This is a huge patch that should be a global NOP.
For unix type platforms it enables -Wconversion to issue warnings (-> error)
for all automatic casts that seem less than ideal but are normally concealed
by the toolchain.
This is things like passing an int to a size_t argument. Once enabled, I
went through all args on my default build (which build most things) and
tried to make the removed default cast explicit.
With that approach it neither change nor bloat the code, since it compiles
to whatever it was doing before, just with the casts made explicit... in a
few cases I changed some length args from int to size_t but largely left
the causes alone.
From now on, new code that is relying on less than ideal casting
will complain and nudge me to improve it by warnings.
By default this doesn't change any existing logging behaviour at all.
But it allows you to define cmake options to force or force-disable the
build of individual log levels using new cmake option bitfields
LWS_LOGGING_BITFIELD_SET and LWS_LOGGING_BITFIELD_CLEAR.
Eg, -DLWS_LOGGING_BITFIELD_SET="(LLL_INFO)" can force INFO log level
built even in release mode. -DLWS_LOGGING_BITFIELD_CLEAR="(LLL_NOTICE)"
will likewise remove NOTICE logging from the build regardless of
DEBUG or RELEASE mode.
Secure Streams is an optional layer on top of lws that separates policy
like endpoint selection and tls cert validation into a device JSON
policy document.
Code that wants to open a client connection just specifies a streamtype name,
and no longer deals with details like the endpoint, the protocol (!) or anything
else other than payloads and optionally generic metadata; the JSON policy
contains all the details for each streamtype. h1, h2, ws and mqtt client
connections are supported.
Logical secure streams outlive any particular connection and supports "nailed-up"
connectivity regardless of underlying connection stability.
Optimizations for memory-tight systems.
Check all previous gaps first for any usage, so gaps we created when
faced with perhaps a relatively large allocation that left a lot of
the last chunk on the table can be backfilled with smaller things as
it goes on.
Separate the members that only live in the head object out of the
buffer management object, reducing the cost of new chunks. Allocate
the head object members as the first thing in the first chunk, and
adjust all the code to look there for them.
Add lwsac helper api to allow user code to perform constant string folding
easily within an lwsac. After isolating a string or blob that it wants to store in
the lwsac and point to, it can check if the string or blob already exists earlier
in the lwsac first, and if so just point to that without copying it in again.
For some formats with repeated strings like JSON, the saving can add up to
something useful.
