## org.w3c.util
Class LRUList

    java.lang.Object
      |
      +--org.w3c.util.LRUList

Direct Known Subclasses:
  AsyncLRUList, SyncLRUList

public abstract class LRUList
extends java.lang.Object

Field Summary
`protected LRUNode` | `head`
`protected LRUNode` | `tail`

Constructor Summary
`LRUList()`

Method Summary
`abstract LRUAble` | `getHead()` Obtain the frontmost node.
`abstract LRUAble` | `getNext(LRUAble node)` Get the next node of this list.
`abstract LRUAble` | `getPrev(LRUAble node)` Get the previous node of this list.
`abstract LRUAble` | `getTail()` Obtain the backmost node.
`abstract LRUAble` | `remove(LRUAble node)` Removes node if it's in list.
`abstract LRUAble` | `removeTail()` Obtain the backmost node, and remove it from list too.
`abstract void` | `toHead(LRUAble node)` Moves node to front of list.
`abstract void` | `toTail(LRUAble node)` Moves node to back of list.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

### head

    protected LRUNode head

### tail

    protected LRUNode tail

Constructor Detail

### LRUList

    public LRUList()

Method Detail

### toHead

    public abstract void toHead(LRUAble node)

  Moves node to front of list. It can be a new node, or it can be an existing node.
  Parameters:
    `node` - the node

### toTail

    public abstract void toTail(LRUAble node)

  Moves node to back of list. It can be a new node, or it can be an existing node.
  Parameters:
    `node` - the node

### remove

    public abstract LRUAble remove(LRUAble node)

  Removes node if it's in list. Does nothing if it's not. When a node is removed, both its links are set to null.
  Parameters:
    `node` - The node to remove
  Returns:
    the same node

### getTail

    public abstract LRUAble getTail()

  Obtain the backmost node.
  Returns:
    the backmost node, or null if list is empty

### getHead

    public abstract LRUAble getHead()

  Obtain the frontmost node.
  Returns:
    the frontmost node, or null if list is empty

### removeTail

    public abstract LRUAble removeTail()

  Obtain the backmost node, and remove it from list too.
  Returns:
    the backmost node, or null if list is empty

### getNext

    public abstract LRUAble getNext(LRUAble node)

  Get the next node of this list.
  Returns:
    The next node, or null if this one was last.

### getPrev

    public abstract LRUAble getPrev(LRUAble node)

  Get the previous node of this list.
  Returns:
    The previous node, or null if this one was last.