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perf: Use charCodeAt instead of TextEncoder for improved UTF string comparison performance. #8779

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perf: Use charCodeAt instead of TextEncoder for improved UTF string comparison performance. #8779

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4 changes: 2 additions & 2 deletions packages/firestore/src/model/path.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@ import { Integer } from '@firebase/webchannel-wrapper/bloom-blob';

import { debugAssert, fail } from '../util/assert';
import { Code, FirestoreError } from '../util/error';
import { primitiveComparator, compareUtf8Strings } from '../util/misc';
import { primitiveComparator, compareUtf16Strings } from '../util/misc';

export const DOCUMENT_KEY_NAME = '__name__';

Expand Down Expand Up @@ -202,7 +202,7 @@ abstract class BasePath<B extends BasePath<B>> {
);
} else {
// both non-numeric
return compareUtf8Strings(lhs, rhs);
return compareUtf16Strings(lhs, rhs);
}
}

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6 changes: 3 additions & 3 deletions packages/firestore/src/model/values.ts
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Expand Up @@ -28,7 +28,7 @@ import { fail } from '../util/assert';
import {
arrayEquals,
primitiveComparator,
compareUtf8Strings
compareUtf16Strings
} from '../util/misc';
import { forEach, objectSize } from '../util/obj';
import { isNegativeZero } from '../util/types';
Expand Down Expand Up @@ -255,7 +255,7 @@ export function valueCompare(left: Value, right: Value): number {
getLocalWriteTime(right)
);
case TypeOrder.StringValue:
return compareUtf8Strings(left.stringValue!, right.stringValue!);
return compareUtf16Strings(left.stringValue!, right.stringValue!);
case TypeOrder.BlobValue:
return compareBlobs(left.bytesValue!, right.bytesValue!);
case TypeOrder.RefValue:
Expand Down Expand Up @@ -404,7 +404,7 @@ function compareMaps(left: MapValue, right: MapValue): number {
rightKeys.sort();

for (let i = 0; i < leftKeys.length && i < rightKeys.length; ++i) {
const keyCompare = compareUtf8Strings(leftKeys[i], rightKeys[i]);
const keyCompare = compareUtf16Strings(leftKeys[i], rightKeys[i]);
if (keyCompare !== 0) {
return keyCompare;
}
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15 changes: 5 additions & 10 deletions packages/firestore/src/util/misc.ts
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Expand Up @@ -75,20 +75,15 @@ export interface Equatable<T> {
isEqual(other: T): boolean;
}

/** Compare strings in UTF-8 encoded byte order */
export function compareUtf8Strings(left: string, right: string): number {
// Convert the string to UTF-8 encoded bytes
const encodedLeft = newTextEncoder().encode(left);
const encodedRight = newTextEncoder().encode(right);

for (let i = 0; i < Math.min(encodedLeft.length, encodedRight.length); i++) {
const comparison = primitiveComparator(encodedLeft[i], encodedRight[i]);
/** Compare strings in UTF-16 encoded byte order */
export function compareUtf16Strings(left: string, right: string): number {
for (let i = 0; i < Math.min(left.length, right.length); i++) {
const comparison = primitiveComparator(left.charCodeAt(i), right.charCodeAt(i));
if (comparison !== 0) {
return comparison;
}
}

return primitiveComparator(encodedLeft.length, encodedRight.length);
return primitiveComparator(left.length, right.length);
}

export interface Iterable<V> {
Expand Down