The plain format implementation resides in this module. The plain format does not use any hashing and basically just wraps a normal filesystem tree in the hashed-storage API.
read function on Blobs coming from a plain tree is susceptible to
file content changes. Since we use mmap in
read, this will break
referential transparency and produce unexpected results. Please always make
sure that all parallel access to the underlying filesystem tree never
mutates files. Unlink + recreate is fine though (in other words, the
plainTreeIO implemented in this module are safe in