Re: [Fwd: Re: caching and XPCOM] (re-sent)

[Reshat Sabiq]

On Mon, 2005-05-30 at 16:14 -0500, Reshat Sabiq wrote:
> On Mon, 2005-05-30 at 15:33 -0500, Reshat Sabiq wrote:
> > email message attachment, "Forwarded message - Re: caching and XPCOM"
> > On Mon, 2005-05-30 at 15:33 -0500, Reshat Sabiq wrote:
> > > On Sun, 2005-05-22 at 21:11 +0200, Christian Biesinger wrote:
> > > > mozilla-netlib would be a better place for this, fwiw
> > > > 
> > > > Reshat Sabiq wrote:
> > > > > I played w/ it a little more, and found the following:
> > > > > The Cache folder above indeed stores temporary files, however, there 
> > > > > are
> > > > > 2 unknowns for me at this time:
> > > > > 1. How would i be able to identify which file an object is in, knowing
> > > > > the object's URL, and possibly other characteristics (size, etc.)? 
> > > > > There
> > > > > appears to be something like md5sum involved, on the basis of several
> > > > > object characteristics.
> > > > 
> > > > So, not all entities are stored as separate files. If they are small 
> > > > enough, they are stored in the _CACHE_00x_ files. Only if they are 
> > > > larger they are stored as a separate file.
> > > > 
> > > > Use nsICacheService 
> > > > (http://lxr.mozilla.org/seamonkey/source/netwerk/cache/public/nsICacheService.idl)
> > > >  
> > > > and related interfaces.
> > > > 
> > > > 
> > > I am able to get the instances of interfaces needed, but i'm getting 
> > > NS_ERROR_CACHE_KEY_NOT_FOUND for every image URL i pass to:
> > > result = cacheSession->OpenCacheEntry(url, nsICache::ACCESS_READ, 
> > >   PR_TRUE,  getter_AddRefs(cacheEntry));
> > > 
> > > I have 2 question about this, and would appreciate any feedback:
> > > 1. Why even when the image is in profile's cache as a separate file, i
> > > still get this error? E.g., for char *url =
> > > "http://us.news3.yimg.com/us.i2.yimg.com/p/rids/20050505/i/r1951409762.jpg?x=380&y=266&sig=Xj2W4LLjWxHTAWQ0QY9evA--";
> > > which in my cache is stored as 3AAC0BF8d01. If the key is not URL, what
> > > is it?
> > > 2. This may be resolved by 1, by do i understand correctly that if item
> > > is not in the Cache folder, then it will have an ICache in memory? The
> > > small images are not in the hard-drive at all. I guess when i know the
> > > key magic from question 1, i will be able to see if i get an ICache for
> > > these as well.
> > > 
> > > Thanks.
> > > 
> I figured it out: i was using he wrong client ID. I didn't realize it
> mattered.
> Interesting, but for the image above, even though that key is also in
> the cache it returns nothing unless the HTTP params are stripped to make
> it:
> http://us.news1.yimg.com/us.yimg.com/p/rids/20050505/i/r1951409762.jpg
> 
> So both of the questions above have been answered. But i now have
> another one:
> How could i save an image cache as a disk file?
> 
> Thanks.
I think my question has been narrowed down to: how do i determine the
data size of in-memory cache? That's what i'm figuring out right now,
and it appears it should be in meta data...

signature.asc
Description: This is a digitally signed message part