propagating many messages from a fast store (typically maildir or a
local IMAP server) to a slow asynchronous store could cause gigabytes of
data being buffered. avoid this by throttling fetches if the target
context reports memory usage above a configurable limit.
REFMAIL: 9737edb14457c71af4ed156c1be0ae59@mpcjanssen.nl
the primary objective is reducing the number of small SSL packets (which
are always padded), but fewer syscalls in the non-SSL case should be
good as well.
instead of keeping the structures in an opaque array (which was a shadow
of the struct pollfd array if poll() was supported), make them directly
addressable.
this has the advantage that notifier-altering operations (mostly
en-/disabling) don't need to look up the structure by file handle each
time.
on the downside, data locality in the main loop is worse.
neither of these have any real effect on performance.
note that the structures are not allocated separately, but embedded into
the the parent structure (like sockets already were).
we should make no assumptions about the layout of OpenSSL's certificate
store, in particular when they are wrong. so copy the interesting part
instead of "deep-linking" into it.
this code is uglier than it should be, but OpenSSL's extensive use of
macros to manage data types would force us to include the ssl headers
into our headers otherwise, which would be even uglier.
REFMAIL: <545442CC.9020400@nodivisions.com>
instead of using a callback which messes with the certificate chain
verification, simply let OpenSSL ignore errors during that phase and
check the result only afterwards.
the combinations of the various options made quite a mess. additionally,
'RequireSSL no' is inherently insecure - "use SSL if available" is plain
stupid.
the old options are still accepted, but will elicit a warning.
it doesn't belong there - it's a property of imap_server_conf_t.
the port setup is now done while reading the config.
this makes socket.[hc] imap-agnostic.
