Struct PageRef 

pub struct PageRef<'a> { /* private fields */ }

A borrowed view of a cached or WAL-staged page.

PageRef is the return type of Pager::read_page. It carries a shared reference to the page’s bytes that lives no longer than the immutable borrow of the pager that produced it — so the borrow checker forbids holding a PageRef across any mutating call on the same pager (write, commit, checkpoint, alloc, free).

Allocation contract

Construction of a PageRef performs no heap allocation on cache hits or WAL-overlay hits: the bytes are already resident in memory and PageRef is a thin wrapper around a &[u8; PAGE_SIZE]. On a cache miss the read-through path issues one pread and inserts the page into the cache, after which the PageRef borrows that cache frame.

Examples

let view = p.read_page(a)?;
let header_byte = view.as_bytes()[0];
// `view` must be dropped (or moved) before the next p.write_page(...).

Implementations

impl<'a> PageRef<'a>

pub fn page_id(&self) -> PageId

The page id this view was read for.

pub fn as_bytes(&self) -> &'a [u8; 4096]

The page’s raw bytes. Includes the per-page CRC32C trailer in its last PAGE_TRAILER_SIZE bytes; callers that want only the payload should slice off the trailer themselves.

pub fn to_owned_page(&self) -> Page

Clone the underlying page into a fresh owned Page. This allocates; only call it when an owned buffer is genuinely required (e.g. to mutate before a subsequent write_page).

Trait Implementations

impl<'a> Debug for PageRef<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.