com.dooapp.gaedo.blueprints.indexable.IndexBrowser Maven / Gradle / Ivy

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package com.dooapp.gaedo.blueprints.indexable;

import java.util.Iterator;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.dooapp.gaedo.blueprints.GraphUtils;
import com.dooapp.gaedo.blueprints.Kind;
import com.dooapp.gaedo.blueprints.Properties;
import com.dooapp.gaedo.blueprints.VertexHasNoPropertyException;
import com.dooapp.gaedo.blueprints.strategies.GraphMappingStrategy;
import com.dooapp.gaedo.blueprints.strategies.UnableToGetVertexTypeException;
import com.dooapp.gaedo.blueprints.transformers.Literals;
import com.tinkerpop.blueprints.CloseableIterable;
import com.tinkerpop.blueprints.IndexableGraph;
import com.tinkerpop.blueprints.Vertex;

/**
 * Browse over an index to find vertex matching given criterias
 *
 * @author ndx
 *
 */
public class IndexBrowser {
	public static interface VertexMatcher {

		String getIdOf(Vertex vertex);

		Kind getKindOf(Vertex vertex);

		String getTypeOf(Vertex vertex);

	}

	private static final Logger logger = Logger.getLogger(IndexBrowser.class.getName());

	public Vertex browseFor(IndexableGraph database, String objectVertexId, String className, VertexMatcher matcher) {
		Vertex defaultVertex = null;
		// If there is no vertex id, don't even
		if (objectVertexId == null)
			return null;
		CloseableIterable matchingIterable = getVerticesWithId(database, objectVertexId);
		try {
			for (Vertex vertex : matchingIterable) {
				String vertexTypeName = null;
				Kind vertexKind = null;
				String vertexId = null;
				try {
					// / BEWARE : order is signifiant here : read id then kind then
					// type for catch clauses to work correctly
					vertexId = matcher.getIdOf(vertex);
					vertexKind = matcher.getKindOf(vertex);
					vertexTypeName = matcher.getTypeOf(vertex);
					// this slow-down is a direct consequence of
					// https://github.com/Riduidel/gaedo/issues/66
					if (objectVertexId.equals(vertexId)) {
						switch (vertexKind) {
						case literal:
						case bnode:
						case uri:
							if (Literals.classes.getTransformer().areEquals(className, vertexTypeName)) {
								return vertex;
							}
							break;
						default:
							return vertex;
						}
					}
				} catch (VertexHasNoPropertyException e) {
					// vertex is clearly not the match we expected so just navigate
					// to next in index
					if (logger.isLoggable(Level.WARNING)) {
						logger.log(Level.WARNING, "your index may be corrupted...\nWhen looking for value=\"" + objectVertexId + "\", that vertex loaded badly", e);
					}
				} catch (UnableToGetVertexTypeException e) {
					if (GraphMappingStrategy.STRING_TYPE.equals(className)) {
						// in that very case, we can use a type-less vertex as our
						// result
						defaultVertex = vertex;
					} else {
						if (Kind.uri == vertexKind && objectVertexId.equals(vertexId))
							defaultVertex = vertex;
					}
				}
			}
		} finally {
			matchingIterable.close();
		}
		return defaultVertex;
	}

	protected CloseableIterable getVerticesWithId(IndexableGraph database, String objectVertexId) {
		return database.getIndex(IndexNames.VERTICES.getIndexName(), Vertex.class).get(Properties.value.name(), objectVertexId);
	}

}