/**
* 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.query;
import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Iterator;
import org.apache.gora.cassandra.client.CassandraClient;
import org.apache.gora.cassandra.client.Row;
import org.apache.gora.cassandra.client.Select;
import org.apache.gora.cassandra.store.CassandraStore;
import org.apache.gora.persistency.Persistent;
import org.apache.gora.query.Query;
import org.apache.gora.query.impl.ResultBase;
import org.apache.gora.store.DataStore;
public class CassandraResult<K, T extends Persistent>
extends ResultBase<K, T> {
private Iterator<Row> rowIter;
private CassandraStore<K, T> store;
private String[] fields;
public CassandraResult(DataStore<K, T> dataStore, Query<K, T> query,
int batchRowCount) throws IOException {
super(dataStore, query);
store = (CassandraStore<K, T>) dataStore;
fields = query.getFields();
boolean isUsingTokens = (query instanceof CassandraPartitionQuery);
String startTokenOrKey;
String endTokenOrKey;
if (isUsingTokens) {
CassandraPartitionQuery<K, T> partitionQuery = (CassandraPartitionQuery<K, T>) query;
startTokenOrKey = partitionQuery.getStartToken();
endTokenOrKey = partitionQuery.getEndToken();
} else {
CassandraQuery<K, T> cassandraQuery = (CassandraQuery<K, T>) query;
startTokenOrKey = cassandraQuery.getStartKey().toString();
endTokenOrKey = cassandraQuery.getEndKey().toString();
}
Select select = store.createSelect(fields);
CassandraClient client = store.getClientByLocation(getLocation(query));
if (isUsingTokens) {
rowIter =
client.getTokenRange(startTokenOrKey, endTokenOrKey,
batchRowCount, select).iterator();
} else {
rowIter = client.getRange(startTokenOrKey, endTokenOrKey,
batchRowCount, select).iterator();
}
}
@Override
public float getProgress() throws IOException {
return 0;
}
@Override
protected boolean nextInner() throws IOException {
if (!rowIter.hasNext()) {
return false;
}
Row row = rowIter.next();
if (row == null) {
return false;
}
key = toKey(row.getKey());
persistent = store.newInstance(row, fields);
return true;
}
@SuppressWarnings("unchecked")
private K toKey(String keyStr) {
Class<K> keyClass = dataStore.getKeyClass();
if (keyClass.isAssignableFrom(String.class)) {
return (K) keyStr;
}
if (keyClass.isAssignableFrom(Integer.class)) {
return (K) (Integer) Integer.parseInt(keyStr);
}
if (keyClass.isAssignableFrom(Float.class)) {
return (K) (Float) Float.parseFloat(keyStr);
}
if (keyClass.isAssignableFrom(Double.class)) {
return (K) (Double) Double.parseDouble(keyStr);
}
if (keyClass.isAssignableFrom(Long.class)) {
return (K) (Long) Long.parseLong(keyStr);
}
if (keyClass.isAssignableFrom(Short.class)) {
return (K) (Short) Short.parseShort(keyStr);
}
if (keyClass.isAssignableFrom(Byte.class)) {
return (K) (Byte) Byte.parseByte(keyStr);
}
throw new RuntimeException("Can't parse " + keyStr +
" as an instance of " + keyClass);
}
@Override
public void close() throws IOException { }
private String getLocation(Query<K, T> query) {
if (!(query instanceof CassandraPartitionQuery)) {
return null;
}
CassandraPartitionQuery<K, T> partitonQuery =
(CassandraPartitionQuery<K, T>) query;
InetAddress[] localAddresses = new InetAddress[0];
try {
localAddresses = InetAddress.getAllByName(InetAddress.getLocalHost().getHostAddress());
} catch (UnknownHostException e) {
throw new AssertionError(e);
}
for (InetAddress address : localAddresses) {
for (String location : partitonQuery.getEndPoints()) {
InetAddress locationAddress = null;
try {
locationAddress = InetAddress.getByName(location);
} catch (UnknownHostException e) {
throw new AssertionError(e);
}
if (address.equals(locationAddress)) {
return location;
}
}
}
return partitonQuery.getEndPoints()[0];
}
}