28 lines
845 B
JavaScript
28 lines
845 B
JavaScript
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import { BeeArgumentError } from "../utils/error.js";
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export const SPAN_SIZE = 8; // we limit the maximum span size in 32 bits to avoid BigInt compatibility issues
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const MAX_SPAN_LENGTH = Math.pow(2, 32) - 1;
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/**
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* Create a span for storing the length of the chunk
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*
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* The length is encoded in 64-bit little endian.
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*
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* @param length The length of the span
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*/
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export function makeSpan(length) {
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if (length <= 0) {
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throw new BeeArgumentError('invalid length for span', length);
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}
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if (length > MAX_SPAN_LENGTH) {
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throw new BeeArgumentError('invalid length (> MAX_SPAN_LENGTH)', length);
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}
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const span = new Uint8Array(SPAN_SIZE);
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const dataView = new DataView(span.buffer);
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const littleEndian = true;
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const lengthLower32 = length & 0xffffffff;
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dataView.setUint32(0, lengthLower32, littleEndian);
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return span;
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}
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