应用程序的进度条

Question

I have implemented a SAAS scenario with my Windows server: a user could upload a file in a website, then Fetch.exe is an application coded in C# hosted in the server, Fetch.exe takes the uploaded file as an input, executes and generates an output to download for the user.

So in my php, I use exec to wrap Fetch.exe:

exec("Fetch.exe " . $inputFile . " > " . $outputFile)

Uploading and executing (ie, Fetch.exe) may take more than several seconds, and I want to show the user that it is processing and everything is going fine.

I have found some threads that discuss how to show a progress bar for the uploading. Whereas, does anyone know what I could do to show the approximate progress of Fetch.exe? Do I have to split it into smaller applications and use several exec?

Answer 1

You could supply Fetch.exe with an randomly generated ID from php, for example from the uniqueid function. Fetch.exe will create a file called <uniqueid>.txt with a progress percentage. From the browser, you could call another script with that unique ID to get the contents of that .txt file. In order, it would be something like this:

• User uploads the file to PHP
• PHP:
  • handles the uploaded file
  • creates a uniqueID
  • starts Fetch.exe with the file and the uniqueID
  • returns a page with the uniqueID embedded

The following happens in parallel:

• Fetch.exe creates a textfile called /progress/uniqueid.txt with the uniqueid as name. It logs the progress into it.
• The browser does an AJAX call to http://example.com/progress/uniqueid.txt and shows the progress to the user

And finally, when the progress reaches 100% the browser downloads the file. The only thing you might want to add is the pruning of the progress files after a while. Say you delete all files older than 10 minutes every hour.