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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.import {  BinaryOptionsArgument,  FileOptionsArgument,  getEncoding,  TextOptionsArgument,} from "./_fs_common.ts";import { Buffer } from "../buffer.ts";import { fromFileUrl } from "../path.ts";import { BinaryEncodings, Encodings, TextEncodings } from "../_utils.ts";import { promisify } from "../internal/util.mjs";
function maybeDecode(data: Uint8Array, encoding: TextEncodings): string;function maybeDecode(  data: Uint8Array,  encoding: BinaryEncodings | null,): Buffer;function maybeDecode(  data: Uint8Array,  encoding: Encodings | null,): string | Buffer {  const buffer = Buffer.from(data.buffer, data.byteOffset, data.byteLength);  if (encoding && encoding !== "binary") return buffer.toString(encoding);  return buffer;}
type TextCallback = (err: Error | null, data?: string) => void;type BinaryCallback = (err: Error | null, data?: Buffer) => void;type GenericCallback = (err: Error | null, data?: string | Buffer) => void;type Callback = TextCallback | BinaryCallback | GenericCallback;
export function readFile(  path: string | URL,  options: TextOptionsArgument,  callback: TextCallback,): void;export function readFile(  path: string | URL,  options: BinaryOptionsArgument,  callback: BinaryCallback,): void;export function readFile(  path: string | URL,  options: null | undefined | FileOptionsArgument,  callback: BinaryCallback,): void;export function readFile(path: string | URL, callback: BinaryCallback): void;export function readFile(  path: string | URL,  optOrCallback?: FileOptionsArgument | Callback | null | undefined,  callback?: Callback,) {  path = path instanceof URL ? fromFileUrl(path) : path;  let cb: Callback | undefined;  if (typeof optOrCallback === "function") {    cb = optOrCallback;  } else {    cb = callback;  }
  const encoding = getEncoding(optOrCallback);
  const p = Deno.readFile(path);
  if (cb) {    p.then((data: Uint8Array) => {      if (encoding && encoding !== "binary") {        const text = maybeDecode(data, encoding);        return (cb as TextCallback)(null, text);      }      const buffer = maybeDecode(data, encoding);      (cb as BinaryCallback)(null, buffer);    }, (err) => cb && cb(err));  }}
export const readFilePromise = promisify(readFile) as (  & ((path: string | URL, opt: TextOptionsArgument) => Promise<string>)  & ((path: string | URL, opt?: BinaryOptionsArgument) => Promise<Buffer>)  & ((path: string | URL, opt?: FileOptionsArgument) => Promise<Buffer>));
export function readFileSync(  path: string | URL,  opt: TextOptionsArgument,): string;export function readFileSync(  path: string | URL,  opt?: BinaryOptionsArgument,): Buffer;export function readFileSync(  path: string | URL,  opt?: FileOptionsArgument,): string | Buffer {  path = path instanceof URL ? fromFileUrl(path) : path;  const data = Deno.readFileSync(path);  const encoding = getEncoding(opt);  if (encoding && encoding !== "binary") {    const text = maybeDecode(data, encoding);    return text;  }  const buffer = maybeDecode(data, encoding);  return buffer;}