There are quite a few linked-lists of things that want events after
some period. This introduces a type binding an lws_dll2 for the
list and a lws_usec_t for the duration.
The wsi timeouts, the hrtimer and the sequencer timeouts are converted
to use these, also in the common event wait calculation.
lws_dll2 removes the downsides of lws_dll and adds new features like a
running member count and explicit owner type... it's cleaner and more
robust (eg, nodes know their owner, so they can casually switch between
list owners and remove themselves without the code knowing the owner).
This deprecates lws_dll, but since it's public it allows it to continue
to be built for 4.0 release if you give cmake LWS_WITH_DEPRECATED_LWS_DLL.
All remaining internal users of lws_dll are migrated to lws_dll2.
It's legal and does something important, if the upgrade fails and stays in http,
it describes how the connection should be handled after sending the error code.
But most ws servers can't cope with it...
Until now lws only parses headers it knows at build-time from its
prebuilt lexical analyzer.
This adds an on-by-default cmake option and a couple of apis
to also store and query "custom", ie, unknown-to-lws headers.
A minimal example is also provided.
At the moment it only works on h1, h2 support needs improvements
to the hpack implementation.
Since it bloats ah memory usage compared to without it if custom
headers are present, the related code and ah footprint can be
disabled with the cmake option LWS_WITH_CUSTOM_HEADERS, but it's
on by default normally. ESP32 platform disables it.
https://github.com/warmcat/libwebsockets/pull/1499
Until now the uv watcher has been composed in the wsi.
This works fine except in the case of a client wsi that
meets a redirect when the event loop is libuv with its
requirement for handle close via the event loop.
We want to reuse the wsi, since the originator of it has
a copy of the wsi pointer, and we want to conceal the
redirect. Since the redirect is commonly to a different
IP, we want to keep the wsi alive while closing its
socket cleanly. That's not too difficult, unless you are
using uv.
With UV the comoposed watcher is a disaster, since after
the close is requested the wsi will start to reconnect.
We tried to deal with that by copying the uv handle and
freeing it when the handle close finalizes. But it turns
out the handle is in a linked-list scheme in uv.
This patch hopefully finally solves it by giving the uv
handle its own allocation from the start. When we want
to close the socket and reuse the wsi, we simply take
responsibility for freeing the handle and set the wsi
watcher pointer to NULL.
