Orcus 0.19.0, Apache Arrow and CMake

[Kohei Yoshida]

Hi there,

I just upgraded on the master branch the orcus library to the latest 
version of 0.19.0.  This version includes an experimental support for 
Apache Parquet format import, but it relies on an external library 
called Apache Arrow[1].  The support for this file format is disabled in 
the libreoffice build.

To enable support for Parquet, we would need to also build the Apache 
Arrow library and its dependency libraries, all of which use CMake as 
their build systems.

Now, it's my understanding that we still don't support use of CMake to 
build our external libraries. My question is, what do people think of 
adding support for CMake in our build system? Would that be too much 
effort and not worth it, or would it be worthwhile to add support for 
it, but so far it has not been anybody's priority, or ... ?

Please let me know what your opinions are.

As an aside, if someone wants to try out this experimental parquet 
import filter, one can build orcus independently with 
--with-parquet-filter passed to configure after also having built the 
apache arrow library, apply this change

https://github.com/kohei-us/core/commit/ae1390947246e44a6cd3d9b8af8c46b60619a698

then build libreoffice with --with-system-orcus.  Then you should be 
able to simply open a parquet file and Calc should open.

Kohei

[1] https://github.com/apache/arrow