Comments on: Integers in PHP, running with scissors, and portability http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/ Percona's MySQL & InnoDB performance and scalability blog Sat, 11 Feb 2012 16:45:54 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Christian Kruse http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/comment-page-1/#comment-567279 Christian Kruse Tue, 26 May 2009 12:01:15 +0000 http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/#comment-567279 Hi, the code you are using has a bug, since integer overflow handling is plattform dependent in PHP. I ran php -r 'var_dump((int)4294967296);' on different plattforms, results vary: - Mac OS X, Intel Core2Duo, 32bit: int(-1) - Linux, Intel Celeron, 32bit: int(0) - Linux, Intel Core2Duo, 64bit: int(4294967296) Hi,

the code you are using has a bug, since integer overflow handling is plattform dependent in PHP. I ran php -r ‘var_dump((int)4294967296);’ on different plattforms, results vary:

- Mac OS X, Intel Core2Duo, 32bit: int(-1)
- Linux, Intel Celeron, 32bit: int(0)
- Linux, Intel Core2Duo, 64bit: int(4294967296)

]]> By: PHP « php http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/comment-page-1/#comment-349816 PHP « php Thu, 28 Aug 2008 09:35:05 +0000 http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/#comment-349816 [...] “Integers in PHP, running with scissors, and portability“. MySQL Performance Blog (27 March 2007). Retrieved on [...] [...] “Integers in PHP, running with scissors, and portability“. MySQL Performance Blog (27 March 2007). Retrieved on [...]

]]> By: Sprazzi di Lucidità » links for 2008-07-25 http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/comment-page-1/#comment-334099 Sprazzi di Lucidità » links for 2008-07-25 Fri, 25 Jul 2008 00:37:56 +0000 http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/#comment-334099 [...] Integers in PHP, running with scissors, and portability | MySQL Performance Blog (tags: php integer bug) [...] [...] Integers in PHP, running with scissors, and portability | MySQL Performance Blog (tags: php integer bug) [...]

]]> By: markus http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/comment-page-1/#comment-332913 markus Tue, 22 Jul 2008 18:33:22 +0000 http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/#comment-332913 These days I dont understand anyone that picks PHP instead of Ruby or Python. PHP is only a success on the www, but other than that is crippled design are a huge problem. These days I dont understand anyone that picks PHP instead of Ruby or Python.

PHP is only a success on the www, but other than that is crippled design are a huge problem.

]]> By: Kuroki Kaze http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/comment-page-1/#comment-332858 Kuroki Kaze Tue, 22 Jul 2008 15:41:08 +0000 http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/#comment-332858 Damn. Damn.

]]> By: Jared http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/comment-page-1/#comment-292047 Jared Fri, 02 May 2008 17:07:33 +0000 http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/#comment-292047 If you don't expect a negative value return from unpack() then test for it, and add 0x100000000 list(, $a) = unpack("N", "\xff\xff\xff\xff"); if ($a < 0) $a += 0x100000000; The add forces a float conversion, and corrects the sign. If you don’t expect a negative value return from unpack() then test for it, and add 0×100000000

list(, $a) = unpack(“N”, “\xff\xff\xff\xff”);
if ($a < 0)
$a += 0×100000000;

The add forces a float conversion, and corrects the sign.

]]> By: Improved Cacti monitoring templates for MySQL at Xaprb http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/comment-page-1/#comment-289141 Improved Cacti monitoring templates for MySQL at Xaprb Mon, 28 Apr 2008 00:43:29 +0000 http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/#comment-289141 [...] script that gathers the data is totally rewritten from scratch, and much improved. For example, the math works on 32-bit systems. It has caching built-in so each poll cycle results in just one request to the server, instead of [...] [...] script that gathers the data is totally rewritten from scratch, and much improved. For example, the math works on 32-bit systems. It has caching built-in so each poll cycle results in just one request to the server, instead of [...]

]]> By: Xaprb http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/comment-page-1/#comment-252475 Xaprb Thu, 13 Mar 2008 15:32:38 +0000 http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/#comment-252475 I am trying to graph some InnoDB stats in Cacti, and must extract them from SHOW INNODB STATUS, which prints them as a hi/lo 64-bit unsigned number, of course. I have to do some math on them to subtract one from the other. I ended up just sending them back to MySQL and doing a SELECT, casting them to string at the same time: <code> $sql = "SELECT " . "CONCAT('', (($innodb_lsn[0] << 32) + $innodb_lsn[1])) " . "AS log_bytes_written, " . "CONCAT('', (($flushed_to[0] << 32) + $flushed_to[1])) " . "AS log_bytes_flushed, " . "CONCAT('', ((($innodb_lsn[0] << 32) + $innodb_lsn[1]) " . "- (($flushed_to[0] << 32) + $flushed_to[1]))) " . "AS unflushed_log"; </code> Not high-performance, but the code sure is easy to write. I am trying to graph some InnoDB stats in Cacti, and must extract them from SHOW INNODB STATUS, which prints them as a hi/lo 64-bit unsigned number, of course. I have to do some math on them to subtract one from the other. I ended up just sending them back to MySQL and doing a SELECT, casting them to string at the same time:


$sql = "SELECT "
. "CONCAT('', (($innodb_lsn[0] << 32) + $innodb_lsn[1])) "
. "AS log_bytes_written, "
. "CONCAT('', (($flushed_to[0] << 32) + $flushed_to[1])) "
. "AS log_bytes_flushed, "
. "CONCAT('', ((($innodb_lsn[0] << 32) + $innodb_lsn[1]) "
. "- (($flushed_to[0] << 32) + $flushed_to[1]))) "
. "AS unflushed_log";

Not high-performance, but the code sure is easy to write.

]]> By: Comment on Integers in PHP, running with scissors, and portability… http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/comment-page-1/#comment-231088 Comment on Integers in PHP, running with scissors, and portability… Tue, 15 Jan 2008 17:12:16 +0000 http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/#comment-231088 [...] Comment on Integers in PHP, running with scissors, and portability… …horrors of PHP, I’m just being an elitist old bitch, with my closures and namespaces and garbage collection which works properly, and what… [...] [...] Comment on Integers in PHP, running with scissors, and portability… …horrors of PHP, I’m just being an elitist old bitch, with my closures and namespaces and garbage collection which works properly, and what… [...]

]]> By: Robert Synnott http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/comment-page-1/#comment-229700 Robert Synnott Fri, 11 Jan 2008 01:26:02 +0000 http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/#comment-229700 <strong>Your PHP Hell</strong> I'm sure that most of you think that when I rant and rave about the horrors of PHP, I'm just being an elitist old bitch, with my closures and namespaces and garbage collection which works properly, and what-not. PHP is... Your PHP Hell

I’m sure that most of you think that when I rant and rave about the horrors of PHP, I’m just being an elitist old bitch, with my closures and namespaces and garbage collection which works properly, and what-not. PHP is…

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