note 100062 deleted from function.crc32 by danbrown

Note Submitter: chernyshevsky at hotmail dot com ---- Here's how you can compute the CRC32 of a stream as it's being read using a stream filter with the help of the crc32_combine() function provided by petteri at qred dot fi: // registering filter class crc32_filter extends php_user_filter { public $params; public function filter($in, $out, &$consumed, $closing) { while($bucket = stream_bucket_make_writeable($in)) { $consumed += $bucket->datalen; $this->params->crc32 = crc32_combine($this->params->crc32, crc32($bucket->data), $bucket->datalen); stream_bucket_append($out, $bucket); } return PSFS_PASS_ON; } } stream_filter_register('crc32', 'crc32_filter'); // usage $params->crc32 = 0; stream_filter_append($file, 'crc32', STREAM_FILTER_READ, $params); while($stuff = fread($file, 10)) { } echo $params->crc32; This technique is useful if you want to use the zlib.deflate filter to compress incoming data, but also need the CRC32 signature of the original file. In this case, you append the crc32 filter first, then append zlib.deflate. When all the data from the stream is read, the crc32 member in the params object is the value you want.