com.github.basking2.sdsai.dsds.node

Interface NodeStore<USERKEY,STOREKEY,VALUE>

Type Parameters:

USERKEY - The user's key.

STOREKEY - The key type used by the storage medium.

VALUE - The values stored.

All Known Implementing Classes:

DirectoryNodeStore, IONodeStore, TransactionalNodeStore

public interface NodeStore<USERKEY,STOREKEY,VALUE>

The bridge code from Java objects to stored documents. Implementors of this interface will be doing much of what a DAO would do, and a little more. Specifically functions like convert(Object) and generateKey(Node, Object) are critical but not something a traditional DAO would exposing.

All exceptions are NodeStoreExceptions which is itself a RuntimeException. Note that loadNode(Object) is unique in that it will throw a NodeStoreNodeNotFoundException (which is a type of NodeStoreException).

Method Summary

Modifier and Type	Method and Description
STOREKEY	convert(USERKEY key) Convert user keys to store keys.
STOREKEY	generateKey(Node<USERKEY,STOREKEY> node, VALUE value) Generate a key to store a node or data element.
VALUE	loadData(STOREKEY key) Load the user's data.
Node<USERKEY,STOREKEY>	loadNode(STOREKEY key) Load a node object from NodeStore.
void	removeData(STOREKEY key) Remove the given data key.
void	removeNode(STOREKEY key) Remove the given node key.
void	store(STOREKEY key, Node<USERKEY,STOREKEY> node) Store the given node.
void	store(STOREKEY key, VALUE data) Store user data.

Method Detail

loadData

VALUE loadData(STOREKEY key)

Load the user's data.

Returns:

the user's data or null if it is not found.

Throws:

NodeStoreException

loadNode

Node<USERKEY,STOREKEY> loadNode(STOREKEY key)

Load a node object from NodeStore.

Throws:

NodeStoreException

NodeStoreNodeNotFoundException - When a node is not found.

store

void store(STOREKEY key,
           VALUE data)

Store user data. If an object already exists at the key, it should be replaced.

Throws:

NodeStoreException

store

void store(STOREKEY key,
           Node<USERKEY,STOREKEY> node)

Store the given node. If an object already exists at the key, it should be replaced.

Throws:

NodeStoreException

removeNode

void removeNode(STOREKEY key)

Remove the given node key. If the key does not exist, this should return without error.

Throws:

NodeStoreException

removeData

void removeData(STOREKEY key)

Remove the given data key. If the key does not exist, this should return without error.

Throws:

NodeStoreException

generateKey

STOREKEY generateKey(Node<USERKEY,STOREKEY> node,
                     VALUE value)

Generate a key to store a node or data element. This key must be unique.

Parameters:

node - This is provided to implementations for some context. If generateKey is being called for the purposes of storing a user key, this will be null.

value - If a key is being generated for a user key value, it will be passed along. This is most useful when things like a PagedList are adding a value, but the List API does not provide a way to specify a key.

Throws:

NodeStoreException

convert

STOREKEY convert(USERKEY key)

Convert user keys to store keys. This method, given a user's key, must always produce the same store key.

Throws:

NodeStoreException - if any error occurs.