Gzip compression - pre-compression vs. on-the-fly

[mike]

Just wondering why there is not a standard method of storing the
gzipped file in a cache directory in nginx. Seems to me that would be
developed before the pre-compression module.

Like in Lighty, there is a /var/tmp/lighttpd/cache/compress/ type
folder, and the server maintains its own cache there, as opposed to it
being up to the user to manually gzip their files in-place (and the
pre-compression module just checks if a {$file}.gz exists)

1) pre-compression - available in 0.6.24
2) on-the-fly compression - standard
3) standard server maintained one-time compression - ??

There could be a good reason for this, and I can see how #1 is pretty
neat (you control what is cached, don't have N copies of the same file
gzipped on each webserver's temp cache dir, etc...) but I am surprised
#3 is not offered.

I know #2 seems to meet most people's needs and from what I've read
has minimal overhead. Wondering why #3 was skipped altogether and #1
was done instead?

Thanks!
- mike