Update the WeakStringCache to keep strong references to smaller strings.

[Erarndt]

Fixes #

Context

The current string cache implementation uses weak GC handles to avoid holding onto references to strings for longer than needed. As a result, the strings are frequently collected and recreated. Additionally, weak references add additional cost to each garbage collection. The proposed implementation would keep only use a weak reference for larger strings since the cost of keeping around smaller strings generally outweighs the cost of recreating them.

Changes Made

Testing

Notes

[SimaTian]

Hello and thank you for looking into possible performance improvements.
Do you have any benchmarking around the possible performance gain please?
If yes, could you share your data?
How was the 500 char threshold selected? (I think that 500 is a threshold that will capture most of the strings that MSBuild generates)

[JanKrivanek]

Related to #11160

[Erarndt]

Hello and thank you for looking into possible performance improvements.
Do you have any benchmarking around the possible performance gain please?
If yes, could you share your data?
How was the 500 char threshold selected? (I think that 500 is a threshold that will capture most of the strings that MSBuild generates)

I have lots of various data including traces with PerfView and build times. If you're looking for something specific, I likely have it :). The value was chosen somewhat arbitrability, but I did see a good number of strings that were significantly larger (1000+). There's likely some tuning we could do on the specific value.