Enum PageHeader._Fields

    • Enum Constant Detail

      • TYPE

        public static final PageHeader._Fields TYPE
        the type of the page: indicates which of the *_header fields is set *
        See Also:
        PageType
      • UNCOMPRESSED_PAGE_SIZE

        public static final PageHeader._Fields UNCOMPRESSED_PAGE_SIZE
        Uncompressed page size in bytes (not including this header) *
      • COMPRESSED_PAGE_SIZE

        public static final PageHeader._Fields COMPRESSED_PAGE_SIZE
        Compressed (and potentially encrypted) page size in bytes, not including this header *
      • CRC

        public static final PageHeader._Fields CRC
        The 32-bit CRC checksum for the page, to be be calculated as follows: - The standard CRC32 algorithm is used (with polynomial 0x04C11DB7, the same as in e.g. GZip). - All page types can have a CRC (v1 and v2 data pages, dictionary pages, etc.). - The CRC is computed on the serialization binary representation of the page (as written to disk), excluding the page header. For example, for v1 data pages, the CRC is computed on the concatenation of repetition levels, definition levels and column values (optionally compressed, optionally encrypted). - The CRC computation therefore takes place after any compression and encryption steps, if any. If enabled, this allows for disabling checksumming in HDFS if only a few pages need to be read.
    • Method Detail

      • values

        public static PageHeader._Fields[] values()
        Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:
        for (PageHeader._Fields c : PageHeader._Fields.values())
            System.out.println(c);
        
        Returns:
        an array containing the constants of this enum type, in the order they are declared
      • valueOf

        public static PageHeader._Fields valueOf​(String name)
        Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
        Parameters:
        name - the name of the enum constant to be returned.
        Returns:
        the enum constant with the specified name
        Throws:
        IllegalArgumentException - if this enum type has no constant with the specified name
        NullPointerException - if the argument is null
      • findByThriftId

        public static PageHeader._Fields findByThriftId​(int fieldId)
        Find the _Fields constant that matches fieldId, or null if its not found.
      • findByThriftIdOrThrow

        public static PageHeader._Fields findByThriftIdOrThrow​(int fieldId)
        Find the _Fields constant that matches fieldId, throwing an exception if it is not found.
      • findByName

        public static PageHeader._Fields findByName​(String name)
        Find the _Fields constant that matches name, or null if its not found.
      • getThriftFieldId

        public short getThriftFieldId()
        Specified by:
        getThriftFieldId in interface org.apache.thrift.TFieldIdEnum
      • getFieldName

        public String getFieldName()
        Specified by:
        getFieldName in interface org.apache.thrift.TFieldIdEnum