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denoland-deno/extensions/fetch/26_fetch.js
2021-04-30 15:51:48 -04:00

307 lines
8.7 KiB
JavaScript

// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
// @ts-check
/// <reference path="../../core/lib.deno_core.d.ts" />
/// <reference path="../web/internal.d.ts" />
/// <reference path="../url/internal.d.ts" />
/// <reference path="../web/lib.deno_web.d.ts" />
/// <reference path="./11_streams_types.d.ts" />
/// <reference path="./internal.d.ts" />
/// <reference path="./lib.deno_fetch.d.ts" />
/// <reference lib="esnext" />
"use strict";
((window) => {
const core = window.Deno.core;
const webidl = window.__bootstrap.webidl;
const { byteLowerCase } = window.__bootstrap.infra;
const { InnerBody, extractBody } = window.__bootstrap.fetchBody;
const {
toInnerRequest,
fromInnerResponse,
redirectStatus,
nullBodyStatus,
networkError,
} = window.__bootstrap.fetch;
const REQUEST_BODY_HEADER_NAMES = [
"content-encoding",
"content-language",
"content-location",
"content-type",
];
/**
* @param {{ method: string, url: string, headers: [string, string][], clientRid: number | null, hasBody: boolean }} args
* @param {Uint8Array | null} body
* @returns {{ requestRid: number, requestBodyRid: number | null }}
*/
function opFetch(args, body) {
return core.opSync("op_fetch", args, body);
}
/**
* @param {number} rid
* @returns {Promise<{ status: number, statusText: string, headers: [string, string][], url: string, responseRid: number }>}
*/
function opFetchSend(rid) {
return core.opAsync("op_fetch_send", rid);
}
/**
* @param {number} rid
* @param {Uint8Array} body
* @returns {Promise<void>}
*/
function opFetchRequestWrite(rid, body) {
return core.opAsync("op_fetch_request_write", rid, body);
}
/**
* @param {number} rid
* @param {Uint8Array} body
* @returns {Promise<number>}
*/
function opFetchResponseRead(rid, body) {
return core.opAsync("op_fetch_response_read", rid, body);
}
/**
* @param {number} responseBodyRid
* @returns {ReadableStream<Uint8Array>}
*/
function createResponseBodyStream(responseBodyRid) {
return new ReadableStream({
type: "bytes",
async pull(controller) {
try {
// This is the largest possible size for a single packet on a TLS
// stream.
const chunk = new Uint8Array(16 * 1024 + 256);
const read = await opFetchResponseRead(
responseBodyRid,
chunk,
);
if (read > 0) {
// We read some data. Enqueue it onto the stream.
controller.enqueue(chunk.subarray(0, read));
} else {
// We have reached the end of the body, so we close the stream.
controller.close();
core.close(responseBodyRid);
}
} catch (err) {
// There was an error while reading a chunk of the body, so we
// error.
controller.error(err);
controller.close();
core.close(responseBodyRid);
}
},
cancel() {
core.close(responseBodyRid);
},
});
}
/**
* @param {InnerRequest} req
* @param {boolean} recursive
* @returns {Promise<InnerResponse>}
*/
async function mainFetch(req, recursive) {
/** @type {ReadableStream<Uint8Array> | Uint8Array | null} */
let reqBody = null;
if (req.body !== null) {
if (req.body.streamOrStatic instanceof ReadableStream) {
if (req.body.length === null) {
reqBody = req.body.stream;
} else {
const reader = req.body.stream.getReader();
const r1 = await reader.read();
if (r1.done) throw new TypeError("Unreachable");
reqBody = r1.value;
const r2 = await reader.read();
if (!r2.done) throw new TypeError("Unreachable");
}
} else {
req.body.streamOrStatic.consumed = true;
reqBody = req.body.streamOrStatic.body;
}
}
const { requestRid, requestBodyRid } = opFetch({
method: req.method,
url: req.currentUrl(),
headers: req.headerList,
clientRid: req.clientRid,
hasBody: reqBody !== null,
}, reqBody instanceof Uint8Array ? reqBody : null);
if (requestBodyRid !== null) {
if (reqBody === null || !(reqBody instanceof ReadableStream)) {
throw new TypeError("Unreachable");
}
const reader = reqBody.getReader();
(async () => {
while (true) {
const { value, done } = await reader.read();
if (done) break;
if (!(value instanceof Uint8Array)) {
await reader.cancel("value not a Uint8Array");
break;
}
try {
await opFetchRequestWrite(requestBodyRid, value);
} catch (err) {
await reader.cancel(err);
break;
}
}
core.close(requestBodyRid);
})();
}
const resp = await opFetchSend(requestRid);
/** @type {InnerResponse} */
const response = {
headerList: resp.headers,
status: resp.status,
body: null,
statusMessage: resp.statusText,
type: "basic",
url() {
if (this.urlList.length == 0) return null;
return this.urlList[this.urlList.length - 1];
},
urlList: req.urlList,
};
if (redirectStatus(resp.status)) {
switch (req.redirectMode) {
case "error":
core.close(resp.responseRid);
return networkError(
"Encountered redirect while redirect mode is set to 'error'",
);
case "follow":
core.close(resp.responseRid);
return httpRedirectFetch(req, response);
case "manual":
break;
}
}
if (nullBodyStatus(response.status)) {
core.close(resp.responseRid);
} else {
response.body = new InnerBody(createResponseBodyStream(resp.responseRid));
}
if (recursive) return response;
if (response.urlList.length === 0) {
response.urlList = [...req.urlList];
}
return response;
}
/**
* @param {InnerRequest} request
* @param {InnerResponse} response
* @returns {Promise<InnerResponse>}
*/
function httpRedirectFetch(request, response) {
const locationHeaders = response.headerList.filter((entry) =>
byteLowerCase(entry[0]) === "location"
);
if (locationHeaders.length === 0) {
return response;
}
const locationURL = new URL(
locationHeaders[0][1],
response.url() ?? undefined,
);
if (locationURL.hash === "") {
locationURL.hash = request.currentUrl().hash;
}
if (locationURL.protocol !== "https:" && locationURL.protocol !== "http:") {
return networkError("Can not redirect to a non HTTP(s) url");
}
if (request.redirectCount === 20) {
return networkError("Maximum number of redirects (20) reached");
}
request.redirectCount++;
if (
response.status !== 303 && request.body !== null &&
request.body.source === null
) {
return networkError(
"Can not redeliver a streaming request body after a redirect",
);
}
if (
((response.status === 301 || response.status === 302) &&
request.method === "POST") ||
(response.status === 303 &&
(request.method !== "GET" && request.method !== "HEAD"))
) {
request.method = "GET";
request.body = null;
for (let i = 0; i < request.headerList.length; i++) {
if (
REQUEST_BODY_HEADER_NAMES.includes(
byteLowerCase(request.headerList[i][0]),
)
) {
request.headerList.splice(i, 1);
i--;
}
}
}
if (request.body !== null) {
const res = extractBody(request.body.source);
request.body = res.body;
}
request.urlList.push(locationURL.href);
return mainFetch(request, true);
}
/**
* @param {RequestInfo} input
* @param {RequestInit} init
*/
async function fetch(input, init = {}) {
const prefix = "Failed to call 'fetch'";
input = webidl.converters["RequestInfo"](input, {
prefix,
context: "Argument 1",
});
init = webidl.converters["RequestInit"](init, {
prefix,
context: "Argument 2",
});
// 1.
const requestObject = new Request(input, init);
// 2.
const request = toInnerRequest(requestObject);
// 10.
if (!requestObject.headers.has("Accept")) {
request.headerList.push(["Accept", "*/*"]);
}
// 12.
const response = await mainFetch(request, false);
if (response.type === "error") {
throw new TypeError(
"Fetch failed: " + (response.error ?? "unknown error"),
);
}
return fromInnerResponse(response, "immutable");
}
window.__bootstrap.fetch ??= {};
window.__bootstrap.fetch.fetch = fetch;
})(this);