From: psurmano at ucalgary dot ca
Operating system: Redhat 8.0
PHP version: 4.3.3
PHP Bug Type: Output Control
Bug description: fread() reads entire file to memory
Description:
------------
When the following code is run in a browser on a very large file php will
first read in the entire file into memory and only afterwards will it
display a download dialog in the browser. This is even though I'm reading
in 8192 bytes at a time.
On a large file this results in a delay of several seconds.
Using readfile() doesn't have this problem but it is unacceptable since I
will need to add code to throttle download speed.
Reproduce code:
---------------
<?php
header("Content-type: application/octet-stream");
header("Content-Disposition: attachment; filename=largeFile");
header("Content-Length: " . filesize("largeFile"));
$handle = fopen ("largeFile", "rb");
do {
$data = fread($handle, 8192);
if (strlen($data) == 0) {
break;
}
echo $data;
} while(true);
fclose ($handle);
?>
Expected result:
----------------
PHP should first show the download dialog and then start reading the file.
This is what happens with readfile()
Actual result:
--------------
The file will first get read entirely into memory resulting in a large
delay. Only then is the user prompted with a download dialog.
--
Edit bug report at http://bugs.php.net/?id=25523&edit=1
--
Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=25523&r=trysnapshot4
Try a CVS snapshot (php5): http://bugs.php.net/fix.php?id=25523&r=trysnapshot5
Fixed in CVS: http://bugs.php.net/fix.php?id=25523&r=fixedcvs
Fixed in release: http://bugs.php.net/fix.php?id=25523&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=25523&r=needtrace
Try newer version: http://bugs.php.net/fix.php?id=25523&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=25523&r=support
Expected behavior: http://bugs.php.net/fix.php?id=25523&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=25523&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=25523&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=25523&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=25523&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=25523&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=25523&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=25523&r=gnused
