[jira] [Comment Edited] (LUCENE-6365) Optimized iteration of finite strings

["Markus Heiden (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/LUCENE-6365?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14490888#comment-14490888 ] 

Markus Heiden edited comment on LUCENE-6365 at 4/11/15 9:45 AM:
----------------------------------------------------------------

Are you talking about {code:xml}for (IntsRef finiteString; (finiteString = iterator.next()) != null;){code}?
For me it is the standard iteration pattern for non-lookahead iterations, like e.g. iterating over an input stream (see e.g. FileCopyUtils of Spring framework).

Does "for (IntsRef finiteString = iterator.next(); finiteString != null; finiteString = iterator.next())" look better for you?
I like my version better, because it is shorter and the iterator.next() is not doubled, but I will you use it, if you like it better.

A simple while loop looks even more bloated to me:
IntsRef finiteString = iterator.next();
while (finiteString != null) {
   // do something

   finiteString = iterator.next();
}



was (Author: markus_heiden):
Are you talking about "for (IntsRef finiteString; (finiteString = iterator.next()) != null;)"?
For me it is the standard iteration pattern for non-lookahead iterations, like e.g. iterating over an input stream (see e.g. FileCopyUtils of Spring framework).

Does "for (IntsRef finiteString = iterator.next(); finiteString != null; finiteString = iterator.next())" look better for you?
I like my version better, because it is shorter and the iterator.next() is not doubled, but I will you use it, if you like it better.

A simple while loop looks even more bloated to me:
IntsRef finiteString = iterator.next();
while (finiteString != null) {
   // do something

   finiteString = iterator.next();
}


> Optimized iteration of finite strings
> -------------------------------------
>
>                 Key: LUCENE-6365
>                 URL: https://issues.apache.org/jira/browse/LUCENE-6365
>             Project: Lucene - Core
>          Issue Type: Improvement
>          Components: core/other
>    Affects Versions: 5.0
>            Reporter: Markus Heiden
>            Priority: Minor
>              Labels: patch, performance
>         Attachments: FiniteStringsIterator.patch
>
>
> Replaced Operations.getFiniteStrings() by an optimized FiniteStringIterator.
> Benefits:
> Avoid huge hash set of finite strings.
> Avoid massive object/array creation during processing.
> "Downside":
> Iteration order changed, so when iterating with a limit, the result may differ slightly. Old: emit current node, if accept / recurse. New: recurse / emit current node, if accept.
> The old method Operations.getFiniteStrings() still exists, because it eases the tests. It is now implemented by use of the new FiniteStringIterator.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
For additional commands, e-mail: dev-help@lucene.apache.org