Changing distributed primitive names to follow standard naming.
Change-Id: I9065584ced95fbb0a1920ba60226548729276cab
diff --git a/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentSetMultimapState.java b/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentSetMultimapState.java
new file mode 100644
index 0000000..0337bbd
--- /dev/null
+++ b/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentSetMultimapState.java
@@ -0,0 +1,754 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.store.primitives.resources.impl;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.HashMultiset;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Multiset;
+import com.google.common.collect.Sets;
+import io.atomix.copycat.server.Commit;
+import io.atomix.copycat.server.Snapshottable;
+import io.atomix.copycat.server.StateMachineExecutor;
+import io.atomix.copycat.server.session.ServerSession;
+import io.atomix.copycat.server.session.SessionListener;
+import io.atomix.copycat.server.storage.snapshot.SnapshotReader;
+import io.atomix.copycat.server.storage.snapshot.SnapshotWriter;
+import io.atomix.resource.ResourceStateMachine;
+import org.onlab.util.CountDownCompleter;
+import org.onlab.util.Match;
+import org.onosproject.store.service.Versioned;
+import org.slf4j.Logger;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.EnumSet;
+import java.util.Map;
+import java.util.Properties;
+import java.util.Set;
+import java.util.TreeMap;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.function.BiConsumer;
+import java.util.function.BinaryOperator;
+import java.util.function.Function;
+import java.util.function.Supplier;
+import java.util.stream.Collector;
+import java.util.stream.Collectors;
+
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.Clear;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.ContainsEntry;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.ContainsKey;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.ContainsValue;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.Entries;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.Get;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.IsEmpty;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.KeySet;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.Keys;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.MultiRemove;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.MultimapCommand;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.Put;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.RemoveAll;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.Replace;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.Size;
+import static org.onosproject.store.primitives.resources.impl.AtomixConsistentMultimapCommands.Values;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * State Machine for {@link AtomixConsistentSetMultimap} resource.
+ */
+public class AtomixConsistentSetMultimapState extends ResourceStateMachine
+ implements SessionListener, Snapshottable {
+
+ private final Logger log = getLogger(getClass());
+ private final AtomicLong globalVersion = new AtomicLong(1);
+ //TODO Add listener map here
+ private final Map<String, MapEntryValue> backingMap = Maps.newHashMap();
+
+ public AtomixConsistentSetMultimapState(Properties properties) {
+ super(properties);
+ }
+
+ @Override
+ public void snapshot(SnapshotWriter writer) {
+ }
+
+ @Override
+ public void install(SnapshotReader reader) {
+ }
+
+ @Override
+ protected void configure(StateMachineExecutor executor) {
+ executor.register(Size.class, this::size);
+ executor.register(IsEmpty.class, this::isEmpty);
+ executor.register(ContainsKey.class, this::containsKey);
+ executor.register(ContainsValue.class, this::containsValue);
+ executor.register(ContainsEntry.class, this::containsEntry);
+ executor.register(Clear.class, this::clear);
+ executor.register(KeySet.class, this::keySet);
+ executor.register(Keys.class, this::keys);
+ executor.register(Values.class, this::values);
+ executor.register(Entries.class, this::entries);
+ executor.register(Get.class, this::get);
+ executor.register(RemoveAll.class, this::removeAll);
+ executor.register(MultiRemove.class, this::multiRemove);
+ executor.register(Put.class, this::put);
+ executor.register(Replace.class, this::replace);
+ }
+
+ @Override
+ public void delete() {
+ super.delete();
+ }
+
+ /**
+ * Handles a Size commit.
+ *
+ * @param commit Size commit
+ * @return number of unique key value pairs in the multimap
+ */
+ protected int size(Commit<? extends Size> commit) {
+ try {
+ return backingMap.values()
+ .stream()
+ .map(valueCollection -> valueCollection.values().size())
+ .collect(Collectors.summingInt(size -> size));
+ } finally {
+ commit.close();
+ }
+ }
+
+ /**
+ * Handles an IsEmpty commit.
+ *
+ * @param commit IsEmpty commit
+ * @return true if the multimap contains no key-value pairs, else false
+ */
+ protected boolean isEmpty(Commit<? extends IsEmpty> commit) {
+ try {
+ return backingMap.isEmpty();
+ } finally {
+ commit.close();
+ }
+ }
+
+ /**
+ * Handles a contains key commit.
+ *
+ * @param commit ContainsKey commit
+ * @return returns true if the key is in the multimap, else false
+ */
+ protected boolean containsKey(Commit<? extends ContainsKey> commit) {
+ try {
+ return backingMap.containsKey(commit.operation().key());
+ } finally {
+ commit.close();
+ }
+ }
+
+ /**
+ * Handles a ContainsValue commit.
+ *
+ * @param commit ContainsValue commit
+ * @return true if the value is in the multimap, else false
+ */
+ protected boolean containsValue(Commit<? extends ContainsValue> commit) {
+ try {
+ if (backingMap.values().isEmpty()) {
+ return false;
+ }
+ Match<byte[]> match = Match.ifValue(commit.operation().value());
+ return backingMap
+ .values()
+ .stream()
+ .anyMatch(valueList ->
+ valueList
+ .values()
+ .stream()
+ .anyMatch(byteValue ->
+ match.matches(byteValue)));
+ } finally {
+ commit.close();
+ }
+ }
+
+ /**
+ * Handles a ContainsEntry commit.
+ *
+ * @param commit ContainsEntry commit
+ * @return true if the key-value pair exists, else false
+ */
+ protected boolean containsEntry(Commit<? extends ContainsEntry> commit) {
+ try {
+ MapEntryValue entryValue =
+ backingMap.get(commit.operation().key());
+ if (entryValue == null) {
+ return false;
+ } else {
+ Match valueMatch = Match.ifValue(commit.operation().value());
+ return entryValue
+ .values()
+ .stream()
+ .anyMatch(byteValue -> valueMatch.matches(byteValue));
+ }
+ } finally {
+ commit.close();
+ }
+ }
+
+ /**
+ * Handles a Clear commit.
+ *
+ * @param commit Clear commit
+ */
+ protected void clear(Commit<? extends Clear> commit) {
+ try {
+ backingMap.clear();
+ } finally {
+ commit.close();
+ }
+ }
+
+ /**
+ * Handles a KeySet commit.
+ *
+ * @param commit KeySet commit
+ * @return a set of all keys in the multimap
+ */
+ protected Set<String> keySet(Commit<? extends KeySet> commit) {
+ try {
+ return ImmutableSet.copyOf(backingMap.keySet());
+ } finally {
+ commit.close();
+ }
+ }
+
+ /**
+ * Handles a Keys commit.
+ *
+ * @param commit Keys commit
+ * @return a multiset of keys with each key included an equal number of
+ * times to the total key-value pairs in which that key participates
+ */
+ protected Multiset<String> keys(Commit<? extends Keys> commit) {
+ try {
+ Multiset keys = HashMultiset.create();
+ backingMap.forEach((key, mapEntryValue) -> {
+ keys.add(key, mapEntryValue.values().size());
+ });
+ return keys;
+ } finally {
+ commit.close();
+ }
+ }
+
+ /**
+ * Handles a Values commit.
+ *
+ * @param commit Values commit
+ * @return the set of values in the multimap with duplicates included
+ */
+ protected Multiset<byte[]> values(Commit<? extends Values> commit) {
+ try {
+ return backingMap
+ .values()
+ .stream()
+ .collect(new HashMultisetValueCollector());
+ } finally {
+ commit.close();
+ }
+ }
+
+ /**
+ * Handles an Entries commit.
+ *
+ * @param commit Entries commit
+ * @return a set of all key-value pairs in the multimap
+ */
+ protected Collection<Map.Entry<String, byte[]>> entries(
+ Commit<? extends Entries> commit) {
+ try {
+ return backingMap
+ .entrySet()
+ .stream()
+ .collect(new EntrySetCollector());
+ } finally {
+ commit.close();
+ }
+ }
+
+ /**
+ * Handles a Get commit.
+ *
+ * @param commit Get commit
+ * @return the collection of values associated with the key or an empty
+ * list if none exist
+ */
+ protected Versioned<Collection<? extends byte[]>> get(
+ Commit<? extends Get> commit) {
+ try {
+ MapEntryValue mapEntryValue = backingMap.get(commit.operation().key());
+ return toVersioned(backingMap.get(commit.operation().key()));
+ } finally {
+ commit.close();
+ }
+ }
+
+ /**
+ * Handles a removeAll commit, and returns the previous mapping.
+ *
+ * @param commit removeAll commit
+ * @return collection of removed values
+ */
+ protected Versioned<Collection<? extends byte[]>> removeAll(
+ Commit<? extends RemoveAll> commit) {
+ if (!backingMap.containsKey(commit.operation().key())) {
+ commit.close();
+ return new Versioned<>(Sets.newHashSet(), -1);
+ } else {
+ return backingMap.get(commit.operation().key()).addCommit(commit);
+ }
+ }
+
+ /**
+ * Handles a multiRemove commit, returns true if the remove results in any
+ * change.
+ * @param commit multiRemove commit
+ * @return true if any change results, else false
+ */
+ protected boolean multiRemove(Commit<? extends MultiRemove> commit) {
+ if (!backingMap.containsKey(commit.operation().key())) {
+ commit.close();
+ return false;
+ } else {
+ return (backingMap
+ .get(commit.operation().key())
+ .addCommit(commit)) != null;
+ }
+ }
+
+ /**
+ * Handles a put commit, returns true if any change results from this
+ * commit.
+ * @param commit a put commit
+ * @return true if this commit results in a change, else false
+ */
+ protected boolean put(Commit<? extends Put> commit) {
+ if (commit.operation().values().isEmpty()) {
+ return false;
+ }
+ if (!backingMap.containsKey(commit.operation().key())) {
+ backingMap.put(commit.operation().key(),
+ new NonTransactionalCommit(1));
+ }
+ return backingMap
+ .get(commit.operation().key())
+ .addCommit(commit) != null;
+ }
+
+ protected Versioned<Collection<? extends byte[]>> replace(
+ Commit<? extends Replace> commit) {
+ if (!backingMap.containsKey(commit.operation().key())) {
+ backingMap.put(commit.operation().key(),
+ new NonTransactionalCommit(1));
+ }
+ return backingMap.get(commit.operation().key()).addCommit(commit);
+ }
+
+ @Override
+ public void register(ServerSession session) {
+ super.register(session);
+ }
+
+ @Override
+ public void unregister(ServerSession session) {
+ super.unregister(session);
+ }
+
+ @Override
+ public void expire(ServerSession session) {
+ super.expire(session);
+ }
+
+ @Override
+ public void close(ServerSession session) {
+ super.close(session);
+ }
+
+ private interface MapEntryValue {
+
+ /**
+ * Returns the list of raw {@code byte[]'s}.
+ *
+ * @return list of raw values
+ */
+ Collection<? extends byte[]> values();
+
+ /**
+ * Returns the version of the value.
+ *
+ * @return version
+ */
+ long version();
+
+ /**
+ * Discards the value by invoke appropriate clean up actions.
+ */
+ void discard();
+
+ /**
+ * Add a new commit and modifies the set of values accordingly.
+ * In the case of a replace or removeAll it returns the set of removed
+ * values. In the case of put or multiRemove it returns null for no
+ * change and a set of the added or removed values respectively if a
+ * change resulted.
+ *
+ * @param commit the commit to be added
+ */
+ Versioned<Collection<? extends byte[]>> addCommit(
+ Commit<? extends MultimapCommand> commit);
+ }
+
+ private class NonTransactionalCommit implements MapEntryValue {
+ private long version;
+ private final TreeMap<byte[], CountDownCompleter<Commit>>
+ valueCountdownMap = Maps.newTreeMap(new ByteArrayComparator());
+ /*This is a mapping of commits that added values to the commits
+ * removing those values, they will not be circular because keys will
+ * be exclusively Put and Replace commits and values will be exclusively
+ * Multiremove commits, each time a Put or replace is removed it should
+ * as part of closing go through and countdown each of the remove
+ * commits depending on it.*/
+ private final HashMultimap<Commit, CountDownCompleter<Commit>>
+ additiveToRemovalCommits = HashMultimap.create();
+
+ public NonTransactionalCommit(
+ long version) {
+ //Set the version to current it will only be updated once this is
+ // populated
+ this.version = globalVersion.get();
+ }
+
+ @Override
+ public Collection<? extends byte[]> values() {
+ return ImmutableSet.copyOf(valueCountdownMap.keySet());
+ }
+
+ @Override
+ public long version() {
+ return version;
+ }
+
+ @Override
+ public void discard() {
+ valueCountdownMap.values().forEach(completer ->
+ completer.object().close());
+ }
+
+ @Override
+ public Versioned<Collection<? extends byte[]>> addCommit(
+ Commit<? extends MultimapCommand> commit) {
+ Preconditions.checkNotNull(commit);
+ Preconditions.checkNotNull(commit.operation());
+ Versioned<Collection<? extends byte[]>> retVersion;
+
+ if (commit.operation() instanceof Put) {
+ //Using a treeset here sanitizes the input, removing duplicates
+ Set<byte[]> valuesToAdd =
+ Sets.newTreeSet(new ByteArrayComparator());
+ ((Put) commit.operation()).values().forEach(value -> {
+ if (!valueCountdownMap.containsKey(value)) {
+ valuesToAdd.add(value);
+ }
+ });
+ if (valuesToAdd.isEmpty()) {
+ //Do not increment or add the commit if no change resulted
+ commit.close();
+ return null;
+ }
+ //When all values from a commit have been removed decrement all
+ //removal commits relying on it and remove itself from the
+ //mapping of additive commits to the commits removing the
+ //values it added. (Only multiremoves will be dependent)
+ CountDownCompleter<Commit> completer =
+ new CountDownCompleter<>(commit, valuesToAdd.size(),
+ c -> {
+ if (additiveToRemovalCommits.containsKey(c)) {
+ additiveToRemovalCommits.
+ get(c).
+ forEach(countdown ->
+ countdown.countDown());
+ additiveToRemovalCommits.removeAll(c);
+ }
+ c.close();
+ });
+ retVersion = new Versioned<>(valuesToAdd, version);
+ valuesToAdd.forEach(value -> valueCountdownMap.put(value,
+ completer));
+ version++;
+ return retVersion;
+
+ } else if (commit.operation() instanceof Replace) {
+ //Will this work?? Need to check before check-in!
+ Set<byte[]> removedValues = Sets.newHashSet();
+ removedValues.addAll(valueCountdownMap.keySet());
+ retVersion = new Versioned<>(removedValues, version);
+ valueCountdownMap.values().forEach(countdown ->
+ countdown.countDown());
+ valueCountdownMap.clear();
+ Set<byte[]> valuesToAdd =
+ Sets.newTreeSet(new ByteArrayComparator());
+ ((Replace) commit.operation()).values().forEach(value -> {
+ valuesToAdd.add(value);
+ });
+ if (valuesToAdd.isEmpty()) {
+ version = globalVersion.incrementAndGet();
+ backingMap.remove(((Replace) commit.operation()).key());
+ //Order is important here, the commit must be closed last
+ //(or minimally after all uses)
+ commit.close();
+ return retVersion;
+ }
+ CountDownCompleter<Commit> completer =
+ new CountDownCompleter<>(commit, valuesToAdd.size(),
+ c -> {
+ if (additiveToRemovalCommits
+ .containsKey(c)) {
+ additiveToRemovalCommits.
+ get(c).
+ forEach(countdown ->
+ countdown.countDown());
+ additiveToRemovalCommits.
+ removeAll(c);
+ }
+ c.close();
+ });
+ valuesToAdd.forEach(value ->
+ valueCountdownMap.put(value, completer));
+ version = globalVersion.incrementAndGet();
+ return retVersion;
+
+ } else if (commit.operation() instanceof RemoveAll) {
+ Set<byte[]> removed = Sets.newHashSet();
+ //We can assume here that values only appear once and so we
+ //do not need to sanitize the return for duplicates.
+ removed.addAll(valueCountdownMap.keySet());
+ retVersion = new Versioned<>(removed, version);
+ valueCountdownMap.values().forEach(countdown ->
+ countdown.countDown());
+ valueCountdownMap.clear();
+ //In the case of a removeAll all commits will be removed and
+ //unlike the multiRemove case we do not need to consider
+ //dependencies among additive and removal commits.
+
+ //Save the key for use after the commit is closed
+ String key = ((RemoveAll) commit.operation()).key();
+ commit.close();
+ version = globalVersion.incrementAndGet();
+ backingMap.remove(key);
+ return retVersion;
+
+ } else if (commit.operation() instanceof MultiRemove) {
+ //Must first calculate how many commits the removal depends on.
+ //At this time we also sanitize the removal set by adding to a
+ //set with proper handling of byte[] equality.
+ Set<byte[]> removed = Sets.newHashSet();
+ Set<Commit> commitsRemovedFrom = Sets.newHashSet();
+ ((MultiRemove) commit.operation()).values().forEach(value -> {
+ if (valueCountdownMap.containsKey(value)) {
+ removed.add(value);
+ commitsRemovedFrom
+ .add(valueCountdownMap.get(value).object());
+ }
+ });
+ //If there is nothing to be removed no action should be taken.
+ if (removed.isEmpty()) {
+ //Do not increment or add the commit if no change resulted
+ commit.close();
+ return null;
+ }
+ //When all additive commits this depends on are closed this can
+ //be closed as well.
+ CountDownCompleter<Commit> completer =
+ new CountDownCompleter<>(commit,
+ commitsRemovedFrom.size(),
+ c -> c.close());
+ commitsRemovedFrom.forEach(commitRemovedFrom -> {
+ additiveToRemovalCommits.put(commitRemovedFrom, completer);
+ });
+ //Save key in case countdown results in closing the commit.
+ String removedKey = ((MultiRemove) commit.operation()).key();
+ removed.forEach(removedValue -> {
+ valueCountdownMap.remove(removedValue).countDown();
+ });
+ //The version is updated locally as well as globally even if
+ //this object will be removed from the map in case any other
+ //party still holds a reference to this object.
+ retVersion = new Versioned<>(removed, version);
+ version = globalVersion.incrementAndGet();
+ if (valueCountdownMap.isEmpty()) {
+ backingMap
+ .remove(removedKey);
+ }
+ return retVersion;
+
+ } else {
+ throw new IllegalArgumentException();
+ }
+ }
+ }
+
+ /**
+ * A collector that creates MapEntryValues and creates a multiset of all
+ * values in the map an equal number of times to the number of sets in
+ * which they participate.
+ */
+ private class HashMultisetValueCollector implements
+ Collector<MapEntryValue,
+ HashMultiset<byte[]>,
+ HashMultiset<byte[]>> {
+ private HashMultiset<byte[]> multiset = null;
+
+ @Override
+ public Supplier<HashMultiset<byte[]>> supplier() {
+ return new Supplier<HashMultiset<byte[]>>() {
+ @Override
+ public HashMultiset<byte[]> get() {
+ if (multiset == null) {
+ multiset = HashMultiset.create();
+ }
+ return multiset;
+ }
+ };
+ }
+
+ @Override
+ public BiConsumer<HashMultiset<byte[]>, MapEntryValue> accumulator() {
+ return (multiset, mapEntryValue) ->
+ multiset.addAll(mapEntryValue.values());
+ }
+
+ @Override
+ public BinaryOperator<HashMultiset<byte[]>> combiner() {
+ return (setOne, setTwo) -> {
+ setOne.addAll(setTwo);
+ return setOne;
+ };
+ }
+
+ @Override
+ public Function<HashMultiset<byte[]>,
+ HashMultiset<byte[]>> finisher() {
+ return (unused) -> multiset;
+ }
+
+ @Override
+ public Set<Characteristics> characteristics() {
+ return EnumSet.of(Characteristics.UNORDERED);
+ }
+ }
+
+ /**
+ * A collector that creates Entries of {@code <String, MapEntryValue>} and
+ * creates a set of entries all key value pairs in the map.
+ */
+ private class EntrySetCollector implements
+ Collector<Map.Entry<String, MapEntryValue>,
+ Set<Map.Entry<String, byte[]>>,
+ Set<Map.Entry<String, byte[]>>> {
+ private Set<Map.Entry<String, byte[]>> set = null;
+
+ @Override
+ public Supplier<Set<Map.Entry<String, byte[]>>> supplier() {
+ return new Supplier<Set<Map.Entry<String, byte[]>>>() {
+ @Override
+ public Set<Map.Entry<String, byte[]>> get() {
+ if (set == null) {
+ set = Sets.newHashSet();
+ }
+ return set;
+ }
+ };
+ }
+
+ @Override
+ public BiConsumer<Set<Map.Entry<String, byte[]>>,
+ Map.Entry<String, MapEntryValue>> accumulator() {
+ return (set, entry) -> {
+ entry
+ .getValue()
+ .values()
+ .forEach(byteValue ->
+ set.add(Maps.immutableEntry(entry.getKey(),
+ byteValue)));
+ };
+ }
+
+ @Override
+ public BinaryOperator<Set<Map.Entry<String, byte[]>>> combiner() {
+ return (setOne, setTwo) -> {
+ setOne.addAll(setTwo);
+ return setOne;
+ };
+ }
+
+ @Override
+ public Function<Set<Map.Entry<String, byte[]>>,
+ Set<Map.Entry<String, byte[]>>> finisher() {
+ return (unused) -> set;
+ }
+
+ @Override
+ public Set<Characteristics> characteristics() {
+ return EnumSet.of(Characteristics.UNORDERED);
+ }
+ }
+ /**
+ * Utility for turning a {@code MapEntryValue} to {@code Versioned}.
+ * @param value map entry value
+ * @return versioned instance or an empty list versioned -1 if argument is
+ * null
+ */
+ private Versioned<Collection<? extends byte[]>> toVersioned(
+ MapEntryValue value) {
+ return value == null ? new Versioned<>(Lists.newArrayList(), -1) :
+ new Versioned<>(value.values(),
+ value.version());
+ }
+
+ private class ByteArrayComparator implements Comparator<byte[]> {
+
+ @Override
+ public int compare(byte[] o1, byte[] o2) {
+ if (Arrays.equals(o1, o2)) {
+ return 0;
+ } else {
+ for (int i = 0; i < o1.length && i < o2.length; i++) {
+ if (o1[i] < o2[i]) {
+ return -1;
+ } else if (o1[i] > o2[i]) {
+ return 1;
+ }
+ }
+ return o1.length > o2.length ? 1 : -1;
+ }
+ }
+ }
+ }