<?php
error_reporting(E_ALL | E_STRICT);

define('__STEP_32'  , 3);
define('__LEFT_32'  , 0xffff0000);
define('__RIGHT_32' , 0x0000ffff);
define('__FACTOR_32', 16);
define('__FORMAT_WRITE_32', 'II');

define('__STEP_64'  , 7);
define('__LEFT_64'  , 0xffffffff00000000);
define('__RIGHT_64' , 0x00000000ffffffff);
define('__FACTOR_64', 32);
define('__FORMAT_WRITE_64', 'NN');

// Default is 32-bit
$__factor = constant('__FACTOR_32');
$__left   = constant('__LEFT_32');
$__right  = constant('__RIGHT_32');
$__format = constant('__FORMAT_WRITE_32');
$__step   = constant('__STEP_32');

if (PHP_INT_SIZE === 8) {
	// Use 64-bit
	$__factor = constant('__FACTOR_64');
	$__left   = constant('__LEFT_64');
	$__right  = constant('__RIGHT_64');
	$__format = constant('__FORMAT_WRITE_64');
	$__step   = constant('__STEP_64');
} // END - if

$str = gzcompress(file_get_contents('test.data'), 9);

$encoded = '';

for ($idx = 0; $idx < strlen($str); $idx += $__step) {
	$big = 0;
	for ($i = 0; $i < $__step; $i++) {
		$factor = ($__step - 1 - $i);

		if (($idx + $i) <= strlen($str)) {
			$ord = ord(substr($str, ($idx + $i), 1));

			$add = $ord * pow(256, $factor);

			$big += $add;

			//print 'idx=' . $idx . ',i=' . $i . ',ord=' . $ord . ',factor=' . $factor . ',add=' . $add . ',big=' . $big . PHP_EOL;
		} // END - if
	} // END - for

	$l = ($big & $__left) >>$__factor;
	$r = $big & $__right;

	$unpacked = str_pad(pack($__format, $l, $r), 8, '0', STR_PAD_LEFT);
	//print 'big=' . $big . ',unpacked('.strlen($unpacked) . ')='.md5($unpacked).PHP_EOL;

	$encoded .= $unpacked;
} // END - for

print 'Hash(' . strlen($encoded) . ')=' . md5($encoded) . PHP_EOL;
print 'Encoded ' . strlen($str) . ' bytes into ' . strlen($encoded) . ' bytes ...' . PHP_EOL;

file_put_contents('test.data.bin' . ($__factor * 2), $encoded);

print 'File size is: ' . filesize('test.data.bin' . ($__factor * 2)) . ' bytes.' . PHP_EOL;

// [EOF]
?>