四好公路
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 

180 lines
5.1 KiB

"use strict";
const http = require("http");
const https = require("https");
const { ono } = require("@jsdevtools/ono");
const url = require("../util/url");
const { ResolverError } = require("../util/errors");
module.exports = {
/**
* The order that this resolver will run, in relation to other resolvers.
*
* @type {number}
*/
order: 200,
/**
* HTTP headers to send when downloading files.
*
* @example:
* {
* "User-Agent": "JSON Schema $Ref Parser",
* Accept: "application/json"
* }
*
* @type {object}
*/
headers: null,
/**
* HTTP request timeout (in milliseconds).
*
* @type {number}
*/
timeout: 5000, // 5 seconds
/**
* The maximum number of HTTP redirects to follow.
* To disable automatic following of redirects, set this to zero.
*
* @type {number}
*/
redirects: 5,
/**
* The `withCredentials` option of XMLHttpRequest.
* Set this to `true` if you're downloading files from a CORS-enabled server that requires authentication
*
* @type {boolean}
*/
withCredentials: false,
/**
* Determines whether this resolver can read a given file reference.
* Resolvers that return true will be tried in order, until one successfully resolves the file.
* Resolvers that return false will not be given a chance to resolve the file.
*
* @param {object} file - An object containing information about the referenced file
* @param {string} file.url - The full URL of the referenced file
* @param {string} file.extension - The lowercased file extension (e.g. ".txt", ".html", etc.)
* @returns {boolean}
*/
canRead (file) {
return url.isHttp(file.url);
},
/**
* Reads the given URL and returns its raw contents as a Buffer.
*
* @param {object} file - An object containing information about the referenced file
* @param {string} file.url - The full URL of the referenced file
* @param {string} file.extension - The lowercased file extension (e.g. ".txt", ".html", etc.)
* @returns {Promise<Buffer>}
*/
read (file) {
let u = url.parse(file.url);
if (process.browser && !u.protocol) {
// Use the protocol of the current page
u.protocol = url.parse(location.href).protocol;
}
return download(u, this);
}
};
/**
* Downloads the given file.
*
* @param {Url|string} u - The url to download (can be a parsed {@link Url} object)
* @param {object} httpOptions - The `options.resolve.http` object
* @param {number} [redirects] - The redirect URLs that have already been followed
*
* @returns {Promise<Buffer>}
* The promise resolves with the raw downloaded data, or rejects if there is an HTTP error.
*/
function download (u, httpOptions, redirects) {
return new Promise(((resolve, reject) => {
u = url.parse(u);
redirects = redirects || [];
redirects.push(u.href);
get(u, httpOptions)
.then((res) => {
if (res.statusCode >= 400) {
throw ono({ status: res.statusCode }, `HTTP ERROR ${res.statusCode}`);
}
else if (res.statusCode >= 300) {
if (redirects.length > httpOptions.redirects) {
reject(new ResolverError(ono({ status: res.statusCode },
`Error downloading ${redirects[0]}. \nToo many redirects: \n ${redirects.join(" \n ")}`)));
}
else if (!res.headers.location) {
throw ono({ status: res.statusCode }, `HTTP ${res.statusCode} redirect with no location header`);
}
else {
// console.log('HTTP %d redirect %s -> %s', res.statusCode, u.href, res.headers.location);
let redirectTo = url.resolve(u, res.headers.location);
download(redirectTo, httpOptions, redirects).then(resolve, reject);
}
}
else {
resolve(res.body || Buffer.alloc(0));
}
})
.catch((err) => {
reject(new ResolverError(ono(err, `Error downloading ${u.href}`), u.href));
});
}));
}
/**
* Sends an HTTP GET request.
*
* @param {Url} u - A parsed {@link Url} object
* @param {object} httpOptions - The `options.resolve.http` object
*
* @returns {Promise<Response>}
* The promise resolves with the HTTP Response object.
*/
function get (u, httpOptions) {
return new Promise(((resolve, reject) => {
// console.log('GET', u.href);
let protocol = u.protocol === "https:" ? https : http;
let req = protocol.get({
hostname: u.hostname,
port: u.port,
path: u.path,
auth: u.auth,
protocol: u.protocol,
headers: httpOptions.headers || {},
withCredentials: httpOptions.withCredentials
});
if (typeof req.setTimeout === "function") {
req.setTimeout(httpOptions.timeout);
}
req.on("timeout", () => {
req.abort();
});
req.on("error", reject);
req.once("response", (res) => {
res.body = Buffer.alloc(0);
res.on("data", (data) => {
res.body = Buffer.concat([res.body, Buffer.from(data)]);
});
res.on("error", reject);
res.on("end", () => {
resolve(res);
});
});
}));
}