/*
* Copyright 2010 The Apache Software Foundation
*
* 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.hadoop.hbase.rest;
import java.io.IOException;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.util.StringUtils;
import org.apache.hadoop.hbase.DoNotRetryIOException;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.HTableInterface;
import org.apache.hadoop.hbase.client.HTablePool;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.regionserver.NoSuchColumnFamilyException;
public class RowResultGenerator extends ResultGenerator {
private static final Log LOG = LogFactory.getLog(RowResultGenerator.class);
private Iterator<KeyValue> valuesI;
private KeyValue cache;
public RowResultGenerator(final String tableName, final RowSpec rowspec,
final Filter filter) throws IllegalArgumentException, IOException {
HTablePool pool = RESTServlet.getInstance().getTablePool();
HTableInterface table = pool.getTable(tableName);
try {
Get get = new Get(rowspec.getRow());
if (rowspec.hasColumns()) {
for (byte[] col: rowspec.getColumns()) {
byte[][] split = KeyValue.parseColumn(col);
if (split.length == 2 && split[1].length != 0) {
get.addColumn(split[0], split[1]);
} else {
get.addFamily(split[0]);
}
}
} else {
// rowspec does not explicitly specify columns, return them all
for (HColumnDescriptor family:
table.getTableDescriptor().getFamilies()) {
get.addFamily(family.getName());
}
}
get.setTimeRange(rowspec.getStartTime(), rowspec.getEndTime());
get.setMaxVersions(rowspec.getMaxVersions());
if (filter != null) {
get.setFilter(filter);
}
Result result = table.get(get);
if (result != null && !result.isEmpty()) {
valuesI = result.list().iterator();
}
} catch (DoNotRetryIOException e) {
// Warn here because Stargate will return 404 in the case if multiple
// column families were specified but one did not exist -- currently
// HBase will fail the whole Get.
// Specifying multiple columns in a URI should be uncommon usage but
// help to avoid confusion by leaving a record of what happened here in
// the log.
LOG.warn(StringUtils.stringifyException(e));
} finally {
pool.putTable(table);
}
}
public void close() {
}
public boolean hasNext() {
if (cache != null) {
return true;
}
if (valuesI == null) {
return false;
}
return valuesI.hasNext();
}
public KeyValue next() {
if (cache != null) {
KeyValue kv = cache;
cache = null;
return kv;
}
if (valuesI == null) {
return null;
}
try {
return valuesI.next();
} catch (NoSuchElementException e) {
return null;
}
}
public void putBack(KeyValue kv) {
this.cache = kv;
}
public void remove() {
throw new UnsupportedOperationException("remove not supported");
}
}