UnlimitedArray

UnlimitedArray.js

/**
 * A wrapper around a standard array supported by Salesforce Commerce Cloud B2C
 * to circumvent the 20.000 items quota limitation.
 * 
 * WARNING: As this circumvents the quota limitation, you are open to high 
 * resource usage and possibly out of memory exceptions.
 */
function UnlimitedArray() {
    const listContainer = new Array();
    listContainer.push(new Array());

    this.listContainer = listContainer;
    this.currentListPosition = 0;

    Object.defineProperty(this, 'length', {
        get: function() {
            var totalLength = 0;

            this.listContainer.forEach(function(list) {
                totalLength += list.length;
            });

            return totalLength;
        }
    } )
}

/**
 * Appends elements to the Array.
 * 
 * @param {Object} value - one or more values that will be appended to the Array.
 * 
 * @returns {Number} - the new length of the Array.
 */
UnlimitedArray.prototype.push = function(value) {
    var currentList = this.listContainer[this.currentListPosition];

    if(currentList.length === 20000) {
        currentList = new Array();
        this.currentListPosition += 1;
        this.listContainer.push(currentList);
    }

    currentList.push(value);

    return this.length;
}

/**
 * Returns if the array contains a specific value.
 * 
 * @param {Object} value - The value to look for.
 * @param {Number} fromIndex - the index from which to start looking for the element.
 * 
 * @returns {boolean} - true if the value is found in the array else false.
 */
UnlimitedArray.prototype.includes = function(value, fromIndex) {
    if(!fromIndex) {
        fromIndex = 0;
    }

    var correctedIndex = 0;

    for(var i = 0; i < this.listContainer.length; i++) {
        var currentList = this.listContainer[i];
        var currentListLength = currentList.length;

        if(fromIndex <= (correctedIndex + currentListLength)) {
            if(currentList.includes(value, fromIndex - correctedIndex)) {
                return true;
            } 
        }

        correctedIndex += currentListLength;
    }

    return false;
} 

/**
 * Returns the first index at which a given element can be found in the array starting 
 * at fromIndex, or -1 if it is not present.
 * 
 * @param {Object} value - the element to locate in the Array.
 * @param {Number} fromIndex - the index from which to start looking for the element.
 * 
 * @returns {Number} - the index of the element or -1 if it is no preset.
 */
UnlimitedArray.prototype.indexOf = function(value, fromIndex ) {
    if(!fromIndex) {
        fromIndex = 0;
    }

    var correctedIndex = 0;

    for(var i = 0; i < this.listContainer.length; i++) {
        var currentList = this.listContainer[i];
        var currentListLength = currentList.length;

        if(fromIndex <= (correctedIndex + currentListLength)) {
            if(currentList.indexOf(value, fromIndex - correctedIndex) >= 0) {
                return correctedIndex + currentList.indexOf(value, fromIndex - correctedIndex);
            } 
        }

        correctedIndex += currentListLength;
    }

    return -1;
}

UnlimitedArray.prototype.get = function(position) {
    var currentTotalIndex = 0;
    var result = null;

    for(var i = 0; i < this.listContainer.length; i++) {
        var list = this.listContainer[i];

        if(!result) {
            var previousTotalIndex = currentTotalIndex;
            currentTotalIndex += list.length;
            
            if(currentTotalIndex > position) {
                result = list[position - previousTotalIndex];
            }
        }   
    };

    return result;
}
 
var unlimitedArray = new UnlimitedArray();

for(var i = 0; i < 120000; i++) {
    unlimitedArray.push(i);
}

unlimitedArray.indexOf(39000);
unlimitedArray.includes(39000, 38000);