edenfunf opened a new pull request, #22789: URL: https://github.com/apache/kafka/pull/22789
## Problem When a prefix has no lexicographically larger successor (e.g. it is all `0xFF` bytes), `prefixScan` computes the exclusive upper bound of its range by incrementing the prefix, which overflows. `RocksDBStore` already handles this by treating the overflow as an unbounded range, but `InMemoryKeyValueStore`, `MemoryNavigableLRUCache` and `CachingKeyValueStore` called `ByteUtils.increment()` directly and threw `IndexOutOfBoundsException`. ## Fix - Centralize the overflow-safe increment as `ByteUtils.incrementWithoutOverflow()`, which returns `null` on overflow. The RocksDB code paths that previously defined a private copy now reuse it. - The three in-memory stores treat a `null` upper bound as "scan to the end of the keyspace" (`tailMap`), matching the behaviour `RocksDBStore` already had. - `ByteUtils.increment()` is left unchanged: `RocksDBStore.deleteRange()` intentionally relies on it throwing, since RocksDB's `deleteRange()` has no null-upper-bound form. ## Testing - Added `prefixScanShouldReturnMatchesWhenPrefixHasNoUpperBound` to `AbstractKeyValueStoreTest`, so it runs against every `KeyValueStore` implementation. It uses `IntegerSerializer`'s encoding of `-1` (`0xFFFFFFFF`) to reproduce the overflow. Verified the test fails on the unpatched in-memory stores and passes with the fix, while the RocksDB-backed stores pass in both cases. - Added unit tests for `ByteUtils.incrementWithoutOverflow()`. ### Committer Checklist (excluded from commit message) - [ ] Verify design and implementation - [ ] Verify test coverage and CI build status - [ ] Verify documentation (including upgrade notes) -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
