/*! @license
* Shaka Player
* Copyright 2016 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
goog.provide('shaka.media.TimeRangesUtils');
/**
* @summary A set of utility functions for dealing with TimeRanges objects.
*/
shaka.media.TimeRangesUtils = class {
/**
* Gets the first timestamp in the buffer.
*
* @param {TimeRanges} b
* @return {?number} The first buffered timestamp, in seconds, if |buffered|
* is non-empty; otherwise, return null.
*/
static bufferStart(b) {
if (!b) {
return null;
}
// Workaround Safari bug: https://bit.ly/2trx6O8
if (b.length == 1 && b.end(0) - b.start(0) < 1e-6) {
return null;
}
// Workaround Edge bug: https://bit.ly/2JYLPeB
if (b.length == 1 && b.start(0) < 0) {
return 0;
}
return b.length ? b.start(0) : null;
}
/**
* Gets the last timestamp in the buffer.
*
* @param {TimeRanges} b
* @return {?number} The last buffered timestamp, in seconds, if |buffered|
* is non-empty; otherwise, return null.
*/
static bufferEnd(b) {
if (!b) {
return null;
}
// Workaround Safari bug: https://bit.ly/2trx6O8
if (b.length == 1 && b.end(0) - b.start(0) < 1e-6) {
return null;
}
return b.length ? b.end(b.length - 1) : null;
}
/**
* Determines if the given time is inside a buffered range. This includes
* gaps, meaning that if the playhead is in a gap, it is considered buffered.
* If there is a small gap between the playhead and buffer start, consider it
* as buffered.
*
* @param {TimeRanges} b
* @param {number} time Playhead time
* @param {number=} smallGapLimit Set in configuration
* @return {boolean}
*/
static isBuffered(b, time, smallGapLimit = 0) {
if (!b || !b.length) {
return false;
}
// Workaround Safari bug: https://bit.ly/2trx6O8
if (b.length == 1 && b.end(0) - b.start(0) < 1e-6) {
return false;
}
if (time > b.end(b.length - 1)) {
return false;
}
// Push the time forward by the gap limit so that it is more likely to be in
// the range.
return (time + smallGapLimit >= b.start(0));
}
/**
* Computes how far ahead of the given timestamp is buffered. To provide
* smooth playback while jumping gaps, we don't include the gaps when
* calculating this.
* This only includes the amount of content that is buffered.
*
* @param {TimeRanges} b
* @param {number} time
* @return {number} The number of seconds buffered, in seconds, ahead of the
* given time.
*/
static bufferedAheadOf(b, time) {
if (!b || !b.length) {
return 0;
}
// Workaround Safari bug: https://bit.ly/2trx6O8
if (b.length == 1 && b.end(0) - b.start(0) < 1e-6) {
return 0;
}
// We calculate the buffered amount by ONLY accounting for the content
// buffered (i.e. we ignore the times of the gaps). We also buffer through
// all gaps.
// Therefore, we start at the end and add up all buffers until |time|.
let result = 0;
for (const {start, end} of shaka.media.TimeRangesUtils.getBufferedInfo(b)) {
if (end > time) {
result += end - Math.max(start, time);
}
}
return result;
}
/**
* Determines if the given time is inside a gap between buffered ranges. If
* it is, this returns the index of the buffer that is *ahead* of the gap.
*
* @param {TimeRanges} b
* @param {number} time
* @param {number} threshold
* @return {?number} The index of the buffer after the gap, or null if not in
* a gap.
*/
static getGapIndex(b, time, threshold) {
const TimeRangesUtils = shaka.media.TimeRangesUtils;
if (!b || !b.length) {
return null;
}
// Workaround Safari bug: https://bit.ly/2trx6O8
if (b.length == 1 && b.end(0) - b.start(0) < 1e-6) {
return null;
}
const idx = TimeRangesUtils.getBufferedInfo(b).findIndex((item, i, arr) => {
return item.start > time &&
(i == 0 || arr[i - 1].end - time <= threshold);
});
return idx >= 0 ? idx : null;
}
/**
* @param {TimeRanges} b
* @return {!Array.<shaka.extern.BufferedRange>}
*/
static getBufferedInfo(b) {
if (!b) {
return [];
}
const ret = [];
for (let i = 0; i < b.length; i++) {
ret.push({start: b.start(i), end: b.end(i)});
}
return ret;
}
};