MemoryCache.Analyzers

MemoryCache.Analyzers is a Roslyn analyzer that identifies creation of System.Runtime.Caching.MemoryCache in modern .NET projects. Microsoft's ASP.NET Core caching guidance recommends Microsoft.Extensions.Caching.Memory over that compatibility API.

Example

SRC1000 reports the MemoryCache object creation in this C# code:

using System;
using System.Runtime.Caching;

MemoryCache cache = new("orders"); // SRC1000
cache.Set("order:42", "ready", DateTimeOffset.UtcNow.AddMinutes(5));

Use Microsoft.Extensions.Caching.Memory instead:

using System;
using Microsoft.Extensions.Caching.Memory;

using MemoryCache cache = new(new MemoryCacheOptions());
cache.Set("order:42", "ready", TimeSpan.FromMinutes(5));

Install

Install the package in each project to analyze:

dotnet add package MemoryCache.Analyzers

Or add a package reference:

<PackageReference Include="MemoryCache.Analyzers"
                  Version="0.1.0"
                  PrivateAssets="all" />

Supported targets

• Language: C#
• Analyzed applications: .NET Standard 2.0, .NET Core, and .NET 5 or later
• Excluded applications: .NET Framework
• Analyzer target framework: netstandard2.0

SRC1000 reports only object creation for System.Runtime.Caching.MemoryCache or a type derived from it. Calls such as Get and Set, other member access, and MemoryCache.Default do not produce diagnostics.

Rules

ID	Category	Severity	Code fix	Title
SRC1000	Compatibility	Warning	No	Avoid System.Runtime.Caching.MemoryCache in .NET Core+

See the rule reference for implementation details. See Guides for installation, configuration, and migration steps.

For experimental patterns and decorators built on IMemoryCache, see memory-cache-solutions.

Configure severity

Use .editorconfig to change the severity of SRC1000:

[*.cs]
dotnet_diagnostic.SRC1000.severity = error

Guides

• Install MemoryCache.Analyzers
• Configure MemoryCache.Analyzers
• Migrate from System.Runtime.Caching.MemoryCache
• GetOrCreate is not atomic: cache stampede in IMemoryCache
• Manual QA: try the local package in a sample project
• Architecture: analyzer flow and build and release flow
• Runbooks: releases, bad releases, and CI failures

Build and test

The repository uses the .NET SDK version in global.json.

dotnet build MemoryCache.Analyzers.sln /p:PedanticMode=true
dotnet test MemoryCache.Analyzers.sln --no-build --settings ./build/targets/tests/test.runsettings

License

MemoryCache.Analyzers is licensed under the MIT License.