[Engine-devel] Use java.util.Collection where possible?

[Asaf Shakarchi]

----- Original Message -----
> From: "Danny Rankevich" <danny.ran at redhat.com>
> To: "Asaf Shakarchi" <ashakarc at redhat.com>
> Cc: "engine-devel" <engine-devel at ovirt.org>
> Sent: Thursday, March 15, 2012 7:52:47 PM
> Subject: Re: [Engine-devel] Use java.util.Collection where possible?
> 
> I ran deRPC with Collection in the parameters AND return type, and
> everything works ok.
> why should there be a problem? the concrete type is serialized in the
> payload...
Yes it works, but again, IIRC gwt compiler, while generating js has to take into account all possible variants of the Collection in the compilation unit, including all the classes impl Collection and Serializable interface in the class path. 
So that will cause the permutations to be much larger, it also affects compile time and the app size.
> 
> ----- Original Message -----
> > From: "Asaf Shakarchi" <ashakarc at redhat.com>
> > To: "Danny Rankevich" <danny.ran at redhat.com>
> > Cc: "engine-devel" <engine-devel at ovirt.org>, "Yair Zaslavsky"
> > <yzaslavs at redhat.com>
> > Sent: Wednesday, March 14, 2012 1:19:18 PM
> > Subject: Re: [Engine-devel] Use java.util.Collection where
> > possible?
> > 
> > Danny are you sure?
> > IIRC GWT RPC Oracle wont be able to pick the right implementation
> > and will generate code for any possible concrete impl,
> > 
> > 
> > Asaf.
> > ----- Original Message -----
> > > From: "Danny Rankevich" <danny.ran at redhat.com>
> > > To: "Yair Zaslavsky" <yzaslavs at redhat.com>
> > > Cc: "engine-devel" <engine-devel at ovirt.org>
> > > Sent: Wednesday, March 14, 2012 12:58:35 PM
> > > Subject: Re: [Engine-devel] Use java.util.Collection where
> > > possible?
> > > 
> > > BWT I did some checks on the GWT RPC that we use (deRPC) and
> > > there
> > > shouldn't be any problems using Collection interface (or any
> > > interface) in the generic api service.
> > > 
> > > ----- Original Message -----
> > > > From: "Allon Mureinik" <amureini at redhat.com>
> > > > To: "Yair Zaslavsky" <yzaslavs at redhat.com>
> > > > Cc: "engine-devel" <engine-devel at ovirt.org>
> > > > Sent: Sunday, March 4, 2012 6:57:24 PM
> > > > Subject: Re: [Engine-devel] Use java.util.Collection where
> > > > possible?
> > > > 
> > > > My two cents:
> > > > 
> > > > There are two meanings of subtyping Collection (or any other
> > > > interface, for that matter) - additional logic and specific
> > > > implementation.
> > > > I think wherever possible, we should use the interface that
> > > > infers
> > > > as
> > > > much logic as possible (e.g., java.util.List for ordering,
> > > > java.util.Set for uniquness, java.util.SortedSet for natural
> > > > ordering, etc.), without inferring any specific implementation
> > > > (e.g., ArrayList, HashSet, etc.).
> > > > 
> > > > The flipside of this notion is that it's a mistake to use an
> > > > overly
> > > > specific class/interface - when your parameter type is
> > > > ArrayList,
> > > > you implicitly tell the user the *order* of his objects matter,
> > > > and
> > > > that it matters to your internal algorithm to be able to do
> > > > get(i)
> > > > as an O(1) operation.
> > > > 
> > > > Bottom line,  now that I'm done with CS 101:
> > > > +1, but be careful not use interfaces that are too low.
> > > > Most methods that now receive an ArrayList will still compile
> > > > if
> > > > you
> > > > change the parameter type to Collection, but make sure that you
> > > > don't implicitly assume some ordering, e.g.
> > > > 
> > > > -Allon
> > > > 
> > > > ----- Original Message -----
> > > > > From: "Yair Zaslavsky" <yzaslavs at redhat.com>
> > > > > To: "engine-devel" <engine-devel at ovirt.org>
> > > > > Sent: Thursday, March 1, 2012 5:18:03 PM
> > > > > Subject: [Engine-devel] Use java.util.Collection where
> > > > > possible?
> > > > > 
> > > > > Hi,
> > > > > I see that in some places in engine-core we use
> > > > > Java.Util.List,
> > > > > or
> > > > > even
> > > > > Java.Util.ArrayList as types of method arguments, while in
> > > > > the
> > > > > method
> > > > > code we do nothing besides iterating over the collection.
> > > > > I then found all kinds of usages like this:
> > > > > 
> > > > > x.foo(new ArrayList<MyType>(myMap.values()));
> > > > > 
> > > > > As you can see need to instantiate a new ArrayList in order
> > > > > to
> > > > > use
> > > > > the
> > > > > values of the map in method foo.
> > > > > Do you see any reason why not change the argument type (at
> > > > > method
> > > > > signature) to Collection in such places, where possible?
> > > > > 
> > > > > Yair
> > > > > 
> > > > > _______________________________________________
> > > > > Engine-devel mailing list
> > > > > Engine-devel at ovirt.org
> > > > > http://lists.ovirt.org/mailman/listinfo/engine-devel
> > > > > 
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> > 
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