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Posted to issues@commons.apache.org by "Ng Tsz Sum (Jira)" <ji...@apache.org> on 2022/04/26 15:28:00 UTC
[jira] [Comment Edited] (COLLECTIONS-770) ToString method is unresponsive after multiple SetUtils union calls
[ https://issues.apache.org/jira/browse/COLLECTIONS-770?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17528243#comment-17528243 ]
Ng Tsz Sum edited comment on COLLECTIONS-770 at 4/26/22 3:27 PM:
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After some test, the problem is the huge number of IteratorChain#hasNext call, but why the count growth so fast need to further investigate.
||number||hasNext_count||
|1|3|
|2|11|
|3|30|
|4|72|
|5|161|
|6|345|
|7|720|
|8|1478|
|9|3003|
|10|6063|
|11|12194|
|12|24468|
|13|49029|
|14|98165|
|15|196452|
|16|393042|
|17|786239|
|18|1572651|
|19|3145494|
|20|6291200|
|21|12582633|
|22|25165521|
|23|50331320|
|24|100662942|
|25|201326211|
|26|402652775|
|27|805305930|
|28|1610612268|
|29|3221224973|
|30|6442450413|
was (Author: samabcde):
After some test, the problem is the huge number of IteratorChain#hasNext call, but why the count growth so fast need to further investigate.
[^countHasNextCall.patch]
||number||hasNext_count||
|1|3|
|2|11|
|3|30|
|4|72|
|5|161|
|6|345|
|7|720|
|8|1478|
|9|3003|
|10|6063|
|11|12194|
|12|24468|
|13|49029|
|14|98165|
|15|196452|
|16|393042|
|17|786239|
|18|1572651|
|19|3145494|
|20|6291200|
|21|12582633|
|22|25165521|
|23|50331320|
|24|100662942|
|25|201326211|
|26|402652775|
|27|805305930|
|28|1610612268|
|29|3221224973|
|30|6442450413|
> ToString method is unresponsive after multiple SetUtils union calls
> -------------------------------------------------------------------
>
> Key: COLLECTIONS-770
> URL: https://issues.apache.org/jira/browse/COLLECTIONS-770
> Project: Commons Collections
> Issue Type: Bug
> Affects Versions: 4.4
> Reporter: Thomas Bürli
> Priority: Minor
> Attachments: SetUtilsTest.java, countHasNextCall.patch, stackdump.txt
>
>
> I had the following code and my application stopped responsing as soon the number of names for a userId got too big.
> {code:java}
> Map<String, Set<String>> stringMap = new TreeMap<>();
> for (String name : names) {
> for (String userId : userIds) {
> stringMap.merge(userId, Collections.singleton(name), SetUtils::union);
> }
> }
> {code}
> I did some debugging and it occurs when the toString method of one the set is called. It looks like the issues is with the iterator of "SetUtils.SetView".
> Here just the method I used to create test sets and in the attachment you find the full tests class and a stack dump. The execution time is growing exponentially with the numbers of times the SetUtils.union is called. So for 29 elements it took 16 seconds to execute toString, and with 30 it took 32 seconds.
> {code:java}
> @Test
> void setWith20Elements() {
> assertTimeout(ofSeconds(2), () -> createSet(30).toString());
> }
> Set<String> createSet(int number) {
> List<String> inputs = new ArrayList<>();
> for (int i = 0; i < number; i++) {
> inputs.add("Test"+ i);
> }
> Set<String> testSet = Collections.singleton("String1");
> for (String element : inputs) {
> Set<String> part = Collections.singleton(element);
> testSet = SetUtils.union(testSet,part);
> }
> return testSet;
> }
> {code}
> Thanks for your support
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