collections.compare(() -> { jdk; apache; eclipse; guava});...• apache commons collection –...

Collections.compare(() -> { JDK; Apache; Eclipse; Guava...}); Nikhil J. Nanivadekar

#CollectionsCompare #GIDS17 @NikhilNanivade

Agenda

1. Introduction 2. History of Java util collections framework 3. Gaps in use cases from the timeline 4. Timeline with other collection frameworks 5. Memory characteristics 6. Use case, domain diagrams 7. Deep dive in use case


Authors

• Donald Raab (@TheDonRaab) • Leonardo Lima (@leomrlima) • Nikhil J. Nanivadekar (@NikhilNanivade)


Speaker

Nikhil J. Nanivadekar – Mechanical Engineer – Software developer – Vice President, Technology at Goldman Sachs – From Pune, Maharashtra currently in Salt Lake City,

Utah

java.util Collections


java.util Collections

• Java Collection Framework has been around since 1998/JDK 1.2. Very basic but critical collection support for Java.

• Interfaces: Maps and Collections (List, Set, Queue, Deque)

• Implementations: Basic and Concurrent versions of the interfaces, sorted and concurrent as well

• Algorithms: Sorting, Shuffling, Routine Data Manipulation, Searching, Composition

• Best way to get started is using the simple and concurrent tutorials

https://docs.oracle.com/javase/tutorial/collections/

https://docs.oracle.com/javase/tutorial/essential/concurrency/collections.html


Java Collections Frameworks Java 2 1998

• Interfaces • Collection • List • Set • Map • SortedSet • SortedMap

Java 5 2005

• Generics • For-each loop • Interfaces

• Iterable • Queue • ConcurrentMap • BlockingQueue

Java 6 2006

•Interfaces •NavigableSet •NavigableMap •Deque •BlockingDeque •ConcurrentNavigableMap

Java 7 2011

• Interfaces • TransferQueue

Java 8 2014

• Lambdas • Method Refs • Default Methods • Interfaces

• BaseStream • Stream • IntStream • LongStream • DoubleStream • Collector • Spliterator • PrimitiveIterator

!java.util Collections?


!java.util Collections

• We’re considering 4 collection frameworks, in alphabetical order:

• Apache Commons Collection – version 4.1

• Eclipse Collections (Formerly GS Collections) – version 8.1.0

• Google Guava – version 21.0

• Javaslang (now called Vavr) – version 2.1.0-alpha

https://commons.apache.org/proper/commons-collections/userguide.html

https://github.com/eclipse/eclipse-collections/blob/master/docs/guide.md

https://github.com/google/guava/wiki

http://www.javaslang.io/javaslang-docs/

http://blog.vavr.io/javaslang-changes-name-to-vavr/


Collection Framework Timelines

Java 2 1998

•Jakarta Collections 1.0 •2001

•Apache Collections 3.0 •2004

Java 6 2006

•Google Collections 1.0 •Dec. 2009

Java 7 2011

•Google Guava 10.0 •Sept. 2011

•GS Collections 1.0 •Jan. 2012

•Apache Collections 4.0 •Nov. 2013

Java 8 2014

•Javaslang 1.0 •Mar. 2014

•Apache Collections 4.1 •Nov. 2015

•Eclipse Collections 7.0 •Jan. 2016

•Eclipse Collections 8.0 (Java 8) •Sept. 2016

•Google Guava 20.0 •Oct. 2016

•Javaslang 2.1a •Nov. 2016

March 2017

•Google Guava 21.0 (Java 8) •Jan. 2017

•Eclipse Collections 8.1 •Mar. 2017

Collections.compare();


Use Case – Deck of Cards

The Collections Compare Project: https://github.com/nikhilnanivadekar/CollectionsCompare


Problem Statement – Deck of Cards

1. Create Deck of Cards – Store Cards in an “Immutable” SortedSet

(Cartesian product of Suit x Rank) – Group the cards by Suit in an “Immutable” SortedSet

“Multimap” (Group By)

2. Get the number of cards – Count By Suit returning “Multiset” or “Bag” – Count By Rank returning “Multiset” or “Bag”

3. Deal five hands of five cards each – Return the cards as an “Immutable” List of five Sets of five

cards


Performance Benchmarks

• JMH – Java Microbenchmark Harness • http://openjdk.java.net/projects/code-tools/jmh/ • Measure Reported – Operations per second • Bigger numbers are better • 4 Core Intel I7, 50 Warm-up iterations, 30

measurement iterations, two forks

http://openjdk.java.net/projects/code-tools/jmh/








cards


Performance Test – Deck of Cards

102,037

79,343 76,982

56,224

91,017

0

20,000

40,000

60,000

80,000

100,000

120,000

Scor

e op

s/s

Framework

Deck of Cards

Apache EC Guava Javaslang JDK


A Deck of Cards – Only the Types public class JDK8DeckOfCards { private SortedSet<Card> cards; private Map<Suit, SortedSet<Card>> cardsBySuit;

public class ApacheCommonsDeckOfCards { private SortedSet<Card> cards; private MultiValuedMap<Suit, Card> cardsBySuit;

public class EclipseCollectionsDeckOfCards { private ImmutableSortedSet<Card> cards; private ImmutableSortedSetMultimap<Suit, Card> cardsBySuit;

public class GoogleGuavaDeckOfCards { private ImmutableSortedSet<Card> cards; private ImmutableSetMultimap<Suit, Card> cardsBySuit;

public class JavaSlangDeckOfCards { private SortedSet<Card> cards; private Map<Suit, ? extends SortedSet<Card>> cardsBySuit;








cards


Shared Code – Cartesian Product public static Stream<Card> streamCards() { return Card.cartesianProduct( EnumSet.allOf(Rank.class), EnumSet.allOf(Suit.class), Card::new); } private static <A, B, C> Stream<C> cartesianProduct( Set<A> set1, Set<B> set2, Function2<A, B, C> function) { return set1.stream().flatMap(first -> set2.stream().map(second -> function.apply(first, second))); }


Performance Test – Cartesian Product

185,087 203,660

465,999

127,439 114,634

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

450,000

500,000

Scor

e op

s/s

Framework

Cartesian Product



JDK Collections – Cartesian Product public class JDK8DeckOfCards { private SortedSet<Card> cards; public JDK8DeckOfCards() { this.cards = Card.streamCards() .collect(Collectors.collectingAndThen( Collectors.toCollection(TreeSet::new), Collections::unmodifiableSortedSet)); }


Apache Collections – Cartesian Product public class ApacheCommonsDeckOfCards { private SortedSet<Card> cards; public ApacheCommonsDeckOfCards() { this.cards = Card.streamCards() .collect(Collectors.collectingAndThen( Collectors.toCollection(TreeSet::new), Collections::unmodifiableSortedSet)); }


Eclipse Collections – Cartesian Product public class EclipseCollectionsDeckOfCards { private ImmutableSortedSet<Card> cards; public EclipseCollectionsDeckOfCards() { this.cards = SortedSets.immutable.with( Card.streamCards() .toArray(Card[]::new)); }


Google Guava – Cartesian Product public class GoogleGuavaDeckOfCards { private ImmutableSortedSet<Card> cards; public GoogleGuavaDeckOfCards() { this.cards = Card.streamCards() .collect(ImmutableSortedSet .toImmutableSortedSet( Comparator.naturalOrder())); }


Javaslang – Cartesian Product public class JavaSlangDeckOfCards { private SortedSet<Card> cards; public JavaSlangDeckOfCards() { this.cards = Card.streamCards() .collect(TreeSet.collector()); }








cards


Performance Test - groupBy

540,396

183,848 231,321

176,412

353,651

-

100,000

200,000

300,000

400,000

500,000

600,000

Scor

e op

s/s

Framework

groupBy



JDK Collections – Group By public class JDK8DeckOfCards { private Map<Suit, SortedSet<Card>> cardsBySuit; public JDK8DeckOfCards() { this.cardsBySuit = Collections.unmodifiableMap( this.cards.stream() .collect(Collectors.groupingBy( Card::getSuit, Collectors.mapping( Function.identity(), Collectors.collectingAndThen( Collectors.toCollection(TreeSet::new), Collections::unmodifiableSortedSet))))); }


Apache Collections – Group By public class ApacheCommonsDeckOfCards { private MultiValuedMap<Suit, Card> cardsBySuit; public ApacheCommonsDeckOfCards() { SetValuedMap<Suit, Card> cbs = MultiMapUtils.newSetValuedHashMap(); this.cards.forEach(card -> cbs.put(card.getSuit(), card)); this.cardsBySuit = MultiMapUtils.unmodifiableMultiValuedMap(cbs); }


Eclipse Collections – Group By public class EclipseCollectionsDeckOfCards { private ImmutableSortedSetMultimap<Suit, Card> cardsBySuit; public EclipseCollectionsDeckOfCards() { this.cardsBySuit = this.cards.groupBy(Card::getSuit); }


Google Guava – Group By public class GoogleGuavaDeckOfCards { private ImmutableSetMultimap<Suit, Card> cardsBySuit; public GoogleGuavaDeckOfCards() { ImmutableSetMultimap.Builder<Suit, Card> builder = new ImmutableSetMultimap.Builder<Suit, Card>() .orderValuesBy(Comparator.naturalOrder()); this.cards.forEach(card -> builder.put(card.getSuit(), card)); this.cardsBySuit = builder.build(); }


Javaslang – Group By public class JavaSlangDeckOfCards { private Map<Suit, ? extends SortedSet<Card>> cardsBySuit; public JavaSlangDeckOfCards() { this.cardsBySuit = this.cards.groupBy(Card::getSuit); }


Performance Test – Deck of Cards

102,037

79,343 76,982

56,224

91,017

0

20,000

40,000

60,000

80,000

100,000

120,000

Scor

e op

s/s

Framework

Deck of Cards


540,396

183,848 231,321 176,412 353,651

-

500,000

1,000,000

Scor

e op

s/s

Framework

groupBy


185,087 203,660

465,999

127,439 114,634

0

200,000

400,000

600,000

Scor

e op

s/s

Framework

Cartesian Product









cards


Performance Test - countsBySuit

706,272

1,096,527

533,728 440,786

724,526

0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

Scor

e op

s/s

Framework



Performance Test - countsByRank

539,252

827,986

444,832 390,134

591,869

0

100,000

200,000

300,000

400,000

500,000

600,000

700,000

800,000

900,000

Scor

e op

s/s

Framework



JDK Collections – Count By

public Map<Suit, Long> countsBySuit() { return this.cards.stream() .collect(Collectors.groupingBy( Card::getSuit, Collectors.counting())); } public Map<Rank, Long> countsByRank() { return this.cards.stream() .collect(Collectors.groupingBy( Card::getRank, Collectors.counting())); }


Apache Collections – Count By

public Bag<Suit> countsBySuit() { return this.cards.stream() .map(Card::getSuit) .collect(Collectors.toCollection(HashBag::new)); } public MultiSet<Rank> countsByRank() { return this.cards.stream() .map(Card::getRank) .collect(Collectors.toCollection( HashMultiSet::new)); }


Eclipse Collections – Count By

public Bag<Suit> countsBySuit() { return this.cards.asLazy() .collect(Card::getSuit) .toBag(); } public Bag<Rank> countsByRank() { return this.cards.asLazy() .collect(Card::getRank) .toBag(); }


Google Guava – Count By public Multiset<Suit> countsBySuit() { return this.cards.stream() .map(Card::getSuit) .collect(Collectors.toCollection( HashMultiset::create)); } public Multiset<Rank> countsByRank() { return this.cards.stream() .map(Card::getRank) .collect(Collectors.toCollection( HashMultiset::create)); }


Javaslang – Count By public java.util.Map<Suit, Long> countsBySuit() { return this.cards.collect( Collectors.groupingBy( Card::getSuit, Collectors.counting())); } public java.util.Map<Rank, Long> countsByRank() { return this.cards.collect( Collectors.groupingBy( Card::getRank, Collectors.counting())); }







3. Deal five hands of five cards each – Return the cards as an “Immutable” List of five Sets of

five cards


Performance Test – Deal Hands

291,488

502,448

305,673

372,466

300,975

0

100,000

200,000

300,000

400,000

500,000

600,000

Scor

e op

s/s

Framework



JDK Collections – Deal Hands public List<Set<Card>> dealHands( Deque<Card> shuffled, int hands, int cardsPerHand) { return IntStream.range(0, hands) .mapToObj(i -> this.deal(shuffled, cardsPerHand)) .collect( Collectors.collectingAndThen( Collectors.toList(), Collections::unmodifiableList)); }


Apache Collections – Deal Hands public List<Set<Card>> dealHands( Deque<Card> shuffled, int hands, int cardsPerHand) { return IntStream.range(0, hands) .mapToObj(i -> this.deal(shuffled, cardsPerHand)) .collect( Collectors.collectingAndThen( Collectors.toList(), Collections::unmodifiableList)); }


Eclipse Collections – Deal Hands

public ImmutableList<Set<Card>> dealHands( MutableStack<Card> shuffled, int hands, int cardsPerHand) { return IntInterval.oneTo(hands) .collect(i -> this.deal(shuffled, cardsPerHand)); }


Google Guava – Deal Hands

public ImmutableList<Set<Card>> dealHands( Deque<Card> shuffled, int hands, int cardsPerHand) { return IntStream.range(0, hands) .mapToObj(i -> this.deal(shuffled, cardsPerHand)) .collect(ImmutableList.toImmutableList()); }


Javaslang – Deal Hands public List<Set<Card>> dealHands( Stack<Card> shuffled, int hands, int cardsPerHand) { List<Set<Card>> list = List.empty(); for (int i = 0; i < hands; i++) { Tuple2<Set<Card>, ? extends Stack<Card>> tuple2 = this.deal(shuffled, cardsPerHand); shuffled = tuple2._2(); list = list.append(tuple2._1()); } return list; }

Memory Benchmarks


Memory Benchmarks

• ObjectExplorer, by Dimitris Andrew • Open Source under Apache License 2.0 • Measure Reported –

– Memory (Kb) vs Size – Memory (Kb) vs List, Set, Map with 1,000,000 elements

• Smaller the better

Sources – GitHub:

https://github.com/DimitrisAndreou/memory-measurer – Found from StackOverflow:

http://stackoverflow.com/a/9368930/5182052

https://github.com/DimitrisAndreou/memory-measurer



http://stackoverflow.com/a/9368930/5182052


List<Integer>


List<String>


Set<Integer>


Set<String>


Map<Integer, Integer>


Map<String, String>

Summary


Link

• The Collections Compare Project https://github.com/nikhilnanivadekar/CollectionsCompare

https://github.com/nikhilnanivadekar/CollectionsCompare



Collection Framework Comparison Feature JDK Apache Guava Eclipse Javaslang 1st, 2nd, 3rd

List, Set, Map ✔ ✖ ✔ JDK, EC, JS

Multiset / Bag ✖ ✔ ✔ ✔ ✖ GG, EC, AC

Multimap ✖ ✔ ✔ ✔ ✔ GG, EC, AC

BiMap ✖ ✔ ✔ ✔ ✖ GG, EC, AC

Stack ✔ ✖ ✔ ✔ EC, JDK, JS

Tree / Trie ✖ ✔ ✖ ✖ ✔ JS, AC

Table ✖ ✖ ✔ ✖ ✖ GG

Additional Types ✔ ✔ ✔ AC, JDK, GG

Immutable? ✖ ✖ ✔ ✔ ✔ JS, EC, GG

Primitives? ✖ ✔ ✖ EC, JDK, GG

Fluent API ✔ ✔ EC, JS, JDK

(E), (L), (S), (P)* , ✔, ✔, ✔

, , ✔, ✖

✖, , ✔, ✖

✔, ✔, ✔, ✔

✔, ✔, ✔, ✖ EC, JDK, JS

Thanks! The Collections Compare Project



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