IMemoryCache-based caching provider for MyCSharp.HttpUserAgentParser.

Repository: https://github.com/mycsharp/HttpUserAgentParser

dotnet add package MyCSharp.HttpUserAgentParser.MemoryCache

Register the provider:

services.AddHttpUserAgentMemoryCachedParser();

Then inject IHttpUserAgentParserProvider:

public sealed class MyService(IHttpUserAgentParserProvider parser)
{
	public HttpUserAgentInformation Parse(string userAgent) => parser.Parse(userAgent);

services.AddHttpUserAgentMemoryCachedParser(options =>
{
	options.CacheEntryOptions.SlidingExpiration = TimeSpan.FromMinutes(60); // default is 1 day
	options.CacheOptions.SizeLimit = 1024; // default is null (= no limit)
});

Notes:

• Each unique user-agent string counts as one cache entry.
• The provider is registered as singleton and owns its internal MemoryCache instance.
• Like any cache, concurrent requests for a new key can race; counters are best-effort.

Telemetry is modular and opt-in.

services
	.AddHttpUserAgentMemoryCachedParser()
	.WithMemoryCacheTelemetry();

Optionally enable core counters too:

services
	.AddHttpUserAgentMemoryCachedParser()
	.WithTelemetry()
	.WithMemoryCacheTelemetry();

EventSource: MyCSharp.HttpUserAgentParser.MemoryCache (constant: HttpUserAgentParserMemoryCacheEventSource.EventSourceName)

• user_agent_parser.cache.hit (incrementing)
• user_agent_parser.cache.miss (incrementing)
• user_agent_parser.cache.size (polling)

dotnet-counters monitor --process-id <pid> MyCSharp.HttpUserAgentParser.MemoryCache

This package can also emit native System.Diagnostics.Metrics instruments.

services
	.AddHttpUserAgentMemoryCachedParser()
	.WithMemoryCacheMeterTelemetry();

Optionally enable core meters too:

services
	.AddHttpUserAgentMemoryCachedParser()
	.WithMeterTelemetry()
	.WithMemoryCacheMeterTelemetry();

Meter: MyCSharp.HttpUserAgentParser.MemoryCache (constant: HttpUserAgentParserMemoryCacheMeters.MeterName)

• user_agent_parser.cache.hit (counter)
• user_agent_parser.cache.miss (counter)
• user_agent_parser.cache.size (observable gauge)

You can collect these counters with OpenTelemetry’s EventCounters instrumentation.

Add the EventSource name:

using OpenTelemetry.Metrics;

metrics.AddEventCountersInstrumentation(options =>
{
	options.AddEventSources(HttpUserAgentParserMemoryCacheEventSource.EventSourceName);
});

From there you can export to:

• OTLP (Collector)
• Prometheus
• Azure Monitor / Application Insights (via an Azure Monitor exporter)

If you enabled native meters (see above), collect them via AddMeter(...):

using OpenTelemetry.Metrics;
using MyCSharp.HttpUserAgentParser.MemoryCache.Telemetry;

metrics.AddMeter(HttpUserAgentParserMemoryCacheMeters.MeterName);

If you prefer a direct listener instead of OpenTelemetry, you can attach an EventListener and forward values into Application Insights.