/**
* 组装文件需要的post参数
* @param string $signature
* @param int $offset
* @return array
*/
public static function getPost($signature, $offset = 0)
{
$key = substr($signature, 0, 2) . "/" . substr($signature, 2, 2);
$key .= "/" . substr($signature, 4, 2) . "/" . substr($signature, 6, 2);
// TODO: 处理组装s3需要的参数
$input = array("Filename" => "{$signature}", "key" => "{$key}/\${filename}");
// 生成数字签名,使用json格式，返回hash格式数据
$output = MUtils::getRequesSignature($input);
$expirationTime = $output["expiration_date"];
$digitalSignature = $output["digital_signature"];
$post = array();
$post["Filename"] = $signature;
$post["AWSAccessKeyId"] = MConst::ACCESS_KEY_ID;
$post["key"] = $signature;
$post["expiration_date"] = $expirationTime;
$post["digital_signature"] = $digitalSignature;
$post["offset"] = $offset;
$post["success_action_status"] = "201";
$post["acl"] = "";
$post["signature"] = "";
$post["policy"] = "";
$post = json_encode($post);
return $post;
}