js/release/map.js

"use strict";
module.exports = function(Promise,
                          PromiseArray,
                          apiRejection,
                          tryConvertToPromise,
                          INTERNAL,
                          debug) {
var getDomain = Promise._getDomain;
var util = require("./util");
var tryCatch = util.tryCatch;
var errorObj = util.errorObj;
var async = Promise._async;

function MappingPromiseArray(promises, fn, limit, _filter) {
    this.constructor$(promises);
    this._promise._captureStackTrace();
    var domain = getDomain();
    this._callback = domain === null ? fn : util.domainBind(domain, fn);
    this._preservedValues = _filter === INTERNAL
        ? new Array(this.length())
        : null;
    this._limit = limit;
    this._inFlight = 0;
    this._queue = [];
    async.invoke(this._asyncInit, this, undefined);
}
util.inherits(MappingPromiseArray, PromiseArray);

MappingPromiseArray.prototype._asyncInit = function() {
    this._init$(undefined, -2);
};

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

MappingPromiseArray.prototype._promiseFulfilled = function (value, index) {
    var values = this._values;
    var length = this.length();
    var preservedValues = this._preservedValues;
    var limit = this._limit;

    if (index < 0) {
        index = (index * -1) - 1;
        values[index] = value;
        if (limit >= 1) {
            this._inFlight--;
            this._drainQueue();
            if (this._isResolved()) return true;
        }
    } else {
        if (limit >= 1 && this._inFlight >= limit) {
            values[index] = value;
            this._queue.push(index);
            return false;
        }
        if (preservedValues !== null) preservedValues[index] = value;

        var promise = this._promise;
        var callback = this._callback;
        var receiver = promise._boundValue();
        promise._pushContext();
        var ret = tryCatch(callback).call(receiver, value, index, length);
        var promiseCreated = promise._popContext();
        debug.checkForgottenReturns(
            ret,
            promiseCreated,
            preservedValues !== null ? "Promise.filter" : "Promise.map",
            promise
        );
        if (ret === errorObj) {
            this._reject(ret.e);
            return true;
        }

        var maybePromise = tryConvertToPromise(ret, this._promise);
        if (maybePromise instanceof Promise) {
            maybePromise = maybePromise._target();
            var bitField = maybePromise._bitField;
            ;
            if (((bitField & 50397184) === 0)) {
                if (limit >= 1) this._inFlight++;
                values[index] = maybePromise;
                maybePromise._proxy(this, (index + 1) * -1);
                return false;
            } else if (((bitField & 33554432) !== 0)) {
                ret = maybePromise._value();
            } else if (((bitField & 16777216) !== 0)) {
                this._reject(maybePromise._reason());
                return true;
            } else {
                this._cancel();
                return true;
            }
        }
        values[index] = ret;
    }
    var totalResolved = ++this._totalResolved;
    if (totalResolved >= length) {
        if (preservedValues !== null) {
            this._filter(values, preservedValues);
        } else {
            this._resolve(values);
        }
        return true;
    }
    return false;
};

MappingPromiseArray.prototype._drainQueue = function () {
    var queue = this._queue;
    var limit = this._limit;
    var values = this._values;
    while (queue.length > 0 && this._inFlight < limit) {
        if (this._isResolved()) return;
        var index = queue.pop();
        this._promiseFulfilled(values[index], index);
    }
};

MappingPromiseArray.prototype._filter = function (booleans, values) {
    var len = values.length;
    var ret = new Array(len);
    var j = 0;
    for (var i = 0; i < len; ++i) {
        if (booleans[i]) ret[j++] = values[i];
    }
    ret.length = j;
    this._resolve(ret);
};

MappingPromiseArray.prototype.preservedValues = function () {
    return this._preservedValues;
};

function map(promises, fn, options, _filter) {
    if (typeof fn !== "function") {
        return apiRejection("expecting a function but got " + util.classString(fn));
    }

    var limit = 0;
    if (options !== undefined) {
        if (typeof options === "object" && options !== null) {
            if (typeof options.concurrency !== "number") {
                return Promise.reject(
                    new TypeError("'concurrency' must be a number but it is " +
                                    util.classString(options.concurrency)));
            }
            limit = options.concurrency;
        } else {
            return Promise.reject(new TypeError(
                            "options argument must be an object but it is " +
                             util.classString(options)));
        }
    }
    limit = typeof limit === "number" &&
        isFinite(limit) && limit >= 1 ? limit : 0;
    return new MappingPromiseArray(promises, fn, limit, _filter).promise();
}

Promise.prototype.map = function (fn, options) {
    return map(this, fn, options, null);
};

Promise.map = function (promises, fn, options, _filter) {
    return map(promises, fn, options, _filter);
};


};