props.js 3.04 KB
"use strict";
module.exports = function(
    Promise, PromiseArray, tryConvertToPromise, apiRejection) {
var util = require("./util");
var isObject = util.isObject;
var es5 = require("./es5");
var Es6Map;
if (typeof Map === "function") Es6Map = Map;

var mapToEntries = (function() {
    var index = 0;
    var size = 0;

    function extractEntry(value, key) {
        this[index] = value;
        this[index + size] = key;
        index++;
    }

    return function mapToEntries(map) {
        size = map.size;
        index = 0;
        var ret = new Array(map.size * 2);
        map.forEach(extractEntry, ret);
        return ret;
    };
})();

var entriesToMap = function(entries) {
    var ret = new Es6Map();
    var length = entries.length / 2 | 0;
    for (var i = 0; i < length; ++i) {
        var key = entries[length + i];
        var value = entries[i];
        ret.set(key, value);
    }
    return ret;
};

function PropertiesPromiseArray(obj) {
    var isMap = false;
    var entries;
    if (Es6Map !== undefined && obj instanceof Es6Map) {
        entries = mapToEntries(obj);
        isMap = true;
    } else {
        var keys = es5.keys(obj);
        var len = keys.length;
        entries = new Array(len * 2);
        for (var i = 0; i < len; ++i) {
            var key = keys[i];
            entries[i] = obj[key];
            entries[i + len] = key;
        }
    }
    this.constructor$(entries);
    this._isMap = isMap;
    this._init$(undefined, isMap ? -6 : -3);
}
util.inherits(PropertiesPromiseArray, PromiseArray);

PropertiesPromiseArray.prototype._init = function () {};

PropertiesPromiseArray.prototype._promiseFulfilled = function (value, index) {
    this._values[index] = value;
    var totalResolved = ++this._totalResolved;
    if (totalResolved >= this._length) {
        var val;
        if (this._isMap) {
            val = entriesToMap(this._values);
        } else {
            val = {};
            var keyOffset = this.length();
            for (var i = 0, len = this.length(); i < len; ++i) {
                val[this._values[i + keyOffset]] = this._values[i];
            }
        }
        this._resolve(val);
        return true;
    }
    return false;
};

PropertiesPromiseArray.prototype.shouldCopyValues = function () {
    return false;
};

PropertiesPromiseArray.prototype.getActualLength = function (len) {
    return len >> 1;
};

function props(promises) {
    var ret;
    var castValue = tryConvertToPromise(promises);

    if (!isObject(castValue)) {
        return apiRejection("cannot await properties of a non-object\u000a\u000a    See http://goo.gl/MqrFmX\u000a");
    } else if (castValue instanceof Promise) {
        ret = castValue._then(
            Promise.props, undefined, undefined, undefined, undefined);
    } else {
        ret = new PropertiesPromiseArray(castValue).promise();
    }

    if (castValue instanceof Promise) {
        ret._propagateFrom(castValue, 2);
    }
    return ret;
}

Promise.prototype.props = function () {
    return props(this);
};

Promise.props = function (promises) {
    return props(promises);
};
};