note 75061 added to function.crc32

In response to quix at free dot fr (http://www.php.net/manual/de/function.crc32.php#31832): Through buffering his CRC32 calculation is about 2-4 times faster: <?php function __crc32_file($name) { // Creates a CRC from a file // Info: look at __crc32_string global $__crc32_table; // Start out with all bits set high. $crc = 0xffffffff; // Open the file $fp = fopen($name, "rb"); // Read the file using a 1MB buffer // This will speed up CRC calculation at least 2-4x! // (5MB file: 15sec instead of 50sec) if ($fp != false) { $buffer = ''; while (!feof($fp)) { $buffer = fread($fp, 1048576); // Buffer 1MByte of file into memory $len = strlen($buffer); // Cache buffer length (just this saves about 10sec on a 5MB file!) for ($i = 0; $i < $len; $i++) { $crc = (($crc >> 8) & 0x00ffffff) ^ $__crc32_table[($crc & 0xFF) ^ ord($buffer[$i])]; } } fclose($fp); } // Exclusive OR the result with the beginning value. return $crc ^ 0xffffffff; } ?> ---- Server IP: 217.160.72.57 Probable Submitter: 194.31.246.249 ---- Manual Page -- http://www.php.net/manual/en/function.crc32.php Edit -- https://master.php.net/note/edit/75061 Del: integrated -- https://master.php.net/note/delete/75061/integrated Del: useless -- https://master.php.net/note/delete/75061/useless Del: bad code -- https://master.php.net/note/delete/75061/bad+code Del: spam -- https://master.php.net/note/delete/75061/spam Del: non-english -- https://master.php.net/note/delete/75061/non-english Del: in docs -- https://master.php.net/note/delete/75061/in+docs Del: other reasons-- https://master.php.net/note/delete/75061 Reject -- https://master.php.net/note/reject/75061 Search -- https://master.php.net/manage/user-notes.php