package com.tinkerpop.blueprints;
/**
* An Index maintains a mapping between some key/value pair and an element.
* An index requires that the developer explicitly put elements of the graph into the index.
* The key/value pair need not be specific to the element properties.
* There is a query method to support index lookups beyond exact matches.
*
* @author Marko A. Rodriguez (http://markorodriguez.com)
*/
public interface Index<T extends Element> {
/**
* Get the name of the index.
*
* @return the name of the index
*/
public String getIndexName();
/**
* Get the class that this index is indexing.
*
* @return the class this index is indexing
*/
public Class<T> getIndexClass();
/**
* Index an element by a key and a value.
*
* @param key the key to index the element by
* @param value the value to index the element by
* @param element the element to index
*/
public void put(String key, Object value, T element);
/**
* Get all elements that are indexed by the provided key/value.
*
* @param key the key of the indexed elements
* @param value the value of the indexed elements
* @return an iterable of elements that have a particular key/value in the index
*/
public CloseableIterable<T> get(String key, Object value);
/**
* Get all the elements that are indexed by the provided key and specified query object.
* This is useful for graph implementations that support complex query capabilities.
* If querying is not supported, simply throw an UnsupportedOperationException.
*
* @param key the key of the indexed elements
* @param query the query object for the indexed elements' keys
* @return an iterable of elements that have a particular key/value in the index that match the query object
*/
public CloseableIterable<T> query(String key, Object query);
/**
* Get a count of elements with a particular key/value pair.
* The semantics are the same as the get method.
*
* @param key denoting the sub-index to search
* @param value the value to search for
* @return the collection of elements that meet that criteria
*/
public long count(String key, Object value);
/**
* Remove an element indexed by a particular key/value.
*
* @param key the key of the indexed element
* @param value the value of the indexed element
* @param element the element to remove given the key/value pair
*/
public void remove(String key, Object value, T element);
}