Looking for pointers how to set up lzma stream using xz-devel

[Bruno Wolff III]

I am working on getting squashfs-tools 4.1 in rawhide. It has wrapper
functions that are set up to use streaming compression/uncompression
from the LZMA SDK 4.65 library.

Currently the LZMA SDK 4.32 library is in Fedora, but is no longer supported
upstream and is not compatible with 4.65.

I think the xz-devel and xz-libs packages support a 4.65 compatible format
using the LZMA1 filter, but I am having trouble figuring out how to use
this library.

I don't think packaging the LZMA SDK 4.65 library is a good option. It would
be a third library doing essentially the same thing and would potentially
be confused with the 4.32 library that currently is used by some legacy lzma
tools that should probably eventually go away as xz provides the same
functions.

So far I have been looking through the include files, but they really aren't
organized in a way that makes figuring out what you need to do easy.
I haven't found any good API documentation yet. The xz source README says
there isn't any, but that it is a lot like zlib.

Possibly looking at the the code for the tools in the xz package will help.

I was hoping someone could point me to either some good documentation or some
good sample code to look at.