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denoland-deno/ext/node/polyfills/_fs/_fs_readFile.ts

121 lines
3.5 KiB
TypeScript

// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
// TODO(petamoriken): enable prefer-primordials for node polyfills
// deno-lint-ignore-file prefer-primordials
import {
BinaryOptionsArgument,
FileOptionsArgument,
getEncoding,
TextOptionsArgument,
} from "ext:deno_node/_fs/_fs_common.ts";
import { Buffer } from "node:buffer";
import { readAll } from "ext:deno_io/12_io.js";
import { FileHandle } from "ext:deno_node/internal/fs/handle.ts";
import { pathFromURL } from "ext:deno_web/00_infra.js";
import {
BinaryEncodings,
Encodings,
TextEncodings,
} from "ext:deno_node/_utils.ts";
import { promisify } from "ext:deno_node/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;
type Path = string | URL | FileHandle;
export function readFile(
path: Path,
options: TextOptionsArgument,
callback: TextCallback,
): void;
export function readFile(
path: Path,
options: BinaryOptionsArgument,
callback: BinaryCallback,
): void;
export function readFile(
path: Path,
options: null | undefined | FileOptionsArgument,
callback: BinaryCallback,
): void;
export function readFile(path: string | URL, callback: BinaryCallback): void;
export function readFile(
path: Path,
optOrCallback?: FileOptionsArgument | Callback | null | undefined,
callback?: Callback,
) {
path = path instanceof URL ? pathFromURL(path) : path;
let cb: Callback | undefined;
if (typeof optOrCallback === "function") {
cb = optOrCallback;
} else {
cb = callback;
}
const encoding = getEncoding(optOrCallback);
let p: Promise<Uint8Array>;
if (path instanceof FileHandle) {
const fsFile = new Deno.FsFile(path.fd);
p = readAll(fsFile);
} else {
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: Path, opt: TextOptionsArgument) => Promise<string>)
& ((path: Path, opt?: BinaryOptionsArgument) => Promise<Buffer>)
& ((path: Path, 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 ? pathFromURL(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;
}