Struct Frame 

pub struct Frame { /* private fields */ }

A buffer frame: a PAGE_SIZE block of memory with metadata for buffer management.

Safety

The data pointer is allocated via std::alloc and must be freed via Frame::drop. Access to the data must be coordinated through:

• pin_count > 0 (frame is in use, cannot be evicted)
• latch (read/write access to the page data)

Implementations

impl Frame

pub fn new() -> Self

Allocate a new frame with zeroed PAGE_SIZE memory.

pub unsafe fn data(&self) -> &[u8]

Get a shared (read-only) reference to the page data.

Safety

Caller must hold a shared latch or pin and ensure no writer exists.

pub unsafe fn data_mut(&self) -> &mut [u8]

Get an exclusive (mutable) reference to the page data.

Safety

Caller must hold an exclusive latch. The &self signature is intentional: Frame uses interior mutability via a raw pointer, coordinated by pin_count and latch.

pub fn page_id(&self) -> PageId

Get the page ID currently loaded in this frame.

pub fn set_page_id(&self, pid: PageId)

Set the page ID for this frame.

pub fn pin_count(&self) -> u32

Get the current pin count.

pub fn pin(&self) -> u32

Increment the pin count.

pub fn unpin(&self) -> u32

Decrement the pin count.

pub fn is_pinned(&self) -> bool

Check if the frame is pinned.

pub fn is_dirty(&self) -> bool

Check if the frame is dirty.

pub fn set_dirty(&self)

Mark the frame as dirty.

pub fn clear_dirty(&self)

Clear the dirty flag.

pub fn is_recently_used(&self) -> bool

Check if the frame was recently used.

pub fn set_recently_used(&self)

Mark the frame as recently used.

pub fn clear_recently_used(&self)

Clear the recently-used flag (second-chance eviction).

pub fn latch(&self) -> &RwLatch

Get a reference to the latch.

pub fn reset(&self)

Reset the frame to an empty state (for after eviction).

pub fn has_valid_page(&self) -> bool

Check if this frame holds a valid page.

Trait Implementations

impl Default for Frame

fn default() -> Self

Returns the “default value” for a type.

impl Drop for Frame

fn drop(&mut self)

Executes the destructor for this type.

impl Send for Frame

impl Sync for Frame