LZ4 - Extremely fast compression - Zephyr

.. _external_module_lz4:

LZ4 - Extremely fast compression ################################

Introduction

LZ4 is a lossless compression algorithm, providing compression speed greater than 500 MB/s per core, scalable with multi-core CPUs. It features an extremely fast decoder, with speed in multiple GB/s per core, typically reaching RAM speed limits on multi-core systems.

Speed can be tuned dynamically by selecting an "acceleration" factor, which trades compression ratio for faster speed. On the other end, a high compression derivative, LZ4_HC, is also provided, trading CPU time for improved compression ratio. All versions feature the same decompression speed.

LZ4 is also compatible with dictionary compression, both at API and CLI levels. It can ingest any input file as a dictionary, though only the final 64KB are used. This capability can be combined

Usage with Zephyr

To pull in lz4 as a Zephyr module, either add it as a West project in the west.yaml file or pull it in by adding a submanifest (e.g. zephyr/submanifests/lz4.yaml) file with the following content and run west update:

.. code-block:: yaml

manifest: projects: - name: lz4 url: https://github.com/zephyrproject-rtos/lz4 revision: zephyr path: modules/lib/lz4 # adjust the path as needed

For more detailed instructions and API documentation, refer to the lz4 documentation_ as well as the provided lz4 examples_.

Reference

.. _lz4 documentation: https://github.com/lz4/lz4/tree/dev/doc

.. _lz4 examples: https://github.com/zephyrproject-rtos/lz4/tree/zephyr/zephyr/samples