Question

我使用nodeJs csv模块解析10000记录大csv和每个记录，即 .on（'record'，func），我必须实现一个耗时的逻辑。但节点不会等到我完成。我该如何处理？文件谈到http://www.adaltas.com/projects/node-csv/ pause（）和resume（）。但是我在哪里使用它？

    var csv = require('csv');
    var fs = require('fs');
    csv()
    .from.stream(fs.createReadStream(__dirname+'/sample.in'))
    .to.path(__dirname+'/sample.out')
    .transform( function(row){
      row.unshift(row.pop());
      return row;
    })
    .on('record', function(row,index){
              //Time consuming logic goes here
    })
    .on('end', function(count){
      console.log('Number of lines: '+count);
    })
    .on('error', function(error){
      console.log(error.message);
    });

Answer 1

我终于有了这个工作。感谢node-csv开发人员

//Read through the csv file one row at a time
csv()
    .from(__dirname+'data.csv', { columns: true })
    .transform(function(row, index, next){
         setTimeout(function(){
         console.log(row);
         next()
         }, 3000); //replace setTimeout with any fn and call next() in the callback

    }, {parallel: 1})
    .on("end", function (count) {
      var finalcount = count;
      var logtext = 'SUMMARY: Total count: ' + finalcount + '\n' 
                    + 'Error count:' + errorcount  + "("+errorArray+")"
                    + '\n' + 'Success count:' + successcount;
      fs.appendFile(config.logfilename, '\n'+ logtext, function (err) {
        console.log(logtext);
      });  


      console.log("done", count);
    });

NodeJs csv模块 - 暂停＆amp;恢复

1 个答案: