lhotari opened a new issue, #21108:
URL: https://github.com/apache/pulsar/issues/21108

   ### Search before asking
   
   - [X] I searched in the [issues](https://github.com/apache/pulsar/issues) 
and found nothing similar.
   
   
   ### Version
   
   any
   
   ### Minimal reproduce step
   
   The `signSafeMod` function used in Pulsar collection classes doesn't work 
with negative input values. This impacts the hash bucket algorithm.
   
   
   ```
   static final int signSafeMod(long n, int max) {
            return (int) (n & (max - 1)) << 2;
   }
   ```
   
   Demonstration in `jshell` with the invalid `signSafeMod` implementation:
   ```
   jshell> static final int signSafeMod(long n, int max) {
      ...>         return (int) (n & (max - 1)) << 2;
      ...>     }
   |  created method signSafeMod(long,int)
   
   jshell> signSafeMod(-2, 8)
   $2 ==> 24
   
   ```
   
   The correct value for signSafeMod(-2, 8) is `6`, not `24`.
   
   
   ### What did you expect to see?
   
   `signSafeMod` function used should really be sign safe and work correctly 
with negative input values.
   
   ### What did you see instead?
   
   This bug wastes CPU cycles because of the inefficient storage and retrieval 
since collisions will be very likely when the used capacity of the collection 
implementation increases.
   
   ### Anything else?
   
   _No response_
   
   ### Are you willing to submit a PR?
   
   - [X] I'm willing to submit a PR!


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