`logos.std.data.persistent.bt.iter`

Module std · package logos-std

Types

struct BtIter

Forward (or reverse-opened) snapshot iterator over a persistent BTree.

leaf_arc is null iff the iter is exhausted; leaf_p is the typed view derived from it.

Fields

cursor: u64

Index of the current entry within the leaf.

leaf_arc: Arc<dyn BTreeNode>

Owns an rc share of the current leaf block, pinning it for the iter’s lifetime.

leaf_p: *mut LeafNode<K, V, STORE_CFG, CFG>

Typed-pointer view of the current leaf; null iff the iter is exhausted/invalid.

path: Vec<IterFrame<K, STORE_CFG, CFG>>

Branch frames from root to the current leaf’s parent.

struct IterFrame

Records one step of a BtIter descent: a pinned branch node plus the child index whose subtree the iterator currently occupies.

Fields

branch_arc: Arc<dyn BTreeNode>

Owns an rc share of the branch block, pinning it for the frame’s lifetime.

branch_p: *mut BranchNode<K, STORE_CFG, CFG>

Typed-pointer view of the branch, derived from branch_arc’s data pointer.

idx: u64

Child index within the branch whose subtree the iterator currently occupies.

fn bt_iter_open(arc: &Arc<dyn BTreeNode>) -> BtIter<K, V, STORE_CFG, CFG>

Opens a forward iter at the leftmost (smallest) entry of the BTree rooted at arc.

fn bt_iter_open_at(arc: &Arc<dyn BTreeNode>, n: u64) -> BtIter<K, V, STORE_CFG, CFG>

Opens a forward iter positioned at the n-th entry (0-based) in sorted order.

Returns an invalid iter (valid()==false) when n >= total size of the tree.

fn bt_iter_open_back(arc: &Arc<dyn BTreeNode>) -> BtIter<K, V, STORE_CFG, CFG>

Opens a reverse iter at the rightmost (largest) entry of the BTree rooted at arc.

Walk backward with step_back(); an empty tree yields an invalid iter (valid()==false).