Caching: migrate HybridCache api surface from asp.net into runtime

src/libraries/Microsoft.Extensions.Caching.Abstractions/ref/Microsoft.Extensions.Caching.Abstractions.cs

@@ -41,6 +41,13 @@ public partial interface IDistributedCache
         void Set(string key, byte[] value, Microsoft.Extensions.Caching.Distributed.DistributedCacheEntryOptions options);
         System.Threading.Tasks.Task SetAsync(string key, byte[] value, Microsoft.Extensions.Caching.Distributed.DistributedCacheEntryOptions options, System.Threading.CancellationToken token = default(System.Threading.CancellationToken));
     }
+    public interface IBufferDistributedCache : IDistributedCache
+    {
+        bool TryGet(string key, System.Buffers.IBufferWriter<byte> destination);
+        System.Threading.Tasks.ValueTask<bool> TryGetAsync(string key, System.Buffers.IBufferWriter<byte> destination, System.Threading.CancellationToken token = default);
+        void Set(string key, System.Buffers.ReadOnlySequence<byte> value, DistributedCacheEntryOptions options);
+        System.Threading.Tasks.ValueTask SetAsync(string key, System.Buffers.ReadOnlySequence<byte> value, DistributedCacheEntryOptions options, System.Threading.CancellationToken token = default);
+    }
 }
 namespace Microsoft.Extensions.Caching.Memory
 {
@@ -156,3 +163,59 @@ public SystemClock() { }
         public System.DateTimeOffset UtcNow { get { throw null; } }
     }
 }
+namespace Microsoft.Extensions.Caching.Hybrid
+{
+    public partial interface IHybridCacheSerializer<T>
+    {
+        T Deserialize(System.Buffers.ReadOnlySequence<byte> source);
+        void Serialize(T value, System.Buffers.IBufferWriter<byte> target);
+    }
+    public interface IHybridCacheSerializerFactory
+    {
+        bool TryCreateSerializer<T>([System.Diagnostics.CodeAnalysis.NotNullWhen(true)] out IHybridCacheSerializer<T>? serializer);
+    }
+    public sealed class HybridCacheEntryOptions
+    {
+        public System.TimeSpan? Expiration { get; init; }
+        public System.TimeSpan? LocalCacheExpiration { get; init; }
+        public HybridCacheEntryFlags? Flags { get; init; }
+    }
+    [System.Flags]
+    public enum HybridCacheEntryFlags
+    {
+        None = 0,
+        DisableLocalCacheRead = 1 << 0,
+        DisableLocalCacheWrite = 1 << 1,
+        DisableLocalCache = DisableLocalCacheRead | DisableLocalCacheWrite,
+        DisableDistributedCacheRead = 1 << 2,
+        DisableDistributedCacheWrite = 1 << 3,
+        DisableDistributedCache = DisableDistributedCacheRead | DisableDistributedCacheWrite,
+        DisableUnderlyingData = 1 << 4,
+        DisableCompression = 1 << 5,
+    }
+    public abstract class HybridCache
+    {
+        [System.Diagnostics.CodeAnalysis.SuppressMessage("ApiDesign", "RS0026:Do not add multiple public overloads with optional parameters", Justification = "Delegate differences make this unambiguous")]
+        public abstract System.Threading.Tasks.ValueTask<T> GetOrCreateAsync<TState, T>(string key, TState state, System.Func<TState, System.Threading.CancellationToken, System.Threading.Tasks.ValueTask<T>> factory,
+            HybridCacheEntryOptions? options = null, System.Collections.Generic.IReadOnlyCollection<string>? tags = null, System.Threading.CancellationToken cancellationToken = default);
+        [System.Diagnostics.CodeAnalysis.SuppressMessage("ApiDesign", "RS0026:Do not add multiple public overloads with optional parameters", Justification = "Delegate differences make this unambiguous")]
+        public System.Threading.Tasks.ValueTask<T> GetOrCreateAsync<T>(string key, System.Func<System.Threading.CancellationToken, System.Threading.Tasks.ValueTask<T>> factory,
+            HybridCacheEntryOptions? options = null, System.Collections.Generic.IReadOnlyCollection<string>? tags = null, System.Threading.CancellationToken cancellationToken = default)
+            => throw new System.NotImplementedException();
+
+        public abstract System.Threading.Tasks.ValueTask SetAsync<T>(string key, T value, HybridCacheEntryOptions? options = null, System.Collections.Generic.IReadOnlyCollection<string>? tags = null, System.Threading.CancellationToken cancellationToken = default);
+
+        [System.Diagnostics.CodeAnalysis.SuppressMessage("ApiDesign", "RS0026:Do not add multiple public overloads with optional parameters", Justification = "Not ambiguous in context")]
+        public abstract System.Threading.Tasks.ValueTask RemoveAsync(string key, System.Threading.CancellationToken cancellationToken = default);
+
+        [System.Diagnostics.CodeAnalysis.SuppressMessage("ApiDesign", "RS0026:Do not add multiple public overloads with optional parameters", Justification = "Not ambiguous in context")]
+        public virtual System.Threading.Tasks.ValueTask RemoveAsync(System.Collections.Generic.IEnumerable<string> keys, System.Threading.CancellationToken cancellationToken = default)
+            => throw new System.NotImplementedException();
+
+       [System.Diagnostics.CodeAnalysis.SuppressMessage("ApiDesign", "RS0026:Do not add multiple public overloads with optional parameters", Justification = "Not ambiguous in context")]
+        public virtual System.Threading.Tasks.ValueTask RemoveByTagAsync(System.Collections.Generic.IEnumerable<string> tags, System.Threading.CancellationToken cancellationToken = default)
+            => throw new System.NotImplementedException();
+        public abstract System.Threading.Tasks.ValueTask RemoveByTagAsync(string tag, System.Threading.CancellationToken cancellationToken = default);
+    }
+
+}

src/libraries/Microsoft.Extensions.Caching.Abstractions/ref/Microsoft.Extensions.Caching.Abstractions.csproj

@@ -16,6 +16,8 @@
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'">
     <Compile Include="$(CoreLibSharedDir)System\Runtime\CompilerServices\IsExternalInit.cs"
              Link="Common\System\Runtime\CompilerServices\IsExternalInit.cs" />
+
+    <PackageReference Include="System.Threading.Tasks.Extensions" Version="$(SystemThreadingTasksExtensionsVersion)" />
   </ItemGroup>
 
   <ItemGroup>

src/libraries/Microsoft.Extensions.Caching.Abstractions/src/Hybrid/HybridCache.cs

@@ -0,0 +1,128 @@
+// 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;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Caching.Distributed;
+
+namespace Microsoft.Extensions.Caching.Hybrid;
+
+/// <summary>
+/// Provides multi-tier caching services building on <see cref="IDistributedCache"/> backends.
+/// </summary>
+public abstract class HybridCache
+{
+    /// <summary>
+    /// Asynchronously gets the value associated with the key if it exists, or generates a new entry using the provided key and a value from the given factory if the key is not found.
+    /// </summary>
+    /// <typeparam name="TState">The type of additional state required by <paramref name="factory"/>.</typeparam>
+    /// <typeparam name="T">The type of the data being considered.</typeparam>
+    /// <param name="key">The key of the entry to look for or create.</param>
+    /// <param name="factory">Provides the underlying data service is the data is not available in the cache.</param>
+    /// <param name="state">Additional state required for <paramref name="factory"/>.</param>
+    /// <param name="options">Additional options for this cache entry.</param>
+    /// <param name="tags">The tags to associate with this cache item.</param>
+    /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
+    /// <returns>The data, either from cache or the underlying data service.</returns>
+    [System.Diagnostics.CodeAnalysis.SuppressMessage("ApiDesign", "RS0026:Do not add multiple public overloads with optional parameters", Justification = "Delegate differences make this unambiguous")]
+    public abstract ValueTask<T> GetOrCreateAsync<TState, T>(string key, TState state, Func<TState, CancellationToken, ValueTask<T>> factory,
+        HybridCacheEntryOptions? options = null, IReadOnlyCollection<string>? tags = null, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Asynchronously gets the value associated with the key if it exists, or generates a new entry using the provided key and a value from the given factory if the key is not found.
+    /// </summary>
+    /// <typeparam name="T">The type of the data being considered.</typeparam>
+    /// <param name="key">The key of the entry to look for or create.</param>
+    /// <param name="factory">Provides the underlying data service is the data is not available in the cache.</param>
+    /// <param name="options">Additional options for this cache entry.</param>
+    /// <param name="tags">The tags to associate with this cache item.</param>
+    /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
+    /// <returns>The data, either from cache or the underlying data service.</returns>
+    [System.Diagnostics.CodeAnalysis.SuppressMessage("ApiDesign", "RS0026:Do not add multiple public overloads with optional parameters", Justification = "Delegate differences make this unambiguous")]
+    public ValueTask<T> GetOrCreateAsync<T>(string key, Func<CancellationToken, ValueTask<T>> factory,
+        HybridCacheEntryOptions? options = null, IReadOnlyCollection<string>? tags = null, CancellationToken cancellationToken = default)
+        => GetOrCreateAsync(key, factory, WrappedCallbackCache<T>.Instance, options, tags, cancellationToken);
+
+    private static class WrappedCallbackCache<T> // per-T memoized helper that allows GetOrCreateAsync<T> and GetOrCreateAsync<TState, T> to share an implementation
+    {
+        // for the simple usage scenario (no TState), pack the original callback as the "state", and use a wrapper function that just unrolls and invokes from the state
+        public static readonly Func<Func<CancellationToken, ValueTask<T>>, CancellationToken, ValueTask<T>> Instance = static (callback, ct) => callback(ct);
+    }
+
+    /// <summary>
+    /// Asynchronously sets or overwrites the value associated with the key.
+    /// </summary>
+    /// <typeparam name="T">The type of the data being considered.</typeparam>
+    /// <param name="key">The key of the entry to create.</param>
+    /// <param name="value">The value to assign for this cache entry.</param>
+    /// <param name="options">Additional options for this cache entry.</param>
+    /// <param name="tags">The tags to associate with this cache entry.</param>
+    /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
+    public abstract ValueTask SetAsync<T>(string key, T value, HybridCacheEntryOptions? options = null, IReadOnlyCollection<string>? tags = null, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Asynchronously removes the value associated with the key if it exists.
+    /// </summary>
+    [System.Diagnostics.CodeAnalysis.SuppressMessage("ApiDesign", "RS0026:Do not add multiple public overloads with optional parameters", Justification = "Not ambiguous in context")]
+    public abstract ValueTask RemoveAsync(string key, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Asynchronously removes the value associated with the key if it exists.
+    /// </summary>
+    /// <remarks>Implementors should treat <c>null</c> as empty</remarks>
+    [System.Diagnostics.CodeAnalysis.SuppressMessage("ApiDesign", "RS0026:Do not add multiple public overloads with optional parameters", Justification = "Not ambiguous in context")]
+    public virtual ValueTask RemoveAsync(IEnumerable<string> keys, CancellationToken cancellationToken = default)
+    {
+        return keys switch
+        {
+            // for consistency with GetOrCreate/Set: interpret null as "none"
+            null or ICollection<string> { Count: 0 } => default,
+            ICollection<string> { Count: 1 } => RemoveAsync(keys.Single(), cancellationToken),
+            _ => ForEachAsync(this, keys, cancellationToken),
+        };
+
+        // default implementation is to call RemoveKeyAsync for each key in turn
+        static async ValueTask ForEachAsync(HybridCache @this, IEnumerable<string> keys, CancellationToken cancellationToken)
+        {
+            foreach (var key in keys)
+            {
+                await @this.RemoveAsync(key, cancellationToken).ConfigureAwait(false);
+            }
+        }
+    }
+
+    /// <summary>
+    /// Asynchronously removes all values associated with the specified tags.
+    /// </summary>
+    /// <remarks>Implementors should treat <c>null</c> as empty</remarks>
+    [System.Diagnostics.CodeAnalysis.SuppressMessage("ApiDesign", "RS0026:Do not add multiple public overloads with optional parameters", Justification = "Not ambiguous in context")]
+    public virtual ValueTask RemoveByTagAsync(IEnumerable<string> tags, CancellationToken cancellationToken = default)
+    {
+        return tags switch
+        {
+            // for consistency with GetOrCreate/Set: interpret null as "none"
+            null or ICollection<string> { Count: 0 } => default,
+            ICollection<string> { Count: 1 } => RemoveByTagAsync(tags.Single(), cancellationToken),
+            _ => ForEachAsync(this, tags, cancellationToken),
+        };
+
+        // default implementation is to call RemoveTagAsync for each key in turn
+        static async ValueTask ForEachAsync(HybridCache @this, IEnumerable<string> keys, CancellationToken cancellationToken)
+        {
+            foreach (var key in keys)
+            {
+                await @this.RemoveByTagAsync(key, cancellationToken).ConfigureAwait(false);
+            }
+        }
+    }
+
+    /// <summary>
+    /// Asynchronously removes all values associated with the specified tag.
+    /// </summary>
+    [System.Diagnostics.CodeAnalysis.SuppressMessage("ApiDesign", "RS0026:Do not add multiple public overloads with optional parameters", Justification = "Not ambiguous in context")]
+    public abstract ValueTask RemoveByTagAsync(string tag, CancellationToken cancellationToken = default);
+}

src/libraries/Microsoft.Extensions.Caching.Abstractions/src/Hybrid/HybridCacheEntryFlags.cs

@@ -0,0 +1,50 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+
+namespace Microsoft.Extensions.Caching.Hybrid;
+
+/// <summary>
+/// Additional flags that apply to a <see cref="HybridCache"/> operation.
+/// </summary>
+[Flags]
+public enum HybridCacheEntryFlags
+{
+    /// <summary>
+    /// No additional flags.
+    /// </summary>
+    None = 0,
+    /// <summary>
+    /// Disables reading from the local in-process cache.
+    /// </summary>
+    DisableLocalCacheRead = 1 << 0,
+    /// <summary>
+    /// Disables writing to the local in-process cache.
+    /// </summary>
+    DisableLocalCacheWrite = 1 << 1,
+    /// <summary>
+    /// Disables both reading from and writing to the local in-process cache.
+    /// </summary>
+    DisableLocalCache = DisableLocalCacheRead | DisableLocalCacheWrite,
+    /// <summary>
+    /// Disables reading from the secondary distributed cache.
+    /// </summary>
+    DisableDistributedCacheRead = 1 << 2,
+    /// <summary>
+    /// Disables writing to the secondary distributed cache.
+    /// </summary>
+    DisableDistributedCacheWrite = 1 << 3,
+    /// <summary>
+    /// Disables both reading from and writing to the secondary distributed cache.
+    /// </summary>
+    DisableDistributedCache = DisableDistributedCacheRead | DisableDistributedCacheWrite,
+    /// <summary>
+    /// Only fetches the value from cache; does not attempt to access the underlying data store.
+    /// </summary>
+    DisableUnderlyingData = 1 << 4,
+    /// <summary>
+    /// Disables compression for this payload.
+    /// </summary>
+    DisableCompression = 1 << 5,
+}

src/libraries/Microsoft.Extensions.Caching.Abstractions/src/Hybrid/HybridCacheEntryOptions.cs

@@ -0,0 +1,38 @@
+// 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 Microsoft.Extensions.Caching.Distributed;
+
+namespace Microsoft.Extensions.Caching.Hybrid;
+
+/// <summary>
+/// Additional options (expiration, etc.) that apply to a <see cref="HybridCache"/> operation. When options
+/// can be specified at multiple levels (for example, globally and per-call), the values are composed; the
+/// most granular non-null value is used, with null values being inherited. If no value is specified at
+/// any level, the implementation may choose a reasonable default.
+/// </summary>
+public sealed class HybridCacheEntryOptions
+{
+    /// <summary>
+    /// Overall cache duration of this entry, passed to the backend distributed cache.
+    /// </summary>
+    public TimeSpan? Expiration { get; init; } // overall cache duration
+
+    /// <summary>
+    /// Cache duration in local cache; when retrieving a cached value
+    /// from an external cache store, this value will be used to calculate the local
+    /// cache expiration, not exceeding the remaining overall cache lifetime.
+    /// </summary>
+    public TimeSpan? LocalCacheExpiration { get; init; } // TTL in L1
+
+    /// <summary>
+    /// Additional flags that apply to this usage.
+    /// </summary>
+    public HybridCacheEntryFlags? Flags { get; init; }
+
+    // memoize when possible
+    private DistributedCacheEntryOptions? _dc;
+    internal DistributedCacheEntryOptions? ToDistributedCacheEntryOptions()
+        => Expiration is null ? null : (_dc ??= new() { AbsoluteExpirationRelativeToNow = Expiration });
+}

src/libraries/Microsoft.Extensions.Caching.Abstractions/src/Hybrid/IHybridCacheSerializer.cs

@@ -0,0 +1,23 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Buffers;
+
+namespace Microsoft.Extensions.Caching.Hybrid;
+
+/// <summary>
+/// Per-type serialization/deserialization support for <see cref="HybridCache"/>.
+/// </summary>
+/// <typeparam name="T">The type being serialized/deserialized.</typeparam>
+public interface IHybridCacheSerializer<T>
+{
+    /// <summary>
+    /// Deserialize a <typeparamref name="T"/> value from the provided <paramref name="source"/>.
+    /// </summary>
+    T Deserialize(ReadOnlySequence<byte> source);
+
+    /// <summary>
+    /// Serialize <paramref name="value"/>, writing to the provided <paramref name="target"/>.
+    /// </summary>
+    void Serialize(T value, IBufferWriter<byte> target);
+}

src/libraries/Microsoft.Extensions.Caching.Abstractions/src/Hybrid/IHybridCacheSerializerFactory.cs

@@ -0,0 +1,20 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Diagnostics.CodeAnalysis;
+
+namespace Microsoft.Extensions.Caching.Hybrid;
+
+/// <summary>
+/// Factory provider for per-type <see cref="IHybridCacheSerializer{T}"/> instances.
+/// </summary>
+public interface IHybridCacheSerializerFactory
+{
+    /// <summary>
+    /// Request a serializer for the provided type, if possible.
+    /// </summary>
+    /// <typeparam name="T">The type being serialized/deserialized.</typeparam>
+    /// <param name="serializer">The serializer.</param>
+    /// <returns><c>true</c> if the factory supports this type, <c>false</c> otherwise.</returns>
+    bool TryCreateSerializer<T>([NotNullWhen(true)] out IHybridCacheSerializer<T>? serializer);
+}