Myasuka commented on code in PR #20405: URL: https://github.com/apache/flink/pull/20405#discussion_r940048340
########## flink-state-backends/flink-statebackend-rocksdb/src/main/java/org/apache/flink/contrib/streaming/state/AbstractRocksDBState.java: ########## @@ -223,4 +223,27 @@ public StateIncrementalVisitor<K, N, V> getStateIncrementalVisitor( throw new UnsupportedOperationException( "Global state entry iterator is unsupported for RocksDb backend"); } + + /** + * Similar to decimal addition, add 1 to the last digit to calculate the upper bound. + * + * @param prefix the starting prefix for seek. + * @return end prefix for seek. + */ + protected final byte[] calculateUpperBound(byte[] prefix) { + byte[] upperBound = new byte[prefix.length]; + System.arraycopy(prefix, 0, upperBound, 0, prefix.length); + boolean overFlow = true; + for (int i = prefix.length - 1; i >= 0; i--) { + int unsignedValue = prefix[i] & 0xff; + int result = unsignedValue + 1; + upperBound[i] = (byte) (result & 0xff); + if (result >> 8 == 0) { + overFlow = false; + break; + } + } + Preconditions.checkArgument(!overFlow, "The upper boundary overflows."); Review Comment: According to [the current implementation](https://github.com/apache/flink/blob/1c40dc15fbc29e8e5e514565109a3fb05b47a83f/flink-runtime/src/main/java/org/apache/flink/runtime/state/CompositeKeySerializationUtils.java#L157-L159) to generate the prefix bytes, we could only have one byte to hold the array if the max key group number is not larger than 128. In this case, we cannot ensure the highest bit of the key is zero. -- 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: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org