This removes all the direct wsi members specific to clients,
most of them are moved to being fake headers in the next 3-layer
header scheme, c_port moves to being a member of the u.hdr
unionized struct.
It gets rid of a lot of fiddly mallocs and frees(), despite it
adds a small internal API to create the fake headers, actually
the patch deletes more than it adds...
Signed-off-by: Andy Green <andy.green@linaro.org>
This big patch replaces the malloc / realloc per header
approach used until now with a single three-level struct
that gets malloc'd during the header union phase and freed
in one go when we transition to a different union phase.
It's more expensive in that we malloc a bit more than 4Kbytes,
but it's a lot cheaper in terms of malloc, frees, heap fragmentation,
no reallocs, nothing to configure. It also moves from arrays of
pointers (8 bytes on x86_64) to unsigned short offsets into the
data array, (2 bytes on all platforms).
The 3-level thing is all in one struct
- array indexed by the header enum, pointing to first "fragment" index
(ie, header type to fragment lookup, or 0 for none)
- array of fragments indexes, enough for 2 x the number of known headers
(fragment array... note that fragments can point to a "next"
fragment if the same header is spread across multiple entries)
- linear char array where the known header payload gets written
(fragments point into null-terminated strings stored in here,
only the known header content is stored)
http headers can legally be split over multiple headers of the same
name which should be concatenated. This scheme does not linearly
conatenate them but uses a linked list in the fragment structs to
link them. There are apis to get the total length and copy out a
linear, concatenated version to a buffer.
Signed-off-by: Andy Green <andy.green@linaro.org>
A new protocol member is defined that controls the size of rx
buffer allocation per connection. For compatibility 0 size
allocates 4096, but you should adapt your protocol definition
array in the user code to declare an appropriate value.
See the changelog for more detail.
The advantage is the rx frame buffer size is now tailored to
what is expected from the protocol, rather than being fixed
to a default of 4096. If your protocol only sends frames of
a dozen bytes this allows you to only allocate an rx frame
buffer of the same size.
For example the per-connection allocation (excluding headers)
for the test server fell from ~4500 to < 750 bytes with this.
Signed-off-by: Andy Green <andy.green@linaro.org>
This reduces the size of struct libwebscocket from 4840 to 4552
on x86_64
There are also big benefits on malloc pool fragmentation and
allocation, the header allocations only exist between the first
peer communication and websocket connection establishment for
both server and client.
Signed-off-by: Andy Green <andy.green@linaro.org>
http://www.yassl.com/yaSSL/Products-cyassl.html
- Small Size: 20-100kB
- Runtime Memory: 1-36kB
- 20X smaller than OpenSSL
So far only tested on Linux.
Note that this requires a bugfix in cyassl, otherwise it will crash. Pull request has been made to the official repos, in the meantime the following repos can be used: git://github.com/JoakimSoderberg/cyassl.git
Libwebsockets is fundamentally singlethreaded... the existence of the
fork and broadcast support, especially in the sample server is
giving the wrong idea about how to use it.
This replaces broadcast in the sample server with
libwebsocket_callback_on_writable_all_protocol(). The whole idea of
'broadcast' is removed.
All of the broadcast proxy stuff is removed: data must now be sent
from the callback only. Doing othherwise is not reliable since the
service loop may close the socket and free the wsi at any time,
invalidating a wsi pointer held by another thread (don't do that!)
Likewise the confirm_legit_wsi api added recently does not help the
other thread case, since if the wsi has been freed dereferencing the
wsi to study if it is legit or not will segfault in that case. So
this is removed too.
The overall effect is to push user code to only operate inside the
protocol callbacks or external poll loops, ie, single thread context.
Signed-off-by: Andy Green <andy.green@linaro.org>
Large chunks of struct libwebsocket members actually have a mutually
exclusive lifecycle, eg, once the http headers are finished they sit
there unused until the instance is destroyed.
This makes a big improvement in memory efficiency by making four
categories of member: always needed, needed for header processing,
needed for http processing, and needed for ws processing. The last
three are mutually exclusive and bound into a union inside the wsi.
Care needs taking now at "union transitions", although we zeroed down
the struct at init, the other union siblings have been writing the
same memory by the time later member siblings start to use it. So
it must be cleared down appropriately when we cross from one
mutually-exclusive use to another.
Signed-off-by: Andy Green <andy.green@linaro.org>
Since v13 was defined as the released ietf version the older versions
are deprecated. This patch strips out everything to do with the older
versions and gets rid of the option to send stuff unmasked.
The in-tree md5 implementation is then also deleted as nothing needs
it any more, 1280 loc are shed in all
Signed-off-by: Andy Green <andy.green@linaro.org>
The new --without-extensions config flag completely removes all code
and data related to extensions from the build throughout the library
when given.
Signed-off-by: Andy Green <andy.green@linaro.org>
Profiling what happens during the ab test, one of the hotspots
was strcasecmp in a loop looking for header name matches each time.
This patch introduces a lexical parser that creates a state machine
in 276 bytes that encodes all the known header names. The fsm is
walked bytewise as chaacters come in... most states do not need any
recursion to match or fail.
The state machine output is cut-and-pasted into parsers.c as an
unsigned char array.
The fsm generator is a bit rough and ready, included in the tree but
not built since normal mortals won't need to touch it.
Signed-off-by: Andy Green <andy.green@linaro.org>
