33 lines
1.0 KiB
JavaScript
33 lines
1.0 KiB
JavaScript
import { TextDecoderLite } from 'text-encoder-lite';
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import base64js from 'base64-js';
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const decoder = new TextDecoderLite('utf-8');
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/**
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*
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* @param {string} chunk
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* Chunk is an undelimited string of valid JSON objects as returned by a streaming endpoint.
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* Each JSON object in a chunk contains two properties:
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* Offset {number} The index from the beginning of the stream at which this JSON object starts
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* Data {string} A base64 encoded string representing the contents of the stream this JSON
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* object represents.
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*/
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export function decode(chunk) {
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const lines = chunk.replace(/\}\{/g, '}\n{').split('\n').without('');
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const frames = lines.map((line) => JSON.parse(line)).filter((frame) => frame.Data);
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if (frames.length) {
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frames.forEach((frame) => (frame.Data = b64decode(frame.Data)));
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return {
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offset: frames[frames.length - 1].Offset,
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message: frames.mapBy('Data').join(''),
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};
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}
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return {};
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}
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function b64decode(str) {
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return decoder.decode(base64js.toByteArray(str));
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}
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