Classes details

The file system transparency improves the package management usability a lot. We are going to examine in depth the PackageFS structure and the technical implementation in order to see how we reach our goals.

As we said PackageFS is written in C++ programming language, and has been developed using Object Oriented Programming paradigm. Thus the whole structure is kept clean, easy to be represented (see figure 5.6) and discussed.

At the moment PackageFS consists of few classes:

• PKGFS that implements the overrider system calls;
• Ventry and Vtree that manage the virtual tree storing the file system data;
• PkgMgr that provides a common interface to low-level package managers;
• PkgDebian that directly interacts with the Debian APT package manager;
• PKGFSCache that saves time during the PackageFS mount operations.

We are not going to show the source code of these classes, but we will briefly explain their purposes and interesting methods.

Figura 5.6: The whole PackageFS structure.