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During split operations, avoid redundant recursive split checks on each child insert. Use insert_without_check for child insertions, then check both children for splits once after all entries are distributed.
Increase SPLIT_COUNT to avoid costly splitting during data ingestion. Add optimize() to recursively distribute and rebalance after ingestion, and for_each_in_range_optimize that lazily optimizes subtrees during range queries. Called when the trace reader pauses for more data.
…memory usage Co-Authored-By: Claude <noreply@anthropic.com>
Change for_each_in_range_ref to use inclusive comparisons so entries exactly at range boundaries are not skipped.
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…r variants Co-Authored-By: Claude <noreply@anthropic.com>
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What?
Optimize the
SelfTimeTreedata structure in the Turbopack trace server for better performance and lower memory usage when loading large trace files, and fix a correctness bug in range queries.Why?
Two issues were identified:
Performance: The tree was splitting and rebalancing on every insert during bulk loading, and each
distribute_entriescall recursively triggered further split checks per entry, creating significant overhead.Correctness: Range query boundary conditions used exclusive comparisons (
</>), incorrectly excluding entries that touched the exact start or end timestamp of the queried range.How?
Performance optimizations:
Batch split checks: Add
insert_without_checkfor inserting entries without triggering a split check per entry. Indistribute_entries, entries are moved to children usinginsert_without_check, andcheck_for_splitis called once per child after all entries are distributed (rather than once per entry).Lazy optimization with memory reclamation: Add an
optimize()method and afor_each_in_range_optimize()traversal method that distribute and rebalance nodes lazily:store.optimize()is called when the reader reaches end-of-data (before waiting for more), doing a bulk pass to properly structure the tree after initial load. After distributing entries to children, each node callsshrink_to_fit()on its entries vec to release excess capacity.for_each_in_range_optimize()distributes and rebalances each node it visits, so query paths are progressively optimized during normal use.Fix
rebalance()bug:check_for_split()was incorrectly called after merging subtrees during rebalance — replaced withdistribute_entries()since the node already has children and needs redistribution, not a fresh split.Correctness fix:
All range boundary comparisons in
for_each_in_range,for_each_in_range_optimize, andlookup_range_countupdated from exclusive (</>) to inclusive (<=/>=), ensuring entries with timestamps exactly equal to the range endpoints are included in results.