buffer/blit is difficult to use, and while buffer/push is the easiet
buffer manipulation function to use it only appends to the buffer.
buffer/push-at lets users manipulate buffers at any index - useful
for buffers used as an in-memory databases, for example.
Added underlying buffer support for buffer instances that cannot
reallocated underlying memory - useful for (small) memory mapped
files and other FFI utilties.
Set an internal flag that disables garbage collection on such
buffers. For all currently correct usage, this should have no effect,
and will fix use cases where buffers are initialized this way and then
passed to the interpreter.
This updates the documentation and adds a function buffer/push, which
is a more useful function than buffer/push-string or buffer/push-byte by
combining both.
This way we can support fewer build configurations. Also, remove
all undefined behavior due to use of memcpy with NULL pointers. GCC
was exploiting this to remove NULL checks in some builds.
Also make integer to size_t casts explicit rather than relying on
int32_t * sizeof(x) = size_t. This is kind of a personal preference for
this problem.
Because we use an amalgated build, feature
test macros should be set in a single file that
is included before any other headers, and is placed
at the top of the amalgamated build.
We normally only track memory allocated with janet_gcalloc, but
if only a few very large normal memory blocks are allocated, the GC
will never run. Se simply need to increment a count when we allocate
memory so that the next time we enter the VM, we will be able to
run a collection if needed.
A consistent style should help with contributors and
readability. We use astyle as the formatter as can make a pretty
good approximation of the current style and my preferred style.
Astyle can be found at http://astyle.sourceforge.net/astyle.html
This should speed up start time and reduce malloc/free
usage to about 15% of what is what previously for startup.
The current cost is slightly larger binary as the representaion
of the image is currently less compact than source code.
