Re: [PATCH 1/1] data_smart.py: make use of expand cache in getVar()

["Xu, Dongxiao" <dongxiao.xu@intel.com>]

> -----Original Message-----
> From: Richard Purdie [mailto:richard.purdie@linuxfoundation.org]
> Sent: Monday, August 29, 2011 9:13 PM
> To: Xu, Dongxiao
> Cc: bitbake-devel@lists.openembedded.org
> Subject: RE: [bitbake-devel] [PATCH 1/1] data_smart.py: make use of expand
> cache in getVar()
> 
> On Mon, 2011-08-29 at 21:07 +0800, Xu, Dongxiao wrote:
> > Hi Richard,
> >
> > > -----Original Message-----
> > > From: Richard Purdie [mailto:richard.purdie@linuxfoundation.org]
> > > Sent: Monday, August 29, 2011 8:55 PM
> > > To: Xu, Dongxiao
> > > Cc: bitbake-devel@lists.openembedded.org
> > > Subject: Re: [bitbake-devel] [PATCH 1/1] data_smart.py: make use of
> > > expand cache in getVar()
> > >
> > > On Mon, 2011-08-29 at 15:33 +0800, Dongxiao Xu wrote:
> > > > Currently if passing expand=True to getVar() function, it will
> > > > pass the handling to getVarFlag(), which doesn't get any benefit
> > > > from the expand cache.
> > > >
> > > > Call the expand() function separately in getVar() to make use of
> > > > the expand cache, which can decrease the parsing time by 40%.
> > > > (from current 49s to 27s)
> > > >
> > > > Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
> > > > ---
> > > >  lib/bb/data_smart.py |    7 ++++++-
> > > >  1 files changed, 6 insertions(+), 1 deletions(-)
> > > >
> > > > diff --git a/lib/bb/data_smart.py b/lib/bb/data_smart.py index
> > > > 301f9e3..d8ba24f 100644
> > > > --- a/lib/bb/data_smart.py
> > > > +++ b/lib/bb/data_smart.py
> > > > @@ -268,7 +268,12 @@ class DataSmart(MutableMapping):
> > > >          self.dict[var]["content"] = value
> > > >
> > > >      def getVar(self, var, expand=False, noweakdefault=False):
> > > > -        return self.getVarFlag(var, "content", expand, noweakdefault)
> > > > +        value = self.getVarFlag(var, "content", False,
> > > > + noweakdefault)
> > > > +
> > > > +        # Call expand() separately to make use of the expand cache
> > > > +        if expand and value:
> > > > +            return self.expand(value, var)
> > > > +        return value
> > > >
> > >
> > > Why can't we have getVarFlag use the expand cache?
> >
> > For expand cache, the format is a list: expand_cache[varname].
> > It doesn't contain information of flag values.
> 
> Good point.
> 
> I'm left wondering why we don't key that cache on the unexpanded value rather
> than a specific variable name (or name+flag).
> 
> I'll take this patch but its something we should consider...

Thanks, I will step into this point further and see if (name+flag) type of cache could benefit us more.

Thanks,
Dongxiao

> 
> Cheers,
> 
> Richard
> 
>