Optimize PHP script to prevent max_execution_time limit

问题

I have written a PHP script on my local server to loop through an array of movie titles and, using http://www.imdbapi.com/, pull down associated metadata.

for ($i=0; $i < count($files['Film']); $i++) { 
    // get data from IMDB based on file title
    $imdb_data = json_decode(file_get_contents('http://www.imdbapi.com/?t='.urlencode($files['Film'][$i]['title'])), true);

    // save poster image
    $img_name = trim(strtolower($imdb_data['Title'])).'.jpg';
    file_put_contents('img/posters/'.$img_name, file_get_contents($imdb_data['Poster']));

    // set film data
    $files['Film'][$i]['year'] = $imdb_data['Year'];
    $files['Film'][$i]['runtime'] = $imdb_data['Runtime'];
    $files['Film'][$i]['rating'] = $imdb_data['Rating'];
    $files['Film'][$i]['summary'] = $imdb_data['Plot'];
    $files['Film'][$i]['image'] = $img_name;
    $files['Film'][$i]['location_id'] = $this->data['Film']['location_id']; 
}

I hit the php max_execution_time on the line that starts file_put_contents. I've noticed that a few images do get downloaded and I also get an incomplete image so I'm guessing I hit the time limit when downloading images.

What can I do to improve my script to prevent this? I don't really like the workaround of increasing the time limit if there's something fundamental I can to that will optimize the script.

回答1:

This is mostly a copy paste from a project (loading data from mysql asynchronously) I was working some month ago. I changed it a little bit to your needs, I have put some comments for you, and creted a new file (getData.php).

I haven't gone exactly in detail with downloading movies, however it downloads an image, and uploads it, pretty much the same process, hope you can adjust it to your needs.

put these two file in a directory and run index.php

This is the firs file: index.php

    <html>
    <head>
    <script type="text/javascript">

    var request = false;
    try { 
      request = new XMLHttpRequest(); 
    } catch (trymicrosoft) {                         
      try { 
        request = new ActiveXObject("Msxml2.XMLHTTP"); 
      } catch (othermicrosoft) {
        try {
          request = new ActiveXObject("Microsoft.XMLHTTP");
        } catch (failed) {                  
          request = false;       
        }
      }
    }

    if (!request) 
      alert("Error initializing XMLHttpRequest!"); 
    </script>

    <script type="text/javascript">
       function getData() 
       {

        //inform the user for to wait a little bit
        var txt=document.getElementById("messageBox")
        txt.innerHTML="Please wait for the image to download...";

            //we will call asychronously getData.php 
            var url = "getData.php";
            var params = "";//no url parameters

            request.open("POST", url, true);//use post for connect harder to attack, lots of data transfer 

            //Some http headers must be set along with any POST request.
            request.setRequestHeader("Content-type", "application/x-www-form-urlencoded;charset=utf-8");
            request.setRequestHeader("Content-length", params.length);
            request.setRequestHeader("Connection", "close");

            request.onreadystatechange = updatePage;
            request.send(params);

       }////////////////////

       //You're looking for a status code of 200 which simply means okay.
       function updatePage() {
         if (request.readyState == 4) {
           if (request.status == 200) 
           {  
                //getData.php sends as the image size, get it
                var r=request.responseText.split("$");//$ is a custom data separator I use  

                //inform the user
                var txt=document.getElementById("messageBox")
                txt.innerHTML="The file was downloaded! Its size is:"+r[0]+"x"+r[1]+" the name is:"+r[2];

                /*r is a javascript array, 0=width, 1=height, 2=file name
                */

                //display the image 
                 document.getElementById("imageBox").style.width = r[0] + 'px';
                 document.getElementById("imageBox").style.height = r[1] + 'px';
                document.getElementById("imageBox").style.backgroundImage = "url("+r[2]+")";

           } 
           else{
             //alert("status is " + request.status);
             }
         }
       }

    </script>
    </head>
    <body onload="getData();">

    <div id='messageBox'></div>
    <div id='imageBox'></div>

<font color=red>
    You see I am under the image but I am already loaded cause 
    I don't have to wait for the image to load cause it loads asychronously.
    Whenever the image is ready the xmlhttp mechanism will let the page
    know and the associated javascript function will update the dom and will
    update the page without reloading it!
    </font>
    </body>
    </html>

This is the second file getData.php

<?PHP

//make a name for the file
$file_name = rand(1,9999).'.jpg';

//download the file
file_put_contents($file_name, file_get_contents('http://chachatelier.fr/programmation/images/mozodojo-original-image.jpg'));


//get the size of the image
$size = getimagesize($file_name);


//send asycnhronously the width, height, and the name
echo $size[0],'$',$size[1],'$',$file_name;

?>

回答2:

You can experiment try using AJAX to load each item in little intervals of time.

Instead of using a for inside PHP, you would use a interval-called function in your javascript, which will load the returned content of a php call.

回答3:

You can use the set_time_limit() function to reset the max_execution_time.

http://www.php.net/manual/en/function.set-time-limit.php

来源：https://stackoverflow.com/questions/7407292/optimize-php-script-to-prevent-max-execution-time-limit

标签

php

downloading-website-files