Struct Page 

pub struct Page {
    pub inner: UnsafeCell<PageInner>,
}

Fields

inner: UnsafeCell<PageInner>

Implementations

impl Page

pub fn new(id: i64) -> Self

pub fn get(&self) -> &mut PageInner

pub fn get_contents(&self) -> &mut PageInner

Returns a mutable reference to PageInner for accessing page contents. Panics if the page buffer is not loaded.

pub fn is_locked(&self) -> bool

pub fn set_locked(&self)

pub fn clear_locked(&self)

pub fn is_dirty(&self) -> bool

pub fn set_dirty(&self)

almost never should be called explicitly - instead Pager::add_dirty method must be used

pub fn clear_dirty(&self)

caller must ensure that Pager::dirty_pages will be updated accordingly

pub fn clear_dirty_keep_wal_tag(&self)

Clear the dirty flag without touching wal_tag. Used when a WAL frame has been durably written and the tag already encodes it.

pub fn is_spilled(&self) -> bool

Returns true if the page has been spilled to WAL and is safe to evict even while dirty.

pub fn set_spilled(&self)

Mark the page as spilled to WAL. Spilled pages remain dirty but may be evicted from cache.

pub fn clear_spilled(&self)

Clear the spilled flag. This is also done implicitly on set_dirty().

pub fn is_loaded(&self) -> bool

pub fn set_loaded(&self)

pub fn clear_loaded(&self)

pub fn is_index(&self) -> Result<bool>

pub fn pin(&self)

Increment the pin count by 1. A pin count >0 means the page is pinned and not eligible for eviction from the page cache.

pub fn unpin(&self)

Decrement the pin count by 1. If the count reaches 0, the page is no longer pinned and is eligible for eviction from the page cache.

pub fn try_unpin(&self) -> bool

Try to decrement the pin count by 1, but do nothing if it was already 0. Returns true if the pin count was decremented.

pub fn is_pinned(&self) -> bool

Returns true if the page is pinned and thus not eligible for eviction from the page cache.

pub fn set_wal_tag(&self, frame: u64, epoch: u32)

Set the WAL tag from a (frame, epoch) pair. If inputs are invalid, stores TAG_UNSET, which will prevent the cached page from being used during checkpoint.

pub fn wal_tag_pair(&self) -> (u64, u32)

Load the (frame, seq) pair from the packed tag.

pub fn clear_wal_tag(&self)

pub fn has_wal_tag(&self) -> bool

Returns true if the page has a valid WAL tag (i.e., was written to WAL and not modified since). Returns false if the wal_tag is TAG_UNSET (page was modified since last WAL write).

pub fn set_write_pending(&self)

Mark page as having a WAL write in progress. This is set before starting a spill/cacheflush so we can detect if the page was modified during the write.

pub fn try_set_wal_tag(&self, frame: u64, epoch: u32) -> bool

Try to set the WAL tag, but only if the page wasn’t modified during the write. Returns true if the tag was set, false if the page was modified (wal_tag became TAG_UNSET).

pub fn is_valid_for_checkpoint(&self, target_frame: u64, epoch: u32) -> bool

Trait Implementations

impl Debug for Page

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

Formats the value using the given formatter.

impl Send for Page

impl Sync for Page