1
0
Fork 0
mirror of https://github.com/denoland/deno.git synced 2024-12-24 08:09:08 -05:00
denoland-deno/std/node/_fs/_fs_readFile.ts
2020-07-14 15:24:17 -04:00

99 lines
2.8 KiB
TypeScript

// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
import {
Encodings,
getEncoding,
FileOptionsArgument,
TextOptionsArgument,
BinaryOptionsArgument,
TextEncodings,
BinaryEncodings,
} from "./_fs_common.ts";
import { Buffer } from "../buffer.ts";
import { fromFileUrl } from "../path.ts";
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 = new Buffer(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,
): void {
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);
}).catch((err) => cb && cb(err));
}
}
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;
}