey(_boxedFalse, chatMessages, options);
 
         if (await ReadCacheAsync(cacheKey, cancellationToken).ConfigureAwait(false) is not { } result)
         {
@@ -68,7 +75,7 @@ public override async IAsyncEnumerable<StreamingChatCompletionUpdate> CompleteSt
             // we make a streaming request, yielding those results, but then convert those into a non-streaming
             // result and cache it. When we get a cache hit, we yield the non-streaming result as a streaming one.
 
-            var cacheKey = GetCacheKey(true, chatMessages, options);
+            var cacheKey = GetCacheKey(_boxedTrue, chatMessages, options);
             if (await ReadCacheAsync(cacheKey, cancellationToken).ConfigureAwait(false) is { } chatCompletion)
             {
                 // Yield all of the cached items.
@@ -93,7 +100,7 @@ public override async IAsyncEnumerable<StreamingChatCompletionUpdate> CompleteSt
         }
         else
         {
-            var cacheKey = GetCacheKey(true, chatMessages, options);
+            var cacheKey = GetCacheKey(_boxedTrue, chatMessages, options);
             if (await ReadCacheStreamingAsync(cacheKey, cancellationToken).ConfigureAwait(false) is { } existingChunks)
             {
                 // Yield all of the cached items.
@@ -118,14 +125,10 @@ public override async IAsyncEnumerable<StreamingChatCompletionUpdate> CompleteSt
         }
     }
 
-    /// <summary>
-    /// Computes a cache key for the specified call parameters.
-    /// </summary>
-    /// <param name="streaming">A flag to indicate if this is a streaming call.</param>
-    /// <param name="chatMessages">The chat content.</param>
-    /// <param name="options">The chat options to configure the request.</param>
-    /// <returns>A string that will be used as a cache key.</returns>
-    protected abstract string GetCacheKey(bool streaming, IList<ChatMessage> chatMessages, ChatOptions? options);
+    /// <summary>Computes a cache key for the specified values.</summary>
+    /// <param name="values">The values to inform the key.</param>
+    /// <returns>The computed key.</returns>
+    protected abstract string GetCacheKey(params ReadOnlySpan<object?> values);
 
     /// <summary>
     /// Returns a previously cached <see cref="ChatCompletion"/>, if available.

src/Libraries/Microsoft.Extensions.AI/ChatCompletion/DistributedCachingChatClient.cs

@@ -20,12 +20,6 @@ namespace Microsoft.Extensions.AI;
 /// </remarks>
 public class DistributedCachingChatClient : CachingChatClient
 {
-    /// <summary>A boxed <see langword="true"/> value.</summary>
-    private static readonly object _boxedTrue = true;
-
-    /// <summary>A boxed <see langword="false"/> value.</summary>
-    private static readonly object _boxedFalse = false;
-
     /// <summary>The <see cref="IDistributedCache"/> instance that will be used as the backing store for the cache.</summary>
     private readonly IDistributedCache _storage;
 
@@ -98,15 +92,11 @@ protected override async Task WriteCacheStreamingAsync(string key, IReadOnlyList
         await _storage.SetAsync(key, newJson, cancellationToken).ConfigureAwait(false);
     }
 
-    /// <inheritdoc />
-    protected override string GetCacheKey(bool streaming, IList<ChatMessage> chatMessages, ChatOptions? options) =>
-        GetCacheKey([streaming ? _boxedTrue : _boxedFalse, chatMessages, options]);
-
-    /// <summary>Gets a cache key based on the supplied values.</summary>
+    /// <summary>Computes a cache key for the specified values.</summary>
     /// <param name="values">The values to inform the key.</param>
     /// <returns>The computed key.</returns>
-    /// <remarks>This provides the default implementation for <see cref="GetCacheKey(bool, IList{ChatMessage}, ChatOptions?)"/>.</remarks>
-    protected string GetCacheKey(ReadOnlySpan<object?> values)
+    /// <remarks>The <paramref name="values"/> are serialized to JSON using <see cref="JsonSerializerOptions"/> in order to compute the key.</remarks>
+    protected override string GetCacheKey(params ReadOnlySpan<object?> values)
     {
         _jsonSerializerOptions.MakeReadOnly();
         return CachingHelpers.GetCacheKey(values, _jsonSerializerOptions);

src/Libraries/Microsoft.Extensions.AI/Embeddings/CachingEmbeddingGenerator.cs

@@ -106,13 +106,10 @@ public override async Task<GeneratedEmbeddings<TEmbedding>> GenerateAsync(
         return results;
     }
 
-    /// <summary>
-    /// Computes a cache key for the specified call parameters.
-    /// </summary>
-    /// <param name="value">The <typeparamref name="TInput"/> for which an embedding is being requested.</param>
-    /// <param name="options">The options to configure the request.</param>
-    /// <returns>A string that will be used as a cache key.</returns>
-    protected abstract string GetCacheKey(TInput value, EmbeddingGenerationOptions? options);
+    /// <summary>Computes a cache key for the specified values.</summary>
+    /// <param name="values">The values to inform the key.</param>
+    /// <returns>The computed key.</returns>
+    protected abstract string GetCacheKey(params ReadOnlySpan<object?> values);
 
     /// <summary>Returns a previously cached <see cref="Embedding{TEmbedding}"/>, if available.</summary>
     /// <param name="key">The cache key.</param>

src/Libraries/Microsoft.Extensions.AI/Embeddings/DistributedCachingEmbeddingGenerator.cs

@@ -74,15 +74,11 @@ protected override async Task WriteCacheAsync(string key, TEmbedding value, Canc
         await _storage.SetAsync(key, newJson, cancellationToken).ConfigureAwait(false);
     }
 
-    /// <inheritdoc />
-    protected override string GetCacheKey(TInput value, EmbeddingGenerationOptions? options) =>
-        GetCacheKey([value, options]);
-
-    /// <summary>Gets a cache key based on the supplied values.</summary>
+    /// <summary>Computes a cache key for the specified values.</summary>
     /// <param name="values">The values to inform the key.</param>
     /// <returns>The computed key.</returns>
-    /// <remarks>This provides the default implementation for <see cref="GetCacheKey(TInput, EmbeddingGenerationOptions?)"/>.</remarks>
-    protected string GetCacheKey(ReadOnlySpan<object?> values)
+    /// <remarks>The <paramref name="values"/> are serialized to JSON using <see cref="JsonSerializerOptions"/> in order to compute the key.</remarks>
+    protected override string GetCacheKey(params ReadOnlySpan<object?> values)
     {
         _jsonSerializerOptions.MakeReadOnly();
         return CachingHelpers.GetCacheKey(values, _jsonSerializerOptions);

test/Libraries/Microsoft.Extensions.AI.Tests/ChatCompletion/DistributedCachingChatClientTest.cs

@@ -815,10 +815,18 @@ private static async Task AssertCompletionsEqualAsync(IReadOnlyList<StreamingCha
     private sealed class CachingChatClientWithCustomKey(IChatClient innerClient, IDistributedCache storage)
         : DistributedCachingChatClient(innerClient, storage)
     {
-        protected override string GetCacheKey(bool streaming, IList<ChatMessage> chatMessages, ChatOptions? options)
+        protected override string GetCacheKey(params ReadOnlySpan<object?> values)
         {
-            var baseKey = base.GetCacheKey(streaming, chatMessages, options);
-            return baseKey + options?.AdditionalProperties?["someKey"]?.ToString();
+            var baseKey = base.GetCacheKey(values);
+            foreach (var value in values)
+            {
+                if (value is ChatOptions options)
+                {
+                    return baseKey + options.AdditionalProperties?["someKey"]?.ToString();
+                }
+            }
+
+            return baseKey;
         }
     }
 

test/Libraries/Microsoft.Extensions.AI.Tests/Embeddings/DistributedCachingEmbeddingGeneratorTest.cs

@@ -350,7 +350,18 @@ private static void AssertEmbeddingsEqual(Embedding<float> expected, Embedding<f
     private sealed class CachingEmbeddingGeneratorWithCustomKey(IEmbeddingGenerator<string, Embedding<float>> innerGenerator, IDistributedCache storage)
         : DistributedCachingEmbeddingGenerator<string, Embedding<float>>(innerGenerator, storage)
     {
-        protected override string GetCacheKey(string value, EmbeddingGenerationOptions? options) =>
-            base.GetCacheKey(value, options) + options?.AdditionalProperties?["someKey"]?.ToString();
+        protected override string GetCacheKey(params ReadOnlySpan<object?> values)
+        {
+            var baseKey = base.GetCacheKey(values);
+            foreach (var value in values)
+            {
+                if (value is EmbeddingGenerationOptions options)
+                {
+                    return baseKey + options.AdditionalProperties?["someKey"]?.ToString();
+                }
+            }
+
+            return baseKey;
+        }
     }
 }