@sap/cds-dk/lib/import/odata/util/MultiMap.js

Command line client and development toolkit for the SAP Cloud Application Programming Model

"use strict";

/**
 * Library for handling multiple values for same key
 */
var Multimap = (function () {
    var mapCtor;
    if (typeof Map !== 'undefined') {
        mapCtor = Map;

        if (!Map.prototype.keys) {
            Map.prototype.keys = function () {
                var keys = [];
                this.forEach(function (item, key) {
                    keys.push(key);
                });
                return keys;
            };
        }
    }

    function Multimap(iterable) {
        var self = this;

        self._map = mapCtor;

        if (Multimap.Map) {
            self._map = Multimap.Map;
        }

        self._ = self._map ? new self._map() : {};

        if (iterable) {
            iterable.forEach(function (i) {
                self.set(i[0], i[1]);
            });
        }
    }

    /**
     * @param {Object} key
     * @return {Array} An array of values, undefined if no such a key;
     */
    Multimap.prototype.get = function (key) {
        return this._map ? this._.get(key) : this._[key];
    };

    /**
     * @param {Object} key
     * @param {Object} val...
     */
    // eslint-disable-next-line no-unused-vars
    Multimap.prototype.set = function (key, val) {
        var args = Array.prototype.slice.call(arguments);

        key = args.shift();

        var entry = this.get(key);
        if (!entry) {
            entry = [];
            if (this._map)
                this._.set(key, entry);
            else
                this._[key] = entry;
        }

        Array.prototype.push.apply(entry, args);
        return this;
    };

    /**
     * @return {Array} all the keys in the map
     */
    Multimap.prototype.keys = function () {
        if (this._map)
            return makeIterator(this._.keys());

        return makeIterator(Object.keys(this._));
    };

    function makeIterator(iterator) {
        if (Array.isArray(iterator)) {
            var nextIndex = 0;

            return {
                next: function () {
                    return nextIndex < iterator.length ?
                        { value: iterator[nextIndex++], done: false } :
                        { done: true };
                }
            };
        }

        return iterator;
    }

    return Multimap;
})();

module.exports = Multimap;