102 lines
2.7 KiB
JavaScript
102 lines
2.7 KiB
JavaScript
export const getStreamContents = async (stream, {init, convertChunk, getSize, truncateChunk, addChunk, getFinalChunk, finalize}, {maxBuffer = Number.POSITIVE_INFINITY} = {}) => {
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if (!isAsyncIterable(stream)) {
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throw new Error('The first argument must be a Readable, a ReadableStream, or an async iterable.');
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}
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const state = init();
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state.length = 0;
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try {
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for await (const chunk of stream) {
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const chunkType = getChunkType(chunk);
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const convertedChunk = convertChunk[chunkType](chunk, state);
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appendChunk({convertedChunk, state, getSize, truncateChunk, addChunk, maxBuffer});
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}
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appendFinalChunk({state, convertChunk, getSize, truncateChunk, addChunk, getFinalChunk, maxBuffer});
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return finalize(state);
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} catch (error) {
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error.bufferedData = finalize(state);
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throw error;
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}
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};
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const appendFinalChunk = ({state, getSize, truncateChunk, addChunk, getFinalChunk, maxBuffer}) => {
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const convertedChunk = getFinalChunk(state);
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if (convertedChunk !== undefined) {
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appendChunk({convertedChunk, state, getSize, truncateChunk, addChunk, maxBuffer});
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}
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};
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const appendChunk = ({convertedChunk, state, getSize, truncateChunk, addChunk, maxBuffer}) => {
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const chunkSize = getSize(convertedChunk);
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const newLength = state.length + chunkSize;
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if (newLength <= maxBuffer) {
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addNewChunk(convertedChunk, state, addChunk, newLength);
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return;
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}
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const truncatedChunk = truncateChunk(convertedChunk, maxBuffer - state.length);
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if (truncatedChunk !== undefined) {
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addNewChunk(truncatedChunk, state, addChunk, maxBuffer);
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}
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throw new MaxBufferError();
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};
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const addNewChunk = (convertedChunk, state, addChunk, newLength) => {
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state.contents = addChunk(convertedChunk, state, newLength);
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state.length = newLength;
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};
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const isAsyncIterable = stream => typeof stream === 'object' && stream !== null && typeof stream[Symbol.asyncIterator] === 'function';
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const getChunkType = chunk => {
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const typeOfChunk = typeof chunk;
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if (typeOfChunk === 'string') {
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return 'string';
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}
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if (typeOfChunk !== 'object' || chunk === null) {
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return 'others';
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}
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// eslint-disable-next-line n/prefer-global/buffer
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if (globalThis.Buffer?.isBuffer(chunk)) {
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return 'buffer';
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}
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const prototypeName = objectToString.call(chunk);
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if (prototypeName === '[object ArrayBuffer]') {
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return 'arrayBuffer';
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}
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if (prototypeName === '[object DataView]') {
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return 'dataView';
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}
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if (
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Number.isInteger(chunk.byteLength)
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&& Number.isInteger(chunk.byteOffset)
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&& objectToString.call(chunk.buffer) === '[object ArrayBuffer]'
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) {
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return 'typedArray';
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}
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return 'others';
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};
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const {toString: objectToString} = Object.prototype;
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export class MaxBufferError extends Error {
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name = 'MaxBufferError';
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constructor() {
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super('maxBuffer exceeded');
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}
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}
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