fmmap 0.1.0

A fast reimplementation of mmap

This module is a reimplementation of Python’s builtin module mmap. It aims to provide better performance while being API compatible with the builtin module.

import fmmap as mmap

Memory mapping is a technique of providing access to a file by mapping it into the virtual address space of the function and letting the operating system handle the input and output instead of explicitely reading from or writing to the file. It can provide better performance over normal file access in some cases. The builtin mmap mobule in Python exposes this functionality, but some of the implementation is not as fast as possible.

Summary of the project status:

Currently only the find() function is improved over the version in the standard library. More might follow, and contributions are welcome.

Installation and usage

The following requirements are supported and tested in all reasonable combinations:

• Python versions: 3.7, 3.8.

• Interpreters: CPython.

pip install --upgrade fmmap

Credits and Resources

The code and tests in this project are based on the standard library’s mmap module. Additional tests from the pypy project is also duplicated here that helped to identify a few bugs. Most functionality is just inherrited from the current runtime. The rest is implemented in optimized Cython code.

Further readding on Wikipedia:

• The mmap(2) system call

• Memory-mapped file

Contributing

1. Clone this repository (git clone ...)

2. Create a virtualenv

3. Install package dependencies: pip install --upgrade pytest tox

4. Change some code

5. Run the tests: in the project root simply execute pytest, and afterwards preferably tox to test the full test matrix. Consider installing as many supported interpreters as possible (having them in your PATH is often sufficient).

6. Submit a pull request and check for any errors reported by the Continuous Integration service.

License

The MPL 2.0 License

Copyright (c) 2020 Friedel Wolff.