Function compute_effective_sizes

crates/ixon/src/sharing.rs:392–409

Compute effective sizes for all subterms in topological order. Returns a map from hash to effective size (total serialized bytes).

(
  info_map: &HashMap<blake3::Hash, SubtermInfo>,
  topo_order: &[blake3::Hash],
)

/// Returns a map from hash to effective size (total serialized bytes).
pub fn compute_effective_sizes(
  info_map: &FxHashMap<blake3::Hash, SubtermInfo>,
  topo_order: &[blake3::Hash],
) -> FxHashMap<blake3::Hash, usize> {
  let mut sizes: FxHashMap<blake3::Hash, usize> = FxHashMap::default();

  for hash in topo_order {
    if let Some(info) = info_map.get(hash) {
      let mut size = info.base_size;
      for child_hash in &info.children {
        size += sizes.get(child_hash).copied().unwrap_or(0);
      }
      sizes.insert(*hash, size);
    }
  }

  sizes
}

/// Analyze sharing statistics for debugging pathological cases.
/// Returns a summary of why sharing may not be effective.
#[allow(dead_code)]