Struct BTree 

pub struct BTree {
    pub root: PageId,
    pub depth: u16,
    pub entry_count: u64,
    /* private fields */
}

B+ tree metadata. Pages stored externally.

Fields

root: PageId

depth: u16

entry_count: u64

Implementations

impl BTree

pub fn new( pages: &mut FxHashMap<PageId, Page>, alloc: &mut PageAllocator, txn_id: TxnId, ) -> Self

Create a new empty B+ tree with a single leaf root.

pub fn from_existing(root: PageId, depth: u16, entry_count: u64) -> Self

Create a BTree from existing metadata (e.g., loaded from commit slot).

pub fn search_at_leaf( pages: &FxHashMap<PageId, Page>, leaf_id: PageId, key: &[u8], ) -> Result<Option<(ValueType, Vec<u8>)>>

pub fn search( &self, pages: &FxHashMap<PageId, Page>, key: &[u8], ) -> Result<Option<(ValueType, Vec<u8>)>>

pub fn lil_would_hit(&self, pages: &FxHashMap<PageId, Page>, key: &[u8]) -> bool

pub fn try_lil_insert( &mut self, pages: &mut FxHashMap<PageId, Page>, alloc: &mut PageAllocator, txn_id: TxnId, key: &[u8], val_type: ValueType, value: &[u8], ) -> Result<Option<bool>>

Combined LIL check + insert. Returns Some(was_new) on hit, None on miss.

pub fn insert( &mut self, pages: &mut FxHashMap<PageId, Page>, alloc: &mut PageAllocator, txn_id: TxnId, key: &[u8], val_type: ValueType, value: &[u8], ) -> Result<bool>

Insert key-value. Returns true if new, false if updated existing.

pub fn insert_at_leaf( &mut self, pages: &mut FxHashMap<PageId, Page>, alloc: &mut PageAllocator, txn_id: TxnId, key: &[u8], val_type: ValueType, value: &[u8], path: Vec<(PageId, usize)>, leaf_id: PageId, ) -> Result<bool>

pub fn insert_or_fetch( &mut self, pages: &mut FxHashMap<PageId, Page>, alloc: &mut PageAllocator, txn_id: TxnId, key: &[u8], val_type: ValueType, value: &[u8], ) -> Result<Option<Vec<u8>>>

pub fn insert_if_absent( &mut self, pages: &mut FxHashMap<PageId, Page>, alloc: &mut PageAllocator, txn_id: TxnId, key: &[u8], val_type: ValueType, value: &[u8], ) -> Result<bool>

pub fn insert_if_absent_at_leaf( &mut self, pages: &mut FxHashMap<PageId, Page>, alloc: &mut PageAllocator, txn_id: TxnId, key: &[u8], val_type: ValueType, value: &[u8], path: Vec<(PageId, usize)>, leaf_id: PageId, ) -> Result<bool>

pub fn upsert_with<F, E>( &mut self, pages: &mut FxHashMap<PageId, Page>, alloc: &mut PageAllocator, txn_id: TxnId, key: &[u8], val_type: ValueType, default_value: &[u8], f: F, ) -> Result<UpsertOutcome, E>

where F: FnMut(&[u8]) -> Result<UpsertAction, E>, E: From<Error>,

pub fn upsert_with_at_leaf<F, E>( &mut self, pages: &mut FxHashMap<PageId, Page>, alloc: &mut PageAllocator, txn_id: TxnId, key: &[u8], val_type: ValueType, default_value: &[u8], path: Vec<(PageId, usize)>, leaf_id: PageId, f: F, ) -> Result<UpsertOutcome, E>

where F: FnMut(&[u8]) -> Result<UpsertAction, E>, E: From<Error>,

pub fn update_sorted( &mut self, pages: &mut FxHashMap<PageId, Page>, alloc: &mut PageAllocator, txn_id: TxnId, pairs: &[(&[u8], &[u8])], ) -> Result<u64>

Bulk-update existing keys. Keys must be sorted.

pub fn delete( &mut self, pages: &mut FxHashMap<PageId, Page>, alloc: &mut PageAllocator, txn_id: TxnId, key: &[u8], ) -> Result<bool>

Delete a key. Returns true if the key was found and deleted.

pub fn delete_at_leaf( &mut self, pages: &mut FxHashMap<PageId, Page>, alloc: &mut PageAllocator, txn_id: TxnId, key: &[u8], path: &mut Vec<(PageId, usize)>, leaf_id: PageId, ) -> Result<bool>

pub fn walk_to_leaf( &self, pages: &FxHashMap<PageId, Page>, key: &[u8], ) -> Result<(Vec<(PageId, usize)>, PageId)>

Walk root to leaf for key. Returns (path, leaf_page_id).

Trait Implementations

impl Clone for BTree

fn clone(&self) -> BTree

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.