Package org.h2.mvstore

Class CursorPos<K,​V>

  • public final class CursorPos<K,​V>
extends java.lang.Object
    A position in a cursor. Instance represents a node in the linked list, which traces path from a specific (target) key within a leaf node all the way up to te root (bottom up path).

    • Field Summary

      Fields 
      Modifier and Type Field Description
      int index
      Index of the key (within page above) used to go down to a lower level in case of intermediate nodes, or index of the target key for leaf a node.
      Page<K,​V> page
      The page at the current level.
      CursorPos<K,​V> parent
      Next node in the linked list, representing the position within parent level, or null, if we are at the root level already.

    • Constructor Summary

      Constructors 
      Constructor Description
      CursorPos​(Page<K,​V> page, int index, CursorPos<K,​V> parent)  

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      (package private) int processRemovalInfo​(long version)
      Calculate the memory used by changes that are not yet stored.
      java.lang.String toString()  
      (package private) static <K,​V>
      CursorPos<K,​V>      		 traverseDown​(Page<K,​V> page, K key)
      Searches for a given key and creates a breadcrumb trail through a B-tree rooted at a given Page.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Field Detail

      • page

        public Page<K,​V> page
        The page at the current level.

      • index

        public int index
        Index of the key (within page above) used to go down to a lower level in case of intermediate nodes, or index of the target key for leaf a node. In a later case, it could be negative, if the key is not present.

      • parent

        public CursorPos<K,​V> parent
        Next node in the linked list, representing the position within parent level, or null, if we are at the root level already.

    • Constructor Detail

      • CursorPos

        public CursorPos​(Page<K,​V> page,
                 int index,
                 CursorPos<K,​V> parent)

    • Method Detail

      • traverseDown

        static <K,​V> CursorPos<K,​V> traverseDown​(Page<K,​V> page,
                                                     K key)
        Searches for a given key and creates a breadcrumb trail through a B-tree rooted at a given Page. Resulting path starts at "insertion point" for a given key and goes back to the root.
        Type Parameters:
        K - key type
        V - value type
        Parameters:
        page - root of the tree
        key - the key to search for
        Returns:
        head of the CursorPos chain (insertion point)

      • processRemovalInfo

        int processRemovalInfo​(long version)
        Calculate the memory used by changes that are not yet stored.
        Parameters:
        version - the version
        Returns:
        the amount of memory

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object