Package org.apache.beam.sdk.coders

Class ByteArrayCoder

  • All Implemented Interfaces:
    java.io.Serializable
    public class ByteArrayCoder
extends AtomicCoder<byte[]>
    A Coder for byte[].

    The encoding format is as follows:

    • If in a non-nested context (the byte[] is the only value in the stream), the bytes are read/written directly.
    • If in a nested context, the bytes are prefixed with the length of the array, encoded via a VarIntCoder.
    See Also:
    Serialized Form

    • Method Detail

      • encode

        public void encode​(byte[] value,
                   java.io.OutputStream outStream)
            throws java.io.IOException,
                   CoderException
        Description copied from class: Coder
        Encodes the given value of type T onto the given output stream.
        Specified by:
        encode in class Coder<byte[]>
        Throws:
        java.io.IOException - if writing to the OutputStream fails for some reason
        CoderException - if the value could not be encoded for some reason

      • encode

        public void encode​(byte[] value,
                   java.io.OutputStream outStream,
                   Coder.Context context)
            throws java.io.IOException,
                   CoderException
        Description copied from class: Coder
        Encodes the given value of type T onto the given output stream in the given context.
        Overrides:
        encode in class Coder<byte[]>
        Throws:
        java.io.IOException - if writing to the OutputStream fails for some reason
        CoderException - if the value could not be encoded for some reason

      • encodeAndOwn

        public void encodeAndOwn​(byte[] value,
                         java.io.OutputStream outStream,
                         Coder.Context context)
                  throws java.io.IOException,
                         CoderException
        Encodes the provided value with the identical encoding to encode(byte[], java.io.OutputStream), but with optimizations that take ownership of the value.

        Once passed to this method, value should never be observed or mutated again.

        Throws:
        java.io.IOException
        CoderException

      • decode

        public byte[] decode​(java.io.InputStream inStream)
              throws java.io.IOException,
                     CoderException
        Description copied from class: Coder
        Decodes a value of type T from the given input stream in the given context. Returns the decoded value.
        Specified by:
        decode in class Coder<byte[]>
        Throws:
        java.io.IOException - if reading from the InputStream fails for some reason
        CoderException - if the value could not be decoded for some reason

      • decode

        public byte[] decode​(java.io.InputStream inStream,
                     Coder.Context context)
              throws java.io.IOException,
                     CoderException
        Description copied from class: Coder
        Decodes a value of type T from the given input stream in the given context. Returns the decoded value.
        Overrides:
        decode in class Coder<byte[]>
        Throws:
        java.io.IOException - if reading from the InputStream fails for some reason
        CoderException - if the value could not be decoded for some reason

      • verifyDeterministic

        public void verifyDeterministic()
        Description copied from class: AtomicCoder
        Throw Coder.NonDeterministicException if the coding is not deterministic.

        In order for a Coder to be considered deterministic, the following must be true:

        • two values that compare as equal (via Object.equals() or Comparable.compareTo(), if supported) have the same encoding.
        • the Coder always produces a canonical encoding, which is the same for an instance of an object even if produced on different computers at different times.
        .

        Unless overridden, does not throw. An AtomicCoder is presumed to be deterministic

        Overrides:
        verifyDeterministic in class AtomicCoder<byte[]>

      • structuralValue

        public java.lang.Object structuralValue​(byte[] value)
        Returns an object with an Object.equals() method that represents structural equality on the argument.

        For any two values x and y of type T, if their encoded bytes are the same, then it must be the case that structuralValue(x).equals(structuralValue(y)).

        Most notably:

        • The structural value for an array coder should perform a structural comparison of the contents of the arrays, rather than the default behavior of comparing according to object identity.
        • The structural value for a coder accepting null should be a proper object with an equals() method, even if the input value is null.

        See also Coder.consistentWithEquals().

        By default, if this coder is Coder.consistentWithEquals(), and the value is not null, returns the provided object. Otherwise, encodes the value into a byte[], and returns an object that performs array equality on the encoded bytes.

        Overrides:
        structuralValue in class Coder<byte[]>
        Returns:
        objects that are equal if the two arrays contain the same bytes.

      • getEncodedElementByteSize

        protected long getEncodedElementByteSize​(byte[] value)
                                  throws java.lang.Exception
        Description copied from class: Coder
        Returns the size in bytes of the encoded value using this coder.
        Overrides:
        getEncodedElementByteSize in class Coder<byte[]>
        Throws:
        java.lang.Exception