@l5i/dashjs/src/streaming/utils/CustomTimeRanges.js

A reference client implementation for the playback of MPEG DASH via Javascript and compliant browsers.

/**
* The copyright in this software is being made available under the BSD License,
* included below. This software may be subject to other third party and contributor
* rights, including patent rights, and no such rights are granted under this license.
*
* Copyright (c) 2013, Dash Industry Forum.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*  * Redistributions of source code must retain the above copyright notice, this
*  list of conditions and the following disclaimer.
*  * Redistributions in binary form must reproduce the above copyright notice,
*  this list of conditions and the following disclaimer in the documentation and/or
*  other materials provided with the distribution.
*  * Neither the name of Dash Industry Forum nor the names of its
*  contributors may be used to endorse or promote products derived from this software
*  without specific prior written permission.
*
*  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS IS AND ANY
*  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
*  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
*  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
*  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
*  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
*  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
*  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
*  POSSIBILITY OF SUCH DAMAGE.
*/
import FactoryMaker from '../../core/FactoryMaker';

function CustomTimeRanges(/*config*/) {
    let customTimeRangeArray = [];
    let length = 0;

    function add(start, end) {
        let i = 0;

        for (i = 0; (i < this.customTimeRangeArray.length) && (start > this.customTimeRangeArray[i].start); i++);

        this.customTimeRangeArray.splice(i, 0, {start: start,end: end});

        for (i = 0; i < this.customTimeRangeArray.length - 1; i++) {
            if (this.mergeRanges(i,i + 1)) {
                i--;
            }
        }
        this.length = this.customTimeRangeArray.length;
    }

    function clear() {
        this.customTimeRangeArray = [];
        this.length = 0;
    }

    function remove(start, end) {
        for (let i = 0; i < this.customTimeRangeArray.length; i++) {
            if (start <= this.customTimeRangeArray[i].start && end >= this.customTimeRangeArray[i].end) {
                //      |--------------Range i-------|
                //|---------------Range to remove ---------------|
                //    or
                //|--------------Range i-------|
                //|--------------Range to remove ---------------|
                //    or
                //                 |--------------Range i-------|
                //|--------------Range to remove ---------------|
                this.customTimeRangeArray.splice(i,1);
                i--;

            } else if (start > this.customTimeRangeArray[i].start && end < this.customTimeRangeArray[i].end) {
                //|-----------------Range i----------------|
                //        |-------Range to remove -----|
                this.customTimeRangeArray.splice(i + 1, 0, {start: end,end: this.customTimeRangeArray[i].end});
                this.customTimeRangeArray[i].end = start;
                break;
            } else if ( start > this.customTimeRangeArray[i].start && start < this.customTimeRangeArray[i].end) {
                //|-----------Range i----------|
                //                    |---------Range to remove --------|
                //    or
                //|-----------------Range i----------------|
                //            |-------Range to remove -----|
                this.customTimeRangeArray[i].end = start;
            } else if ( end > this.customTimeRangeArray[i].start && end < this.customTimeRangeArray[i].end) {
                //                     |-----------Range i----------|
                //|---------Range to remove --------|
                //            or
                //|-----------------Range i----------------|
                //|-------Range to remove -----|
                this.customTimeRangeArray[i].start = end;
            }
        }

        this.length = this.customTimeRangeArray.length;
    }

    function mergeRanges(rangeIndex1, rangeIndex2) {
        let range1 = this.customTimeRangeArray[rangeIndex1];
        let range2 = this.customTimeRangeArray[rangeIndex2];

        if (range1.start <=  range2.start && range2.start <= range1.end && range1.end <= range2.end) {
            //|-----------Range1----------|
            //                    |-----------Range2----------|
            range1.end = range2.end;
            this.customTimeRangeArray.splice(rangeIndex2,1);
            return true;

        } else if (range2.start <= range1.start && range1.start <= range2.end && range2.end <= range1.end) {
            //                |-----------Range1----------|
            //|-----------Range2----------|
            range1.start = range2.start;
            this.customTimeRangeArray.splice(rangeIndex2,1);
            return true;
        } else if (range2.start <= range1.start && range1.start <= range2.end && range1.end <= range2.end) {
            //      |--------Range1-------|
            //|---------------Range2--------------|
            this.customTimeRangeArray.splice(rangeIndex1,1);
            return true;
        } else if (range1.start <= range2.start && range2.start <= range1.end && range2.end <= range1.end) {
            //|-----------------Range1--------------|
            //        |-----------Range2----------|
            this.customTimeRangeArray.splice(rangeIndex2,1);
            return true;
        }
        return false;
    }

    function checkIndex(index) {
        const isInt = index !== null && !isNaN(index) && (index % 1 === 0);

        if (!isInt) {
            throw new Error('index argument is not an integer');
        }
    }

    function start(index) {
        checkIndex(index);

        if (index >= this.customTimeRangeArray.length || index < 0) {
            return NaN;
        }

        return this.customTimeRangeArray[index].start;
    }

    function end(index) {
        checkIndex(index);

        if (index >= this.customTimeRangeArray.length || index < 0) {
            return NaN;
        }

        return this.customTimeRangeArray[index].end;
    }

    return {
        customTimeRangeArray: customTimeRangeArray,
        length: length,
        add: add,
        clear: clear,
        remove: remove,
        mergeRanges: mergeRanges,
        start: start,
        end: end
    };
}
CustomTimeRanges.__dashjs_factory_name = 'CustomTimeRanges';
export default FactoryMaker.getClassFactory(CustomTimeRanges);