CODEWITHSUNDEEP
phpfile
hex4
hex4

Reputation: 695

php read & write from file at the same time

Basically I have an XML file to populate data with and I will have a cron (in PHP) that updates it every 5 minutes. But at the same time, I will have users accessing this file all the time (and I'm talking about thousands of users).

When I tried a script myself by writing 2million text lines in a .txt file and reading it at the same time, of course the file_get_contents() was getting the current text in the .txt file and does not wait for it to end and get the contents when it's finished. So what I did is, I write to a temporary file and then rename it to the original .txt file. The renaming process on my PC takes up 0.003 seconds (calculated using microtime()).

Do you think this is a suitable solution or there will be users which will end up having an error that the file does not exists?

Upvotes: 2

Views: 2782

Answers (1)

Sherif elKhatib
Sherif elKhatib

Reputation: 45942

Of course this is not suitable.. You have to lock the file in this 0.003 microseconds.

A very simple way is a flag

For example create file called isReplacing

After replacing is done, delete file isReplacing

When a user wants the file say in getfile.php

 while(file_exists("isReplacing"))
 {}
 //NOW echo file_get_contents()

 //BETTER:
 if(file_exists("isReplacing"))
 {
      //GET DATA FROM DATABASE
 }
 else
 {
      //ECHO THE FILE
 }

NOTE this is a dumb way but I just want to demonstrate

Upvotes: 2

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