33 lines
1.6 KiB
TypeScript
33 lines
1.6 KiB
TypeScript
export function utf8Encode(text: string): Uint8Array {
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if (typeof TextEncoder !== "undefined") return new TextEncoder().encode(text);
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if (typeof Buffer !== "undefined") return new Uint8Array(Buffer.from(text, "utf-8"));
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const bytes = new Uint8Array(text.length * 4);
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let len = 0;
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for (let i = 0; i < text.length; i += 1) {
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const code = text.codePointAt(i) as number;
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if (code < 0x80) bytes[len++] = code;
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else if (code < 0x800) { bytes[len++] = 0xc0 | (code >> 6); bytes[len++] = 0x80 | (code & 0x3f); }
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else if (code < 0x10000) { bytes[len++] = 0xe0 | (code >> 12); bytes[len++] = 0x80 | ((code >> 6) & 0x3f); bytes[len++] = 0x80 | (code & 0x3f); }
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else { bytes[len++] = 0xf0 | (code >> 18); bytes[len++] = 0x80 | ((code >> 12) & 0x3f); bytes[len++] = 0x80 | ((code >> 6) & 0x3f); bytes[len++] = 0x80 | (code & 0x3f); i += 1; }
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}
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return bytes.subarray(0, len);
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}
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/** Return the current Unix time in milliseconds for MTP protocol fields. */
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export function unixTimeMillis(): bigint {
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return BigInt(Date.now());
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}
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export function writeU64BE(value: bigint): Uint8Array {
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if (value < 0n || value > 0xffff_ffff_ffff_ffffn) throw new Error("u64 value out of range");
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const out = new Uint8Array(8);
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for (let i = 7; i >= 0; i -= 1) { out[i] = Number(value & 0xffn); value >>= 8n; }
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return out;
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}
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export function concatBytes(parts: Uint8Array[]): Uint8Array {
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const out = new Uint8Array(parts.reduce((sum, part) => sum + part.length, 0));
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let offset = 0;
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for (const part of parts) { out.set(part, offset); offset += part.length; }
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return out;
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}
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