[GitHub] [pulsar] mingyifei opened a new issue, #19808: [Bug]

["mingyifei (via GitHub)" <gi...@apache.org>]

mingyifei opened a new issue, #19808:
URL: https://github.com/apache/pulsar/issues/19808

   ### Search before asking
   
   - [X] I searched in the [issues](https://github.com/apache/pulsar/issues) and found nothing similar.
   
   
   ### Version
   
   2.11
   org.apache.bookkeeper.mledger.impl.OpFindNewest#readEntryComplete
   
   
   ### Minimal reproduce step
   
   ![image](https://user-images.githubusercontent.com/38995810/225040223-5f4a081e-b0a9-443c-9fd4-6d637729a915.png)
   
   
   1.state = checkFirst, condition.apply(entry) = true
   The following code is executed:
   
   ```
   lastMatchedPosition = position;
                   // check last entry
                   state = State.checkLast;
                   PositionImpl lastPosition = ledger.getLastPosition();
                   searchPosition = ledger.getPositionAfterN(searchPosition, max, PositionBound.startExcluded);
                   if (lastPosition.compareTo(searchPosition) < 0) {
                       if (log.isDebugEnabled()) {
                           log.debug("first position {} matches, last should be {}, but moving to lastPos {}", position,
                                   searchPosition, lastPosition);
                       }
                       searchPosition = lastPosition;
                   }
                   find();
   ```
   crux of the problem：
   The calculated searchPosition may be equal to the current entry position, then, after calling find(), state=checkLast is executed the next time, this causes condition.apply(entry) to be called twice, and with the same entry.
   
   
   
   
   
   
   
   ### What did you expect to see?
   
   I'd like to add a check code, for example:
   ```
   if (position.equals(searchPosition)) {
                       callback.findEntryComplete(position, OpFindNewest.this.ctx);
                       return;
                   }
   ```
   
   ```
           case checkFirst:
               if (!condition.apply(entry)) {
                   // If no entry is found that matches the condition, it is expected to pass null to the callback.
                   // Otherwise, a message before the expiration date will be deleted due to message TTL.
                   // cf. https://github.com/apache/pulsar/issues/5579
                   callback.findEntryComplete(null, OpFindNewest.this.ctx);
                   return;
               } else {
                   lastMatchedPosition = position;
                   // check last entry
                   state = State.checkLast;
                   PositionImpl lastPosition = ledger.getLastPosition();
                   searchPosition = ledger.getPositionAfterN(searchPosition, max, PositionBound.startExcluded);
                   if (position.equals(searchPosition)) {
                       callback.findEntryComplete(position, OpFindNewest.this.ctx);
                       return;
                   }
                   if (lastPosition.compareTo(searchPosition) < 0) {
                       if (log.isDebugEnabled()) {
                           log.debug("first position {} matches, last should be {}, but moving to lastPos {}", position,
                                   searchPosition, lastPosition);
                       }
                       searchPosition = lastPosition;
                   }
                   find();
               }
               break;
   ```
   
   ### What did you see instead?
   
   condition.apply(entry) is executed twice 
   
   ### Anything else?
   
   no
   
   ### Are you willing to submit a PR?
   
   - [X] I'm willing to submit a PR!


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[GitHub] [pulsar] mingyifei closed issue #19808: [Bug] org.apache.bookkeeper.mledger.impl.OpFindNewest#readEntryComplete

["mingyifei (via GitHub)" <gi...@apache.org>]

mingyifei closed issue #19808: [Bug]  org.apache.bookkeeper.mledger.impl.OpFindNewest#readEntryComplete 
URL: https://github.com/apache/pulsar/issues/19808


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