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