Struct RecursiveModelIndex 

pub struct RecursiveModelIndex { /* private fields */ }

Two-level Recursive Model Index for O(1) expected lookups

Architecture

Level 1 (Root):   [Linear Model] → routes to leaf model
Level 2 (Leaves): [PLM 0] [PLM 1] ... [PLM N] → position predictions

Performance

• Space: O(M × params) where M = number of models
• Lookup: O(1) average, O(log ε) for binary search in error range

Implementations

impl RecursiveModelIndex

pub fn build(keys: &[u64], num_leaves: usize, leaf_max_error: usize) -> Self

Build a 2-level RMI

Arguments

• keys - Sorted keys
• num_leaves - Number of leaf models (typically √N)
• leaf_max_error - Max error per leaf segment

pub fn lookup(&self, key: u64, data_len: usize) -> Option<(usize, usize)>

Look up position bounds for a key

pub fn size_bytes(&self) -> usize

Get space usage in bytes

pub fn num_leaves(&self) -> usize

Get number of leaf models

pub fn total_segments(&self) -> usize

Get total segment count across all leaves

Trait Implementations

impl Debug for RecursiveModelIndex

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

Formats the value using the given formatter.