Logging Performance Improvements with Source Generators in C# .NET

The post shows how source generators can be used for logging in .NET through Microsoft.Extensions.Logging. It presents partial static logging methods marked with LoggerMessage, then shows how the generated code is compiled with the project and used in application code.

Reading notes

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• Source-generated logging in .NET can streamline logging calls, reduce overhead, and provide more efficient, type-safe logging.
• The setup uses Microsoft.Extensions.Logging and Microsoft.Extensions.Logging.Abstractions packages.
• Logging methods are defined in a static partial class with the LoggerMessage attribute.
• The examples include an informational log for item processing and an error log for failed processing.
• The generated code is compiled with the project as part of the partial class.
• The generated methods check whether the log level is enabled before continuing.
• The generated methods build structured log state and then call logger.Log(...).
• The article says source-generated logging is more performant because it avoids reflection and dynamic code generation at runtime.
• It says the approach gives compile-time errors when parameters or message templates do not match.
• It says the generator reduces repetitive logging code and keeps messages consistent in one place.
• The practical tips are to use descriptive names, keep related methods in the same partial class, assign unique event IDs, choose log levels carefully, and match templates to parameters exactly.
• The example keeps logging methods grouped in a Log partial class and calls them from a Todo class with an injected ILogger<Todo>.