bytesfunc 3.4.1

Fast bytes and bytearray processing functions

Authors:

Michael Griffin

Version:

3.4.1 for 2023-04-22

Copyright:

2014 - 2023

License:

This document may be distributed under the Apache 2.0 License.

Language:

Python 3.6 or later

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Introduction

The BytesFunc module provides high speed array processing functions for use with Python ‘bytes’ and ‘bytearray’ objects. These functions are patterned after the functions in the standard Python “operator” module together with some additional ones from other sources.

The purpose of these functions is to perform mathematical calculations on “bytes” and “bytearray” objects significantly faster than using native Python.

See full documentation at: https://bytesfunc.readthedocs.io/en/latest/

If you are installing on an ARM platform such as the Raspberry Pi, see the installation notes at the end before attempting to install from PyPI using PIP.

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Function Summary

The compare operators used for ‘ball’, ‘bany’, and ‘findindex’ are examples only, and other compare operations are available. Many functions will accept other parameter combinations of sequences and numeric parameters. See the details for each function for what parameter combinations are valid.

Brief Description

Function	Equivalent to
and_	Perform a bitwise AND across the sequence.
ball	True if all elements of the sequence meet the match criteria.
bany	True if any elements of the sequence meet the match criteria.
bmax	Return the maximum value in the sequence.
bmin	Return the minimum value in the sequence.
bsum	Return the sum of the sequence.
eq	True if all elements of the sequence equal the compare value.
findindex	Returns the index of the first value in an array to meet the specified criteria.
ge	True if all elements of the sequence are greater than or equal to the compare value.
gt	True if all elements of the sequence are greater than the compare value.
invert	Perform a bitwise invert across the sequence.
le	True if all elements of the sequence are less than or equal to the compare value.
lshift	Perform a bitwise left shift across the sequence.
lt	True if all elements of the sequence are less than the compare value.
ne	True if all elements of the sequence are not equal the compare value.
or_	Perform a bitwise OR across the sequence.
rshift	Perform a bitwise right shift across the sequence.
xor	Perform a bitwise XOR across the sequence.

Python Equivalent

Function	Equivalent to
and_	[x & param for x in sequence1]
ball	all([(x > param) for x in array])
bany	any([(x > param) for x in array])
bmax	max(sequence)
bmin	min(sequence)
bsum	sum(sequence)
eq	all([x == param for x in sequence])
findindex	[x for x,y in enumerate(array) if y > param][0]
ge	all([x >= param for x in sequence])
gt	all([x > param for x in sequence])
invert	[~x for x in sequence1]
le	all([x <= param for x in sequence])
lshift	[x << param for x in sequence1]
lt	all([x < param for x in sequence])
ne	all([x != param for x in sequence])
or_	[x | param for x in sequence1]
rshift	[x >> param for x in sequence1]
xor	[x ^ param for x in sequence1]

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Supported Sequence Types

BytesFunc supports Python native “bytes” and “bytearray” objects.

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Performance

Average performance increase on x86_64 Ubuntu with GCC is 600 times faster than native Python. Performance will vary depending on the function, with the performance increase ranging from 7 times to 1500 times.

Other platforms show similar improvements.

Detailed performance figures are listed in the full documentation.

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Platform support

BytesFunc is written in ‘C’ and uses the standard C libraries to implement the underlying math functions. BytesFunc has been tested on the following platforms.

OS	Hardware	Bits	Compiler	Python Version
Debian 11	i686	32	GCC	3.9.2
Debian 11	x86_64	64	GCC	3.9.2
Ubuntu 22.04	x86_64	64	GCC	3.10.6
Ubuntu 23.04	x86_64	64	GCC	3.11.2
opensuse-leap 15.4	x86_64	64	GCC	3.6.15
almalinux 9.1	x86_64	64	GCC	3.9.14
alpine 3.17.3	i686	32	GCC	3.10.11
FreeBSD 13.2	amd64	64	Clang	3.9.16
OpenBSD 7.3	amd64	64	Clang	3.10.10
MS Windows 10	AMD64	64	MSC	3.11.0
MS Windows 11	AMD64	64	MSC	3.11.0
Raspbian 11	armv7l	32	GCC	3.9.2
Ubuntu 22.04	aarch64	64	GCC	3.10.6

amd64 is another name for x86_64 and does not indicate the CPU brand. armv7l is 32 bit ARM. The test hardware is a Raspberry Pi 3. aarch64 is 64 bit ARM. The test hardware is a Raspberry Pi 4.

• The Rasberry Pi 3 tests were conducted on a Raspberry Pi 3 ARM CPU running in 32 bit mode.

• The Ubuntu ARM tests were conducted on a Raspberry Pi 4 ARM CPU running in 64 bit mode.

• All others were conducted using VMs running on x86 hardware.

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Installation

Please note that this is a Python 3 package. To install using Pip, you will need (with Debian package in brackets):

• The appropriate C compiler and header files (gcc and build-essential).

• The Python3 development headers (python3-dev).

• Pip3 together with the corresponding Setuptools (python3-pip).

example:

# Install from PyPI.
pip3 install bytesfunc
# Force install from PyPI source instead of using a binary wheel.
pip3 install --user --force-reinstall --no-binary=:all: bytesfunc
# Install from a local copy of the source package (Linux).
pip3 install --no-index --find-links=. bytesfunc
# Install a local package as a user package.
pip3 install --user --no-index --find-links=. bytesfunc
# Windows, FreeBSD, and OpenBSD seems to use "pip" instead
# of "pip3" for some reason.
pip install bytesfunc

Newer versions of OpenBSD and FreeBSD will not install this package correctly when running setup.py directly. Use pip to install, even for local package installs. Testing of this package has been changed to use only pip (or pip3) in order to provide a common testing method for all platforms. Testing using setup.py directly is no longer done.

Recent versions of PyPI seem to be building their own binary wheels for some platforms using their own infrastruction. This may result in an invalid ARM binary on Raspberry Pi.

If you have difficulties, then either download the tar.gz version and install it locally (see the above instructions for a local install). Alternatively, see the above example for how to force a binary install instead of using a wheel. There is also a bash script called “setupuser.sh” which will call setup. py directly with the appropriate parameters.

The setup.py file has platform detection code which it uses to pass the correct flags to the C compiler. For ARM, this includes the CPU type. If you are using an ARM CPU type which is not recognized then setup.py may not compile in SIMD features. You can experiment with modifying setup.py to add new ARM models, but be sure that anything you try is compatible with the existing ones.

Installing on Linux with PIP and PEP-668

PEP-668 (PEPs describe changes to Python) introduced a new feature which can affect how packages are installed with PIP. If PIP is configured to be EXTERNALLY-MANAGED it will refuse to install a package outside of a virtual environment.

The intention of this is to prevent conflicts between packages which are installed using the system package manager, and ones which are installed using PIP.

Linux distros which are affeced by this include the latest versions of Debian and Ubuntu.

As this package is a library which is intended to be used by other applications, there is no one right way to install it, whether inside or outside of a virtual environment. Review the options available with PIP to see what is suitable for your application.

For testing purposes this package was installed by setting the environment variable PIP_BREAK_SYSTEM_PACKAGES to “1”, which effectively disables this feature in PIP.

example:

export PIP_BREAK_SYSTEM_PACKAGES=1

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Release History

• 3.4.1 - Update to testing and support. There were no code. changes.

  Ubuntu version updated to 23.04. AlmaLinux updated to 9.1. Alpine Linux updated to 3.17.3. FreeBSD updated to 13.2. OpenBSD updated to 7.3. On Ubuntu 23.04, the installation method has changed due to how PEP-668 was implemented by Debian and how this affects “pip”. Some other distros may experience the same problems if they made the same changes. See the README.TxT for details.

• 3.4.0 - Added pyproject.toml file to satisfy Python 3.11 requirements.

  Updated build scripts to use python3 -m build instead of calling setup.py directly. Test targets were updated, Ubuntu 20.04 was dropped, Ubuntu 22.10 was added, FreeBSD python version upgraded to 3.9, OpenBSD upgraded to 7.2, Windows 10 Python upgraded to 3.11, Windows 11 Python upgraded to 3.11. Added __version__ attribute to allow checking package version number at run time. Added version unit test. Updated setup.py and other files to allow the version number to be automatically updated from a single source at build time.

• 3.3.0 - Major performance improvements for bsum through the use of SIMD and

  other optimizations. Used splint (GCC lint) on all C code and fixed warnings. Other than bsum, no changes in functionality.

• 3.2.1 - Fixed formatting error in README.rst.

• 3.2.0 - Update to testing and support. Tested with new releases of Ubuntu

  22.04 and OpenBSD 7.1. Changed “simdsupport” to also report the architecture the binary was compiled for. “Simdsupport” is only used for testing and benchmarking and is not a stable part of the release.

• 3.1.2 - Bump to correct minor documentation error in README.rst.

• 3.1.1 - Update to testing and support. Raspberry Pi 32 bit OS updated to

  version 2022-04-04. Update to setup.py to improve ARM version detection.

• 3.1.0 - Update to testing and support. On Windows 10 the Python version is

  3.10. Centos has been replaced by AlmaLinux due to Red Hat ending long term support for Centos. Ubuntu Server 21.04 replaced by 21.10. No actual code changes.

• 3.0.0 - Major speed improvement to lshfit and rshift on x86-64 due to adding

  SIMD support. Debian test platforms were updated to latest versions (11).

• 2.2.0 - Updated benchmarks to make each one a separate file. Centos and

  OpenSuse test platforms updated to latest versions.

• 2.1.1 - Documentation updated and version number bumped to reflect testing

  with Ubuntu 21.04, FreeBSD 13.0, and OpenBSD 6.9. No code changes.

• 2.1.0 - Changed setup.py to detect Raspberry Pi 4 and set the compiler args

  accordingly. Added support for Pi 4. Dropped testing of 64 bit mode on Pi 3.

• 2.0.1 - Documentation updated to reflect testing with the release version

  of Ubuntu 20.04 ARM (Rasberry Pi), Ubuntu 2010 (x86-64), OpenBSD 6.8, and Python 3.9 on Windows. No code changes and no change in version number.

• 2.0.0 - Documentation updated to reflect testing with the release version

  of Ubuntu 20.04. No code changes and no change in version number.

• 2.0.0 - Added SIMD support for ARMv8 AARCH64. This is 64 bit ARM on a

  Raspberry Pi3 when running 64 bit Ubuntu. Raspbian is 32 bit only and has 64 bit SIMD vectors. 64 bit ARM has 128 bit SIMD vectors and so offers improved performance.

• 1.0.0 - First release.