infocusmodereal opened a new pull request, #27527:
URL: https://github.com/apache/flink/pull/27527

   This PR addresses FLINK-39000.
   
   Problem
   - Operator list state restore performs FSDataInputStream.seek(offset) for 
every element in OperatorStateRestoreOperation.deserializeOperatorStateValues, 
even when offsets are already sequential.
   - On object stores (S3/GCS/Ceph/etc.) and for some stream wrappers (e.g. 
compressed input streams), repeated seeks can be expensive and dominate restore 
time for large operator list state.
   
   Changes
   - Track the current stream position and only call seek() when the desired 
offset differs.
   - Add a unit test that wraps the state handle input stream to count seek() 
calls and asserts that sequential offsets result in minimal seeks (covers 
snapshot compression enabled/disabled).
   
   Tests
   - ./mvnw -pl flink-runtime -Dtest=OperatorStateRestoreOperationTest test 
-Djdk17 -Pjava17-target
   


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