[Python-Dev] PEP 296 - The Buffer Problem

[Thomas Heller]

> > > 
> > > They do, but the referenced "inner-thing" needs it's own reference
> > count to
> > > know how many "bytes-views" are sharing it.  When a bytes-view gets
> > cleaned
> > > up, it decrefs the reference count of the inner-thing it is referring
> > to,
> > > and if the reference count goes to zero, the bytes-view calls the
> > > destructor for the inner-thing.
> > > 
> > Hm, I thought the 'inner-thing' is a python object (with it's own
> > refcount) itself. Isn't the 'inner-thing' the bytes object owning
> > the allocated memory? And the 'outer-things' (the views) simply
> > viewing slices of this memory?
> > 
> 
> The outer-thing is definitely the "bytes object", since that's what people
> will work with directly.  It has to be a true Python object in all its
> glory.
> 
> The inner-thing _could_ be a Python object (and Guido suggested that maybe
> it should be), but that's an implementation detail.  I don't know why
> anyone would want to work with the inner-thing directly.  However, one good
> use case and I'll be sold on the idea.
> 
> I'll definitely add some verbage to clarify this in the next revision.
> 
I've quickly read the pep again.
I see no mentioning of an 'inner object' and an 'outer object'
there, so I would recommend you try to explain this (if you want to stay
with this decision).

OTOH, your 'inner thing' has a refcount, an (optional) destructor
which is a kind of closure, instance variables (memory pointer,
readonly flag), so there is not too much missing for a full
python object.

Could the 'inner thing' have the same type as the 'outer thing':
the inner thing being a full view of itself, and the outer thing
probably a view viewing only a slice of the inner thing?

Thomas