Struct Cursor 

pub struct Cursor { /* private fields */ }

B+ tree cursor position with root-to-leaf path.

Implementations

impl Cursor

pub fn seek(pages: &impl PageMap, root: PageId, key: &[u8]) -> Result<Self>

Seek to first key >= key. Empty key = first entry.

pub fn first(pages: &impl PageMap, root: PageId) -> Result<Self>

Position the cursor at the first entry in the tree.

pub fn last(pages: &impl PageMap, root: PageId) -> Result<Self>

Position the cursor at the last entry in the tree.

pub fn is_valid(&self) -> bool

Whether the cursor is at a valid position.

pub fn leaf_page_id(&self) -> PageId

Current leaf page ID.

pub fn cell_index(&self) -> u16

Current cell index within the leaf.

pub fn set_leaf_page_id(&mut self, id: PageId)

Update the current leaf page ID after a CoW operation.

pub fn current(&self, pages: &impl PageMap) -> Option<CursorEntry>

pub fn current_ref<'a, P: PageMap>(&self, pages: &'a P) -> Option<LeafCell<'a>>

pub fn next(&mut self, pages: &impl PageMap) -> Result<bool>

Move the cursor to the next entry (forward).

pub fn prev(&mut self, pages: &impl PageMap) -> Result<bool>

Move the cursor to the previous entry (backward).

pub fn seek_lazy( pages: &mut impl PageLoader, root: PageId, key: &[u8], ) -> Result<Self>

Seek with lazy page loading — only loads the root-to-leaf path.

pub fn current_ref_lazy<'a, P: PageLoader>( &self, pages: &'a mut P, ) -> Option<LeafCell<'a>>

Read the current entry, loading the leaf page if needed.

pub fn next_lazy(&mut self, pages: &mut impl PageLoader) -> Result<bool>

Advance to the next entry, loading pages on demand.