shaka-player
Version:
DASH/EME video player library
288 lines (253 loc) • 8.99 kB
JavaScript
/*! @license
* Shaka Player
* Copyright 2016 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
goog.provide('shaka.offline.DownloadManager');
goog.require('shaka.net.NetworkingEngine');
goog.require('shaka.offline.DownloadProgressEstimator');
goog.require('shaka.util.ArrayUtils');
goog.require('shaka.util.BufferUtils');
goog.require('shaka.util.Destroyer');
goog.require('shaka.util.Error');
goog.require('shaka.util.IDestroyable');
goog.require('shaka.util.Pssh');
/**
* This manages downloading segments.
*
* @implements {shaka.util.IDestroyable}
* @final
*/
shaka.offline.DownloadManager = class {
/**
* Create a new download manager. It will use (but not own) |networkingEngine|
* and call |onProgress| after each download.
*
* @param {!shaka.net.NetworkingEngine} networkingEngine
*/
constructor(networkingEngine) {
/** @private {shaka.net.NetworkingEngine} */
this.networkingEngine_ = networkingEngine;
/**
* We group downloads. Within each group, the requests are executed in
* series. Between groups, the requests are executed in parallel. We store
* the promise chain that is doing the work.
*
* @private {!Map<number, !Promise>}
*/
this.groups_ = new Map();
/** @private {!shaka.util.Destroyer} */
this.destroyer_ = new shaka.util.Destroyer(() => {
// Add a "catch" block to stop errors from being returned.
return this.abortAll().catch(() => {});
});
/**
* A list of callback functions to cancel any in-progress downloads.
*
* @private {!Array<function(): !Promise>}
*/
this.abortCallbacks_ = [];
/**
* A callback for when a segment has been downloaded. The first parameter
* is the progress of all segments, a number between 0.0 (0% complete) and
* 1.0 (100% complete). The second parameter is the total number of bytes
* that have been downloaded.
*
* @private {function(number, number)}
*/
this.onProgress_ = (progress, size) => {};
/**
* A callback for when a segment has new PSSH data and we pass
* on the initData to storage
*
* @private {function(!Uint8Array, string)}
*/
this.onInitData_ = (initData, systemId) => {};
/** @private {shaka.offline.DownloadProgressEstimator} */
this.estimator_ = new shaka.offline.DownloadProgressEstimator();
/** @private {boolean} */
this.aborted_ = false;
}
/** @override */
destroy() {
return this.destroyer_.destroy();
}
/**
* @param {function(number, number)} onProgress
* @param {function(!Uint8Array, string)} onInitData
*/
setCallbacks(onProgress, onInitData) {
this.onProgress_ = onProgress;
this.onInitData_ = onInitData;
}
/**
* Aborts all in-progress downloads.
* @return {!Promise} A promise that will resolve once the downloads are fully
* aborted.
*/
abortAll() {
this.aborted_ = true;
const promises = this.abortCallbacks_.map((callback) => callback());
this.abortCallbacks_ = [];
return Promise.all(promises);
}
/**
* @return {boolean}
*/
isAborted() {
return this.aborted_;
}
/**
* Adds a byte length to the download estimate.
*
* @param {number} estimatedByteLength
* @return {number} estimateId
*/
addDownloadEstimate(estimatedByteLength) {
return this.estimator_.open(estimatedByteLength);
}
/**
* Add a request to be downloaded as part of a group.
*
* @param {number} groupId
* The group to add this segment to. If the group does not exist, a new
* group will be created.
* @param {shaka.extern.Request} request
* @param {number} estimateId
* @param {boolean} isInitSegment
* @param {function(BufferSource):!Promise} onDownloaded
* The callback for when this request has been downloaded. Downloading for
* |group| will pause until the promise returned by |onDownloaded| resolves.
* @return {!Promise} Resolved when this request is complete.
*/
queue(groupId, request, estimateId, isInitSegment, onDownloaded) {
this.destroyer_.ensureNotDestroyed();
const group = this.groups_.get(groupId) || Promise.resolve();
// Add another download to the group.
const newPromise = group.then(async () => {
const response = await this.fetchSegment_(request);
// Make sure we stop downloading if we have been destroyed.
if (this.destroyer_.destroyed()) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.STORAGE,
shaka.util.Error.Code.OPERATION_ABORTED);
}
// Update initData
if (isInitSegment) {
const segmentBytes = shaka.util.BufferUtils.toUint8(response);
const pssh = new shaka.util.Pssh(segmentBytes);
for (const key in pssh.data) {
const index = Number(key);
const data = pssh.data[index];
const systemId = pssh.systemIds[index];
this.onInitData_(data, systemId);
}
}
// Update all our internal stats.
this.estimator_.close(estimateId, response.byteLength);
this.onProgress_(
this.estimator_.getEstimatedProgress(),
this.estimator_.getTotalDownloaded());
return onDownloaded(response);
});
this.groups_.set(groupId, newPromise);
return newPromise;
}
/**
* Add already-downloaded data to a group.
*
* @param {number} groupId
* The group to add this segment to. If the group does not exist, a new
* group will be created.
* @param {!BufferSource} queueData
* @param {number} estimateId
* @param {boolean} isInitSegment
* @param {function(BufferSource):!Promise} onDownloaded
* The callback for when this request has been downloaded. Downloading for
* |group| will pause until the promise returned by |onDownloaded| resolves.
* @return {!Promise} Resolved when this request is complete.
*/
queueData(groupId, queueData, estimateId, isInitSegment, onDownloaded) {
this.destroyer_.ensureNotDestroyed();
const group = this.groups_.get(groupId) || Promise.resolve();
// Add another download to the group.
const newPromise = group.then(() => {
// Make sure we stop downloading if we have been destroyed.
if (this.destroyer_.destroyed()) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.STORAGE,
shaka.util.Error.Code.OPERATION_ABORTED);
}
// Update initData
if (isInitSegment) {
const segmentBytes = shaka.util.BufferUtils.toUint8(queueData);
const pssh = new shaka.util.Pssh(segmentBytes);
for (const key in pssh.data) {
const index = Number(key);
const data = pssh.data[index];
const systemId = pssh.systemIds[index];
this.onInitData_(data, systemId);
}
}
// Update all our internal stats.
this.estimator_.close(estimateId, queueData.byteLength);
this.onProgress_(
this.estimator_.getEstimatedProgress(),
this.estimator_.getTotalDownloaded());
return onDownloaded(queueData);
});
this.groups_.set(groupId, newPromise);
return newPromise;
}
/**
* Add additional async work to the group work queue.
*
* @param {number} groupId
* The group to add this group to. If the group does not exist, a new
* group will be created.
* @param {function():!Promise} callback
* The callback for the async work. Downloading for this group will be
* blocked until the Promise returned by |callback| resolves.
* @return {!Promise} Resolved when this work is complete.
*/
queueWork(groupId, callback) {
this.destroyer_.ensureNotDestroyed();
const group = this.groups_.get(groupId) || Promise.resolve();
const newPromise = group.then(async () => {
await callback();
});
this.groups_.set(groupId, newPromise);
return newPromise;
}
/**
* Get a promise that will resolve when all currently queued downloads have
* finished.
*
* @return {!Promise<number>}
*/
async waitToFinish() {
await Promise.all(this.groups_.values());
return this.estimator_.getTotalDownloaded();
}
/**
* Download a segment and return the data in the response.
*
* @param {shaka.extern.Request} request
* @return {!Promise<BufferSource>}
* @private
*/
async fetchSegment_(request) {
const type = shaka.net.NetworkingEngine.RequestType.SEGMENT;
/** @type {!shaka.net.NetworkingEngine.PendingRequest} */
const action = this.networkingEngine_.request(type, request);
const abortCallback = () => {
return action.abort();
};
this.abortCallbacks_.push(abortCallback);
const response = await action.promise;
shaka.util.ArrayUtils.remove(this.abortCallbacks_, abortCallback);
return response.data;
}
};