Website Structure

Frontend-Learner/node_modules/get-stream/source/array-buffer.js

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+import {getStreamContents} from './contents.js';
+import {noop, throwObjectStream, getLengthProp} from './utils.js';
+
+export async function getStreamAsArrayBuffer(stream, options) {
+	return getStreamContents(stream, arrayBufferMethods, options);
+}
+
+const initArrayBuffer = () => ({contents: new ArrayBuffer(0)});
+
+const useTextEncoder = chunk => textEncoder.encode(chunk);
+const textEncoder = new TextEncoder();
+
+const useUint8Array = chunk => new Uint8Array(chunk);
+
+const useUint8ArrayWithOffset = chunk => new Uint8Array(chunk.buffer, chunk.byteOffset, chunk.byteLength);
+
+const truncateArrayBufferChunk = (convertedChunk, chunkSize) => convertedChunk.slice(0, chunkSize);
+
+// `contents` is an increasingly growing `Uint8Array`.
+const addArrayBufferChunk = (convertedChunk, {contents, length: previousLength}, length) => {
+	const newContents = hasArrayBufferResize() ? resizeArrayBuffer(contents, length) : resizeArrayBufferSlow(contents, length);
+	new Uint8Array(newContents).set(convertedChunk, previousLength);
+	return newContents;
+};
+
+// Without `ArrayBuffer.resize()`, `contents` size is always a power of 2.
+// This means its last bytes are zeroes (not stream data), which need to be
+// trimmed at the end with `ArrayBuffer.slice()`.
+const resizeArrayBufferSlow = (contents, length) => {
+	if (length <= contents.byteLength) {
+		return contents;
+	}
+
+	const arrayBuffer = new ArrayBuffer(getNewContentsLength(length));
+	new Uint8Array(arrayBuffer).set(new Uint8Array(contents), 0);
+	return arrayBuffer;
+};
+
+// With `ArrayBuffer.resize()`, `contents` size matches exactly the size of
+// the stream data. It does not include extraneous zeroes to trim at the end.
+// The underlying `ArrayBuffer` does allocate a number of bytes that is a power
+// of 2, but those bytes are only visible after calling `ArrayBuffer.resize()`.
+const resizeArrayBuffer = (contents, length) => {
+	if (length <= contents.maxByteLength) {
+		contents.resize(length);
+		return contents;
+	}
+
+	const arrayBuffer = new ArrayBuffer(length, {maxByteLength: getNewContentsLength(length)});
+	new Uint8Array(arrayBuffer).set(new Uint8Array(contents), 0);
+	return arrayBuffer;
+};
+
+// Retrieve the closest `length` that is both >= and a power of 2
+const getNewContentsLength = length => SCALE_FACTOR ** Math.ceil(Math.log(length) / Math.log(SCALE_FACTOR));
+
+const SCALE_FACTOR = 2;
+
+const finalizeArrayBuffer = ({contents, length}) => hasArrayBufferResize() ? contents : contents.slice(0, length);
+
+// `ArrayBuffer.slice()` is slow. When `ArrayBuffer.resize()` is available
+// (Node >=20.0.0, Safari >=16.4 and Chrome), we can use it instead.
+// eslint-disable-next-line no-warning-comments
+// TODO: remove after dropping support for Node 20.
+// eslint-disable-next-line no-warning-comments
+// TODO: use `ArrayBuffer.transferToFixedLength()` instead once it is available
+const hasArrayBufferResize = () => 'resize' in ArrayBuffer.prototype;
+
+const arrayBufferMethods = {
+	init: initArrayBuffer,
+	convertChunk: {
+		string: useTextEncoder,
+		buffer: useUint8Array,
+		arrayBuffer: useUint8Array,
+		dataView: useUint8ArrayWithOffset,
+		typedArray: useUint8ArrayWithOffset,
+		others: throwObjectStream,
+	},
+	getSize: getLengthProp,
+	truncateChunk: truncateArrayBufferChunk,
+	addChunk: addArrayBufferChunk,
+	getFinalChunk: noop,
+	finalize: finalizeArrayBuffer,
+};