Package org.apache.beam.sdk.coders

Class SnappyCoder<T>

java.lang.Object
org.apache.beam.sdk.coders.Coder<T>
org.apache.beam.sdk.coders.StructuredCoder<T>
org.apache.beam.sdk.coders.SnappyCoder<T>
All Implemented Interfaces:
Serializable
public class SnappyCoder<T> extends StructuredCoder<T>
Wraps an existing coder with Snappy compression. It makes sense to use this coder only when it's likely that the encoded value is quite large and compressible.
See Also:

  • Method Details

    • of

      public static <T> SnappyCoder<T> of(Coder<T> innerCoder)
      Wraps the given coder into a SnappyCoder.

    • encode

      public void encode(T value, OutputStream os) throws IOException
      Description copied from class: Coder
      Encodes the given value of type T onto the given output stream. Multiple elements can be encoded next to each other on the output stream, each coder should encode information to know how many bytes to read when decoding. A common approach is to prefix the encoding with the element's encoded length.
      Specified by:
      encode in class Coder<T>
      Throws:
      IOException - if writing to the OutputStream fails for some reason

    • decode

      public T decode(InputStream is) throws IOException
      Description copied from class: Coder
      Decodes a value of type T from the given input stream in the given context. Returns the decoded value. Multiple elements can be encoded next to each other on the input stream, each coder should encode information to know how many bytes to read when decoding. A common approach is to prefix the encoding with the element's encoded length.
      Specified by:
      decode in class Coder<T>
      Throws:
      IOException - if reading from the InputStream fails for some reason

    • getCoderArguments

      public List<? extends Coder<?>> getCoderArguments()
      Description copied from class: Coder
      If this is a Coder for a parameterized type, returns the list of Coders being used for each of the parameters in the same order they appear within the parameterized type's type signature. If this cannot be done, or this Coder does not encode/decode a parameterized type, returns the empty list.
      Specified by:
      getCoderArguments in class Coder<T>

    • verifyDeterministic

      public void verifyDeterministic() throws Coder.NonDeterministicException
      Description copied from class: Coder
      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.
      Specified by:
      verifyDeterministic in class Coder<T>
      Throws:
      Coder.NonDeterministicException - if this coder is not deterministic.