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 --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Lift" group. 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