David,

Can one leave proxies in place for things that are not actually
serializable?

Best wishes,

--greg

On Mon, Aug 24, 2009 at 12:55 PM, David Pollak <
[email protected]> wrote:

>
>
> On Mon, Aug 24, 2009 at 12:36 PM, marius d. <[email protected]>wrote:
>
>>
>> Just a FYI. I briefly talked with Martin and he said this idea is
>> possible but quite tricky. Stephane Micheloud did something similar
>> and he may share some of his work. I'm waiting some feedback from him.
>
>
> I think we can do it at runtime in development mode.  This is just for data
> gathering, not for actual implementation.  We just need to calculate whether
> a given class is serializable once... so we don't have to worry about cyclic
> graphs or anything else... just... are the "slots" (instance variables) for
> each class serializable.
>
>
>>
>>
>> Br's,
>> Marius
>>
>> On Aug 24, 10:46 am, "marius d." <[email protected]> wrote:
>> > On Aug 24, 10:39 am, Viktor Klang <[email protected]> wrote:
>> >
>> >
>> >
>> > > On Mon, Aug 24, 2009 at 8:13 AM, marius d. <[email protected]>
>> wrote:
>> >
>> > > > On Aug 24, 12:06 am, David Pollak <[email protected]>
>> > > > wrote:
>> > > > > On Sun, Aug 23, 2009 at 10:45 AM, marius d. <
>> [email protected]>
>> > > > wrote:
>> >
>> > > > > > Hmmm .. I'm wondering if we can write aScalacompilerpluginthat
>> > > > > > transform functions provided to Lift's S/SHtml function etc.
>> into a
>> > > > > > richer FunctionX implementation that knows how to "serialize"
>> it's
>> > > > > > members. We could restrict the types that as LiftSerializable on
>> top
>> > > > > > of primitives, Calenars, SessionVar/RequestVar etc. If users
>> need
>> > > > > > their own classes to be LiftSerilizable they would have to
>> implement
>> > > > > > LiftSerializable trait.
>> >
>> > > > > I think we can do it without explicit traits.  I think we just
>> need to
>> > > > walk
>> > > > > the graph for everything that's added to the LiftSession and see
>> where it
>> > > > > leads.  Any graph we can walk is something that we can
>> serialize... even
>> > > > > without Java serialization.  Any graph that ends in globals or
>> some class
>> > > > > that refers to native stuff (e.g., IO), then we're toast.
>> >
>> > > > Totally agree. The rationale for explicit LiftSerializable would be
>> > > > just for user defined types. Otherwise user's won't have to use it.
>> > > > Graphs may also have be cyclic paths ... it shouldn't be too big of
>> a
>> > > > pain though. Furthermore if a dependency graph path leads say to an
>> IO
>> > > > reference maybe that's unintentional user code doesn't really use
>> that
>> > > > but compiler put it for whatever reason. If such cases are possible
>> > > > and could be determined maybe we could exclude that silently from
>> the
>> > > > serialization operation and add a compile time warning.
>> >
>> > > > I guess we need to dig more intoscalacompilerpluginsystem.
>> >
>> > > 1. Isn't there a problem with references _inside_ methods that are
>> > > impure/sideeffecting?
>> >
>> > > s => { Db.myCachedInfoNotInSession foo s  }
>> >
>> > > Regarding member references, a simple check for "transient"
>> > > (sca...@transient == java *transient*) to forcve people to use
>> transient
>> > > members for non-serializable state.
>> >
>> > > But IMHO the serialization problem is a (negative?) sideeffect of
>> Lifts rich
>> > > model GUID=>Func approach.
>> > > Perhpas there is a middle way, a way where we can replicate just
>> enough to
>> > > survive a node crash?
>> >
>> > That's exactly it. We probably don't need everything that Java
>> > Serialization does. Just enough to make it consistent ... the
>> > dependency graphs that is actually used by the user's function.
>> >
>> >
>> >
>> > > > > > Thoughts?
>> >
>> > > > > > Br's,
>> > > > > > Marius
>> >
>> > > > > > On Aug 23, 8:30 pm, "marius d." <[email protected]>
>> wrote:
>> > > > > > > At a first glace Java serialization is needed because of its
>> > > > awareness
>> > > > > > > of the reference graph. But in the same time it does not
>> perform
>> > > > well.
>> > > > > > > One way might be the byte level instrumentation that would
>> induce
>> > > > code
>> > > > > > > to figure out the reference graph and know how to stream-ify
>> it using
>> > > > > > > a given efficient protocol. But that induces risks and it
>> involves
>> > > > > > > tons of work. I think would be doable though.
>> >
>> > > > > > > The problem is not really the technology of propagating
>> session
>> > > > > > > information to other nodes. That's the easiest part, but tough
>> one is
>> > > > > > > figuring out the low level reference graph and serialization
>> > > > > > > semantics. This is why JINI, JavaSpaces, JGroups, CORBA, JXTA,
>> you
>> > > > > > > name it, are unlikely to help solving the fundamental problem.
>> >
>> > > > > > > Br's,
>> > > > > > > Marius
>> >
>> > > > > > > On Aug 23, 8:16 pm, Arthur <[email protected]> wrote:
>> >
>> > > > > > > > On Sun, Aug 23, 2009 at 7:04 PM, David
>> >
>> > > > > > > > Pollak<[email protected]> wrote:
>> > > > > > > > > On Sun, Aug 23, 2009 at 4:50 AM, Kevin Wright
>> > > > > > > > > <[email protected]> wrote:
>> >
>> > > > > > > > >> I'm wondering if we can't leverage JavaSpaces to handle a
>> lot of
>> > > > > > this
>> > > > > > > > >> stuff.  From my experience with the technology it seems
>> to be a
>> > > > > > pretty good
>> > > > > > > > >> fit for the problem.
>> >
>> > > > > > > > > Two reasons:
>> > > > > > > > > - JavaSpaces is as far as I know, GPL and we will not mix
>> any GPL
>> > > > > > into Lift
>> >
>> > > > > > > > JavaSpaces is just the specification. There are two
>> implementations
>> > > > I
>> > > > > > > > know of: BlitzJavaSpaces (BSD) and GigaSpaces
>> (proprietary?). I
>> > > > don't
>> > > > > > > > have hands on experience with either.
>> >
>> > > > > > > > > - It doesn't solve the issue with low-level session
>> replication
>> > > > which
>> > > > > > relies
>> > > > > > > > > on serialization of the session data for transfer to
>> another app
>> > > > > > server
>> > > > > > > > > instance.
>> >
>> > > > > > > > Arthur
>> >
>> > > > > --
>> > > > > Lift, the simply functional web frameworkhttp://liftweb.net
>> > > > > BeginningScalahttp://www.apress.com/book/view/1430219890
>> > > > > Follow me:http://twitter.com/dpp
>> > > > > Git some:http://github.com/dpp
>> >
>> > > --
>> > > Viktor Klang
>> >
>> > > Blog: klangism.blogspot.com
>> > > Twttr: viktorklang
>> >
>> > > Lift Committer - liftweb.com
>> > > AKKA Committer - akkasource.org
>> > > Cassidy - github.com/viktorklang/Cassidy.git
>> > > SoftPub founder:http://groups.google.com/group/softpub
>>
>>
>
>
> --
> Lift, the simply functional web framework http://liftweb.net
> Beginning Scala http://www.apress.com/book/view/1430219890
> Follow me: http://twitter.com/dpp
> Git some: http://github.com/dpp
>
> >
>


-- 
L.G. Meredith
Managing Partner
Biosimilarity LLC
1219 NW 83rd St
Seattle, WA 98117

+1 206.650.3740

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