ID: 48152
Updated by: lbarn...@php.net
Reported By: mgr at woodwing dot com
-Status: Open
+Status: Bogus
Bug Type: Performance problem
Operating System: *
PHP Version: 5.2.9
New Comment:
Please do not submit the same bug more than once. An existing
bug report already describes this very problem. Even if you feel
that your issue is somewhat different, the resolution is likely
to be the same.
Thank you for your interest in PHP.
Duplicate of fixed bug #47487
Previous Comments:
------------------------------------------------------------------------
[2009-05-05 14:25:37] mgr at woodwing dot com
Description:
------------
When using file_get_contents or fread to read a file completely in
memory, PHP allocates twice the filesize memory.
PHP versions 5.2.5 and 5.2.6 don't have this problem but 5.2.8 and
5.2.9 do.
We're working a lot with large files and this problem affects the
memory usage (out of memory) and the performance (longer duration).
Are there any alternatives to work-around this problem besides not
reading the complete file in memory?
Reproduce code:
---------------
$filePath = tempnam(sys_get_temp_dir(), '');
$data = str_pad('', 1024);
if (($fh = fopen($filePath, 'wb'))){
for ($i=0; $i < 4096; $i++){
fputs($fh, $data);
}
fclose($fh);
$filesize = filesize($filePath);
print "filesize = " . number_format($filesize) . "\n";
print "Memory usage at start\n";
print "mem = " . number_format(memory_get_usage()) . "; peak = " .
number_format(memory_get_peak_usage()) . "\n";
$x = file_get_contents($filePath);
print "\nAfter\n";
print "mem = " . number_format(memory_get_usage()) . "; peak = " .
number_format(memory_get_peak_usage()) . "\n";
unlink($filePath);
}
Expected result:
----------------
PHP allocates once the filesize memory.
filesize = 4,194,304
Memory usage at start
mem = 66,992; peak = 90,228
After
mem = 4,261,396; peak = 4,269,740
Actual result:
--------------
filesize = 4,194,304
Memory usage at start
mem = 71,300; peak = 96,044
After
mem = 4,265,704; peak = 8,460,160
------------------------------------------------------------------------
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Edit this bug report at http://bugs.php.net/?id=48152&edit=1
