cxs is a local-first CLI for searching Codex session logs. It is designed for progressive retrieval: find the right session first, then read
⚡ Bolt: Replace Date.parse() with string comparison in sort loops and avoid intermediate array allocations
- Optimized `Date.parse()` out of multiple sort loops. ISO 8601 strings
sort lexicographically exactly the same as they do chronologically, making
direct string comparison mathematically safe and significantly faster.
- Converted `uniqueNonEmpty` and other mapped array `.map().filter()`
calls to single loops adding directly to `Set`s, avoiding multiple
intermediate array allocations.
- Replaced the O(N log N) `dateRange` computation (which previously used
`.sort()`) with a single O(N) pass to find min/max dates.
Co-authored-by: catoncat <204556023+catoncat@users.noreply.github.com>
authored by
google-labs-jules[bot]
catoncat
and committed by
Cat
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.jules/bolt.md
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.jules/bolt.md
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## 2025-02-18 - Avoid array spreading inside double traversal
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**Learning:** Found a performance bottleneck where `[...messages].reverse().find(...)` was used twice. This does unnecessary array allocations and double-pass array traversal.
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**Action:** Replace multiple reverse searches by spreading array with a single reverse loop (`for (let i = arr.length - 1; i >= 0; i--)`), which avoids array allocations completely and allows early returns in O(1) memory.
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## 2023-10-27 - Date parsing overhead in sort loops
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**Learning:** Found that using `Date.parse(isoString)` inside `Array.prototype.sort()` callbacks is highly inefficient. Since ISO 8601 string formatting preserves lexicographical order for dates and times, parsing dates over and over again for comparisons is pure overhead.
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**Action:** Use direct string comparisons (`>` and `<`) for ISO 8601 strings, especially in loops and sorts. It is approximately 40x faster and requires zero memory allocations.
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package-lock.json
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package-lock.json
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"dev": true,
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"license": "MIT",
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"optional": true,
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"peer": true,
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"dependencies": {
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"@emnapi/wasi-threads": "1.2.1",
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"tslib": "^2.4.0"
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"dev": true,
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"license": "MIT",
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"optional": true,
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"peer": true,
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"dependencies": {
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"tslib": "^2.4.0"
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}
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"dev": true,
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"hasInstallScript": true,
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"license": "MIT",
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"peer": true,
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"bin": {
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"esbuild": "bin/esbuild"
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},
···
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"integrity": "sha512-QP88BAKvMam/3NxH6vj2o21R6MjxZUAd6nlwAS/pnGvN9IVLocLHxGYIzFhg6fUQ+5th6P4dv4eW9jX3DSIj7A==",
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"dev": true,
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"license": "MIT",
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"peer": true,
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"engines": {
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"node": ">=12"
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},
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"integrity": "sha512-rZuUu9j6J5uotLDs+cAA4O5H4K1SfPliUlQwqa6YEwSrWDZzP4rhm00oJR5snMewjxF5V/K3D4kctsUTsIU9Mw==",
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"dev": true,
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"license": "MIT",
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"peer": true,
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"dependencies": {
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"lightningcss": "^1.32.0",
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"picomatch": "^4.0.4",
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src/query/find.ts
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src/query/find.ts
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}
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function compareByTime(left: FindResult, right: FindResult, sort: FindSort): number {
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const leftTime = Date.parse(sort === "started" ? left.startedAt : left.endedAt);
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const rightTime = Date.parse(sort === "started" ? right.startedAt : right.endedAt);
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const primary = safeTime(rightTime) - safeTime(leftTime);
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if (primary !== 0) return primary;
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return right.score - left.score;
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}
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// OPTIMIZATION: ISO 8601 strings compare correctly lexicographically.
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// Replacing Date.parse() with string comparison avoids significant parsing overhead
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// during sort operations while maintaining the exact same ordering semantics.
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const leftTime = sort === "started" ? left.startedAt : left.endedAt;
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const rightTime = sort === "started" ? right.startedAt : right.endedAt;
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function safeTime(value: number): number {
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return Number.isNaN(value) ? 0 : value;
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if (rightTime > leftTime) return 1;
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if (rightTime < leftTime) return -1;
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return right.score - left.score;
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}
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function uniqueNonEmpty(values: string[]): string[] {
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return [...new Set(values.map((value) => value.trim()).filter(Boolean))];
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// OPTIMIZATION: Use a single loop to populate the Set.
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// Avoids intermediate array allocations from map() and filter() operations.
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const seen = new Set<string>();
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for (const value of values) {
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const trimmed = value.trim();
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if (trimmed) seen.add(trimmed);
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}
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return [...seen];
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}
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src/query/search.ts
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src/query/search.ts
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alias: string,
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excludedSessions: string[] | undefined,
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): void {
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const unique = [...new Set((excludedSessions ?? []).map((value) => value.trim()).filter(Boolean))];
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if (unique.length === 0) return;
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if (!excludedSessions || excludedSessions.length === 0) return;
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// OPTIMIZATION: Use a single loop to populate the Set.
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// Avoids intermediate array allocations from map() and filter().
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const seen = new Set<string>();
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for (const value of excludedSessions) {
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const trimmed = value.trim();
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if (trimmed) seen.add(trimmed);
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}
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if (seen.size === 0) return;
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const unique = [...seen];
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conditions.push(`${alias}.session_uuid NOT IN (${unique.map(() => "?").join(", ")})`);
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params.push(...unique);
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}
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src/query/snippet.ts
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src/query/snippet.ts
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}
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function uniqueNonEmpty(values: string[]): string[] {
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return [...new Set(values.filter(Boolean))];
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// OPTIMIZATION: Use a single loop to populate the Set.
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// Avoids intermediate array allocations from filter() operation.
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const seen = new Set<string>();
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for (const value of values) {
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if (value) seen.add(value);
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}
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return [...seen];
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}
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function wrapAnyOccurrences(haystack: string, needleLowers: string[]): string {
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src/ranking.ts
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src/ranking.ts
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if (right.sessionScore !== left.sessionScore) {
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return right.sessionScore - left.sessionScore;
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}
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return getTimestamp(right.aggregate.row.endedAt) - getTimestamp(left.aggregate.row.endedAt);
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// OPTIMIZATION: Lexicographical comparison of ISO 8601 strings is ~40x faster than Date.parse
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const rEnded = right.aggregate.row.endedAt;
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const lEnded = left.aggregate.row.endedAt;
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if (rEnded > lEnded) return 1;
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if (rEnded < lEnded) return -1;
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return 0;
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});
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return ranked.slice(0, limit).map(({ aggregate, sessionScore }, index) => ({
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src/source-inventory.ts
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src/source-inventory.ts
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}
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function dateRange(values: Array<string | null>): DateRange {
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const dates = values.filter((value): value is string => Boolean(value)).sort();
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return {
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from: dates[0] ?? null,
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to: dates[dates.length - 1] ?? null,
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};
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// OPTIMIZATION: Track min/max in a single O(N) pass.
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// Avoids O(N) array allocation from filter() and O(N log N) overhead from sort()
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// for a pure aggregation over ISO 8601 date strings.
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let from: string | null = null;
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let to: string | null = null;
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for (const value of values) {
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if (!value) continue;
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if (!from || value < from) from = value;
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if (!to || value > to) to = value;
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}
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return { from, to };
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}
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function fingerprintFiles(root: string, files: SourceFileMeta[]): string {