Struct MdCache 

pub struct MdCache { /* private fields */ }

A bounded memo of source text → rendered El for one MarkdownOptions configuration.

struct ChatApp {
    md_cache: RefCell<MdCache>, // interior-mutable: written during build
    // …
}

// per visible message, every frame:
let rendered = self.md_cache.borrow_mut().get(&message.text);

Keys are the full source text (no hash-collision risk); values are El subtrees cloned out on hit. A streaming message changes text each delta, so it naturally misses (re-parses) while growing and starts hitting once stable; superseded partial entries age out via LRU.

Implementations

impl MdCache

pub fn new(options: MarkdownOptions) -> Self

A cache rendering with options, holding up to [DEFAULT_CAPACITY] entries.

pub fn with_capacity(options: MarkdownOptions, capacity: usize) -> Self

A cache with an explicit entry cap. Size it to your visible window plus scroll-back margin; each entry holds the source text and the rendered subtree.

pub fn get(&mut self, text: &str) -> El

The rendered tree for text — a clone of the cached subtree on hit, a fresh parse (then cached) on miss.

pub fn parses(&self) -> u64

Number of cache misses so far — each one was a real markdown parse.

pub fn len(&self) -> usize

Entries currently held.

pub fn is_empty(&self) -> bool

True when nothing is cached yet.

pub fn clear(&mut self)

Drop everything (e.g. on theme change if your message trees bake theme-derived values — stock md output is theme-neutral and does not need this).