Bandwidth control with PHP
I was given a task to restrict number of downloads , divide the total bandwidth into 2 groups and control the speed of the downloads. So i came up with the idea of doing it with PHP cause mod_bandwidth or mod_throttle werent tailored for the job.
Here is the part where i attempt to control the speed of the download.
$filedownload = “files/abc.exe”;
$time = 10000;
$obytes = 150*1024; //150k download speed restriction
$fd = fopen ($filedownload, “rb”);
while (!feof ($fd)) {
list($usec, $sec) = explode(” “, microtime());
$time_start = $usec + $sec;
$bytes = ceil($obytes/100);
echo fread($fd, $bytes);
flush();
if($time < 10000) usleep(10000-$time);
$i++;
list($usec, $sec) = explode(” “, microtime());
$time_end = $usec + $sec;
$time = ceil(($time_end - $time_start)*1000000)+10;
}
fclose ($fd);
Basically we know how many max bytes we need to send per sec , so we calculate the time in microseconds it took for the code iteration to take place and deduct that time from 1 sec and usleep it for that long , if it took more than 1 sec to complete the iteration ( for example the user is on dialup and cannt receive 150k per sec) than dont put in the delay.
Hope this helps someone.
