Z85base91 - Base91 and Z85 Encodings

This repository provides C and Python implementations of three encoding schemes: Z85P, Base91, and Z85B.

The C-based shared libraries are optimized for performance, while Python implementations provide a fallback when the C libraries are not available.

The repository contains:

• Base91 encoding: A binary-to-text encoding scheme that uses 91 printable ASCII characters.
• Z85B encoding: A variant of Z85 used for efficient binary-to-text encoding.
• Z85P encoding: Another variant of Z85, with different padding scheme.

Features

• C-based implementation for each encoding scheme for maximum performance.
• Pure Python fallback for environments where the C libraries are not available.
• Easy-to-use API for encoding and decoding with detailed error handling and logging.
• Cross-platform support (Linux, macOS, Windows) via system architecture detection.

Benchmarks

Encoding	Avg Encoding Time (ns)	Avg Decoding Time (ns)	Avg Size Increase	Encoding Rank	Decoding Rank	Size Increase Rank
pybase64	1131 ns	2946 ns	1.35x	1 🥇	1 🥇	4
base91	622324 ns	38632 ns	1.23x	5	4	1 🥇
base64	7113 ns	7051 ns	1.35x	3 🥉	3 🥉	4
base16	5953 ns	5859 ns	2.00x	2 🥈	2 🥈	6
z85b	626214 ns	871890 ns	1.25x	6	6	2 🥈
z85p	633825 ns	775821 ns	1.28x	7	5	3 🥉
base32	503698 ns	882194 ns	1.62x	4	7	5
z85p_py	940859 ns	1159043 ns	1.28x	8	8	3 🥉
z85b_py	983796 ns	1314734 ns	1.25x	9	9	2 🥈
base91_py	1414374 ns	2080957 ns	1.23x	10	10	1 🥇

Usage

You can use the provided classes to encode and decode data using the supported encoding schemes.

Z85P Encoding

from z85p import Z85P

# Encode data
data = b"Hello, World!"
encoded = Z85P.encode(data)
print("Encoded Z85P:", encoded)

# Decode data
decoded = Z85P.decode(encoded)
print("Decoded Z85P:", decoded)

Base91 Encoding

from base91 import B91

# Encode data
data = b"Hello, World!"
encoded = B91.encode(data)
print("Encoded Base91:", encoded)

# Decode data
decoded = B91.decode(encoded)
print("Decoded Base91:", decoded)

Z85B Encoding

from z85b import Z85B

# Encode data
data = b"Hello, World!"
encoded = Z85B.encode(data)
print("Encoded Z85B:", encoded)

# Decode data
decoded = Z85B.decode(encoded)
print("Decoded Z85B:", decoded)

Error Handling

The library automatically falls back to the Python implementation if the C libraries are not found or fail to load. Any issues related to encoding or decoding will raise a ValueError with a detailed message.

In the case of missing C libraries, warnings will be logged using Python's built-in logging module.

Logging

The library uses the logging module to provide useful runtime information:

2025-01-08 12:34:56,789 - WARNING - Z85P C library not available: Library load error. Falling back to pure Python implementation.