README.md

A set of JMH benchmarks for various JVM constructions, written in Java and Kotlin.

Build:

mvn clean package

Tests includes:

• Loops through lists and arrays
• Comparing different DataTime API available for JVM, like joda.time, time4j, java.util.Calendar, java.time, threeten.bp. Comparing typical operations plusDays, plusWeeks, daysBetween, etc.
• Comparing mutable and immutable collections

Mutable vs immutable collections

Comparision between:

• Standard JDK mutable collections
• Persistent collections https://github.com/hrldcpr/pcollections
• Eclipse collections mutable and immutable https://github.com/eclipse/eclipse-collections
• Guava immutable collections
• Java immutable collections https://github.com/brianburton/java-immutable-collections
• Androidx collections like ArraySet, SparseArray

Lists

Add new item to a list 1000 000 times

Collection	Score ns/op
ArrayList	4854015
JImmutableLinkedStack	4822985
LinkedList	5921889
ConsPStack	6740323
JImmutableListBuilder	8467454
JImmutableTreeList	181495708
TreePVector	537843369

Check if list contains an item with 100 000 items

Collection	Score ns/op
ArrayList	21330
ConsPStack	26286
JImmutableLinkedStack	32304
Stack	85272
LinkedList	160295
JImmutableTreeList	882873
TreePVector	2061153

Iterate through list and sum up all its 200 000 items

Collection	Score ns/op
ArrayList	239669
JImmutableLinkedStack	717536
ConsPStack	819618
LinkedList	853572
TreePVector	3996926
JImmutableTreeList	4090843
Stack	5069004

Insert 100 000 items in the middle of the list

Collection	Score ns/op
JImmutableTreeList	20964836
TreePVector	71693585
ArrayList	353459261
ArrayList with predefined size	353432854
Stack	354646074
LinkedList	4779051906
ConsPStack	StackOverflowError

ConsPStack uses recursion to add a new element, so it get crashed.

Remove 74 900 items from the middle of a list with 100 000 items

Collection	Score ns/op
JImmutableTreeList	19354452
Stack	4442481048
ArrayList	4802332800
LinkedList	10669939267
TreePVector	71387068447
ConsPStack	StackOverflowError

Sets

Add new item to a set 1000 000 times

Collection	Score ns/op
HashSet	130738821
JImmutableSetBuilder	288206431
JImmutableHashSet	434394386
TreeSet	782037380
MapPSet	1025752840
JImmutableTreeSet	1089905931
ArraySet	41545653723

Check if set contains an item with 100 000 items

Collection	Score ns/op
HashSet	9.2
TreeSet	23.5
JImmutableHashSet	27.0
ArraySet	27.3
JImmutableMultiset	28.3
MapPSet	54.5

Iterate through set and sum up all its 200 000 items

Collection	Score ns/op
ArraySet	444388
HashSet	1984468
TreeSet	2321796
MapPSet	10379233
JImmutableMultiset	19757874
JImmutableHashSet	19788659

Remove 49 900 items from the set with 100 000 items

Collection	Score ns/op
HashSet	157829
ArraySet	1637993
TreeSet	1683893
MapPSet	7255522
JImmutableHashSet	9835587
JImmutableMultiset	11816974

Maps

Put new value to a map 100 000 times

Collection	Score ns/op
EclipseUnifiedMap	4616675
HashMap	5903254
LinkedHashMap	6696584
EclipseConcurrentHashMap	9804946
ConcurrentHashMap	11176820
JImmutableMapBuilder	26891367
JImmutableHashMap	39071872
IntPMap	49561724
JImmutableTreeMap	62281212
HashPMap	70886001
SparseArray	316250855
ArrayMap	506483387
EclipseImmutableMap	112506483387
GuavaImmutableMap	212506483387

EclipseImmutableMap and GuavaImmutableMap totally recreate map when adding new element, that's why they are so slow

Check if map contains a key with 500 000 items

Collection	Score ns/op
HashMap	5.4
LinkedHashMap	5.6
EclipseMutableMap	6.4
EclipseImmutableMap	6.6
GuavaImmutableMap	7.4
SparseArray	28.7
ArrayMap	31.2
JImmutableHashMap	31.5
TreeMap	39.6
IntTreePMap	46.3
HashPMap	72.7
JImmutableTreeMap	80.0

Check if map contains a value 500 000 items

Collection	Score ns/op
SparseArray	14385
ArrayMap	31600
GuavaImmutableMap	68962
EclipseImmutableMap	205202
HashMap	372728
EclipseMutableMap	433659
LinkedHashMap	484310
TreeMap	489393
IntTreePMap	844354
HashPMap	1109556
JImmutableTreeMap	3297182
JImmutableHashMap	7285167

Iterate through map and sum up all its 100 000 items

Collection	Score ns/op
ArrayMap	232476
EclipseMutableMap	446745
GuavaImmutableMap	520165
EclipseImmutableMap	567447
HashMap	595179
TreeMap	682662
IntTreePMap	2403714
HashPMap	3510105
JImmutableTreeMap	7237417
JImmutableHashMap	13431226

Random access to map with 100 000 items, 100 000 times

Collection	Score ns/op
GuavaImmutableMap	4168899
EclipseMutableMap	4190743
EclipseImmutableMap	4338962
LinkedHashMap	7382515
HashMap	7877748
JImmutableHashMap	16173780
SparseArray	16062088
ArrayMap	17775730
IntTreePMap	27638864
HashPMap	38952774
TreeMap	40107206
JImmutableTreeMap	48937962

Remove 99 900 items from the middle of map with 100 000 items

Collection	Score ns/op
LinkedHashMap	303094
HashMap	315987
EclipseMutableMap	434462
ArrayMap	2422169
TreeMap	3033837
SparseArray	4741959
IntTreePMap	10098933
HashPMap	11884758
JImmutableTreeMap	15688043
JImmutableHashMap	20559828
EclipseImmutableMap	128161834031
GuavaImmutableMap	231715633402