/
fake_segment_prefetch.js
128 lines (113 loc) · 3.29 KB
/
fake_segment_prefetch.js
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/*! @license
* Shaka Player
* Copyright 2016 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
/**
* A fake SegmentPrefetch class that is used for testing
* segment prefetching functionality.
*
* @final
* @struct
* @extends {shaka.media.SegmentPrefetch}
*/
shaka.test.FakeSegmentPrefetch = class {
/**
* Suppress the JSC_PRIVATE_OVERRIDE error for overriding prefetchPosTime_
* @suppress {visibility}
*/
constructor(prefetchLimit, stream, segmentData) {
/** @private {number} */
this.prefetchLimit_ = prefetchLimit;
/** @private {(Set.<!shaka.media.SegmentReference|
* !shaka.media.InitSegmentReference>)} */
this.requestedReferences_ = new Set();
/** @private {shaka.extern.Stream} */
this.streamObj_ = stream;
/**
* @private {!Object.<string, shaka.test.FakeMediaSourceEngine.SegmentData>}
*/
this.segmentData_ = segmentData;
/** @private {Array<number>} */
this.evictions_ = [];
/** @private {number} */
this.prefetchPosTime_ = 0;
/** @private {number} */
this.segmentNum_ = 0;
}
/** @override */
replaceFetchDispatcher(fetchDispatcher) {
// empty fake for now
}
/** @override */
getLastKnownPosition() {
return this.prefetchPosTime_;
}
/** @override */
prefetchSegmentsByTime(currTime) {
const maxTime = Math.max(currTime, this.prefetchPosTime_);
const iterator = this.streamObj_.segmentIndex.getIteratorForTime(maxTime);
let reference = iterator.next().value;
while (this.segmentNum_ < this.prefetchLimit_ && reference != null) {
if (!this.requestedReferences_.has(reference)) {
if (reference instanceof shaka.media.SegmentReference) {
this.segmentNum_++;
}
this.requestedReferences_.add(reference);
}
this.prefetchPosTime_ = reference.startTime;
reference = iterator.next().value;
}
}
/** @override */
switchStream(stream) {
if (stream !== this.streamObj_) {
this.requestedReferences_.clear();
}
}
/** @override */
resetLimit(limit) {
this.clearAll();
}
/** @override */
clearAll() {
this.requestedReferences_.clear();
this.segmentNum_ = 0;
this.prefetchPosTime_ = 0;
}
/** @override */
evict(time) {
this.evictions_.push(time);
}
/**
* @override
* @param {shaka.media.InitSegmentReference|
* shaka.media.SegmentReference} reference
*/
getPrefetchedSegment(reference) {
if (!(reference instanceof shaka.media.SegmentReference)) {
return null;
}
/**
* The unit tests assume a segment is already prefetched
* if it was ever passed to prefetchSegmentsByTime() as param.
* Otherwise return null so the streaming engine being tested
* will do actual fetch.
*/
if (this.requestedReferences_.has(reference)) {
const segmentData = this.segmentData_[this.streamObj_.type];
return new shaka.net.NetworkingEngine.PendingRequest(
Promise.resolve({
uri: reference.getUris()[0],
data: segmentData.segments[
segmentData.segmentStartTimes.indexOf(reference.startTime)
],
headers: {},
}),
() => Promise.resolve(null),
new shaka.net.NetworkingEngine.NumBytesRemainingClass(),
);
}
return null;
}
};