/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.gora.cassandra.store;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import me.prettyprint.cassandra.model.BasicColumnFamilyDefinition;
import me.prettyprint.cassandra.service.ThriftCfDef;
import me.prettyprint.hector.api.ddl.ColumnFamilyDefinition;
import me.prettyprint.hector.api.ddl.ColumnType;
import me.prettyprint.hector.api.ddl.ComparatorType;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class CassandraMapping {
public static final Logger LOG = LoggerFactory.getLogger(CassandraMapping.class);
private static final String MAPPING_FILE = "gora-cassandra-mapping.xml";
private static final String KEYSPACE_ELEMENT = "keyspace";
private static final String NAME_ATTRIBUTE = "name";
private static final String MAPPING_ELEMENT = "class";
private static final String COLUMN_ATTRIBUTE = "qualifier";
private static final String FAMILY_ATTRIBUTE = "family";
private static final String SUPER_ATTRIBUTE = "type";
private static final String CLUSTER_ATTRIBUTE = "cluster";
private static final String HOST_ATTRIBUTE = "host";
private String hostName;
private String clusterName;
private String keyspaceName;
/**
* List of the super column families.
*/
private List<String> superFamilies = new ArrayList<String>();
/**
* Look up the column family associated to the Avro field.
*/
private Map<String, String> familyMap = new HashMap<String, String>();
/**
* Look up the column associated to the Avro field.
*/
private Map<String, String> columnMap = new HashMap<String, String>();
/**
* Look up the column family from its name.
*/
private Map<String, BasicColumnFamilyDefinition> columnFamilyDefinitions =
new HashMap<String, BasicColumnFamilyDefinition>();
/**
* Simply gets the Cassandra host name.
* @return hostName
*/
public String getHostName() {
return this.hostName;
}
/**
* Simply gets the Cassandra cluster (the machines (nodes)
* in a logical Cassandra instance) name.
* Clusters can contain multiple keyspaces.
* @return clusterName
*/
public String getClusterName() {
return this.clusterName;
}
/**
* Simply gets the Cassandra namespace for ColumnFamilies, typically one per application
* @return
*/
public String getKeyspaceName() {
return this.keyspaceName;
}
/**
* Primary class for loading Cassandra configuration from the 'MAPPING_FILE'.
*/
public CassandraMapping(Element keyspace, Element mapping) {
if (keyspace == null) {
LOG.warn("Error locating Cassandra Keyspace element!");
} else {
// LOG.info("Located Cassandra Keyspace: '" + KEYSPACE_ELEMENT + "'");
}
this.keyspaceName = keyspace.getAttributeValue(NAME_ATTRIBUTE);
if (this.keyspaceName == null) {
LOG.warn("Error locating Cassandra Keyspace name attribute!");
} else {
// LOG.info("Located Cassandra Keyspace name: '" + NAME_ATTRIBUTE + "'");
}
this.clusterName = keyspace.getAttributeValue(CLUSTER_ATTRIBUTE);
if (this.clusterName == null) {
LOG.warn("Error locating Cassandra Keyspace cluster attribute!");
} else {
// LOG.info("Located Cassandra Keyspace cluster: '" + CLUSTER_ATTRIBUTE + "'");
}
this.hostName = keyspace.getAttributeValue(HOST_ATTRIBUTE);
if (this.hostName == null) {
LOG.warn("Error locating Cassandra Keyspace host attribute!");
} else {
// LOG.info("Located Cassandra Keyspace host: '" + HOST_ATTRIBUTE + "'");
}
// load column family definitions
List<Element> elements = keyspace.getChildren();
for (Element element: elements) {
BasicColumnFamilyDefinition cfDef = new BasicColumnFamilyDefinition();
String familyName = element.getAttributeValue(NAME_ATTRIBUTE);
if (familyName == null) {
LOG.warn("Error locating column family name attribute!");
} else {
// LOG.info("Located column family name: '" + NAME_ATTRIBUTE + "'");
}
String superAttribute = element.getAttributeValue(SUPER_ATTRIBUTE);
if (superAttribute != null) {
// LOG.info("Located super column family");
this.superFamilies.add(familyName);
// LOG.info("Added super column family: '" + familyName + "'");
cfDef.setColumnType(ColumnType.SUPER);
cfDef.setSubComparatorType(ComparatorType.BYTESTYPE);
}
cfDef.setKeyspaceName(this.keyspaceName);
cfDef.setName(familyName);
cfDef.setComparatorType(ComparatorType.BYTESTYPE);
cfDef.setDefaultValidationClass(ComparatorType.BYTESTYPE.getClassName());
this.columnFamilyDefinitions.put(familyName, cfDef);
}
// load column definitions
elements = mapping.getChildren();
for (Element element: elements) {
String fieldName = element.getAttributeValue(NAME_ATTRIBUTE);
String familyName = element.getAttributeValue(FAMILY_ATTRIBUTE);
String columnName = element.getAttributeValue(COLUMN_ATTRIBUTE);
BasicColumnFamilyDefinition columnFamilyDefinition = this.columnFamilyDefinitions.get(familyName);
if (columnFamilyDefinition == null) {
LOG.warn("Family " + familyName + " was not declared in the keyspace.");
}
this.familyMap.put(fieldName, familyName);
this.columnMap.put(fieldName, columnName);
}
}
public String getFamily(String name) {
return this.familyMap.get(name);
}
public String getColumn(String name) {
return this.columnMap.get(name);
}
/**
* Read family super attribute.
* @param family the family name
* @return true is the family is a super column family
*/
public boolean isSuper(String family) {
return this.superFamilies.indexOf(family) != -1;
}
public List<ColumnFamilyDefinition> getColumnFamilyDefinitions() {
List<ColumnFamilyDefinition> list = new ArrayList<ColumnFamilyDefinition>();
for (String key: this.columnFamilyDefinitions.keySet()) {
ColumnFamilyDefinition columnFamilyDefinition = this.columnFamilyDefinitions.get(key);
ThriftCfDef thriftCfDef = new ThriftCfDef(columnFamilyDefinition);
list.add(thriftCfDef);
}
return list;
}
}