Package org.apache.spark.sql.streaming

Interface MapState<K,V>

All Superinterfaces:
Serializable
public interface MapState<K,V> extends Serializable
Interface used for arbitrary stateful operations with the v2 API to capture map value state.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clear()
    Function to remove the state for the current grouping key.
    boolean
    containsKey(K key)
    Function to check if the user map key is contained in the map for the current grouping key.
    boolean
    exists()
    Function to check whether any user map entry exists for current grouping key or not.
    V
    getValue(K key)
    Function to get the state value for current grouping key and user map key.
    scala.collection.Iterator<scala.Tuple2<K,V>>
    iterator()
    Function to return the iterator of user map key-value pairs present in the map for the current grouping key.
    scala.collection.Iterator<K>
    keys()
    Function to return the user map keys present in the map for the current grouping key.
    void
    removeKey(K key)
    Function to remove the user map key from the map for the current grouping key.
    void
    updateValue(K key, V value)
    Function to add or update the map entry for the current grouping key.
    scala.collection.Iterator<V>
    values()
    Function to return the user map values present in the map for the current grouping key.

  • Method Details

    • clear

      void clear()
      Function to remove the state for the current grouping key. Note that this removes the entire map state associated with the current grouping key.

    • containsKey

      boolean containsKey(K key)
      Function to check if the user map key is contained in the map for the current grouping key.

      Parameters:
      key - - user map key

      Returns:
      - true if the user key is present in the map, false otherwise.

    • exists

      boolean exists()
      Function to check whether any user map entry exists for current grouping key or not.

      Returns:
      - true if state exists, false otherwise.

    • getValue

      V getValue(K key)
      Function to get the state value for current grouping key and user map key. If the state exists, the value is returned. If the state does not exist, the default value for the type is returned for AnyVal types and null for AnyRef types.

      Note that it's always recommended to check whether the state exists or not by calling exists() before calling get().

      Parameters:
      key - (undocumented)
      Returns:
      - the value of the state if it exists. If the state does not exist, the default value for the type is returned for AnyVal types and null for AnyRef types.

    • iterator

      scala.collection.Iterator<scala.Tuple2<K,V>> iterator()
      Function to return the iterator of user map key-value pairs present in the map for the current grouping key.

      Returns:
      - iterator of user map key-value pairs if the map is not empty and empty iterator otherwise.

    • keys

      scala.collection.Iterator<K> keys()
      Function to return the user map keys present in the map for the current grouping key.

      Returns:
      - iterator of user map keys if the map is not empty, empty iterator otherwise.

    • removeKey

      void removeKey(K key)
      Function to remove the user map key from the map for the current grouping key.

      Note that this function will remove the user map key and its associated value from the map associated with the current grouping key. If the user map key is not present in the map, this function will not do anything.

      Parameters:
      key - - user map key

    • updateValue

      void updateValue(K key, V value)
      Function to add or update the map entry for the current grouping key.

      Note that this function will add the user map key and value if the user map key is not present in the map associated with the current grouping key. If the user map key is already present in the associated map, the value for the user key will be updated to the new user map value.

      Parameters:
      key - - user map key
      value - - user map value

    • values

      scala.collection.Iterator<V> values()
      Function to return the user map values present in the map for the current grouping key.

      Returns:
      - iterator of user map values if the map is not empty, empty iterator otherwise.