WIP: Memory map files in disk storage
Before raising this MR, consider whether the following are required, and complete if so:
- Unit tests
- Documentation update(s)
If not required, please explain in brief why not.
Memory map files for buildgrid disk storage. This should increase read performance (we will be able to leverage the OS's paging algorithm to manage our memory). This approach seems to also be used in buildbarn for their local disk storage.
This MR is still experimental, suggestions are welcome though!