refactor(db): optimize orderedEntriesArrayReversed to use single pass

github-actions[bot] · kevin-dp · github-actions[bot] · commit 50a5fa2f3d1b · 2026-01-12T10:37:47.000Z
Replace three-iteration approach (spread, reverse, map) with a single
backwards for loop for better performance.

Co-authored-by: Kevin &lt;kevin-dp@users.noreply.github.com&gt;
diff --git a/packages/db/src/indexes/basic-index.ts b/packages/db/src/indexes/basic-index.ts
@@ -428,9 +428,12 @@ export class BasicIndex<
   }
 
   get orderedEntriesArrayReversed(): Array<[any, Set<TKey>]> {
-    return [...this.sortedValues]
-      .reverse()
-      .map((value) => [value, this.valueMap.get(value) ?? new Set()])
+    const result: Array<[any, Set<TKey>]> = []
+    for (let i = this.sortedValues.length - 1; i >= 0; i--) {
+      const value = this.sortedValues[i]
+      result.push([value, this.valueMap.get(value) ?? new Set()])
+    }
+    return result
   }
 
   get valueMapData(): Map<any, Set<TKey>> {

Original file line number	Diff line number	Diff line change
`@@ -428,9 +428,12 @@ export class BasicIndex<`
`428`	`428`	`}`
`429`	`429`
`430`	`430`	`get orderedEntriesArrayReversed(): Array<[any, Set<TKey>]> {`
`431`		`- return [...this.sortedValues]`
`432`		`- .reverse()`
`433`		`- .map((value) => [value, this.valueMap.get(value) ?? new Set()])`
	`431`	`+ const result: Array<[any, Set<TKey>]> = []`
	`432`	`+ for (let i = this.sortedValues.length - 1; i >= 0; i--) {`
	`433`	`+ const value = this.sortedValues[i]`
	`434`	`+ result.push([value, this.valueMap.get(value) ?? new Set()])`
	`435`	`+ }`
	`436`	`+ return result`
`434`	`437`	`}`
`435`	`438`
`436`	`439`	`get valueMapData(): Map<any, Set<TKey>> {`