WebDAV ucb provider: neon, serf, ideas...

[Michael Stahl]

On 21.07.2016 08:51, Giuseppe Castagno wrote:

> 4) Curl for WebDAV as well?
> ===========================
> 4) the idea came up reading 
> <http://nabble.documentfoundation.org/Build-WebDAV-neon-serf-differences-among-the-two-tp4157134p4157624.html>.
> 
> I'd like to spend some time to see about libcurl doing the work neon 
> does, by implementing first OPTIONS, HEAD GET methods, the one needed 
> for standard web access.
> The (very brave and challenging) idea is to substitute neon with libcurl 
> in the future.
>         From LO code POV, libcurl is very similar to serf: an external 
> library that performs the bare needs of 'http://' protocol.
> So some idea on how to use libcurl stem out from both the serf software 
> connection structure in ucb provider, and the way  libcurl is used in 
> libcmis.
> Obviously, in this case, the unit tests for WebDAV will follow the road 
> used in libcmis for libcurl.
> 
> Need some advice on this: is it worth the effort? In terms of license, 
> other libs libcurl uses, etc...
> 
> I think that implementing the basic methods for standard Web reading 
> (OPTIONS, HEAD, GET) will give me an idea of what I'm facing.
> 
> If libcurl works as I expect, we will get rid of both neon and serf.
> What do you think?
> As a reference, libcurl site: <https://curl.haxx.se/>.

that's an awesome idea with a lot of potential for simplifying things,
without introducing new problems since we already bundle curl, but also
quite some work i'm afraid.  maybe the general structure and some code
can be taken from the serf UCP, since it operates at a similar
abstraction level being a HTTP library with no special DAV support?

> 5) A very small cache implementation
> ==================================
> A little Web cache should be implemented, limited to cache GET methods 
> results for Web resources only.
> For the time being this is just an idea I'm playing with...
> RFC7234 defines http cache behaviour:
> <https://tools.ietf.org/html/rfc7234>

this would be a useful feature to have, at least as an in-memory cache,
especially for documents that are copy-and-paste from a browser, these
may have lots of linked "button" images that are all identical but we
currently download them N times.

then again, cache invalidation is known to be one of the 2 hard problems
in informatics :)