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alexander-akaitalexander-akait
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perf: improve
1 parent 72ce205 commit d506580

24 files changed

Lines changed: 347 additions & 41 deletions

‎.changeset/buffers-all-sources.md‎

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---
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"webpack-sources": patch
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---
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Implements more effective `buffers` and `buffer` for `ReplaceSource` and improve performance in other places.

‎benchmark/cases/original-source/index.bench.mjs‎

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@@ -43,6 +43,18 @@ export default function register(bench) {
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}
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});
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bench.add("original-source: buffers() (from string)", () => {
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for (let i = 0; i < 50; i++) {
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new sources.OriginalSource(fixtureCode, "fixture.js").buffers();
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}
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});
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bench.add("original-source: buffers() (from buffer)", () => {
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for (let i = 0; i < 50; i++) {
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new sources.OriginalSource(fixtureBuffer, "fixture.js").buffers();
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}
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});
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bench.add("original-source: size()", () => {
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for (let i = 0; i < 50; i++) {
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new sources.OriginalSource(fixtureCode, "fixture.js").size();

‎benchmark/cases/prefix-source/index.bench.mjs‎

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@@ -68,6 +68,14 @@ export default function register(bench) {
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for (let i = 0; i < 10; i++) ps.buffer();
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});
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bench.add("prefix-source: buffers()", () => {
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const ps = new sources.PrefixSource(
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"\t",
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new sources.RawSource(fixtureCode),
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);
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for (let i = 0; i < 10; i++) ps.buffers();
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});
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bench.add("prefix-source: size()", () => {
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const ps = new sources.PrefixSource(
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"\t",

‎benchmark/cases/raw-source/index.bench.mjs‎

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@@ -43,6 +43,19 @@ export default function register(bench) {
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for (let i = 0; i < 50; i++) new sources.RawSource(fixtureBuffer).buffer();
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});
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bench.add("raw-source: buffers() (from string)", () => {
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for (let i = 0; i < 50; i++) new sources.RawSource(fixtureCode).buffers();
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});
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bench.add("raw-source: buffers() (from buffer)", () => {
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for (let i = 0; i < 50; i++) new sources.RawSource(fixtureBuffer).buffers();
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});
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bench.add("raw-source: buffers() cached", () => {
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const src = new sources.RawSource(fixtureBuffer);
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for (let i = 0; i < 500; i++) src.buffers();
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});
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bench.add("raw-source: size()", () => {
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for (let i = 0; i < 50; i++) new sources.RawSource(fixtureCode).size();
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});

‎benchmark/cases/replace-source/index.bench.mjs‎

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@@ -96,6 +96,22 @@ export default function register(bench) {
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buildManyReplacements(1000).buffer();
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});
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bench.add("replace-source: buffer() (no replacements)", () => {
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for (let i = 0; i < 100; i++) {
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new sources.ReplaceSource(new sources.RawSource(fixtureCode)).buffer();
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}
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});
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bench.add("replace-source: buffers() (no replacements)", () => {
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for (let i = 0; i < 100; i++) {
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new sources.ReplaceSource(new sources.RawSource(fixtureCode)).buffers();
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}
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});
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bench.add("replace-source: buffers() (1000 small replacements)", () => {
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buildManyReplacements(1000).buffers();
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});
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bench.add("replace-source: map() (no replacements)", () => {
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for (let i = 0; i < 10; i++) {
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new sources.ReplaceSource(

‎benchmark/cases/size-only-source/index.bench.mjs‎

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@@ -44,6 +44,17 @@ export default function register(bench) {
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}
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});
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bench.add("size-only-source: buffers() (throws)", () => {
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const src = new sources.SizeOnlySource(1024);
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for (let i = 0; i < 100; i++) {
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try {
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src.buffers();
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} catch {
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// expected
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}
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}
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});
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bench.add("size-only-source: map() (throws)", () => {
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const src = new sources.SizeOnlySource(1024);
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for (let i = 0; i < 100; i++) {

‎benchmark/cases/source-map-source/index.bench.mjs‎

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@@ -66,6 +66,26 @@ export default function register(bench) {
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}
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});
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bench.add("source-map-source: buffers() (from string)", () => {
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for (let i = 0; i < 50; i++) {
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new sources.SourceMapSource(
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fixtureCode,
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"fixture.js",
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fixtureMap,
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).buffers();
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}
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});
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bench.add("source-map-source: buffers() (from buffer)", () => {
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for (let i = 0; i < 50; i++) {
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new sources.SourceMapSource(
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fixtureBuffer,
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"fixture.js",
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fixtureMap,
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).buffers();
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}
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});
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bench.add("source-map-source: size()", () => {
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for (let i = 0; i < 50; i++) {
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new sources.SourceMapSource(fixtureCode, "fixture.js", fixtureMap).size();

‎lib/CompatSource.js‎

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@@ -54,6 +54,9 @@ class CompatSource extends Source {
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return this._sourceLike.source();
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}
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/**
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* @returns {Buffer} buffer
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*/
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buffer() {
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if (typeof this._sourceLike.buffer === "function") {
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return this._sourceLike.buffer();
@@ -71,6 +74,9 @@ class CompatSource extends Source {
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return super.buffers();
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}
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/**
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* @returns {number} size
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*/
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size() {
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if (typeof this._sourceLike.size === "function") {
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return this._sourceLike.size();

‎lib/ConcatSource.js‎

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@@ -88,6 +88,9 @@ class ConcatSource extends Source {
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}
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}
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/**
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* @returns {Buffer} buffer
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*/
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buffer() {
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return Buffer.concat(this.buffers());
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}
@@ -97,12 +100,19 @@ class ConcatSource extends Source {
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*/
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buffers() {
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if (!this._isOptimized) this._optimize();
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const children = /** @type {SourceLike[]} */ (this._children);
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const childCount = children.length;
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/** @type {Buffer[]} */
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const buffers = [];
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for (const child of /** @type {SourceLike[]} */ (this._children)) {
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// Indexed loop + manual splat avoids the iterator allocation per
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// child and the inner for-of allocation per child.buffers() call.
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// Hot path during webpack's emit on deeply-nested ConcatSources.
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for (let ci = 0; ci < childCount; ci++) {
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const child = children[ci];
103112
if (typeof child.buffers === "function") {
104-
for (const buffer of child.buffers()) {
105-
buffers.push(buffer);
113+
const childBuffers = child.buffers();
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for (let bi = 0, blen = childBuffers.length; bi < blen; bi++) {
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buffers.push(childBuffers[bi]);
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}
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} else if (typeof child.buffer === "function") {
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buffers.push(child.buffer());
@@ -124,18 +134,25 @@ class ConcatSource extends Source {
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*/
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source() {
126136
if (!this._isOptimized) this._optimize();
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const children = /** @type {Source[]} */ (this._children);
138+
const childCount = children.length;
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let source = "";
128-
for (const child of this._children) {
129-
source += /** @type {Source} */ (child).source();
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for (let ci = 0; ci < childCount; ci++) {
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source += children[ci].source();
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}
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return source;
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}
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/**
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* @returns {number} size
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*/
134149
size() {
135150
if (!this._isOptimized) this._optimize();
151+
const children = /** @type {Source[]} */ (this._children);
152+
const childCount = children.length;
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let size = 0;
137-
for (const child of this._children) {
138-
size += /** @type {Source} */ (child).size();
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for (let ci = 0; ci < childCount; ci++) {
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size += children[ci].size();
139156
}
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return size;
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}
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*/
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updateHash(hash) {
310327
if (!this._isOptimized) this._optimize();
328+
const children = /** @type {Source[]} */ (this._children);
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const childCount = children.length;
311330
hash.update("ConcatSource");
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for (const item of this._children) {
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/** @type {Source} */
314-
(item).updateHash(hash);
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for (let ci = 0; ci < childCount; ci++) {
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children[ci].updateHash(hash);
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}
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}
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‎lib/OriginalSource.js‎

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@@ -71,6 +71,9 @@ class OriginalSource extends Source {
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return this._value;
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}
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/**
75+
* @returns {Buffer} buffer
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*/
7477
buffer() {
7578
if (this._valueAsBuffer === undefined) {
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const value = Buffer.from(/** @type {string} */ (this._value), "utf8");
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}
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8588
/**
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* Override Source.prototype.size (= `this.buffer().length`) to avoid
87-
* allocating a Buffer just to read the byte length, and memoize the
88-
* result so repeated calls don't re-scan the string.
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* @returns {number} byte length
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* @returns {number} size
9090
*/
9191
size() {
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if (this._cachedSize !== undefined) return this._cachedSize;

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