Re: Re: shared memory extention

Ok, I now understand whats going on with the zvals and I have figured out how to setup the array references properly. I have chosen to go with the PHP licence, so I just need to add the required files, comments etc, and clean up the code as per PHP standards. Anyway, here is a simple benchmark to test the performance of my unserialize code vs unserialize <?PHP $b = '123'; $array = array( 'ref1' => &$b, 'ref2' => &$b, 'norm' => $b ); $array['self'] = &$array; unset($b); $a = serialize(&$array); sm_set('test', &$array); $time = microtime(true); for($i = 0; $i < 100000; ++$i) unserialize($a); echo "unserialize: " . (microtime(true) - $time) . "\n"; $time = microtime(true); for($i = 0; $i < 100000; ++$i) sm_get('test'); echo "sm_get : " . (microtime(true) - $time) . "\n"; ?> Outputs: unserialize: 0.18884897232056 sm_get : 0.15477204322815 My unserialization code is much faster then unserialize, which I did not expect. They both provide identical output with debug_zval_dump -Geoff On Fri, 2010-04-16 at 09:56 +1000, Geoffrey McRae wrote: > On Thu, 2010-04-15 at 14:29 -0700, Stanislav Malyshev wrote: > > Hi! > > > > > Or even better yet, is there a way to compare two zval's and see if they > > > are pointing to the the same data? > > > > Two different zvals shouldn't be pointing to the same data unless > > they're objects, in which case they'd have same handler table and object > > ID values. > > > > You may want to look at serialization code in ext/standard/var.c for an > > example of how you deal with references when serializing. > > Ok, I think I have actually found a bug in php itself, since the > serialize function does not behave as expected... > > If serialize is called by value, a new zval is provided and the > serialize function cant detect first level references back to itself. > See the sample code provided and its output. > > <?PHP > $b = '123'; > $array = array( > 'ref1' => &$b, > 'ref2' => &$b, > 'norm' => $b > ); > $array['self'] = &$array; > > serialize(&$array) . "\n"; > serialize($array) . "\n"; > ?> > > Outputs: > > > a:4:{s:4:"ref1";s:3:"123";s:4:"ref2";R:2;s:4:"norm";s:3:"123";s:4:"self";R:1;} > > a:4:{s:4:"ref1";s:3:"123";s:4:"ref2";R:2;s:4:"norm";s:3:"123";s:4:"self";a:4:{s:4:"ref1";R:2;s:4:"ref2";R:2;s:4:"norm";s:3:"123";s:4:"self";R:4;}} > > If this is not a bug, it should be documented on the serialize function > at php.net to pass its value by ref, but it would make more sense to fix > the function, someone has already noticed this issue here: > http://www.php.net/manual/en/function.serialize.php#93313 > > I am plagued by the same problem in my serialization code, if I pass by > ref things work fine. > > -Geoff