Until now, f->tmpname was removed by move_file when the move
operation succeeded. However, since a HTTP operation can fail before
move_file is called, the temporary file must also be removed.
This feature allows admins to set a specific quota for each user, in
MiB. This feature is particularly useful for shared instances, where
unlimited user storage might be unfeasible or even dangerous for the
server.
Also, a nice HTML5 <progress> element has been added to the site that
shows how much of the quota has been consumed.
If no quota is set, slcl falls back to the default behaviour i.e.,
assume unlimited storage.
Limitations:
- While HTTP does specify a Content-Length, which determines the length
of the whole request, it does not specify how many files are involved
or their individual sizes.
- Because of this, if multiple files are uploaded simultaneously, the
whole request would be dropped if user quota is exceeded, even if not
all files exceeded it.
- Also, Content-Length adds the length of some HTTP boilerplate
(e.g.: boundaries), but slcl must rely on this before accepting the
whole request. In other words, this means some requests might be
rejected by slcl because of the extra bytes caused by such boilerplate.
- When the quota is exceeded, slcl must close the connection so that
the rest of the transfer is cancelled. Unfortunately, this means no
HTML can be sent back to the customer to inform about the situation.
POSIX functions ftw(3) and nftw(3) do not allow passing an opaque
pointer to the callback they call, so it forces the use of statically
allocated data.
ctfw (from "custom ftw") is a custom implementation that solves this,
while also removing unneeded stuff.
This function will be used by future commits.
Cookies without "Expires" are considered non-persistent and thus can be
removed by the web browser. Instead, slcl now sets persistent cookies
that last for 1 year.
According to C99 §7.20.3.4:
If memory for the new object cannot be allocated, the old object is not
deallocated and its value is unchanged.
Therefore, a temporary pointer must be used to ensure the original
object can still be deallocated should realloc(3) return a null pointer.
