Crate slice_ring_buf

A fast ring buffer implementation written in Rust. Copies/reads with slices are implemented with memcpy.

This is optimized for manipulating data in bulk with slices. The performance of indexing individual elements one at a time will be limited by the performance of the modulo (remainder) operation on an isize value. If your use case needs better indexing performance at the cost of possibly larger buffer sizes, and is not dependent on the buffer being an exact length, then take a look at my crate bit_mask_ring_buf: https://crates.io/crates/bit_mask_ring_buf.

This crate has no consumer/producer logic, and is meant to be used as a raw data structure or a base for other data structures.

Installation

Add slice_ring_buf as a dependency in your Cargo.toml:

slice_ring_buf = 0.1

Example

use slice_ring_buf::{SliceRB, SliceRbRef};

// Create a ring buffer with type u32. The data will be
// initialized with the default value (0 in this case).
let mut rb = SliceRB::<u32>::from_len(4);
assert_eq!(rb.capacity(), 4);

// Memcpy data from a slice into the ring buffer at arbitrary
// `isize` indexes. Earlier data will not be copied if it will
// be overwritten by newer data, avoiding unecessary memcpy's.
// The correct placement of the newer data will still be preserved.
rb.write_latest(&[0, 2, 3, 4, 1], 0);
assert_eq!(rb[0], 1);
assert_eq!(rb[1], 2);
assert_eq!(rb[2], 3);
assert_eq!(rb[3], 4);

// Memcpy into slices at arbitrary `isize` indexes and length
let mut read_buffer = [0u32; 7];
rb.read_into(&mut read_buffer, 2);
assert_eq!(read_buffer, [3, 4, 1, 2, 3, 4, 1]);

// Read/write by retrieving slices directly
let (s1, s2) = rb.as_slices_len(1, 4);
assert_eq!(s1, &[2, 3, 4]);
assert_eq!(s2, &[1]);

// Read/write to buffer by indexing. Performance will be limited
// by the modulo (remainder) operation on an isize value.
rb[0] = 0;
rb[1] = 1;
rb[2] = 2;
rb[3] = 3;

// Wrap when reading/writing outside of bounds. Performance will be
// limited by the modulo (remainder) operation on an isize value.
assert_eq!(rb[-1], 3);
assert_eq!(rb[10], 2);

// Aligned/stack data may also be used
let mut stack_data = [0u32, 1, 2, 3];
let mut rb_ref = SliceRbRef::new(&mut stack_data);
rb_ref[-4] = 5;
let (s1, s2) = rb_ref.as_slices_len(0, 3);
assert_eq!(s1, &[5, 1, 2]);
assert_eq!(s2, &[]);

Structs

SliceRB	A fast ring buffer implementation optimized for working with slices. Copies/reads with slices are implemented with memcpy.
SliceRbRef	A fast ring buffer implementation optimized for working with slices. Copies/reads with slices are implemented with memcpy. This works the same as [SliceRB] except it uses a reference as its data source instead of an internal Vec.