I've just been reading through RFC 2718 (Guidelines for new URL Schemes)
because the zlib and bzip2 wrappers have been playing on my mind recently.
With the new wrappers implementation, I changed "zlib:" to "zlib://" and
required all wrappers to have "://" after scheme part, as Sascha pointed
out that there is an ambiguity when dealing with file names or paths
that contain a ":" character.
RFC 2718 takes great pains in highlighting that "://" should only be
used in URLs that refer to a commonly accessible root of a hierarchy.
So, the original "zlib:" wrapper was the correct way of specifying it,
even if it was ambiguous in the context of fopen wrappers.
The other side of things is that zlib (and now bzip2) wrappers are
polluting the URL namespace.
I'm wondering what the best way of avoiding ambiguities and namespace
pollution might be. Here are some suggestions:
1. Don't change anything; keep things as they are.
2. For ambiguous URLs (that is, those that match scheme:schemespecific,
rather than scheme://genericipurl), the wrapper system will treat
scheme:foobar as a plain file named "scheme:foobar", but will treat
<scheme:foobar> as the foobar resource using the wrapper named scheme.
Likewise for <URL:scheme:foobar>; IIRC there is an RFC for that, but I
couldn't find it.
3. To avoid/reduce namespace issues, move zlib and bzip wrappers into
our php:// namespace. So the new usage would look like this:
// create a bz2 version of the php tarball
copy("php://zlib:php-4.2.tar.gz", "php://bzip2:php-4.2.tar.bz2");
There would be two wrapper registration functions; one for
top-level schemes, and another for registering wrappers within the PHP
namespace. I actually quite like this idea; it is quite a clean solution.
4. Your suggestions...
--Wez.
--
Wez Furlong
The Brain Room Ltd.
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