Re: Using multiple instances of Saxon processors

  Hi,

  I second that. Besides, all parts that need access to the engine should
keep a reference to it (the compiled pipeline, a runtime instance of it,
maybe some compiled steps, etc.)

  Regards,
 On 14 Dec 2013 17:01, "David Lee" <dlee@calldei.com> wrote:

> My knee jerk reaction is don't do it.
> Once you go singleton you can't go back.
> Callers could still make your class a singleton but I have been bit hard
> by libraries that make the assumption that they are the only center of the
> world
>
> Sent from my iPad (excuse the terseness)
> David A Lee
> dlee@calldei.com
>
>
> > On Dec 14, 2013, at 11:13 AM, "Norman Walsh" <ndw@nwalsh.com> wrote:
> >
> > Hi,
> >
> > In the architecture of XML Calabash V2, there's a different API.
> > There's an XProcEngine (name's kind of awful but whatever) that
> > contains the Saxon processor and other "global" configuration data.
> > You obtain a pipeline compiler and runtime from the engine.
> >
> > I am sorely tempted to make the engine a singleton. The only drawback
> > that I can see is that it wouldn't then be possible to write a program
> > that ran multiple pipelines with different Saxon configurations (Saxon
> > HE and EE, for example) or with different implementations of the same
> > step.
> >
> > The advantage is API simplification. Everywhere that the Saxon
> > processor or some other bit of global configuration is needed, it has
> > to be passed around either as part of the constructor for an object or
> > as a parameter to static methods because there's no way other way to
> > get at it. With a singleton engine object, it would always be
> > available.
> >
> > Most users would never notice, but I know some folks have used the XML
> > Calabash APIs to build larger systems.
> >
> > Anyone feel like pushing back on the singleton idea?
> >
> >                                        Be seeing you,
> >                                          norm
> >
> > --
> > Norman Walsh
> > Lead Engineer
> > MarkLogic Corporation
> > Phone: +1 512 761 6676
> > www.marklogic.com
>
>