Bugfix

src/main/java/it/cavallium/dbengine/database/disk/LLLocalDictionary.java

@@ -287,7 +287,7 @@ public class LLLocalDictionary implements LLDictionary {
 				assert !Schedulers.isInNonBlockingThread() : "Called isRangeEmpty in a nonblocking thread";
 				startedContains.increment();
 				try {
-					var result = containsTime.recordCallable(() -> {
+					Boolean isRangeEmpty = containsTime.recordCallable(() -> {
 						if (range.isSingle()) {
 							return !containsKey(snapshot, range.getSingleUnsafe());
 						} else {
@@ -330,7 +330,7 @@ public class LLLocalDictionary implements LLDictionary {
 										rocksIterator.seekToFirst();
 									}
 									rocksIterator.status();
-									return rocksIterator.isValid();
+									return !rocksIterator.isValid();
 								}
 							} finally {
 								if (slice1 != null) {
@@ -342,8 +342,8 @@ public class LLLocalDictionary implements LLDictionary {
 							}
 						}
 					});
-					assert result != null;
-					sink.next(!result);
+					assert isRangeEmpty != null;
+					sink.next(isRangeEmpty);
 				} catch (RocksDBException ex) {
 					sink.error(new RocksDBException("Failed to read range " + LLUtils.toStringSafe(range)
 							+ ": " + ex.getMessage()));

src/main/java/it/cavallium/dbengine/database/memory/LLMemoryDictionary.java

@@ -515,10 +515,7 @@ public class LLMemoryDictionary implements LLDictionary {
 	@Override
 	public Mono<Boolean> isRangeEmpty(@Nullable LLSnapshot snapshot, Mono<Send<LLRange>> rangeMono, boolean fillCache) {
 		return getRangeKeys(snapshot, rangeMono)
-				.map(buf -> {
-					buf.receive().close();
-					return true;
-				})
+				.doOnNext(buf -> buf.receive().close())
 				.count()
 				.map(count -> count == 0);
 	}