RSCG – TelemetryLogging

RSCG – TelemetryLogging
 
 

Generating deep logging messages for a class

This is how you can use TelemetryLogging .

The code that you start with is

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net7.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>
	<PropertyGroup>
        <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
        <CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)\GX</CompilerGeneratedFilesOutputPath>
    </PropertyGroup>
	<ItemGroup>
		<PackageReference Include="Microsoft.Extensions.Logging.Console" Version="8.0.0" />
		<PackageReference Include="Microsoft.Extensions.Telemetry.Abstractions" Version="8.0.0" />
	</ItemGroup>
</Project>

The code that you will use is

using System.Text.Json;
using Microsoft.Extensions.Logging;

using ILoggerFactory loggerFactory = LoggerFactory.Create(
    builder =>
    {
        //builder.AddSimpleConsole();
        builder.AddJsonConsole(
            options =>
            options.JsonWriterOptions = new JsonWriterOptions()
            {
                Indented = true
            });
    }
        
    ) ;

ILogger<Person> logger = loggerFactory.CreateLogger<Person>();
logger.LogInformation("test");
(new LoggingSample(logger)).TestLogging();
public record Person (string firstName,string LastName)
{
}

using Microsoft.Extensions.Logging;

public partial class LoggingSample
{
    private readonly ILogger _logger;

    public LoggingSample(ILogger logger)
    {
        _logger = logger;
    }

    [LoggerMessage(
        EventId = 20,
        Level = LogLevel.Critical,
        Message = "Value is {value:E}")]
    public static partial void UsingFormatSpecifier(
        ILogger logger,double value);

    [LoggerMessage(
        EventId = 19,
        Level = LogLevel.Information,
        Message = "Logging all person properties",
        EventName = "PersonLogging")]
    public partial void LogWithProperties([LogProperties] Person person);


    [LoggerMessage(
        EventId = 9,
        Level = LogLevel.Trace,
        Message = "Fixed message",
        EventName = "CustomEventName")]
    public partial void LogWithCustomEventName();

    [LoggerMessage(
        EventId = 10,
        Message = "Welcome to {city} {province}!")]
    public partial void LogWithDynamicLogLevel(
        string city,LogLevel level,string province);

    public void  TestLogging()
    {
        LogWithProperties(new Person("Andrei","Ignat"));
        //LogWithCustomEventName();

        //LogWithDynamicLogLevel("Vancouver",LogLevel.Warning,"BC");
        //LogWithDynamicLogLevel("Vancouver",LogLevel.Information,"BC");

        //UsingFormatSpecifier(_logger,12345.6789);
    }
}

The code that is generated is

// <auto-generated/>
#nullable enable
#pragma warning disable CS1591 // Compensate for https://github.com/dotnet/roslyn/issues/54103
partial class LoggingSample
{
    /// <summary>
    /// Logs "Value is {value:E}" at "Critical" level.
    /// </summary>
    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Gen.Logging","8.0.0.0")]
    public static partial void UsingFormatSpecifier(global::Microsoft.Extensions.Logging.ILogger logger,double value)
    {
        var state = global::Microsoft.Extensions.Logging.LoggerMessageHelper.ThreadLocalState;

        _ = state.ReserveTagSpace(2);
        state.TagArray[1] = new("value",value);
        state.TagArray[0] = new("{OriginalFormat}","Value is {value:E}");

        logger.Log(
            global::Microsoft.Extensions.Logging.LogLevel.Critical,
            new(20,nameof(UsingFormatSpecifier)),
            state,
            null,
            static (s,_) =>
            {
                var value = s.TagArray[1].Value;
                return global::System.FormattableString.Invariant($"Value is {value:E}");
            });

        state.Clear();
    }

    /// <summary>
    /// Logs "Logging all person properties" at "Information" level.
    /// </summary>
    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Gen.Logging","8.0.0.0")]
    public partial void LogWithProperties(global::Person person)
    {
        if (!_logger.IsEnabled(global::Microsoft.Extensions.Logging.LogLevel.Information))
        {
            return;
        }

        var state = global::Microsoft.Extensions.Logging.LoggerMessageHelper.ThreadLocalState;

        _ = state.ReserveTagSpace(3);
        state.TagArray[2] = new("person.firstName",person?.firstName);
        state.TagArray[1] = new("person.LastName",person?.LastName);
        state.TagArray[0] = new("{OriginalFormat}","Logging all person properties");

        _logger.Log(
            global::Microsoft.Extensions.Logging.LogLevel.Information,
            new(19,"PersonLogging"),
            state,
            null,
            static (s,_) =>
            {
                return "Logging all person properties";
            });

        state.Clear();
    }

    /// <summary>
    /// Logs "Fixed message" at "Trace" level.
    /// </summary>
    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Gen.Logging","8.0.0.0")]
    public partial void LogWithCustomEventName()
    {
        if (!_logger.IsEnabled(global::Microsoft.Extensions.Logging.LogLevel.Trace))
        {
            return;
        }

        var state = global::Microsoft.Extensions.Logging.LoggerMessageHelper.ThreadLocalState;

        _ = state.ReserveTagSpace(1);
        state.TagArray[0] = new("{OriginalFormat}","Fixed message");

        _logger.Log(
            global::Microsoft.Extensions.Logging.LogLevel.Trace,
            new(9,"CustomEventName"),
            state,
            null,
            static (s,_) =>
            {
                return "Fixed message";
            });

        state.Clear();
    }

    /// <summary>
    /// Logs "Welcome to {city} {province}!".
    /// </summary>
    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Gen.Logging","8.0.0.0")]
    public partial void LogWithDynamicLogLevel(string city,global::Microsoft.Extensions.Logging.LogLevel level,string province)
    {
        if (!_logger.IsEnabled(level))
        {
            return;
        }

        var state = global::Microsoft.Extensions.Logging.LoggerMessageHelper.ThreadLocalState;

        _ = state.ReserveTagSpace(3);
        state.TagArray[2] = new("city",city);
        state.TagArray[1] = new("province",province);
        state.TagArray[0] = new("{OriginalFormat}","Welcome to {city} {province}!");

        _logger.Log(
            level,
            new(10,nameof(LogWithDynamicLogLevel)),
            state,
            null,
            static (s,_) =>
            {
                var city = s.TagArray[2].Value ?? "(null)";
                var province = s.TagArray[1].Value ?? "(null)";
                return global::System.FormattableString.Invariant($"Welcome to {city} {province}!");
            });

        state.Clear();
    }
}

Code and pdf at

https://ignatandrei.github.io/RSCG_Examples/v2/docs/TelemetryLogging