twibint

Rust crate for arbitrarily big integers, signed or unsigned.

The main API of this crate is to export 2 types: BigUint and BigInt, meant to represent unsigned or signed integers of arbitrarily large absolute value. They are meant to be used in almost any way a regular integer can be used, though they don't implement the Copy trait.

These types let you choose the underlying digit representation (u32 or u64) via a generic type parameter. All features are identical. You're welcome to try both to see what's most efficient for your use case on your particular machine. Typical usage include defining type BigUint = BigUint<u64>; at the beginning of your project.

Each integer can also be saved to, or imported from, a file, using BigUint::write_to_file, or Imported::read_from_file. The import creates an enum with one variant per available integer type. See documentation for more info.

Build, documentation, and tests are available the usual way calling the following:

cargo build
cargo docs
cargo test

For benchmarks, please visit the benches folder.

This crate relies only on the standard library for its core features. Some dependencies are optional, depending on a specific feature (see list of features below).

Performance

More details and scripts about performance are available in the benches folder.

TL;DR -> The current state of twibints performance (v0.3.0) is: Addition, Subtraction and Multiplication are faster than for Python integers (Division is slightly slower), and sometimes faster then num-bigint at some scales. Division remains quite slower than num-bigint.

List of features

• rand: exports the function gen_random_biguint: enables the possibility to generate a random integer with a specific number of bits. Uses rand crate as a dependency.
• pyo3: Only used to generate python bindings, it's only meant to be used indirectly via the pip install . command. Uses pyo3 crate as a dependency.
• unsafe: Enables accelerations that use unsafe Rust. Enabled by default. Disabled via the flag --no-default-features for pure safe Rust (compile time enforced).

Install as a Python package

Simply use from the base directory

python3 -m pip install .

This crate seems faster than the default Python integers for addition and multiplication above a certain numbers of bits (between 1000 and 10000 bits).

Python tests are available to be run in the pytest framework. They are located in the tests folder and should provide ample example usage. Run the tests with

pytest tests

Performance comparison with Python's default integers are available in the benches folder.

Notice for version 0.2

This contains hardware acceleration for x86_64 architectures that use unsafe code. Forusers wanting extra security (i.e. only safe Rust), use with the flag --no-default-features for a slower experience, but fully compiled in safe Rust.

Notice for version 0.3

This contains new algorithms for division that make this crate more usable. Additionally starts supporting exporting integers to file and importing them from a file.