理清思路：
引入了兩個概念：塊（block）和片（chunk）。每個塊由一到多個片組成，而一個資源則由一到多個塊組成
塊是服務端的永久數據存儲單位，片則只在分片上傳過程中作為臨時存儲的單位。服務端會以約一個月為單位周期性的清除上傳后未被合並為塊的數據片
實現過程：
將文件分割，分片上傳，然后合並
前端核心code：
var fileForm = document.getElementById("file");
var upstartBtn = document.getElementById('upstart');
var stopBtn = document.getElementById('stop');
var startBtn = document.getElementById('restart');
var rate = document.getElementById('rate');
var divlog = document.getElementById('divlog');
//---------------------------
const LENGTH = 1024 * 1024 * 1;
var start = 0;
var end = start + LENGTH;
var blob;
var blob_num = 1;
var is_stop = 0
var file = null;
var md5filename = '';
//-----------------------------
var upload_instance = new Upload();
fileForm.onchange = function()
{
browserMD5File(fileForm.files[0], function (err, md5) { //如果文件大，md5值生成較慢 md5值生成后才能上傳處理，自己優化下吧
md5filename = md5; //如果需要刷新后也能斷點，可利用cookie記錄，自行完善
divlog.innerHTML = '文件md5為：' + md5filename;
});
}
upstartBtn.onclick = function(){
upload_instance.addFileAndSend(fileForm);
}
stopBtn.onclick = function(){
upload_instance.stop();
}
startBtn.onclick = function(){
upload_instance.start();
}
function Upload(){
var xhr = new XMLHttpRequest();
var form_data = new FormData();
//對外方法，傳入文件對象
this.addFileAndSend = function(that){
file = that.files[0];
blob = cutFile(file);
sendFile(blob,file);
blob_num += 1;
}
//停止文件上傳
this.stop = function(){
xhr.abort();
is_stop = 1;
}
this.start = function(){
sendFile(blob,file);
is_stop = 0;
}
//切割文件
function cutFile(file){
var file_blob = file.slice(start,end);
start = end;
end = start + LENGTH;
return file_blob;
};
//發送文件
function sendFile(blob,file){
var total_blob_num = Math.ceil(file.size / LENGTH);
form_data.append('file',blob);
form_data.append('blob_num',blob_num);
form_data.append('total_blob_num',total_blob_num);
form_data.append('md5_file_name',md5filename);
form_data.append('file_name',file.name);
xhr.open('POST','./index.php',false);
xhr.onreadystatechange = function () {
var progress;
var progressObj = document.getElementById('finish');
if(total_blob_num == 1){
progress = '100%';
}else{
progress = (Math.min(100,(blob_num/total_blob_num)* 100 )).toFixed(2) +'%';
}
console.log('progress-----'+progress);
progressObj.style.width = progress;
rate.innerHTML = progress;
var t = setTimeout(function(){
if(start < file.size && is_stop === 0){
blob = cutFile(file);
sendFile(blob,file);
blob_num += 1;
}else{
//setTimeout(t);
}
},1000);
}
xhr.send(form_data);
}
}
后端code
<?php
class Upload{
private $filepath = './upload'; //上傳目錄
private $tmpPath; //PHP文件臨時目錄
private $blobNum; //第幾個文件塊
private $totalBlobNum; //文件塊總數
private $fileName; //文件名
private $md5FileName;
public function __construct($tmpPath,$blobNum,$totalBlobNum,$fileName, $md5FileName){
$this->tmpPath = $tmpPath;
$this->blobNum = $blobNum;
$this->totalBlobNum = $totalBlobNum;
$this->fileName = $this->createName($fileName, $md5FileName);
$this->moveFile();
$this->fileMerge();
}
//判斷是否是最后一塊，如果是則進行文件合成並且刪除文件塊
private function fileMerge(){
if($this->blobNum == $this->totalBlobNum){
$blob = '';
for($i=1; $i<= $this->totalBlobNum; $i++){
$blob .= file_get_contents($this->filepath.'/'. $this->fileName.'__'.$i);
}
file_put_contents($this->filepath.'/'. $this->fileName,$blob);
$this->deleteFileBlob();
}
}
//刪除文件塊
private function deleteFileBlob(){
for($i=1; $i<= $this->totalBlobNum; $i++){
@unlink($this->filepath.'/'. $this->fileName.'__'.$i);
}
}
private function moveFile(){
$this->touchDir();
$filename = $this->filepath.'/'. $this->fileName.'__'.$this->blobNum;
move_uploaded_file($this->tmpPath,$filename);
}
//API返回數據
public function apiReturn(){
if($this->blobNum == $this->totalBlobNum){
if(file_exists($this->filepath.'/'. $this->fileName)){
$data['code'] = 2;
$data['msg'] = 'success';
$data['file_path'] = 'http://'.$_SERVER['HTTP_HOST'].dirname($_SERVER['DOCUMENT_URI']).str_replace('.','',$this->filepath).'/'. $this->fileName;
}
}else{
if(file_exists($this->filepath.'/'. $this->fileName.'__'.$this->blobNum)){
$data['code'] = 1;
$data['msg'] = 'waiting';
$data['file_path'] = '';
}
}
header('Content-type: application/json');
echo json_encode($data);
}
private function touchDir(){
if(!file_exists($this->filepath)){
return mkdir($this->filepath);
}
}
private function createName($fileName, $md5FileName){
return $md5FileName . '.' . pathinfo($fileName)['extension'];
}
}
$upload = new Upload($_FILES['file']['tmp_name'],$_POST['blob_num'],$_POST['total_blob_num'],$_POST['file_name'],$_POST['md5_file_name']);
$upload->apiReturn();
效果展示：
詳細代碼可參考我寫的這篇文章：http://blog.ncmem.com/wordpress/2019/08/12/php%e4%b8%8a%e4%bc%a0%e5%a4%a7%e6%96%87%e4%bb%b6-3/