Package org.datavec.api.io

Class WritableUtils

  • public final class WritableUtils
extends Object

    • Constructor Detail

      • WritableUtils

        public WritableUtils()

    • Method Detail

      • displayByteArray

        public static void displayByteArray​(byte[] record)

      • clone

        public static <T extends Writable> T clone​(T orig,
                                           Configuration conf)
        Make a copy of a writable object using serialization to a buffer.
        Parameters:
        orig - The object to copy
        Returns:
        The copied object

      • writeVInt

        public static void writeVInt​(DataOutput stream,
                             int i)
                      throws IOException
        Serializes an integer to a binary stream with zero-compressed encoding. For -120 <= i <= 127, only one byte is used with the actual value. For other values of i, the first byte value indicates whether the integer is positive or negative, and the number of bytes that follow. If the first byte value v is between -121 and -124, the following integer is positive, with number of bytes that follow are -(v+120). If the first byte value v is between -125 and -128, the following integer is negative, with number of bytes that follow are -(v+124). Bytes are stored in the high-non-zero-byte-first order.
        Parameters:
        stream - Binary output stream
        i - Integer to be serialized
        Throws:
        IOException

      • writeVLong

        public static void writeVLong​(DataOutput stream,
                              long i)
                       throws IOException
        Serializes a long to a binary stream with zero-compressed encoding. For -112 <= i <= 127, only one byte is used with the actual value. For other values of i, the first byte value indicates whether the long is positive or negative, and the number of bytes that follow. If the first byte value v is between -113 and -120, the following long is positive, with number of bytes that follow are -(v+112). If the first byte value v is between -121 and -128, the following long is negative, with number of bytes that follow are -(v+120). Bytes are stored in the high-non-zero-byte-first order.
        Parameters:
        stream - Binary output stream
        i - Long to be serialized
        Throws:
        IOException

      • readVLong

        public static long readVLong​(DataInput stream)
                      throws IOException
        Reads a zero-compressed encoded long from input stream and returns it.
        Parameters:
        stream - Binary input stream
        Returns:
        deserialized long from stream.
        Throws:
        IOException

      • readVInt

        public static int readVInt​(DataInput stream)
                    throws IOException
        Reads a zero-compressed encoded integer from input stream and returns it.
        Parameters:
        stream - Binary input stream
        Returns:
        deserialized integer from stream.
        Throws:
        IOException

      • isNegativeVInt

        public static boolean isNegativeVInt​(byte value)
        Given the first byte of a vint/vlong, determine the sign
        Parameters:
        value - the first byte
        Returns:
        is the value negative

      • decodeVIntSize

        public static int decodeVIntSize​(byte value)
        Parse the first byte of a vint/vlong to determine the number of bytes
        Parameters:
        value - the first byte of the vint/vlong
        Returns:
        the total number of bytes (1 to 9)

      • getVIntSize

        public static int getVIntSize​(long i)
        Get the encoded length if an integer is stored in a variable-length format
        Returns:
        the encoded length

      • readEnum

        public static <T extends Enum<T>> T readEnum​(DataInput in,
                                             Class<T> enumType)
                                      throws IOException
        Read an Enum value from DataInput, Enums are read and written using String values.
        Type Parameters:
        T - Enum type
        Parameters:
        in - DataInput to read from
        enumType - Class type of Enum
        Returns:
        Enum represented by String read from DataInput
        Throws:
        IOException

      • writeEnum

        public static void writeEnum​(DataOutput out,
                             Enum<?> enumVal)
                      throws IOException
        writes String value of enum to DataOutput.
        Parameters:
        out - Dataoutput stream
        enumVal - enum value
        Throws:
        IOException

      • skipFully

        public static void skipFully​(DataInput in,
                             int len)
                      throws IOException
        Skip len number of bytes in input streamin
        Parameters:
        in - input stream
        len - number of bytes to skip
        Throws:
        IOException - when skipped less number of bytes

      • toByteArray

        public static byte[] toByteArray​(Writable... writables)
        Convert writables to a byte array