Smmap wraps an interface around mmap and tracks the mapped files as
well as the amount of clients who use it. If the system runs out of
resources, or if a memory limit is reached, it will automatically
unload unused maps to allow continued operation.
To allow processing large files even on 32 bit systems, it allows
only portions of the file to be mapped. Once the user reads beyond
the mapped region, smmap will automatically map the next required
region, unloading unused regions using a LRU algorithm.
The interface also works around the missing offset parameter in python
implementations up to python 2.5.
Although the library can be used most efficiently with its native
interface, a Buffer implementation is provided to hide these details
behind a simple string-like interface.
For performance critical 64 bit applications, a simplified version of
memory mapping is provided which always maps the whole file, but
still provides the benefit of unloading unused mappings on demand.