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https://issues.apache.org/jira/browse/ANY23-336?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16416545#comment-16416545
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Hans Brende commented on ANY23-336:
-----------------------------------
[~p_ansell] Thank you, with your {{setSharedCache(false)}} suggestion and one
tweak to {{JarCacheStorage}}, I've managed to increase the parsing speed *by an
order of magnitude*. I'll submit a pull request shortly.
One question before I proceed: in {{JarCacheStorage.getEntry(String key)}}, is
there a reason that you check the delegate cache _after_ you scan the classpath
for jar files, rather than before? Shouldn't it be the other way around: check
the delegate cache, and if the delegate cache returns a null value, _then_
check the classpath? Since the delegate cache seems to always be implemented as
{{BasicHttpCacheStorage}} (i.e., a {{LinkedHashMap}}), it will be much quicker
to check that one first, being a constant-time operation. (Also, in the case of
Any23, we're not even using the classpath option at all, so our *only* cached
values will be found in the delegate cache--so it doesn't seem to make much
sense to turn what could be a constant-time operation into an operation
proportional to the size of the classpath).
Thoughts?
> Parsing json-ld content takes prohibitively long time
> -----------------------------------------------------
>
> Key: ANY23-336
> URL: https://issues.apache.org/jira/browse/ANY23-336
> Project: Apache Any23
> Issue Type: Bug
> Components: core, extractors
> Affects Versions: 2.2
> Reporter: Hans Brende
> Assignee: Peter Ansell
> Priority: Critical
> Fix For: 2.3
>
> Attachments: Screen Shot 2018-03-27 at 2.52.15 PM.png, Screen Shot
> 2018-03-27 at 2.54.43 PM.png
>
>
> Using the page [https://www.guthriegreen.com|https://www.guthriegreen.com/]
> as a benchmark, a page fetch took about 100 ms, while simply *parsing* the
> json-ld content on that page took a *staggering 27400 ms*. For reference, I'm
> using Java 8, build 162, on a Macbook Pro (early 2015).
> The bad news is that this is not our fault.
> I've profiled this behavior down to the
> {{com.github.jsonldjava.utils.JsonUtils.fromURL(URL, CloseableHttpClient)}}
> function. 94% of the parsing time is spent there. This function is called
> when trying to load remote json-ld contexts.
> In order to avoid loading remote contexts repeatedly, this function tries to
> *cache* them by using a {{CachingHttpClient}} from the httpclient-osgi
> library.
> Unfortunately, that strategy is *not* working, as I have recorded exactly
> *zero* cache hits, meaning that *every* retrieval is a cache miss and a
> remote context is re-fetched via http every single time it's accessed.
>
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