在大文件上传中批量处理数据时，如何避免PHP / WordPress内存致命错误？

我根据问题中的链接和其他一些修补方法，开发了以下解决方案。

在WordPress服务器端，加载javascript文件时，我根据内存分配情况确定服务器可以处理的行数，

$limit = ini_get('memory_limit');
$limit = wp_convert_hr_to_bytes($limit) / MB_IN_BYTES; //in MBs.
switch(true){
    case $limit >= 512:
        $limit = 1000;
        break;
    default:
        $limit = 500;
        break;
}
wp_enqueue_script( 'my-javascript-file');
wp_localize_script( 'my-javascript-file', 'cirData', array(
    'limit'=>$limit
));

您应该根据自己的过程确定并设置自己的限制。

在javascript文件中，使用jQuery，

var reader,formData, lineMarker=0, csvLines, isEOF=false, $file, $form ;
  $(document).ready(function(){
    $file = $(':file'); //file input field
    $form = $('form');  //form
    //when the file field changes....
    $file.on('change', function(){
      //check if the file field has a value.
      if($file.val()){
        //setup file reader.
        reader = new FileReader();
        //now listen for when the file is ready to be read.
        reader.addEventListener('load', function (e) {
          csvLines = e.target.result.split("\n");
          batchProcess(); //launch process.
        });
        //when the form is being submitted, start reading the file.
        $(document).on('click', ':submit', function(e){
          e.preventDefault(); //disable normal submit.
          //setup data for the ajax.
          formData = new FormData($form.get(0));

          //read the file and batch request to server.
          reader.readAsBinaryString($file.get(0).files[0]);
        })
      }
    })
  });

  // Methods
  //posting
  function postCSVdata(csvdata){
    formData.set('csvlines', csvdata); //set the current datat to send.
    $.ajax({
      type: 'POST',
      url: $form.attr('action'),
      data: formData,
      contentType: false,
      processData: false,
      cache: false,
      success: function(data){
        var msg ="";
        if(isEOF){ //is this end of the file?
          console.log("success!");
        }else{ //continue reading file.
          console.log("uploaded:"+ Math.round(lineMarker/csvLines.length*100)+"%");
          batchProcess(); //process the next part of the file.
        }
      }
    })
  }
  //batch process.
  function batchProcess(){
    //csvlines is the array containing all the lines read from the file.
    //lineMarker is the index of the last line read.
    var parsedata='', stop = csvLines.length - lineMarker, line='';

    for(var i = 0; i < stop; i++) {
      line = csvLines[i+lineMarker];
      parsedata +=line+"\n"; //add a new line char for server to process.
      //check if max limit of lines server can process is reached.
      if(i>(cirData.limit-2)) break; //batch limit.
    }
    lineMarker += i;
    if(i==stop) isEOF = true;
    postCSVdata(parsedata); //send to server.
  }

这会以顺序方式在服务器能够处理的几行行中发送多个AJAX请求，而不会出现致命的内存错误。