[
https://issues.apache.org/jira/browse/LUCENE-6409?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14485316#comment-14485316
]
Luc Vanlerberghe commented on LUCENE-6409:
------------------------------------------
While looking over the code, I have some more remarks on Fixed-/LongBitSet that
should be investigated:
* Harmonize the use of numWords vs. bits.length vs. numBits
** E.g.: cardinality scans up to bits.length, while "or" asserts on
index<numWords
* Performance: If a BitSet is allocated with n bits, ensureCapacity with the
same number n shouldn't grow the BitSet
** Either both the constructor and ensureCapacity should allocate a larger
array than really needed or neither. ensureCapacity contains:
{code}
if (numBits < bits.length()) {
return bits;
} else {
int numWords = bits2words(numBits);
long[] arr = bits.getBits();
if (numWords >= arr.length) {
arr = ArrayUtil.grow(arr, numWords + 1);
}
return new FixedBitSet(arr, arr.length << 6);
}
{code}
The first "if" will fail and the second "if" will succeed, causing arr to be
grown to at least 1 more...
> LongBitSet.ensureCapacity overflows on numBits > Integer.MaxValue
> -------------------------------------------------------------------
>
> Key: LUCENE-6409
> URL: https://issues.apache.org/jira/browse/LUCENE-6409
> Project: Lucene - Core
> Issue Type: Bug
> Components: core/other
> Reporter: Luc Vanlerberghe
>
> LongBitSet.ensureCapacity calculates the number of longs required to store
> the number of bits correctly and allocates a long[] accordingly, but then
> shifts the array length (which is an int!) left by 6 bits. The int should be
> cast to long *before* performing the shift.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
