perf: optimize hot paths in persistence, scheduling, and React hooks#1542
Open
KyleAMathews wants to merge 2 commits into
Open
perf: optimize hot paths in persistence, scheduling, and React hooks#1542KyleAMathews wants to merge 2 commits into
KyleAMathews wants to merge 2 commits into
Conversation
Reduce unnecessary allocations and algorithmic complexity: - Schwartzian transform for Set/Map sorting in toStableSerializable (O(n) vs O(n log n) serializations) - splice(0) queue flush instead of while/shift (O(n) vs O(n²)) - Map-based lookup in KeyScheduler.updateTransactions (O(n+m) vs O(n*m)) - Set-based filtering in loadPendingTransactions - Lazy property access in useLiveQuery — status-only consumers skip entries() entirely - Hoist Date.now() in resetRetryDelays for consistent timestamps The useLiveQuery lazy getters share a single entries snapshot to prevent tearing between state and data access. Co-Authored-By: Claude Opus 4.6 <[email protected]>
Co-Authored-By: Claude Opus 4.6 <[email protected]>
Contributor
|
No actionable comments were generated in the recent review. 🎉 ℹ️ Recent review info⚙️ Run configurationConfiguration used: defaults Review profile: CHILL Plan: Pro Run ID: 📒 Files selected for processing (9)
📝 WalkthroughWalkthroughThis PR optimizes hot paths across three packages: stable deterministic ordering and splice-based queue draining in SQLite persistence; Map-based bulk transaction updates and Set-based filtering in offline-transactions; and lazy entry materialization in useLiveQuery to avoid full collection traversal when only status is accessed. ChangesHot-Path Performance Optimizations
🎯 3 (Moderate) | ⏱️ ~25 minutes
🚥 Pre-merge checks | ✅ 4 | ❌ 1❌ Failed checks (1 warning)
✅ Passed checks (4 passed)
✏️ Tip: You can configure your own custom pre-merge checks in the settings. ✨ Finishing Touches📝 Generate docstrings
🧪 Generate unit tests (beta)
Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out. Comment |
More templates
@tanstack/angular-db
@tanstack/browser-db-sqlite-persistence
@tanstack/capacitor-db-sqlite-persistence
@tanstack/cloudflare-durable-objects-db-sqlite-persistence
@tanstack/db
@tanstack/db-ivm
@tanstack/db-sqlite-persistence-core
@tanstack/electric-db-collection
@tanstack/electron-db-sqlite-persistence
@tanstack/expo-db-sqlite-persistence
@tanstack/node-db-sqlite-persistence
@tanstack/offline-transactions
@tanstack/powersync-db-collection
@tanstack/query-db-collection
@tanstack/react-db
@tanstack/react-native-db-sqlite-persistence
@tanstack/rxdb-db-collection
@tanstack/solid-db
@tanstack/svelte-db
@tanstack/tauri-db-sqlite-persistence
@tanstack/trailbase-db-collection
@tanstack/vue-db
commit: |
Contributor
|
Size Change: 0 B Total Size: 117 kB ℹ️ View Unchanged
|
Contributor
|
Size Change: 0 B Total Size: 4.24 kB ℹ️ View Unchanged
|
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Optimize hot paths across three packages to reduce unnecessary allocations and improve algorithmic complexity. The headline win is in
useLiveQuery— status-only consumers (isReady,isLoading,status) now skip entry materialization entirely, dropping from ~2.3ms to ~0.001ms on 50k-row collections.Root cause
Several hot paths used patterns with unnecessary overhead:
JSON.stringify—toStableSerializablecalledJSON.stringifyon both operands in every sort comparison, producing O(n log n) serializations instead of O(n)while/shift— repeatedshift()on a long array is O(n²) due to re-indexingfindIndexloops —KeyScheduler.updateTransactionsandloadPendingTransactionsused O(n×m) lookups where O(n+m) sufficeduseLiveQuerycalledArray.from(collection.entries())on every snapshot, even when the consumer only read status flagsApproach
@tanstack/db-sqlite-persistence-coreJSON.stringifyin the comparator.splice(0)queue flush replaceswhile/shift— detaches the queue atomically in O(n), then iterates. Items arriving during async processing accumulate in the original array for the next flush.@tanstack/offline-transactionsKeyScheduler.updateTransactions— builds a Map from the update array, then single-pass updates. O(n+m) instead of O(n×m).getEarliestRetryTimemoved toKeySchedulerwith a simple loop — avoids spreading intoMath.min(...array)which could stack-overflow on large arrays.loadPendingTransactionsfor removed transaction detection.Date.now()inresetRetryDelays— all transactions get the same timestamp.@tanstack/react-dbuseLiveQuery—stateanddataare now getters that defercollection.entries()until first access. Status flags (isReady,isLoading, etc.) are plain properties that never trigger materialization.Key invariants
stateanddataderive from a shared lazygetEntries()snapshot. If a consumer reads both, they see the same point-in-time view of the collection. ThesingleResultpath also usesgetEntries()for consistency, intentionally trading some getter-level speed for correctness.splice(0)detaches the queue before iterating. This is safe becauseisHydratingisfalseby the time flush runs, so no new items can be pushed during processing.KeyScheduler.updateTransactionsre-sorts bycreatedAtafter bulk updates to maintain execution order.Non-goals
dataorstateis accessed. Fixing that requires incremental update propagation from change payloads, which is a much larger effort.singleResultoptimization — an earlier version usedcollection.values().next().valueto avoid full materialization, but this could tear relative tostate. Correctness was chosen over the extra speed.Benchmarks
Local runs via
pnpm bench:perfon Node v24.11.1 / macOS arm64. Numbers are medians. Baseline numbers are from the pre-change implementation where available; the queue-drain benchmark compares the oldshift()strategy to the new cursor/splice-style strategy.useLiveQuerystatus-only, 50k rowsuseLiveQuerydata access, 50k rowsuseLiveQuerysingleResult, 50k rowsKeyScheduler.updateTransactionsall pending, 1kKeyScheduler.updateTransactionsall pending, 5kTransactionExecutor.loadPendingTransactionshalf filtered, 1kTransactionExecutor.loadPendingTransactionshalf filtered, 5kshift()→ cursor/splice-style)Additional after-change benchmark now covered by the harness:
KeyScheduler.getEarliestRetryTimewith setup, 5kMath.min(...array)argument-spread risk. No pre-change median was captured for this specific case.Verification
Files changed
packages/react-db/src/useLiveQuery.tsstate/datawith shared entries snapshotpackages/react-db/tests/useLiveQuery.test.tsxpackages/db-sqlite-persistence-core/src/persisted.tspackages/db-sqlite-persistence-core/tests/persisted.test.tspackages/offline-transactions/src/executor/KeyScheduler.tspackages/offline-transactions/src/executor/TransactionExecutor.tspackages/offline-transactions/tests/KeyScheduler.test.tspackage.jsonbench:perfscript🤖 Generated with Claude Code
Summary by CodeRabbit
New Features
Performance
Tests