On Mon, Jul 24, 2017 at 07:19:09PM +0300, Evgeny Kotkov wrote: > However, there are a couple of difficulties with porting this approach to > mod_dav_svn, i.e., if we introduce the SVNCompression directive. There > are clients that don't use LZ4, so, presumably, this options would require > specifying all formats that a server can use, in the preferred order: > > SVNCompression "lz4, zlib" > > While such approach is explicit, it also has a couple of drawbacks, as it: > - leaves a window for mistakes (say, if the user sets "SVNCompression lz4" > and inadvertently disables compression for older clients), > - is not forward-compatible, as new compression algorithms require the > server to be reconfigured, and > - adds complexity.
Does mod_dav_svn really need an option for this? Can't lz4 (svndiff2) be negotiated as a mutual protocol capability of client and server? Why won't a simple logic such as the following work: If the client announces lz4 compression level 1 support, use it. Else, use zlib. As an admin or user my expectation would be that clients and servers pick the most suitable protocol automatically. At best, options I set should indicate what I think the ideal protocol configuration would be, but if that won't work (e.g. because an old client conencts) I would expect a fallback. I think we should also consider which decision people who are not experts will make if we give them such options. I would expect many admins would use a logic such as: lz4 is better (newer) than zlib! compression level 9 is better than level 1! and then set their server to lz4 with compression-level 9... Not even having to think about any of these options is much better for our users and saves them time.
