Question

OneDrive 和 GDrive 中有 50 个文件夹，每个文件夹包含 500 个文件。 onedriveUrls和gdriveUrls是length 50 的数组，分别包含指向这些文件夹的链接。

混淆！以下代码预计会在2个级别并行运行，首先是async.parallel，第二个是async.map，是正确的代码还是async.map应该包含在setTimeout中以确保所有级别都并行运行？

async.parallel({
        onedrive: function(callback){
            async.map(onedriveUrls, request, function(err, results) {
                if (err) throw(err);          // handle error
                callback(null,results);  
            });
        },
        gdrive: function(callback){                
            async.map(gdriveUrls, request, function(err, results) {
                if (err) throw(err);          // handle error
                callback(null,results);  
            });
        }
    },
    function(err, results) {
        // results is now equals to: {onedrive: [array_of_length_x], gdrive: [array_of_length_y]}
    });

async.map还返回了什么 - 承诺还是什么？

快乐帮助！

Answer 1

是正确的代码还是async.map应该包含在setTimeout中以确保所有级别都是并行运行的？

没有。 SELECT BANINST1_SZVIRST.SZVIRST_TERM_DESC, SUM(IIF(BANINST1_SZVIRST.SZVIRST_FULL_PART_IND="F", 1, 0)) as [FullTime], SUM(IIF(BANINST1_SZVIRST.SZVIRST_FULL_PART_IND="P", 1, 0)) as [PartTime], SUM(IIF(SZVIRST_LEVL_CODE="01", 1, 0)) as [Graduate], SUM(IIF(SZVIRST_LEVL_CODE="02", 1, 0)) as [UnderGraduate], SUM(IIF(BANINST1_SZVIRST.SZVIRST_FULL_PART_IND="F" AND SZVIRST_LEVL_CODE="02", 1, 0)) AS [FullTimeUnderGraduates], SUM(IIF(BANINST1_SZVIRST.SZVIRST_FULL_PART_IND="P" AND SZVIRST_LEVL_CODE="02", 1, 0)) AS [PartTimeUnderGraduates], SUM(IIF(BANINST1_SZVIRST.SZVIRST_FULL_PART_IND="F" AND SZVIRST_LEVL_CODE="01", 1, 0)) AS [FullTimeGraduates], SUM(IIF(BANINST1_SZVIRST.SZVIRST_FULL_PART_IND="P" AND SZVIRST_LEVL_CODE="01", 1, 0)) AS [PartTimeGraduates] FROM BANINST1_SZVIRST GROUP BY BANINST1_SZVIRST.SZVIRST_TERM_DESC, BANINST1_SZVIRST.SZVIRST_TERM_CODE, BANINST1_SZVIRST.SZVIRST_LEVL_CODE, BANINST1_SZVIRST.SZVIRST_FULL_PART_IND WHERE BANINST1_SZVIRST.SZVIRST_TERM_CODE IN ("201020","201120","201220","201320","201420","201520","201620")预计是异步的，一切都很好。在request中包装任何内容都无济于事。

async.map还返回了什么 - 承诺还是什么？

无。 map像大多数其他异步函数一样返回setTimeout，它只用结果数组调用它的回调。

顺便说一句，您应该将代码简化为

undefined

Node.JS async.parallel混淆| async.map返回的内容

1 个答案: