Couple of measurements of object size in Java
Build:
./gradlew build
Run:
./gradlew run
Guides how to measure object size:
- https://www.baeldung.com/java-size-of-object
- https://www.javaspecialists.eu/archive/Issue142.html
- https://stackoverflow.com/questions/54162849/can-i-measure-the-size-of-a-list-in-the-memory-including-elements-using-instrume
- https://github.com/jbellis/jamm
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
| List<Integer> | Size in bytes |
|---|---|
| Integer[] | 1997968 |
| ArrayList | 1997992 |
| JImmutableTreeList | 2064624 |
| JImmutableLinkedStack | 3997976 |
| LinkedList | 3997984 |
| ConsPStack | 4797984 |
| TreePVector | 5598048 |
| Set<Integer> | Size in bytes |
|---|---|
| Integer[] | 1997968 |
| ArraySet | 2398016 |
| JImmutableTreeSet | 5598032 |
| TreeSet | 5598032 |
| HashSet | 5846624 |
| JImmutableHashSet | 9246216 |
| MapPSet | 11198104 |
| Map<Integer, Integer> | Size in bytes |
|---|---|
| Integer[] | 1997968 |
| SparseArrayCompat | 2646576 |
| ArrayMap | 3186664 |
| EclipseMutableMap | 3695152 |
| EclipseImmutableMap | 3695168 |
| TreeMap | 5598000 |
| JImmutableTreeMap | 5598008 |
| IntTreePMap | 5598024 |
| HashMap | 5846608 |
| GuavaImmutableMap | 6495176 |
| LinkedHashMap | 6646600 |
| JImmutableHashMap | 9246200 |
| HashPMap | 11198088 |
