Weibin Zeng

fix(c++): fix link error -lgar_arrow_static not found when link static graphar build arrow from source

4

### Reason for this PR as issue #627 describes, the gar_arrow_static symbol is not valid when the graphar building is done. consider to link to the $GAR_ARROW_STATIC_LIB, instead gar_arrow_static ###...

### Describe the bug, including details regarding any error messages, version, and platform. ### build graphar with arrow from source ```bash cmake .. -DBUILD_ARROW_FROM_SOURCE=ON -DGRAPHAR_BUILD_STATIC=ON make -j && sudo make...

feat(c++): use nested namespace to distinguish different level reader/writer

1

### Describe the enhancement requested Currently GraphAr c++ library use the class name to distinguish different level reader/writer like `VertexPropertyChunkInfoReader` as info level vertex property reader and `VertexPropertyArrowChunkReader` as arrow...

bug(c++,spark): clean the output directory when generating data in unit test

8

### Describe the bug, including details regarding any error messages, version, and platform. In c++ or spark unit test, we usually creating the graphar data to `/tmp` dir and may...