Pooled arrays for tags?

[corentinaltepe]

Hello,

All documentation instanciate a new string array for tags every time we need to increment a metrics counter. Example:

service.Increment("example_metric.increment", tags: new[] { "environment:dev" });

I'd like to limit the array allocations in order to limit stress to the GC. When possible, I set tags as static readonly, for example:

private static readonly string[] _myTags = ["environment:dev"];

public void DoSomething() {
  service.Increment("example_metric.increment", tags: _myTags);
}

It's often not possible to use a static array of tags. Is it possible to recycle an array of tags to multiple calls to service.Increment with different values of the tags, for example as follows ?

// Re-use an array of tags, but change the value of one of the tags
public void DoSomething() {
  var myTags = ["environment:dev", "myTag:A"];
  service.Increment("example_metric.increment", tags: _myTags);

  // Change the value of the second tag
  myTags[1] = "myTag:B";
  service.Increment("example_metric.increment", tags: _myTags);
}

// Borrow the tags array from a pool
public void DoSomethingElse() {
  var myTags = ArrayPool<string>.Shared.Rent(2);
  
  myTags[0] = "environment:dev";
  myTags[1] = "myTag:A";
  service.Increment("example_metric.increment", tags: _myTags);

  ArrayPool<string>.Shared.Return(myTags);
}

I'm afraid the tags arrays are processed (serialized) asynchronously, which mean we must ensure the array is not modified after a call to service.Increment.