[PR] OAK-10872 - Replace use of StringBuilder by string concatenation in PathUtils.concat(String,String) [jackrabbit-oak]

[via GitHub]

nfsantos opened a new pull request, #1515:
URL: https://github.com/apache/jackrabbit-oak/pull/1515

   Using String concatenation in this case is much faster, because the JVM will 
use invokedynamic to concatenate the Strings. The method 
`PathUtils.concat(String, String)` is heavily used by Oak, so it is worth to 
optimize.
   
   With the following test code, using String concatenation provides a 2x 
speedup:
   ```
       public static void main(String[] args) {
           var p1 = "parent";
           var start = Stopwatch.createStarted();
           long totalSize = 0;
           for (int i = 0; i < 500_000_000; i++) {
               totalSize += PathUtils.concat(p1, "child"+i).length();
           }
           System.out.println("totalSize: " + totalSize + " start.elapsed() = " 
+ start.elapsed(TimeUnit.MILLISECONDS) + " ms" );
       }
   ```
   
   Baseline, with StringBuilder:
   ```
   TotalSize: 10388888890
   Duration: 21056 ms
   ```
   Optimized with String concatenation:
   ```
   TotalSize: 10388888890
   Duration: 11215 ms
   ```


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: dev-unsubscr...@jackrabbit.apache.org

For queries about this service, please contact Infrastructure at:
us...@infra.apache.org