package org.neo4j.server.extension.test.delete;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.PropertyContainer;
import org.neo4j.graphdb.Relationship;
import org.neo4j.graphdb.Transaction;
import org.neo4j.graphdb.index.Index;
import org.neo4j.graphdb.index.IndexManager;
import org.neo4j.graphdb.index.RelationshipIndex;
import org.neo4j.kernel.AbstractGraphDatabase;
import org.neo4j.kernel.GraphDatabaseAPI;
import java.lang.reflect.Field;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
/**
* @author mh
* @since 02.03.11
*/
public class Neo4jDatabaseCleaner {
private GraphDatabaseAPI graph;
public Neo4jDatabaseCleaner(GraphDatabaseAPI graph) {
this.graph = graph;
}
public Map<String, Object> cleanDb() {
return cleanDb(Long.MAX_VALUE);
}
public Map<String, Object> cleanDb(long maxNodesToDelete) {
Map<String, Object> result = new HashMap<String, Object>();
Transaction tx = graph.beginTx();
try {
clearIndex(result);
removeNodes(result, maxNodesToDelete);
tx.success();
} finally {
tx.finish();
}
return result;
}
private void removeNodes(Map<String, Object> result, long maxNodesToDelete) {
Node refNode = graph.getReferenceNode();
long nodes = 0, relationships = 0;
for (Node node : graph.getAllNodes()) {
for (Relationship rel : node.getRelationships()) {
rel.delete();
relationships++;
}
if (!refNode.equals(node)) {
node.delete();
nodes++;
}
if (nodes >= maxNodesToDelete) break;
}
result.put("maxNodesToDelete", maxNodesToDelete);
result.put("nodes", nodes);
result.put("relationships", relationships);
}
private void clearIndex(Map<String, Object> result) {
IndexManager indexManager = graph.index();
result.put("node-indexes", Arrays.asList(indexManager.nodeIndexNames()));
result.put("relationship-indexes", Arrays.asList(indexManager.relationshipIndexNames()));
try {
for (String ix : indexManager.nodeIndexNames()) {
final Index<Node> index = indexManager.forNodes(ix);
getMutableIndex(index).delete();
}
for (String ix : indexManager.relationshipIndexNames()) {
final RelationshipIndex index = indexManager.forRelationships(ix);
getMutableIndex(index).delete();
}
} catch (UnsupportedOperationException uoe) {
throw new RuntimeException("Implementation detail assumption failed for cleaning readonly indexes, please make sure that the version of this extension and the Neo4j server align");
}
}
private <T extends PropertyContainer> Index<T> getMutableIndex(Index<T> index) {
final Class<? extends Index> indexClass = index.getClass();
if (indexClass.getName().endsWith("ReadOnlyIndexToIndexAdapter")) {
try {
final Field delegateIndexField = indexClass.getDeclaredField("delegate");
delegateIndexField.setAccessible(true);
return (Index<T>) delegateIndexField.get(index);
} catch (Exception e) {
throw new UnsupportedOperationException(e);
}
} else {
return index;
}
}
}