/**
* @license
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
goog.provide('shaka.net.HttpFetchPlugin');
goog.require('goog.asserts');
goog.require('shaka.net.HttpPluginUtils');
goog.require('shaka.net.NetworkingEngine');
goog.require('shaka.util.AbortableOperation');
goog.require('shaka.util.Error');
goog.require('shaka.util.MapUtils');
goog.require('shaka.util.Timer');
/**
* @namespace
* @summary A networking plugin to handle http and https URIs via the Fetch API.
* @param {string} uri
* @param {shaka.extern.Request} request
* @param {shaka.net.NetworkingEngine.RequestType} requestType
* @param {shaka.extern.ProgressUpdated=} progressUpdated Called when a progress
* event happened.
* @return {!shaka.extern.IAbortableOperation.<shaka.extern.Response>}
* @export
*/
shaka.net.HttpFetchPlugin = function(
uri, request, requestType, progressUpdated) {
const headers = new shaka.net.HttpFetchPlugin.Headers_();
shaka.util.MapUtils.asMap(request.headers).forEach((value, key) => {
headers.append(key, value);
});
const controller = new shaka.net.HttpFetchPlugin.AbortController_();
/** @type {!RequestInit} */
const init = {
// Edge does not treat null as undefined for body; https://bit.ly/2luyE6x
body: request.body || undefined,
headers: headers,
method: request.method,
signal: controller.signal,
credentials: request.allowCrossSiteCredentials ? 'include' : undefined,
};
/** @type {shaka.net.HttpFetchPlugin.AbortStatus} */
const abortStatus = {
canceled: false,
timedOut: false,
};
const pendingRequest = shaka.net.HttpFetchPlugin.request_(
uri, requestType, init, abortStatus, progressUpdated);
/** @type {!shaka.util.AbortableOperation} */
const op = new shaka.util.AbortableOperation(pendingRequest, () => {
abortStatus.canceled = true;
controller.abort();
return Promise.resolve();
});
// The fetch API does not timeout natively, so do a timeout manually using the
// AbortController.
const timeoutMs = request.retryParameters.timeout;
if (timeoutMs) {
const timer = new shaka.util.Timer(() => {
abortStatus.timedOut = true;
controller.abort();
});
timer.tickAfter(timeoutMs / 1000);
// To avoid calling |abort| on the network request after it finished, we
// will stop the timer when the requests resolves/rejects.
op.finally(() => {
timer.stop();
});
}
return op;
};
/**
* @param {string} uri
* @param {shaka.net.NetworkingEngine.RequestType} requestType
* @param {!RequestInit} init
* @param {shaka.net.HttpFetchPlugin.AbortStatus} abortStatus
* @param {shaka.extern.ProgressUpdated=} progressUpdated
* @return {!Promise<!shaka.extern.Response>}
* @private
*/
shaka.net.HttpFetchPlugin.request_ = async function(
uri, requestType, init, abortStatus, progressUpdated) {
const fetch = shaka.net.HttpFetchPlugin.fetch_;
const ReadableStream = shaka.net.HttpFetchPlugin.ReadableStream_;
let response;
let arrayBuffer;
let loaded = 0;
let lastLoaded = 0;
// Last time stamp when we got a progress event.
let lastTime = Date.now();
try {
// The promise returned by fetch resolves as soon as the HTTP response
// headers are available. The download itself isn't done until the promise
// for retrieving the data (arrayBuffer, blob, etc) has resolved.
response = await fetch(uri, init);
// Getting the reader in this way allows us to observe the process of
// downloading the body, instead of just waiting for an opaque promise to
// resolve.
// We first clone the response because calling getReader locks the body
// stream; if we didn't clone it here, we would be unable to get the
// response's arrayBuffer later.
const reader = response.clone().body.getReader();
const contentLengthRaw = response.headers.get('Content-Length');
const contentLength = contentLengthRaw ? parseInt(contentLengthRaw, 10) : 0;
let start = (controller) => {
let push = async () => {
let readObj;
try {
readObj = await reader.read();
} catch (e) {
// If we abort the request, we'll get an error here. Just ignore it
// since real errors will be reported when we read the buffer below.
shaka.log.v1('error reading from stream', e.message);
return;
}
if (!readObj.done) {
loaded += readObj.value.byteLength;
}
let currentTime = Date.now();
// If the time between last time and this time we got progress event
// is long enough, or if a whole segment is downloaded, call
// progressUpdated().
if (currentTime - lastTime > 100 || readObj.done) {
progressUpdated(currentTime - lastTime, loaded - lastLoaded,
contentLength - loaded);
lastLoaded = loaded;
lastTime = currentTime;
}
if (readObj.done) {
goog.asserts.assert(!readObj.value,
'readObj should be unset when "done" is true.');
controller.close();
} else {
controller.enqueue(readObj.value);
push();
}
};
push();
};
// Create a ReadableStream to use the reader. We don't need to use the
// actual stream for anything, though, as we are using the response's
// arrayBuffer method to get the body, so we don't store the ReadableStream.
new ReadableStream({start}); // eslint-disable-line no-new
arrayBuffer = await response.arrayBuffer();
} catch (error) {
if (abortStatus.canceled) {
throw new shaka.util.Error(
shaka.util.Error.Severity.RECOVERABLE,
shaka.util.Error.Category.NETWORK,
shaka.util.Error.Code.OPERATION_ABORTED,
uri, requestType);
} else if (abortStatus.timedOut) {
throw new shaka.util.Error(
shaka.util.Error.Severity.RECOVERABLE,
shaka.util.Error.Category.NETWORK,
shaka.util.Error.Code.TIMEOUT,
uri, requestType);
} else {
throw new shaka.util.Error(
shaka.util.Error.Severity.RECOVERABLE,
shaka.util.Error.Category.NETWORK,
shaka.util.Error.Code.HTTP_ERROR,
uri, error, requestType);
}
}
const headers = {};
/** @type {Headers} */
const responseHeaders = response.headers;
responseHeaders.forEach(function(value, key) {
// Since IE/Edge incorrectly return the header with a leading new line
// character ('\n'), we trim the header here.
headers[key.trim()] = value;
});
return shaka.net.HttpPluginUtils.makeResponse(headers,
arrayBuffer, response.status, uri, response.url, requestType);
};
/**
* @typedef {{
* canceled: boolean,
* timedOut: boolean
* }}
* @property {boolean} canceled
* Indicates if the request was canceled.
* @property {boolean} timedOut
* Indicates if the request timed out.
*/
shaka.net.HttpFetchPlugin.AbortStatus;
/**
* Determine if the Fetch API is supported in the browser. Note: this is
* deliberately exposed as a method to allow the client app to use the same
* logic as Shaka when determining support.
* @return {boolean}
* @export
*/
shaka.net.HttpFetchPlugin.isSupported = function() {
// On Edge, ReadableStream exists, but attempting to construct it results in
// an error. See https://bit.ly/2zwaFLL
// So this has to check that ReadableStream is present AND usable.
if (window.ReadableStream) {
try {
new ReadableStream({}); // eslint-disable-line no-new
} catch (e) {
return false;
}
} else {
return false;
}
return !!(window.fetch && window.AbortController);
};
/**
* Overridden in unit tests, but compiled out in production.
*
* @const {function(string, !RequestInit)}
* @private
*/
shaka.net.HttpFetchPlugin.fetch_ = window.fetch;
/**
* Overridden in unit tests, but compiled out in production.
*
* @const {function(new: AbortController)}
* @private
*/
shaka.net.HttpFetchPlugin.AbortController_ = window.AbortController;
/**
* Overridden in unit tests, but compiled out in production.
*
* @const {function(new: ReadableStream, !Object)}
* @private
*/
shaka.net.HttpFetchPlugin.ReadableStream_ = window.ReadableStream;
/**
* Overridden in unit tests, but compiled out in production.
*
* @const {function(new: Headers)}
* @private
*/
shaka.net.HttpFetchPlugin.Headers_ = window.Headers;
if (shaka.net.HttpFetchPlugin.isSupported()) {
shaka.net.NetworkingEngine.registerScheme('http', shaka.net.HttpFetchPlugin,
shaka.net.NetworkingEngine.PluginPriority.PREFERRED);
shaka.net.NetworkingEngine.registerScheme('https', shaka.net.HttpFetchPlugin,
shaka.net.NetworkingEngine.PluginPriority.PREFERRED);
}