PHP: obtener el nº total de +1 de Google+ para una URL

Sencilla función PHP usando CURL y JSON para obtener el número total de +1 de google plus de una determinada url:

function total_googleplus($url){
	$curl = curl_init();
	curl_setopt($curl, CURLOPT_URL, "https://clients6.google.com/rpc");
	curl_setopt($curl, CURLOPT_POST, true);
	curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
	curl_setopt($curl, CURLOPT_POSTFIELDS, '[{"method":"pos.plusones.get","id":"p","params":{"nolog":true,"id":"'.rawurldecode($url).'","source":"widget","userId":"@viewer","groupId":"@self"},"jsonrpc":"2.0","key":"p","apiVersion":"v1"}]');
	curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
	curl_setopt($curl, CURLOPT_HTTPHEADER, array('Content-type: application/json'));
	$curl_results = curl_exec ($curl);
	curl_close ($curl);
	$json = json_decode($curl_results, true);
	return isset($json[0]['result']['metadata']['globalCounts']['count'])?intval( $json[0]['result']['metadata']['globalCounts']['count'] ):0;
}

echo total_googleplus('https://www.bufa.es');