From:
Operating system: Any
PHP version: 5.3.3
Package: hash related
Bug Type: Feature/Change Request
Bug description:Adler32 algorithm is very slow
Description:
------------
Now adler32 algorithm for each byte uses two operations " % 65521". It is
very slow.
I propose to change the function PHP_ADLER32Update in the file
hash_adler32.c
{
php_hash_uint32 i, s[2];
s[0] = context->state & 0xffff;
s[1] = (context->state >> 16) & 0xffff;
for (i = 0; i < len; ++i) {
s[0] += input[i];
s[1] += s[0];
if (s[1]>0x7fffffff)
{
s[0] = s[0] % 65521;
s[1] = s[1] % 65521;
}
}
s[0] = s[0] % 65521;
s[1] = s[1] % 65521;
context->state = s[0] + (s[1] << 16);
}
Test script:
---------------
<?php
$t = microtime(true);
echo hash_file('adler32','/home/user/testfile')."\n"; // I used testfile
size 400 MB with random content
echo sprintf('%0.3d',(microtime(true)-$t)*1000)." ms\n\n";
?>
Actual result:
--------------
PHP 5.3.3 showed:
85ffb2c5
2174 ms
After modification the file:
85ffb2c5
664 ms
Speed was higher than about 3 times
--
Edit bug report at http://bugs.php.net/bug.php?id=53213&edit=1
--
Try a snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=53213&r=trysnapshot52
Try a snapshot (PHP 5.3):
http://bugs.php.net/fix.php?id=53213&r=trysnapshot53
Try a snapshot (trunk):
http://bugs.php.net/fix.php?id=53213&r=trysnapshottrunk
Fixed in SVN:
http://bugs.php.net/fix.php?id=53213&r=fixed
Fixed in SVN and need be documented:
http://bugs.php.net/fix.php?id=53213&r=needdocs
Fixed in release:
http://bugs.php.net/fix.php?id=53213&r=alreadyfixed
Need backtrace:
http://bugs.php.net/fix.php?id=53213&r=needtrace
Need Reproduce Script:
http://bugs.php.net/fix.php?id=53213&r=needscript
Try newer version:
http://bugs.php.net/fix.php?id=53213&r=oldversion
Not developer issue:
http://bugs.php.net/fix.php?id=53213&r=support
Expected behavior:
http://bugs.php.net/fix.php?id=53213&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=53213&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=53213&r=submittedtwice
register_globals:
http://bugs.php.net/fix.php?id=53213&r=globals
PHP 4 support discontinued: http://bugs.php.net/fix.php?id=53213&r=php4
Daylight Savings: http://bugs.php.net/fix.php?id=53213&r=dst
IIS Stability:
http://bugs.php.net/fix.php?id=53213&r=isapi
Install GNU Sed:
http://bugs.php.net/fix.php?id=53213&r=gnused
Floating point limitations:
http://bugs.php.net/fix.php?id=53213&r=float
No Zend Extensions:
http://bugs.php.net/fix.php?id=53213&r=nozend
MySQL Configuration Error:
http://bugs.php.net/fix.php?id=53213&r=mysqlcfg
