Khalid ⚡Dec 29, 2023

Silly question for #dotnet folks. Does Release mode automatically call `String.Intern` on strings? I only ask because I ran a benchmark, and doing it explicitly versus not doing it amounts to identical results.

It might also be a release optimization for `StreamReader`.

Show threaddavidwengierDec 29, 2023
@khalidabuhakmeh this implies you have string literals in your code, for every line of the file. Odd scenario.
Show threadKhalid ⚡Dec 29, 2023

@davidwengier doh, missing more context.

The "reader" is reading from a log file that might have duplicate lines (which is common).

Hope that clears it up?

Show threaddavidwengier
@khalidabuhakmeh oh, you want to dedupe strings in memory? I think you just want a dictionary. AFAIK string.Intern doesn't add to the intern pool.
Dec 29, 2023 at 6:53pmWeb
Show threadKhalid ⚡Dec 29, 2023

@davidwengier the on-method documentation says it does 🤔

And yes, a local pool would be the best option.

Show threadKirill OsenkovDec 29, 2023
@davidwengier @khalidabuhakmeh +1 just use Dictionary<string, string>. Here's a good article on this: https://sergeyteplyakov.github.io/Blog/benchmarking/2023/12/10/Intern_or_Not_Intern.html
String Interning - To Use or Not to Use? A Performance Question

I recently join a new team and one of the projects was having a high memory footprint issues. There are a few mitigations put in place and one of them was to de-duplicate strings by using string interning.

Dissecting the Code
Show threadKirill OsenkovDec 29, 2023
@davidwengier @khalidabuhakmeh basically never use String.Intern. If you need to dedupe, roll your own Dictionary or ConcurrentDictionary.
Show threadMatt WDec 31, 2023
@KirillOsenkov @davidwengier @khalidabuhakmeh Why not use a hashset?
Show threaddavidwengierDec 31, 2023
@waltza @KirillOsenkov @khalidabuhakmeh a hashset will tell you if the string is in the pool, but it won't help you return it from the pool efficiency. However if your hashset has a GetKeyByKey method, then go for it!
Show threadKhalid ⚡Dec 29, 2023
@KirillOsenkov @davidwengier funny this is similar to the post I was thinking of writing 😅