prajna.structure.accessor

Class DataCoordinator

java.lang.Object

prajna.structure.AbstractDataAccessor<DataRecord,DataRecord>

prajna.structure.accessor.RecordAccessor

prajna.structure.accessor.DataCoordinator

All Implemented Interfaces:

DataAccessor<DataRecord,DataRecord>

public class DataCoordinator
extends RecordAccessor

The DataCoordinator class is a SemanticAccessor which uses multiple underlying SemanticAccessors. The DataCoordinator maintains a list of which data structures are available in each underlying accessor. When a request is made, the DataCoordinator forwards the request to the underlying SemanticAccessor, and returns the resulting data.

The DataCoordinator differs from the FusionAccessor in that the DataCoordinator simply queries multiple data sources independently of each other, with no attempt to coordinate the data among the different accessors. The FusionAccessor attempts to merge the various data sources into a single source of information.

Author:

Edward Swing

Constructor Summary

Constructors

Constructor and Description
DataCoordinator()

Method Summary

Methods

Modifier and Type	Method and Description
void	addAccessor(RecordAccessor accessor) Add a semantic accessor to this data coordinator.
void	addFieldHandler(java.lang.String fieldName, FieldHandler handler) Add a field handler for a particular field.
boolean	extendGraph(java.lang.String graphName, Graph<DataRecord,DataRecord> graph, DataRecord node) Extend the given graph around the specified node.
boolean	extendTree(java.lang.String treeName, Tree<DataRecord> tree, DataRecord node) Extend the given tree around the specified node.
java.util.Set<DataRecord>	getDataset(java.lang.String datasetName) Retrieve the dataset from the underlying data source.
java.util.Set<java.lang.String>	getDatasetNames() Get the names of the available datasets from this accessor
Graph<DataRecord,DataRecord>	getGraph(java.lang.String graphName) Retrieve the graph from the underlying data source.
java.util.Set<java.lang.String>	getGraphNames() Get the names of the available graphs from this accessor.
Grid<DataRecord>	getGrid(java.lang.String gridName) Retrieve the grid from the underlying data source.
java.util.Set<java.lang.String>	getGridNames() Get the names of the available grids from this accessor
DataStructureType	getStructureType(java.lang.String dataName) Get the data type for the specified dataName.
Tree<DataRecord>	getTree(java.lang.String treeName) Retrieve the tree from the underlying data source.
java.util.Set<java.lang.String>	getTreeNames() Get the names of the available trees from this accessor
protected java.util.Set<DataRecord>	retrieveRecords(DataTemplate template) Retrieve a set of data records for a particular DataTemplate.
void	setInitParameters(java.util.Map<java.lang.String,java.lang.String> parameters) Set any initialization parameters required by this data accessor.
void	setQuery(java.lang.String query) Set the query string used to retrieve records.

Methods inherited from class prajna.structure.accessor.RecordAccessor

addToGraph, addToTree, createReferenceNode, getFieldHandler, getMaxRecords, getReasoner, getStructureReasoners, setMaxRecords, setReasoner, setReasoner

Methods inherited from class prajna.structure.AbstractDataAccessor

addStructure, addTemplate, getSpec, getTemplate, getTemplateNames, setConfig, setConfigFile, setConfigFile

Methods inherited from class java.lang.Object

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

Constructor Detail

DataCoordinator

public DataCoordinator()

Method Detail

addAccessor

public void addAccessor(RecordAccessor accessor)

Add a semantic accessor to this data coordinator.

Parameters:

accessor - the new accessor

addFieldHandler

public void addFieldHandler(java.lang.String fieldName,
                   FieldHandler handler)

Add a field handler for a particular field. The field handler can be used to perform more complex handling of a data field. The FieldHandler.handleField() method is invoked when a new value is added to the named data field. The DataCoordinator sets the field handler on all of the underlying accessors.

Overrides:

addFieldHandler in class RecordAccessor

Parameters:

fieldName - the data field within the DataRecord

handler - the field handler

extendGraph

public boolean extendGraph(java.lang.String graphName,
                  Graph<DataRecord,DataRecord> graph,
                  DataRecord node)

Extend the given graph around the specified node. The DataCoordinator will simply forward the request to the appropriate accessor.

Specified by:

extendGraph in interface DataAccessor<DataRecord,DataRecord>

Overrides:

extendGraph in class RecordAccessor

Parameters:

graphName - The name of the graph

graph - The graph to extend

node - The node to use as an extension point.

Returns:

true if more data was added to the graph, false otherwise.

extendTree

public boolean extendTree(java.lang.String treeName,
                 Tree<DataRecord> tree,
                 DataRecord node)

Extend the given tree around the specified node. This method adds any children which are not already part of the tree. The DataCoordinator simply forwards the request to the appropriate sub-accessor.

Specified by:

extendTree in interface DataAccessor<DataRecord,DataRecord>

Overrides:

extendTree in class RecordAccessor

Parameters:

treeName - The name of the graph

tree - The graph to extend

node - The node to use as an extension point.

Returns:

true if more data was added to the tree, false otherwise.

getDataset

public java.util.Set<DataRecord> getDataset(java.lang.String datasetName)

Retrieve the dataset from the underlying data source. The DataCoordinator simply forwards the request to the appropriate sub-accessor.

Specified by:

getDataset in interface DataAccessor<DataRecord,DataRecord>

Overrides:

getDataset in class RecordAccessor

Parameters:

datasetName - the name of the dataset

Returns:

the dataset

getDatasetNames

public java.util.Set<java.lang.String> getDatasetNames()

Get the names of the available datasets from this accessor

Specified by:

getDatasetNames in interface DataAccessor<DataRecord,DataRecord>

Overrides:

getDatasetNames in class AbstractDataAccessor<DataRecord,DataRecord>

Returns:

the set of dataset names

getGraph

public Graph<DataRecord,DataRecord> getGraph(java.lang.String graphName)

Retrieve the graph from the underlying data source. The DataCoordinator simply forwards the request to the appropriate sub-accessor.

Specified by:

getGraph in interface DataAccessor<DataRecord,DataRecord>

Overrides:

getGraph in class RecordAccessor

Parameters:

graphName - the name of the graph

Returns:

the graph

getGraphNames

public java.util.Set<java.lang.String> getGraphNames()

Get the names of the available graphs from this accessor.

Specified by:

getGraphNames in interface DataAccessor<DataRecord,DataRecord>

Overrides:

getGraphNames in class AbstractDataAccessor<DataRecord,DataRecord>

Returns:

the set of graph names

getGrid

public Grid<DataRecord> getGrid(java.lang.String gridName)

Retrieve the grid from the underlying data source. The DataCoordinator simply forwards the request to the appropriate sub-accessor.

Specified by:

getGrid in interface DataAccessor<DataRecord,DataRecord>

Overrides:

getGrid in class RecordAccessor

Parameters:

gridName - the name of the grid

Returns:

the grid

getGridNames

public java.util.Set<java.lang.String> getGridNames()

Get the names of the available grids from this accessor

Specified by:

getGridNames in interface DataAccessor<DataRecord,DataRecord>

Overrides:

getGridNames in class AbstractDataAccessor<DataRecord,DataRecord>

Returns:

the set of grid names

getStructureType

public DataStructureType getStructureType(java.lang.String dataName)

Get the data type for the specified dataName.

Specified by:

getStructureType in interface DataAccessor<DataRecord,DataRecord>

Overrides:

getStructureType in class AbstractDataAccessor<DataRecord,DataRecord>

Parameters:

dataName - the name of the data

Returns:

the data type

getTree

public Tree<DataRecord> getTree(java.lang.String treeName)

Retrieve the tree from the underlying data source. The DataCoordinator simply forwards the request to the appropriate sub-accessor.

Specified by:

getTree in interface DataAccessor<DataRecord,DataRecord>

Overrides:

getTree in class RecordAccessor

Parameters:

treeName - the name of the tree

Returns:

the tree

getTreeNames

public java.util.Set<java.lang.String> getTreeNames()

Get the names of the available trees from this accessor

Specified by:

getTreeNames in interface DataAccessor<DataRecord,DataRecord>

Overrides:

getTreeNames in class AbstractDataAccessor<DataRecord,DataRecord>

Returns:

the set of tree names

retrieveRecords

protected java.util.Set<DataRecord> retrieveRecords(DataTemplate template)

Retrieve a set of data records for a particular DataTemplate. This method is used by the default implementation of the various getStructure methods. The method should create the individual DataRecord objects. The DataCoordinator class overrides all of the getStructure methods, requesting the data from the underlying accessors. Therefore, this method is never called and returns null.

Specified by:

retrieveRecords in class RecordAccessor

Parameters:

template - The data template specifying field mappings and descriptions

Returns:

the set of DataRecords for the template

setInitParameters

public void setInitParameters(java.util.Map<java.lang.String,java.lang.String> parameters)

Set any initialization parameters required by this data accessor. The DataCoordinator forwards all parameters to each of its underlying accessors. It also stores the initialization parameters, so that other accessors may also be initialized with them.

Parameters:

parameters - a map of initialization parameters

setQuery

public void setQuery(java.lang.String query)

Set the query string used to retrieve records. This accessor simply passes the query string to its component accessors.

Specified by:

setQuery in class AbstractDataAccessor<DataRecord,DataRecord>

Parameters:

query - the query string