Package com.couchbase.client.java.transcoder.subdoc

Class AbstractByteArrayFragmentTranscoder

  • All Implemented Interfaces:
    FragmentTranscoder
    Direct Known Subclasses:
    JacksonFragmentTranscoder
    public abstract class AbstractByteArrayFragmentTranscoder
extends AbstractFragmentTranscoder
    An AbstractFragmentTranscoder that further implements decoding and encoding of messaging, easing the implementation of a concrete FragmentTranscoder based on byte arrays zero-copied from ByteBuf. Note that the serialization/deserialization mean should be able to work with byte arrays and write to an OutputStream, and that byte arrays should be treated as transient (eg. not used to back long living objects), as they may be tied to the original ByteBuf which will get released.
    Since:
    2.3
    Author:
    Simon Baslé

    • Constructor Detail

      • AbstractByteArrayFragmentTranscoder

        public AbstractByteArrayFragmentTranscoder()

    • Method Detail

      • decodeWithMessage

        public <T> T decodeWithMessage​(com.couchbase.client.deps.io.netty.buffer.ByteBuf encoded,
                               Class<? extends T> clazz,
                               String transcodingErrorMessage)
                        throws TranscodingException
        Description copied from interface: FragmentTranscoder
        Decode content in a ByteBuf **without releasing it**. Suitable for populating a DocumentFragment's content.
        Type Parameters:
        T - the type of the decoded fragment.
        Parameters:
        encoded - the encoded fragment value (will not be released).
        clazz - the target class for decoded value. Using Object.class implies a generic decode, where dictionaries are represented by JsonObject and arrays by JsonArray.
        transcodingErrorMessage - the error message to be used in the thrown TranscodingException if the decoding couldn't happen.
        Returns:
        a decoded fragment.
        Throws:
        TranscodingException - if the decoding couldn't happen.

      • doEncodeSingle

        protected <T> com.couchbase.client.deps.io.netty.buffer.ByteBuf doEncodeSingle​(T value,
                                                                               String transcodingErrorMessage)
                                                                        throws TranscodingException
        Description copied from class: AbstractFragmentTranscoder
        Encode a single mutation value to a ByteBuf suitable for use in the sub-document protocol.
        Specified by:
        doEncodeSingle in class AbstractFragmentTranscoder
        Type Parameters:
        T - the type of the fragment being encoded.
        Parameters:
        value - the value to encode.
        transcodingErrorMessage - the error message to be used in the thrown TranscodingException if the encoding couldn't happen.
        Returns:
        a ByteBuf representation of the fragment value.
        Throws:
        TranscodingException - if the encoding couldn't happen.

      • byteArrayToGenericObject

        protected abstract Object byteArrayToGenericObject​(byte[] byteArray,
                                                   int offset,
                                                   int length)
                                            throws IOException
        Deserializes a byte array into a generic Object. The provided offset and length must be considered when processing the array, which may hold more data that just the value to deserialize. Note that he byte array should not be considered reliable for long-term usage (eg. backing a String) as it might be tied to the original ByteBuf, which will get released from the heap. If the array represents a non-scalar value, implementations may choose different classes like a JsonObject or a Map to instantiate it. This method is called by decodeWithMessage(ByteBuf, Class, String) when the clazz parameter is Object.class.
        Parameters:
        byteArray - the array of bytes containing the value to deserialize (you'll need to copy it if long term usage is needed).
        offset - the offset in the array at which the value starts.
        length - the number of bytes after the offset that represents the value.
        Returns:
        an instance of a suitable generic Object representation of the value.
        Throws:
        IOException

      • byteArrayToClass

        protected abstract <T> T byteArrayToClass​(byte[] byteArray,
                                          int offset,
                                          int length,
                                          Class<? extends T> clazz)
                                   throws IOException
        Deserializes a byte array into a specific class instance. The provided offset and length must be considered when processing the array, which may hold more data that just the value to deserialize. Note that he byte array should not be considered reliable for long-term usage (eg. backing a String) as it might be tied to the original ByteBuf, which will get released from the heap. This method is called by decodeWithMessage(ByteBuf, Class, String) when the clazz parameter isn't Object.class.
        Parameters:
        byteArray - the array of bytes containing the value to deserialize (you'll need to copy it if long term usage is needed).
        offset - the offset in the array at which the value starts.
        length - the number of bytes after the offset that represents the value.
        clazz - the Class to deserialize to.
        Returns:
        an instance of a suitable generic Object representation of the value.
        Throws:
        IOException

      • writeValueAsBytes

        protected abstract <T> byte[] writeValueAsBytes​(T value)
                                         throws IOException
        Serializes a single value object as an array of bytes. The array will be backing a ByteBuf, so modifications to the array will be visible in the ByteBuf.
        Parameters:
        value - the value object to serialize.
        Returns:
        the array of bytes representing the serialized value object.
        Throws:
        IOException

      • writeValueIntoStream

        protected abstract void writeValueIntoStream​(OutputStream out,
                                             Object o)
                                      throws IOException
        Serializes a single object out of a sequence of multiple values, into the sequence's OutputStream. Implementation should simply write the bytes corresponding to the serialized value object into the stream.
        Parameters:
        out - the OutputStream of bytes representing a JSON sequence of serialized values.
        o - the value among the sequence that is currently serialized.
        Throws:
        IOException