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Module

std/io/read_long.ts

Deno standard library
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// Copyright 2018-2023 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 (will be removed after 1.0.0) Use Web Streams 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);}