Module histogram32 

Implementation of a histogram using 32-bit unsigned integers as counters.

This module provides an efficient for creating a histogram which supplies you with the byte occurrences in data. It’s particularly optimized for processing large amounts of data quickly.

Key Features

• Fast histogram generation from byte slices
• Optimized for different input sizes and hardware capabilities
• Supports x86 and x86_64 specific optimizations (with nightly Rust)

Main Types

• Histogram32: The primary struct representing a histogram with 32-bit counters.

Main Functions

• histogram32_from_bytes: Efficiently creates a histogram from a byte slice.

Examples

Basic usage:

use lossless_transform_utils::histogram::histogram32_from_bytes;
use lossless_transform_utils::histogram::Histogram32;

let data = [1, 2, 3, 1, 2, 1];
let mut histogram = Histogram32::default();
histogram32_from_bytes(&data, &mut histogram);

assert_eq!(histogram.inner.counter[1], 3); // Byte value 1 appears 3 times
assert_eq!(histogram.inner.counter[2], 2); // Byte value 2 appears 2 times
assert_eq!(histogram.inner.counter[3], 1); // Byte value 3 appears 1 time

Performance Considerations

The implementations in this module are optimized for different input sizes:

• Small inputs (< 64 bytes) use a simple, efficient implementation.
• Larger inputs use batched processing with loop unrolling for better performance.
• On x86_64 and x86 platforms (with nightly Rust), BMI1 instructions are utilized if available.

Not optimized for non-x86 platforms, as I (Sewer) don’t own any hardware.

Safety

While some functions in this module use unsafe code internally for performance reasons, all public interfaces are safe to use from safe Rust code.

Structs

Histogram32

Implementation of a histogram using unsigned 32 bit integers as the counter.

Functions

histogram32_from_bytes

Calculates a new histogram given a byte slice.