Package org.apache.heron.api.tuple

Interface Tuple

  • All Superinterfaces:
    Serializable
    public interface Tuple
extends Serializable
    The tuple is the main data structure in Heron. A tuple is a named list of values, where each value can be any type. Tuples are dynamically typed -- the types of the fields do not need to be declared. Tuples have helper methods like getInteger and getString to get field values without having to cast the result.

    Heron needs to know how to serialize all the values in a tuple. By default, Heron knows how to serialize the primitive types, strings, and byte arrays. If you want to use another type, you'll need to implement and register a serializer for that type.

    See Also:
    Storm serialization

    • Method Detail

      • size

        int size()
        Returns the number of fields in this tuple.

      • fieldIndex

        int fieldIndex​(String field)
        Returns the position of the specified field in this tuple.

      • contains

        boolean contains​(String field)
        Returns true if this tuple contains the specified name of the field.

      • getValue

        Object getValue​(int i)
        Gets the field at position i in the tuple. Returns object since tuples are dynamically typed.

      • getString

        String getString​(int i)
        Returns the String at position i in the tuple. If that field is not a String, you will get a runtime error.

      • getInteger

        Integer getInteger​(int i)
        Returns the Integer at position i in the tuple. If that field is not an Integer, you will get a runtime error.

      • getLong

        Long getLong​(int i)
        Returns the Long at position i in the tuple. If that field is not a Long, you will get a runtime error.

      • getBoolean

        Boolean getBoolean​(int i)
        Returns the Boolean at position i in the tuple. If that field is not a Boolean, you will get a runtime error.

      • getShort

        Short getShort​(int i)
        Returns the Short at position i in the tuple. If that field is not a Short, you will get a runtime error.

      • getByte

        Byte getByte​(int i)
        Returns the Byte at position i in the tuple. If that field is not a Byte, you will get a runtime error.

      • getDouble

        Double getDouble​(int i)
        Returns the Double at position i in the tuple. If that field is not a Double, you will get a runtime error.

      • getFloat

        Float getFloat​(int i)
        Returns the Float at position i in the tuple. If that field is not a Float, you will get a runtime error.

      • getBinary

        byte[] getBinary​(int i)
        Returns the byte array at position i in the tuple. If that field is not a byte array, you will get a runtime error.

      • getStringByField

        String getStringByField​(String field)

      • getLongByField

        Long getLongByField​(String field)

      • getShortByField

        Short getShortByField​(String field)

      • getByteByField

        Byte getByteByField​(String field)

      • getDoubleByField

        Double getDoubleByField​(String field)

      • getFloatByField

        Float getFloatByField​(String field)

      • getBinaryByField

        byte[] getBinaryByField​(String field)

      • getValues

        List<Object> getValues()
        Gets all the values in this tuple.

      • getFields

        Fields getFields()
        Gets the names of the fields in this tuple.

      • select

        List<Object> select​(Fields selector)
        Returns a subset of the tuple based on the fields selector.

      • getSourceGlobalStreamId

        org.apache.heron.api.generated.TopologyAPI.StreamId getSourceGlobalStreamId()
        Returns the global stream id (component + stream) of this tuple.

      • getSourceComponent

        String getSourceComponent()
        Gets the id of the component that created this tuple.

      • getSourceTask

        int getSourceTask()
        Gets the id of the task that created this tuple.

      • getSourceStreamId

        String getSourceStreamId()
        Gets the id of the stream that this tuple was emitted to.

      • resetValues

        void resetValues()
        Resets the tuple values to null TODO:- Is this needed