The main goal of code-data-share-for-python is to improve the efficiency of importing python module, including time and memory footprint, by persistence of code object of imported modules with a memory-mapped file.

For more information not included in this README, e.g. detailed user and developer guide, performance results, please refer to our wiki page.

code-data-share-for-python provides mechanism to determine imported packages, dump a memory mapped file from the list of packages and import packages directly from the memory mapped file.

pip install code-data-share

# tracer: list imported packages to mod.lst
PYCDSMODE=TRACE PYCDSLIST=mod.lst python -c 'import json'

# dumper: create archive named mod.img from mod.lst
python -c 'import cds.dump; cds.dump.run_dump("mod.lst", "mod.img")'

# replayer
PYCDSMODE=SHARE PYCDSARCHIVE=mod.img python -c 'import json'

The design is inspired by the Application Class-Data Sharing (AppCDS) feature, introduced in OpenJDK. AppCDS allows a set of application classes to be pre-processed into a shared archive file, which can then be memory-mapped at runtime to reduce startup time and memory footprint.