Re: Meta-data storage

Yes, ETag is an identifier for a specific content version or variant
for the given URL.

Ah, now I follow what you are up to. Collapsing of identical entries
with different URL's. Entirely different story. I don't have a good
sugesstion on how to best do this with the current store index
layout.. You could perhaps use special marker objects acting like
symbolic links.

Rewriting the store to allow for more than one key per object is a
fairly big change.

Regards
Henrik

On Sunday 21 April 2002 15:26, Yee Man Chan wrote:
> Hi Henrik,
>
> I think ETag is more like an identifier for a
> certain version of the content located at a particular
> URL. Do you still use URL (or more accurately, MD5 of
> method+URI) to lookup a StoreEntry?
>
> The idea I am pursuing is like you compute the MD5
> of each incoming transfer, and save it to the disk
> based on the MD5. Since there are mirroring activity
> going on somewhere, it is possible that content from
> different URLs yield the same Content MD5. In that
> case, I want to only store one copy of the content and
> save all the mappings from those URLs to this MD5.
> Therefore I need the metadata to keep track of these
> mappings.
>
> Regards,
> Yee Man
>
> --- Henrik Nordstrom <hno@squid-cache.org> wrote:
> > Not sure what you are up to here. Can you explain a
> > bit more?
> >
> > At a first glance is seems similar to ETag indexing
> > where there may
> > be several different content variants in one URL
> > index position. See
> > http://devel.squid-cache.org/ETag/ for how I did it
> > there.
> >
> > Regards
> > Henrik
> >
> > On Sunday 21 April 2002 00:30, Yee Man Chan wrote:
> > > Thanks for your reply, Henrik. I was trying to the
> > > URL-indexed StoreEntry with
> >
> > Content-Digest-indexed. So
> >
> > > I need to store Metadata that maps multiple URLs
> >
> > to a
> >
> > > content digest. This mapping is kind of dynamic
> > > because the content at a particular URL may change
> >
> > and
> >
> > > then this URL will then map to a different content
> > > digest. Do you have any recommendation on how I
> >
> > should
> >
> > > store these mappings?
> > >
> > > Thanks a lot.
> > > Yee Man
> > >
> > > --- Henrik Nordstrom <hno@squid-cache.org> wrote:
> > > > No.
> > > >
> > > > In the long run this will be up to each store
> > > > implementation to deal
> > > > with how the data gets stored.. along with how
> >
> > to
> >
> > > > deal with metadata
> > > > and header updates.. but the store API needs a
> >
> > few
> >
> > > > revisions before
> > > > we are fully there.
> > > >
> > > >
> > > > Regards
> > > > Henrik
> > >
> > > __________________________________________________
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Received on Sun Apr 21 2002 - 08:32:04 MDT