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Module

std/io/read_long.ts

The Deno Standard Library
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// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
import type { BufReader } from "./buf_reader.ts";import { readInt } from "./read_int.ts";
const MAX_SAFE_INTEGER = BigInt(Number.MAX_SAFE_INTEGER);
/** * Read big endian 64bit long from BufReader * @param buf * * @deprecated This will be removed in 1.0.0. Use the {@link https://developer.mozilla.org/en-US/docs/Web/API/Streams_API | Web Streams API} instead. */export async function readLong(buf: BufReader): Promise<number | null> { const high = await readInt(buf); if (high === null) return null; const low = await readInt(buf); if (low === null) throw new Deno.errors.UnexpectedEof(); const big = (BigInt(high) << 32n) | BigInt(low); // We probably should provide a similar API that returns BigInt values. if (big > MAX_SAFE_INTEGER) { throw new RangeError( "Long value too big to be represented as a JavaScript number.", ); } return Number(big);}