join.js 8.03 KB
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"use strict";
module.exports =
function(Promise, PromiseArray, tryConvertToPromise, INTERNAL, async,
         getDomain) {
var util = require("./util");
var canEvaluate = util.canEvaluate;
var tryCatch = util.tryCatch;
var errorObj = util.errorObj;
var reject;

if (!false) {
if (canEvaluate) {
    var thenCallback = function(i) {
        return new Function("value", "holder", "                             \n\
            'use strict';                                                    \n\
            holder.pIndex = value;                                           \n\
            holder.checkFulfillment(this);                                   \n\
            ".replace(/Index/g, i));
    };

    var promiseSetter = function(i) {
        return new Function("promise", "holder", "                           \n\
            'use strict';                                                    \n\
            holder.pIndex = promise;                                         \n\
            ".replace(/Index/g, i));
    };

    var generateHolderClass = function(total) {
        var props = new Array(total);
        for (var i = 0; i < props.length; ++i) {
            props[i] = "this.p" + (i+1);
        }
        var assignment = props.join(" = ") + " = null;";
        var cancellationCode= "var promise;\n" + props.map(function(prop) {
            return "                                                         \n\
                promise = " + prop + ";                                      \n\
                if (promise instanceof Promise) {                            \n\
                    promise.cancel();                                        \n\
                }                                                            \n\
            ";
        }).join("\n");
        var passedArguments = props.join(", ");
        var name = "Holder$" + total;


        var code = "return function(tryCatch, errorObj, Promise, async) {    \n\
            'use strict';                                                    \n\
            function [TheName](fn) {                                         \n\
                [TheProperties]                                              \n\
                this.fn = fn;                                                \n\
                this.asyncNeeded = true;                                     \n\
                this.now = 0;                                                \n\
            }                                                                \n\
                                                                             \n\
            [TheName].prototype._callFunction = function(promise) {          \n\
                promise._pushContext();                                      \n\
                var ret = tryCatch(this.fn)([ThePassedArguments]);           \n\
                promise._popContext();                                       \n\
                if (ret === errorObj) {                                      \n\
                    promise._rejectCallback(ret.e, false);                   \n\
                } else {                                                     \n\
                    promise._resolveCallback(ret);                           \n\
                }                                                            \n\
            };                                                               \n\
                                                                             \n\
            [TheName].prototype.checkFulfillment = function(promise) {       \n\
                var now = ++this.now;                                        \n\
                if (now === [TheTotal]) {                                    \n\
                    if (this.asyncNeeded) {                                  \n\
                        async.invoke(this._callFunction, this, promise);     \n\
                    } else {                                                 \n\
                        this._callFunction(promise);                         \n\
                    }                                                        \n\
                                                                             \n\
                }                                                            \n\
            };                                                               \n\
                                                                             \n\
            [TheName].prototype._resultCancelled = function() {              \n\
                [CancellationCode]                                           \n\
            };                                                               \n\
                                                                             \n\
            return [TheName];                                                \n\
        }(tryCatch, errorObj, Promise, async);                               \n\
        ";

        code = code.replace(/\[TheName\]/g, name)
            .replace(/\[TheTotal\]/g, total)
            .replace(/\[ThePassedArguments\]/g, passedArguments)
            .replace(/\[TheProperties\]/g, assignment)
            .replace(/\[CancellationCode\]/g, cancellationCode);

        return new Function("tryCatch", "errorObj", "Promise", "async", code)
                           (tryCatch, errorObj, Promise, async);
    };

    var holderClasses = [];
    var thenCallbacks = [];
    var promiseSetters = [];

    for (var i = 0; i < 8; ++i) {
        holderClasses.push(generateHolderClass(i + 1));
        thenCallbacks.push(thenCallback(i + 1));
        promiseSetters.push(promiseSetter(i + 1));
    }

    reject = function (reason) {
        this._reject(reason);
    };
}}

Promise.join = function () {
    var last = arguments.length - 1;
    var fn;
    if (last > 0 && typeof arguments[last] === "function") {
        fn = arguments[last];
        if (!false) {
            if (last <= 8 && canEvaluate) {
                var ret = new Promise(INTERNAL);
                ret._captureStackTrace();
                var HolderClass = holderClasses[last - 1];
                var holder = new HolderClass(fn);
                var callbacks = thenCallbacks;

                for (var i = 0; i < last; ++i) {
                    var maybePromise = tryConvertToPromise(arguments[i], ret);
                    if (maybePromise instanceof Promise) {
                        maybePromise = maybePromise._target();
                        var bitField = maybePromise._bitField;
                        ;
                        if (((bitField & 50397184) === 0)) {
                            maybePromise._then(callbacks[i], reject,
                                               undefined, ret, holder);
                            promiseSetters[i](maybePromise, holder);
                            holder.asyncNeeded = false;
                        } else if (((bitField & 33554432) !== 0)) {
                            callbacks[i].call(ret,
                                              maybePromise._value(), holder);
                        } else if (((bitField & 16777216) !== 0)) {
                            ret._reject(maybePromise._reason());
                        } else {
                            ret._cancel();
                        }
                    } else {
                        callbacks[i].call(ret, maybePromise, holder);
                    }
                }

                if (!ret._isFateSealed()) {
                    if (holder.asyncNeeded) {
                        var domain = getDomain();
                        if (domain !== null) {
                            holder.fn = util.domainBind(domain, holder.fn);
                        }
                    }
                    ret._setAsyncGuaranteed();
                    ret._setOnCancel(holder);
                }
                return ret;
            }
        }
    }
    var $_len = arguments.length;var args = new Array($_len); for(var $_i = 0; $_i < $_len; ++$_i) {args[$_i] = arguments[$_i];};
    if (fn) args.pop();
    var ret = new PromiseArray(args).promise();
    return fn !== undefined ? ret.spread(fn) : ret;
};

};