30 lines
1.1 KiB
TypeScript
30 lines
1.1 KiB
TypeScript
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"use strict";
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import { ethers } from "ethers";
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export function randomBytes(seed: string, lower: number, upper?: number): Uint8Array {
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if (!upper) { upper = lower; }
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if (upper === 0 && upper === lower) { return new Uint8Array(0); }
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let result = ethers.utils.arrayify(ethers.utils.keccak256(ethers.utils.toUtf8Bytes(seed)));
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while (result.length < upper) {
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result = ethers.utils.concat([result, ethers.utils.keccak256(result)]);
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}
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let top = ethers.utils.arrayify(ethers.utils.keccak256(result));
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let percent = ((top[0] << 16) | (top[1] << 8) | top[2]) / 0x01000000;
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return result.slice(0, lower + Math.floor((upper - lower) * percent));
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}
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export function randomHexString(seed: string, lower: number, upper?: number): string {
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return ethers.utils.hexlify(randomBytes(seed, lower, upper));
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}
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export function randomNumber(seed: string, lower: number, upper: number): number {
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let top = randomBytes(seed, 3);
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let percent = ((top[0] << 16) | (top[1] << 8) | top[2]) / 0x01000000;
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return lower + Math.floor((upper - lower) * percent);
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}
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