import com.google.common.base.MoreObjects;
import com.google.common.base.Preconditions;
import com.google.common.base.Strings;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import javax.annotation.Nullable;
/**
* The LeastLoadedCandidateSelectionStrategy assigns ownership for an entity to the candidate which owns the least
* number of entities.
*/
public class LeastLoadedCandidateSelectionStrategy extends AbstractEntityOwnerSelectionStrategy {
- private static final Logger LOG = LoggerFactory.getLogger(LeastLoadedCandidateSelectionStrategy.class);
-
- private Map<String, Long> localStatistics = new HashMap<>();
+ private final Map<String, Long> localStatistics = new HashMap<>();
protected LeastLoadedCandidateSelectionStrategy(long selectionDelayInMillis, Map<String, Long> initialStatistics) {
super(selectionDelayInMillis, initialStatistics);
}
@Override
- public String newOwner(String currentOwner, Collection<String> viableCandidates) {
+ @SuppressFBWarnings(value = "NP_PARAMETER_MUST_BE_NONNULL_BUT_MARKED_AS_NULLABLE",
+ justification = "Unrecognised NullableDecl")
+ public String newOwner(@Nullable String currentOwner, Collection<String> viableCandidates) {
Preconditions.checkArgument(viableCandidates.size() > 0);
String leastLoadedCandidate = null;
long leastLoadedCount = Long.MAX_VALUE;
- if(!Strings.isNullOrEmpty(currentOwner)){
+ if (!Strings.isNullOrEmpty(currentOwner)) {
long localVal = MoreObjects.firstNonNull(localStatistics.get(currentOwner), 0L);
localStatistics.put(currentOwner, localVal - 1);
}
- for(String candidateName : viableCandidates){
+ for (String candidateName : viableCandidates) {
long val = MoreObjects.firstNonNull(localStatistics.get(candidateName), 0L);
- if(val < leastLoadedCount){
+ if (val < leastLoadedCount) {
leastLoadedCount = val;
leastLoadedCandidate = candidateName;
}
}
- if(leastLoadedCandidate == null){
+ if (leastLoadedCandidate == null) {
leastLoadedCandidate = viableCandidates.iterator().next();
}
}
@VisibleForTesting
- Map<String, Long> getLocalStatistics(){
+ Map<String, Long> getLocalStatistics() {
return localStatistics;
}
}