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Implementation of gaedo mechanisms backed by blueprints graph layer
package com.dooapp.gaedo.blueprints.operations;
import java.io.Serializable;
import java.lang.reflect.Modifier;
import java.lang.reflect.Proxy;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import javax.persistence.CascadeType;
import javax.persistence.FetchType;
import javax.persistence.ManyToMany;
import javax.persistence.OneToMany;
import com.dooapp.gaedo.blueprints.AbstractBluePrintsBackedFinderService;
import com.dooapp.gaedo.blueprints.CollectionLazyLoader;
import com.dooapp.gaedo.blueprints.GraphDatabaseDriver;
import com.dooapp.gaedo.blueprints.GraphUtils;
import com.dooapp.gaedo.blueprints.MapLazyLoader;
import com.dooapp.gaedo.blueprints.ObjectCache;
import com.dooapp.gaedo.blueprints.ObjectCache.ValueLoader;
import com.dooapp.gaedo.blueprints.strategies.GraphMappingStrategy;
import com.dooapp.gaedo.blueprints.transformers.LiteralHelper;
import com.dooapp.gaedo.blueprints.transformers.ClassIsNotAKnownLiteralException;
import com.dooapp.gaedo.finders.id.AnnotationsFinder.Annotations;
import com.dooapp.gaedo.finders.repository.ServiceRepository;
import com.dooapp.gaedo.patterns.WriteReplaceable;
import com.dooapp.gaedo.properties.Property;
import com.dooapp.gaedo.utils.Utils;
import com.tinkerpop.blueprints.Direction;
import com.tinkerpop.blueprints.Edge;
import com.tinkerpop.blueprints.Graph;
import com.tinkerpop.blueprints.IndexableGraph;
import com.tinkerpop.blueprints.Vertex;
public class Loader {
public class LoadProperties extends AbstractCardinalityDistinguishingOperation {
private final ObjectCache objectsBeingAccessed;
private final ClassLoader classLoader;
private final DataType returned;
private final Vertex objectVertex;
private final GraphMappingStrategy strategy;
private final ServiceRepository repository;
private final GraphDatabaseDriver driver;
private LoadProperties(ObjectCache objectsBeingAccessed, ClassLoader classLoader, DataType returned, Vertex objectVertex,
GraphMappingStrategy strategy, ServiceRepository repository, GraphDatabaseDriver driver) {
this.objectsBeingAccessed = objectsBeingAccessed;
this.classLoader = classLoader;
this.returned = returned;
this.objectVertex = objectVertex;
this.strategy = strategy;
this.repository = repository;
this.driver = driver;
}
@Override
protected void operateOnSingle(Property p, CascadeType cascade) {
loadSingle(driver, strategy, classLoader, repository, p, returned, objectVertex, objectsBeingAccessed);
}
@Override
protected void operateOnMap(Property p, CascadeType cascade) {
loadMap(driver, strategy, classLoader, repository, p, returned, objectVertex, objectsBeingAccessed);
}
@Override
protected void operateOnCollection(Property p, CascadeType cascade) {
loadCollection(driver, strategy, classLoader, repository, p, returned, objectVertex, objectsBeingAccessed);
}
}
/**
* @deprecated due to {@link AbstractBluePrintsBackedFinderService#getDriver()} deprecation
* @see #loadObject(AbstractBluePrintsBackedFinderService, GraphDatabaseDriver, Vertex, ObjectCache)
*/
@Deprecated
public DataType loadObject(AbstractBluePrintsBackedFinderService service, Vertex objectVertex, ObjectCache objectsBeingAccessed) {
return loadObject(service, service.getDriver(), objectVertex, objectsBeingAccessed);
}
public DataType loadObject(AbstractBluePrintsBackedFinderService service, GraphDatabaseDriver driver, Vertex objectVertex, ObjectCache objectsBeingAccessed) {
String objectVertexId = driver.getIdOf(objectVertex);
return loadObject(service, driver, objectVertexId, objectVertex, objectsBeingAccessed);
}
/**
* Load object with given vertex id and vertex node
* @param driver TODO
* @param objectVertexId
* @param objectVertex
* @param objectsBeingAccessed map of objects currently being accessed, it avoid some loops during loading, but is absolutely NOT a persistent cache
*
* @return loaded object
*/
public DataType loadObject(final AbstractBluePrintsBackedFinderService service, final GraphDatabaseDriver driver, final String objectVertexId, final Vertex objectVertex, final ObjectCache objectsBeingAccessed) {
ValueLoader loader = new ValueLoader() {
@Override
public Object get() {
// Shortcut
if (objectVertex == null) {
objectsBeingAccessed.put(objectVertexId, null);
return null;
} else {
ClassLoader classLoader = service.getContainedClass().getClassLoader();
ServiceRepository repository = service.getRepository();
DataType returned = (DataType) GraphUtils.createInstance(driver, service.getStrategy(), classLoader, objectVertex, Object.class /* we use object here, as this default type should not be used */, repository, objectsBeingAccessed);
try {
if (service.getStrategy().shouldLoadPropertiesOf(objectVertexId, objectVertex, objectsBeingAccessed)) {
Map> containedProperties = service.getStrategy().getContainedProperties(returned, objectVertex, CascadeType.MERGE);
objectsBeingAccessed.put(objectVertexId, returned);
loadObjectProperties(driver, service.getStrategy(), classLoader, repository, objectVertex, returned, containedProperties, objectsBeingAccessed);
}
return returned;
} finally {
// make sure loading call is always called, even if something failed during loading
service.getStrategy().loaded(objectVertexId, objectVertex, returned, objectsBeingAccessed);
// objectsBeingAccessed.remove(objectVertexId);
}
}
}
};
return (DataType) objectsBeingAccessed.get(objectVertexId, loader);
}
public void loadObjectProperties(
final GraphDatabaseDriver driver,
final GraphMappingStrategy strategy,
final ClassLoader classLoader,
final ServiceRepository repository,
final Vertex objectVertex,
final DataType returned,
final Map> containedProperties,
final ObjectCache objectsBeingAccessed) {
new OperateOnProperties().execute(containedProperties, CascadeType.REFRESH, new LoadProperties(objectsBeingAccessed, classLoader, returned, objectVertex, strategy, repository, driver));
}
/**
* Implementation tied to the future implementation of {@link #updateMap(Property, Object, Vertex, CascadeType)}
*
* @param strategy TODO
* @param p
* @param returned
* @param objectVertex
*/
private void loadMap(GraphDatabaseDriver driver, GraphMappingStrategy strategy, ClassLoader classLoader, ServiceRepository repository, Property p, DataType returned, Vertex objectVertex, ObjectCache objectsBeingAccessed) {
boolean eagerLoad = false;
// property may be associated to a onetomany or manytomany mapping. in such a case, check if there is an eager loading info
OneToMany oneToMany = p.getAnnotation(OneToMany.class);
if (oneToMany != null) {
eagerLoad = FetchType.EAGER.equals(oneToMany.fetch());
}
if (!eagerLoad) {
ManyToMany manyToMany = p.getAnnotation(ManyToMany.class);
if (manyToMany != null) {
eagerLoad = FetchType.EAGER.equals(manyToMany.fetch());
}
}
Map generatedCollection = (Map) Utils.generateMap((Class) p.getType(), null);
MapLazyLoader handler = new MapLazyLoader(driver, strategy, classLoader, repository, p, objectVertex, generatedCollection, objectsBeingAccessed);
if (eagerLoad) {
handler.loadMap(generatedCollection, objectsBeingAccessed);
p.set(returned, generatedCollection);
} else {
// Java proxy code
p.set(returned, Proxy.newProxyInstance(
classLoader,
new Class[]{p.getType(), Serializable.class, WriteReplaceable.class},
handler));
}
}
/**
* Load a single-valued property from graph
*
* @param strategy TODO
* @param p
* @param returned
* @param objectVertex
* @param objectsBeingAccessed
*/
private void loadSingle(GraphDatabaseDriver driver, GraphMappingStrategy strategy, ClassLoader classloader, ServiceRepository repository, Property p, DataType returned, Vertex objectVertex, ObjectCache objectsBeingAccessed) {
Iterator iterator = strategy.getOutEdgesFor(objectVertex, p).iterator();
Object value = null;
if (iterator.hasNext()) {
// yeah, there is a value !
Edge edge = iterator.next();
Vertex firstVertex = edge.getVertex(Direction.IN);
value = GraphUtils.createInstance(driver, strategy, classloader, firstVertex, p.getType(), repository, objectsBeingAccessed);
if (repository.containsKey(value.getClass())) {
// value requires fields loading
AbstractBluePrintsBackedFinderService blueprints = (AbstractBluePrintsBackedFinderService) repository.get(value.getClass());
value = loadObject(blueprints, firstVertex, objectsBeingAccessed);
}
} else {
if(hasLiteralProperty(p, objectVertex)) {
value = loadSingleLiteral(classloader, p, objectVertex, objectsBeingAccessed);
}
}
if(value!=null) {
p.set(returned, value);
}
}
public boolean hasLiteralProperty(Property p, Vertex objectVertex) {
return objectVertex.getProperty(GraphUtils.getEdgeNameFor(p))!=null;
}
public static Object loadSingleLiteral(ClassLoader classloader, Property p, Vertex objectVertex, ObjectCache objectsBeingAccessed) {
// if no edge exist, we may be in the case of a literal stored in node property. In that case, check if vertex has a property having same name than edge
String propertyValue = objectVertex.getProperty(GraphUtils.getEdgeNameFor(p));
if(propertyValue==null)
return null;
return LiteralHelper.getLiteralFromText(classloader, objectsBeingAccessed, p, propertyValue);
}
/**
* Load collection corresponding to the given property for the given vertex.
* BEWARE : here be lazy loading !
*
* @param strategy TODO
* @param p
* @param returned
* @param objectVertex
*/
private void loadCollection(
GraphDatabaseDriver driver,
GraphMappingStrategy strategy,
ClassLoader classLoader,
ServiceRepository repository,
Property p,
DataType returned,
Vertex objectVertex,
ObjectCache objectsBeingAccessed) {
// Figure out whether we want to lazy- or eager-load
boolean eagerLoad = false;
// property may be associated with a one-to-many or many-to-many mapping. in such a case, check if
// there is an eager loading info
OneToMany oneToMany = p.getAnnotation(OneToMany.class);
if (oneToMany != null) {
eagerLoad = FetchType.EAGER.equals(oneToMany.fetch());
}
if (!eagerLoad) {
ManyToMany manyToMany = p.getAnnotation(ManyToMany.class);
if (manyToMany != null) {
eagerLoad = FetchType.EAGER.equals(manyToMany.fetch());
}
}
// Get down to brass tacks
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