Hi all,
The JavaDoc on this method reminded me of one of the points I wanted to
suggest. If there are multiple methods for counting records, it may be
good to discuss the semantics. If I recall, some of the methods in
GeoTools have the idea that returning a -1 is suitable way to
communicate that getting the exact count would be too expensive.
As an anchor point, I'm kinda happy when I see a distributed system
scanning over a million-ish records per second. With that back of the
envelope, if a filter matched a billion or so features, it may take
10-15 minutes to get an exact count.
In GeoMesa, we implemented a system property around returning exact
counts or not. I think we noticed this the most when GeoServer returned
GeoJson since that request pathway calls getCount and then getFeatures
(which is GeoMesa's case basically repeats the query!).
Anyhow, having an 'int' method and a 'long' method to call may help
limit the amount of time spent counting;).
Cheers,
Jim
On 9/2/2020 1:54 PM, Andrea Aime wrote:
Hi Jody,
I like this road, works fine for FeatureSource.
What about FeatureCollection though? It's already using "int size()",
from the interface:
/** * Please note this operation may be expensive when working with
remote content. * * @see java.util.Collection#size() */ int size();
Cheers
Andrea
On Wed, Sep 2, 2020 at 7:45 PM Jody Garnett <jody.garn...@gmail.com
<mailto:jody.garn...@gmail.com>> wrote:
Here is another softer approach:
/**
* @return Returns the number of features in this collection, if
this collection contains more than Integer.MAX_VALUE elements,
returns Integer.MAX_VALUE.
* @deprecated Please use count()
*/
public int getCount();
public long size();
This gives us a clear api migration and does not immediately break
projects when they upgrade. The size() name matches how
Collections.size() handles a size greater than the range of
Integer.MAX_VALUE.
--
Jody Garnett
On Wed, 2 Sep 2020 at 06:43, Andrea Aime
<andrea.a...@geo-solutions.it
<mailto:andrea.a...@geo-solutions.it>> wrote:
Hi, any other opinion on this?
Personally I would not like breaking all existing store
implementations and clients, for a "clean break" it seems
quite bloody :-D
But Jody suggests to go that way.
Some tie breaker, or even multiple votes leading to another
tie, would be appreciated, ha!
Cheers
Andrea
On Thu, Aug 27, 2020 at 11:16 PM Andrea Aime
<andrea.a...@geo-solutions.it
<mailto:andrea.a...@geo-solutions.it>> wrote:
Hi Jody,
comment inline.
On Thu, Aug 27, 2020 at 11:06 PM Jody Garnett
<jody.garn...@gmail.com <mailto:jody.garn...@gmail.com>>
wrote:
We are just about to start a new release cycle, API
changes are a short-term pain, but the most
maintainable approach long term.
As for the change, how about returning a returning
long? Existing client code that used integrer would be
easy to update.
long count = featureSource.getCount(query);
Or:
int count = (int) featureSource.getCount(query);
We can gauge how easy it is by doing the switch in GT/GS...
Maybe it could be done as a refactor... but I cannot
imagine exactly how yet. Closest thing to something
working may be:
1) Rename existing getCount to getCountOld via refactor
2) Add a new method called getCount, returning long, make
it abstract, have a default implementation of getCountOld
delegating to getCount
3) Fix all implementations, switching them from
getCountOld to getCount
4) Inline getCountOld, that should fix all calling points
Hopefully that should not be too much work, I hope there
are few implementations of FeatureSource/Collection but many
client code calls using them.
If you really want Java 8 has Math.toIntExact
method, that produces an exception if the long is out
of range:
int count = Math. toIntExact(
featureSource.getCount(query) );
That would also work yes
Cheers
Andrea
== GeoServer Professional Services from the experts! Visit
http://goo.gl/it488V for more information. == Ing. Andrea
Aime @geowolf Technical Lead GeoSolutions S.A.S. Via di
Montramito 3/A 55054 Massarosa (LU) phone: +39 0584 962313
fax: +39 0584 1660272 mob: +39 339 8844549
http://www.geo-solutions.it
http://twitter.com/geosolutions_it
-------------------------------------------------------
/Con riferimento alla normativa sul trattamento dei dati
personali (Reg. UE 2016/679 - Regolamento generale sulla
protezione dei dati “GDPR”), si precisa che ogni
circostanza inerente alla presente email (il suo
contenuto, gli eventuali allegati, etc.) è un dato la cui
conoscenza è riservata al/i solo/i destinatario/i indicati
dallo scrivente. Se il messaggio Le è giunto per errore, è
tenuta/o a cancellarlo, ogni altra operazione è illecita.
Le sarei comunque grato se potesse darmene notizia. This
email is intended only for the person or entity to which
it is addressed and may contain information that is
privileged, confidential or otherwise protected from
disclosure. We remind that - as provided by European
Regulation 2016/679 “GDPR” - copying, dissemination or use
of this e-mail or the information herein by anyone other
than the intended recipient is prohibited. If you have
received this email by mistake, please notify us
immediately by telephone or e-mail./
--
Regards, Andrea Aime
== GeoServer Professional Services from the experts! Visit
http://goo.gl/it488V for more information. == Ing. Andrea Aime
@geowolf Technical Lead GeoSolutions S.A.S. Via di Montramito
3/A 55054 Massarosa (LU) phone: +39 0584 962313 fax: +39 0584
1660272 mob: +39 339 8844549 http://www.geo-solutions.it
http://twitter.com/geosolutions_it
------------------------------------------------------- /Con
riferimento alla normativa sul trattamento dei dati personali
(Reg. UE 2016/679 - Regolamento generale sulla protezione dei
dati “GDPR”), si precisa che ogni circostanza inerente alla
presente email (il suo contenuto, gli eventuali allegati,
etc.) è un dato la cui conoscenza è riservata al/i solo/i
destinatario/i indicati dallo scrivente. Se il messaggio Le è
giunto per errore, è tenuta/o a cancellarlo, ogni altra
operazione è illecita. Le sarei comunque grato se potesse
darmene notizia. This email is intended only for the person or
entity to which it is addressed and may contain information
that is privileged, confidential or otherwise protected from
disclosure. We remind that - as provided by European
Regulation 2016/679 “GDPR” - copying, dissemination or use of
this e-mail or the information herein by anyone other than the
intended recipient is prohibited. If you have received this
email by mistake, please notify us immediately by telephone or
e-mail./
--
Regards, Andrea Aime
== GeoServer Professional Services from the experts! Visit
http://goo.gl/it488V for more information. == Ing. Andrea Aime
@geowolf Technical Lead GeoSolutions S.A.S. Via di Montramito 3/A
55054 Massarosa (LU) phone: +39 0584 962313 fax: +39 0584 1660272 mob:
+39 339 8844549 http://www.geo-solutions.it
http://twitter.com/geosolutions_it
------------------------------------------------------- /Con
riferimento alla normativa sul trattamento dei dati personali (Reg. UE
2016/679 - Regolamento generale sulla protezione dei dati “GDPR”), si
precisa che ogni circostanza inerente alla presente email (il suo
contenuto, gli eventuali allegati, etc.) è un dato la cui conoscenza è
riservata al/i solo/i destinatario/i indicati dallo scrivente. Se il
messaggio Le è giunto per errore, è tenuta/o a cancellarlo, ogni altra
operazione è illecita. Le sarei comunque grato se potesse darmene
notizia. This email is intended only for the person or entity to which
it is addressed and may contain information that is privileged,
confidential or otherwise protected from disclosure. We remind that -
as provided by European Regulation 2016/679 “GDPR” - copying,
dissemination or use of this e-mail or the information herein by
anyone other than the intended recipient is prohibited. If you have
received this email by mistake, please notify us immediately by
telephone or e-mail./
_______________________________________________
GeoTools-Devel mailing list
GeoTools-Devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/geotools-devel
_______________________________________________
GeoTools-Devel mailing list
GeoTools-Devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/geotools-devel
