组成
EncryptionVariant variants 集合
bytes encryptedKey
Stream stripeStatistics
bytes fileStatistics
DataMask
EncryptionKey key
keyName_
algorithm_
bitField0_
KeyProviderKind ：KeyProvider的类型，文件中不存储Keyprovider信息
映射的JAVA类：ReaderEncryption
KeyProvider keyProvider
ReaderEncryptionKey[] keys
name
version
algorithm
List<ReaderEncryptionVariant> roots
MaskDescriptionImpl[] masks
name
String[] parameters
List<TypeDescription> columns
ReaderEncryptionVariant[] variants
KeyProvider provider
ReaderEncryptionKey key
LocalKey[] localKeys
byte[] encryptedKey
Key decryptedKey
LocalKey footerKey
List<OrcProto.Stream> stripeStats
ReaderEncryptionVariant[] columnVariants
