HHH-19850 replace arraylist by bitSet when resolving dirty attribute indexes #11104
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…indexes This aims to reduce memory usage by reducing allocations when resolving
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Thanks for the contribution @Meehdi, I left a few comments.
As with any primarily performance-related changes, we usually run (micro)benchmarks and profiling to verify we are actually seeing improvements in real-world scenarios, see for example this repository.
Have you tried verifying if there is a significant gain (or loss) in performance with this change?
| if ( propertyUpdateability[position] && !fields.get( position ) ) { | ||
| fields.set( position ); |
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No need to check !fields.get( position ), as setting an already-set bit is idempotent.
| if ( index != null && propertyUpdateability[index] && !fields.get( index ) ) { | ||
| fields.set( index ); |
| @JiraKey("HHH-19850") | ||
| public class AbstractEntityPersisterTest extends BaseCoreFunctionalTestCase { | ||
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| private AbstractEntityPersister persister; |
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We already have existing tests which should check the behavior of the method you changed, no need to create one which artificially tests it through internal-only calls. It would be great if you could modify an existing one instead, adding any assertions if needed.
2 participants
This aims to reduce memory usage by reducing allocations when resolving dirty attribute indexes
Changes
I added the tests before making the changes to make sure my modifications didn't break the logic afterwards.
This optimizes memory usage by replacing ArrayList with BitSet for better memory allocation by:
Eliminating boxing overhead (Integer objects)
More efficient lookup with BitSet comapred to ArrayList "contains"
Converting to int[] only at the end and allocating exact size using bitSet.cardinality()
Related Issue
Fixes HHH-19850
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license
and can be relicensed under the terms of the LGPL v2.1 license in the future at the maintainers' discretion.
For more information on licensing, please check here.
https://hibernate.atlassian.net/browse/HHH-19850