Lib.rs

In many logging scenarios, it is often useful to limit the logs to some maximum size while keeping only the most recent content. A common approach is to use a fixed-size circular buffer, where more space can be made for new content by deleting old content.

This crate supports one principle type, StringRing, which is a circular buffer for UTF-8 encoded strings. Multiple Granularity modes are supported for various applications, which control how old content is removed.

Examples

The following is an example of the basic Granularity::Character mode:

# use string_ring::*;
// example of a 16-byte circular string buffer
let mut buf = StringRing::new(16, Granularity::Character);
buf.push("hello world!");
assert_eq!(buf.make_contiguous(), "hello world!");
buf.push("more content!");
assert_eq!(buf.make_contiguous(), "ld!more content!");

The following is an example of the Granularity::Line mode, which is often more useful for logging:

# use string_ring::*;
// example of a 26-byte circular string buffer
let mut buf = StringRing::new(26, Granularity::Line);
buf.push("hello world!\n");
assert_eq!(buf.make_contiguous(), "hello world!\n");
buf.push("more!\n");
assert_eq!(buf.make_contiguous(), "hello world!\nmore!\n");
buf.push("too much!\n");
assert_eq!(buf.make_contiguous(), "more!\ntoo much!\n");

no-std

This crate supports building in no-std environments by disabling default features:

[dependencies]
string-ring = { version = "...", use-default-features = false }

Note that the alloc crate is still required in this case, as there is not currently a heapless version of StringRing.