C# Class s1ck.GraphDB.Plugins.Index.BinaryTree.BinaryTreeIndex

This class represents a sample index for the sones GraphDB. It is part of the tutorial on "Custom Indices" which can be found here: http://developers.sones.de/wiki/doku.php?id=documentation:plugins:database:indices The implementation is a binary search tree as it is described here: http://en.wikipedia.org/wiki/Binary_tree The index can be used as 1:1 or 1:n mapping between keys and associated values. It is not designed for production use, there is no concerning about parallel access or persistence. Feel free to use this index as a starting point for own implementations. Author: Martin "s1ck" Junghanns ([email protected])

Inheritance: sones.Plugins.Index.Abstract.ASonesIndex, IPluginable

Show file Open project: sones/sones-bstindex-tutorial

Public Methods

Method	Description
Add ( IComparable myKey, long myVertexID, IndexAddStrategy myIndexAddStrategy = IndexAddStrategy.MERGE ) : void	Adds a search key and its associated value to the index. If IndexAddStrategy is REPLACE, an existing values associated with the key will be replaced by the new value. If IndexAddStrategy is MERGE, the new value will be added to the existing set. If IndexAddStrategy is UNIQUE, an exception will be thrown if the key already exists.
BinaryTreeIndex ( ) : System	Empty constructor. This one is important for the sones PluginManager.
BinaryTreeIndex ( IList myPropertyIDs ) : System	Initializes the binary tree index and assigns a list of propertyIDs to the internal member.
Clear ( ) : void	Resets the index by setting the root node to null and letting the GC do the work.
ContainsKey ( IComparable myKey ) : bool	Checks if a given key exists in the index.
Dispose ( ) : void	Releases all resources which are hold by the index.
GetKeyType ( ) : Type	Returns the type of the indexed keys. Note: If the index is empty the typeof(IComparable) will be returned.
InitializePlugin ( string UniqueString, object>.Dictionary myParameters = null ) : IPluginable	This method is called by the plugin manager when the plugin is loaded. It loads the indexed propertyIDs out of the parameter dictionary and initializes the index with these propertyIDs
KeyCount ( ) : long	Returns the number of keys stored in the index.
Keys ( ) : IEnumerable	Returns sorted keys stored in the tree.
Optimize ( ) : void	Currently nothing happens here. TODO: maybe some rebalancing
Remove ( IComparable myKey ) : bool	Removes the given key and all associated values from the index.
RemoveRange ( IEnumerable myKeys ) : void	Removes multiple keys from the index
TryGetValues ( IComparable myKey, IEnumerable &myVertexIDs ) : bool	Writes the associated value to the out param if the key exists.
TryRemoveValue ( IComparable myKey, long myValue ) : bool	Checks if a given value is associated with a given key and if yes, the key will be deleted from the index. TODO: this method checks first if key and value exists and then removes it. maybe this can be done in one step by duplicating the remove method.
ValueCount ( ) : long	Returns the number of values stored in the index.
this ( IComparable myKey ) : IEnumerable	Returns the values associated with the given key or throws an Exception if the key does not exist.

Private Methods

Method	Description
Add ( BinaryTreeNode myTreeNode, IComparable myKey, System.Int64 myValue, IndexAddStrategy myIndexAddStrategy ) : void	Adds a given search key and the associated value to the index.
Find ( BinaryTreeNode myTreeNode, IComparable myKey ) : BinaryTreeNode	Checks if a given key exists in the tree
FindMinNodeIn ( BinaryTreeNode myTreeNode ) : BinaryTreeNode	Returns the minimum BinaryTreeNode in a subtree. The minimum node is the most left node in the subtree.
Remove ( BinaryTreeNode myTreeNode, IComparable myKey, bool &myRemoved ) : BinaryTreeNode	Removes a given key from the tree, if it exists. Returns the new (or existing) root node.
RemoveMinIn ( BinaryTreeNode myTreeNode ) : BinaryTreeNode	Removes the minium BinaryTreeNode in a tree. The minimum node is the most left node in the subtree.
TraverseInOrder ( BinaryTreeNode myTreeNode, List &myResult ) : void	Traverses the tree in-order: Left-Root-Right This means the keys are returned sorted.

Method Details

Add() public method

Adds a search key and its associated value to the index. If IndexAddStrategy is REPLACE, an existing values associated with the key will be replaced by the new value. If IndexAddStrategy is MERGE, the new value will be added to the existing set. If IndexAddStrategy is UNIQUE, an exception will be thrown if the key already exists.

public Add ( IComparable myKey, long myVertexID, IndexAddStrategy myIndexAddStrategy = IndexAddStrategy.MERGE ) : void
myKey	IComparable	Search key
myVertexID	long	Associated value
myIndexAddStrategy	IndexAddStrategy	Define what happens, if the key already exists.
return	void

BinaryTreeIndex() public method

Empty constructor. This one is important for the sones PluginManager.

public BinaryTreeIndex ( ) : System
return	System

BinaryTreeIndex() public method

Initializes the binary tree index and assigns a list of propertyIDs to the internal member.

public BinaryTreeIndex ( IList myPropertyIDs ) : System
myPropertyIDs	IList	A list of indexed propertyIDs
return	System

Clear() public method

Resets the index by setting the root node to null and letting the GC do the work.

public Clear ( ) : void
return	void

ContainsKey() public method

Checks if a given key exists in the index.

public ContainsKey ( IComparable myKey ) : bool
myKey	IComparable	Search key
return	bool

Dispose() public method

Releases all resources which are hold by the index.

public Dispose ( ) : void
return	void

GetKeyType() public method

Returns the type of the indexed keys. Note: If the index is empty the typeof(IComparable) will be returned.

public GetKeyType ( ) : Type
return	System.Type

InitializePlugin() public method

This method is called by the plugin manager when the plugin is loaded. It loads the indexed propertyIDs out of the parameter dictionary and initializes the index with these propertyIDs

public InitializePlugin ( string UniqueString, object>.Dictionary myParameters = null ) : IPluginable
UniqueString	string
myParameters	object>.Dictionary
return	IPluginable

KeyCount() public method

Returns the number of keys stored in the index.

public KeyCount ( ) : long
return	long

Keys() public method

Returns sorted keys stored in the tree.

public Keys ( ) : IEnumerable
return	IEnumerable

Optimize() public method

Currently nothing happens here. TODO: maybe some rebalancing

public Optimize ( ) : void
return	void

Remove() public method

Removes the given key and all associated values from the index.

public Remove ( IComparable myKey ) : bool
myKey	IComparable	Search key
return	bool

RemoveRange() public method

Removes multiple keys from the index

public RemoveRange ( IEnumerable myKeys ) : void
myKeys	IEnumerable	search keys to remove
return	void

TryGetValues() public method

Writes the associated value to the out param if the key exists.

public TryGetValues ( IComparable myKey, IEnumerable &myVertexIDs ) : bool
myKey	IComparable	Search key
myVertexIDs	IEnumerable	Stores the values (if any exist)
return	bool

TryRemoveValue() public method

Checks if a given value is associated with a given key and if yes, the key will be deleted from the index. TODO: this method checks first if key and value exists and then removes it. maybe this can be done in one step by duplicating the remove method.

public TryRemoveValue ( IComparable myKey, long myValue ) : bool
myKey	IComparable	search key
myValue	long	associated value
return	bool

ValueCount() public method

Returns the number of values stored in the index.

public ValueCount ( ) : long
return	long

this() public method

Returns the values associated with the given key or throws an Exception if the key does not exist.

public this ( IComparable myKey ) : IEnumerable
myKey	IComparable	Search key
return	IEnumerable