This provides very memory-efficient CBOR stream parsing
and writing.
The parser converts pieces of CBOR into callbacks that define
the structure and collate string and blobs into buffer chunks
for extensible and easy access.
It is fragementation-safe and does not need all the CBOR in
the same place at one time, chunks of CBOR are parsed and
discarded as provided.
It does not allocate and just needs a few hundred bytes of
stack for even huge CBOR objects. Huge strings and blobs
are handled without needing memory to hold them atomically.
Includes ./minimal-examples/api-tests/api-test-lecp that
unit tests it against 82 official example CBORs and
26 additional test vectors from COSE (just checking the CBOR
parsing).
The writing apis allow printf style semantics with a variety
of CBOR-aware %-formats. The apis write into a context that
manages output buffer usage, if the output buffer fills,
then the apis return with an AGAIN code that lets you issue
and reset the output buffer and repeat the api all to issue
more output. The subsequent calls can occur much later or
from a different function context, so this is perfect for
WRITEABLE-mediated output from the network parts of lws.
See ./READMEs/README.cbor-lecp.md
Add the ability to just build plugins into the main library.
They are already designed to have a pinhole export for when
they are used as dynamic lib plugins so their namespace
does not conflict.
This is complicated by the fact extern on a function declaration implies
visibility... we have to make LWS_EXTERN empty when building static.
And, setting target_compile_definitions() doesn't work inside macros,
so it has to be set explicitly for the plugins.
Checking the symbol status needs nm -C -D as per
https://stackoverflow.com/questions/37934388/symbol-visibility-not-working-as-expected
after this patch, libwebsockets.a shows no symbols when checked like that and
the static-linked minimal examples only show -U for their other dynamic
imports.
In a handful of cases we use LWS_EXTERN on extern data declarations,
those then need to change to explicit extern.
LWS_EXTERN needs to be empty for windows when declaring functions in the
headers. But for data, it needs the explicit extern otherwise on windows
or mingw based builds, it thinks we are redeclaring the data each time.
Establish a new distributed CMake architecture with CMake code related to
a source directory moving to be in the subdir in its own CMakeLists.txt.
In particular, there's now one in ./lib which calls through to ones
further down the directory tree like ./lib/plat/xxx, ./lib/roles/xxx etc.
This cuts the main CMakelists.txt from 98KB -> 33KB, about a 66% reduction,
and it's much easier to maintain sub-CMakeLists.txt that are in the same
directory as the sources they manage, and conceal all the details that that
level.
Child CMakelists.txt become responsible for:
- include_directories() definition (this is not supported by CMake
directly, it passes it back up via PARENT_SCOPE vars in helper
macros)
- Addition child CMakeLists.txt inclusion, for example toplevel ->
role -> role subdir
- Source file addition to the build
- Dependent library path resolution... this is now a private thing
in the child CMakeLists.txt, it just passes back any adaptations
to include_directories() and the LIB_LIST without filling the
parent namespace with the details
