Package com.googlecode.concurrenttrees.radix.node.concrete.chararray

Class CharArrayNodeDefault

java.lang.Object
com.googlecode.concurrenttrees.radix.node.concrete.chararray.CharArrayNodeDefault
All Implemented Interfaces:
Node, NodeCharacterProvider, Serializable
public class CharArrayNodeDefault extends Object implements Node
A non-optimized implementation of the Node interface. Stores all variables and supports all behaviours required by the tree, but not very memory efficient.

See NodeFactory for documentation on how alternative node implementations can be created to reduce memory overhead. See the Node interface for details on how to write memory-efficient nodes.

This implementation stores references to child nodes in an AtomicReferenceArray, in ascending sorted order of the first character of the edges which child nodes define.

The getOutgoingEdge(Character) method uses binary search to locate a requested node, given the first character of an edge indicated. The node is then read and returned atomically from the AtomicReferenceArray.

The updateOutgoingEdge(com.googlecode.concurrenttrees.radix.node.Node) method ensures that any attempt to update a reference to a child node preserves the constraints defined in the Node interface. New child nodes are written atomically to the AtomicReferenceArray.

The constraints defined in the Node interface ensure that the AtomicReferenceArray always remains in ascending sorted order regardless of modifications performed concurrently, as long as the modifications comply with the constraints. This node enforces those constraints.

See Also:

  • Field Details

    • incomingEdgeCharArray

      private final char[] incomingEdgeCharArray

    • outgoingEdges

      private final AtomicReferenceArray<Node> outgoingEdges

    • outgoingEdgesAsList

      private final List<Node> outgoingEdgesAsList

    • value

      private final Object value

  • Constructor Details

  • Method Details

    • getIncomingEdge

      public CharSequence getIncomingEdge()
      Description copied from interface: Node
      Returns all characters of the "edge" encoded in this node, belonging to the connection from a parent node to this node.
      Specified by:
      getIncomingEdge in interface Node
      Returns:
      All characters of the "edge" encoded in this node

    • getIncomingEdgeFirstCharacter

      public Character getIncomingEdgeFirstCharacter()
      Description copied from interface: Node
      Returns the first character of the "edge" encoded in this node, belonging to the connection from a parent node to this node.

      Specified by:
      getIncomingEdgeFirstCharacter in interface Node
      Specified by:
      getIncomingEdgeFirstCharacter in interface NodeCharacterProvider
      Returns:
      The first character of the "edge" encoded in this node

    • getValue

      public Object getValue()
      Description copied from interface: Node
      Returns a value object which has been associated with a key and which is stored in this node, or returns null if no value is stored in this node.
      Specified by:
      getValue in interface Node
      Returns:
      A value object which has been associated with a key and which is stored in this node, or returns null if no value is stored in this node

    • getOutgoingEdge

      public Node getOutgoingEdge(Character edgeFirstCharacter)
      Description copied from interface: Node
      Returns the child of this node whose edge starts with the given first character.

      This read must be performed atomically, in relation to writes made via Node.updateOutgoingEdge(Node).

      Specified by:
      getOutgoingEdge in interface Node
      Parameters:
      edgeFirstCharacter - The first character of the edge for which the associated child node is required
      Returns:
      The child of this node whose edge starts with the given first character, or null if this node has no such outgoing edge

    • updateOutgoingEdge

      public void updateOutgoingEdge(Node childNode)
      Description copied from interface: Node
      Updates the child node reference for a given edge (identified by its first character) to point to a different child node.

      The first character of the given child node's edge must match the first character of an existing outgoing edge from this node.

      This write must be performed atomically, in relation to reads made via Node.getOutgoingEdge(Character).

      Specified by:
      updateOutgoingEdge in interface Node
      Parameters:
      childNode - The new child node to associated with this edge

    • getOutgoingEdges

      public List<Node> getOutgoingEdges()
      Description copied from interface: Node
      Returns a read-only list of the child nodes to which this node has outgoing edges, i.e. child nodes which have incoming edges from this node.

      It is intended that this method will be used for copying/cloning nodes.

      Specified by:
      getOutgoingEdges in interface Node
      Returns:
      A read-only list of the child nodes to which this node has outgoing edges

    • toString

      public String toString()
      Overrides:
      toString in class Object