CODEWITHSUNDEEP
phptime
Abs
Abs

Reputation: 57926

PHP sleep accuracy

I use the following code to see how long a user is on a particular page. I use a hidden image with a src attribute to this script:

$timer_seconds = 1;

while(!connection_aborted()) { 
   echo "\n";
   flush();
   sleep(1);
   $timer_seconds++;
}

I sometimes find this can be off by 5-10 seconds! I am guessing its the load of the server that effects the timing??

Is there anyway I can make this accurate?

Thanks all for any help.

Upvotes: 2

Views: 649

Answers (6)

DoubleZero
DoubleZero

Reputation: 31

as @erjiang said echo and flush take time and after that you put script to sleep... so if for flush was needed 1 seccond and then you sleep 1 seccond thats 2 secconds and you add only one!

solution would be to write a start and end time and then find difference:

$start = time();

while(!connection_aborted()){ 
  echo "\n"; //probably not needed...
  flush(); //same probably not needed :)
  sleep(1); //so just a sleep to not continue the code
}

$end = time();
$diff = $end - $start;
$days=floor($diff/86400);
$hours=floor(($diff-($days*86400))/3600);
$minutes=floor(($diff-(($days*86400)+($hours*3600)))/60);
$secconds=floor(($diff-((($days*86400)+($hours*3600))+($minutes*60))));

echo "\n\n".$hours."/".$minutes."/".$secconds;

that will do it! ;)

Upvotes: 0

FRAGA
FRAGA

Reputation: 5158

You've got some nice tools (in javascript) to do that.

http://chartbeat.com

http://analytics.google.com

these are some of used on the company i work.

Upvotes: 1

zzzzBov
zzzzBov

Reputation: 179086

Using jQuery you could make a synchronous ajax call onbeforeunload (I know it's not exactly ajax any more) to tell how long the user was on the page.

The truth of the matter is that It really doesn't tell you much of anything. Just because someone is on a page doesn't mean they're looking at the page. Just because they look at the page very briefly, doesn't mean they dislike it either.

Upvotes: 2

erjiang
erjiang

Reputation: 45667

echo and flush can take time, so your loop sleeps for 1 second + the time spent on echo and flush. Try something like:

$begin_time = time();
$elapsed_time = 0;

while(!connection_aborted()) {
  echo "\n";
  flush();
  sleep(1);
  $elapsed_time = time() - $begin_time;
}

Upvotes: 4

user499054
user499054

Reputation:

You should probably use Javascript do this. E.g., request something from the client (using Ajax or an image request) on the unload event of the document.

Upvotes: 5

Oliver Charlesworth
Oliver Charlesworth

Reputation: 272517

There is no reliable way to do this from the server.

Upvotes: 0

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