HDDS-14330. MinHeapMergeIterator should use key comparator while popping out entries from the heap #9576
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…ing out entries from the heap Change-Id: Ia196692c74237ae100180b27dc5c2b5b661ba783
swamirishi
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jojochuang
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Jan 1, 2026
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jojochuang
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jojochuang
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is it a hypothetical problem or is there a case to reproduce?
| class TestMinHeapMergeIterator { | ||
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| private static final Comparator<String> STRING_COMPARATOR = String::compareTo; | ||
| private static final Comparator<byte[]> BYTE_COMPARATOR = UnsignedBytes.lexicographicalComparator(); |
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is updating String to byte array a necessary change to reproduce the problem?
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The iterator need not be always an Itr it can be Itr<KeyValue<String, >> and KeyValue doesn't implement equals method
| KeyValue<KEY, Object> defaultNullValue = newKeyValue(null, null); | ||
| Comparator<KeyValue<KEY, Object>> comparator = Comparator.comparing(KeyValue::getKey, keyComparator); | ||
| return new MinHeapMergeIterator<KeyValue<KEY, Object>, Table.KeyValueIterator<KEY, Object>, | ||
| KeyValue<KEY, Collection<Object>>>(table.length + 1, comparator) { |
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I don't recall why it was table.length + 1 before.
jojochuang
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Jan 2, 2026
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Thank you @jojochuang for reviewing the patch |
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What changes were proposed in this pull request?
MinHeapMergeIterator should use key comparator while popping out entries from the heap. Currently it uses Object.equals() which can fetch wrong results when comparing the key without the key comparator.
What is the link to the Apache JIRA
https://issues.apache.org/jira/browse/HDDS-14330
How was this patch tested?
Updated unit tests to use byte array