| /** |
| * 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.quotas; |
| |
| import java.io.Closeable; |
| import java.io.IOException; |
| import java.util.Iterator; |
| import java.util.LinkedList; |
| import java.util.Objects; |
| import java.util.Queue; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.hbase.util.Bytes; |
| import org.apache.yetus.audience.InterfaceAudience; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| import org.apache.hadoop.hbase.client.Connection; |
| import org.apache.hadoop.hbase.client.ConnectionFactory; |
| import org.apache.hadoop.hbase.client.Result; |
| import org.apache.hadoop.hbase.client.ResultScanner; |
| import org.apache.hadoop.hbase.client.Scan; |
| import org.apache.hadoop.hbase.client.Table; |
| import org.apache.hadoop.util.StringUtils; |
| |
| /** |
| * Scanner to iterate over the quota settings. |
| */ |
| @InterfaceAudience.Public |
| public class QuotaRetriever implements Closeable, Iterable<QuotaSettings> { |
| private static final Logger LOG = LoggerFactory.getLogger(QuotaRetriever.class); |
| |
| private final Queue<QuotaSettings> cache = new LinkedList<>(); |
| private ResultScanner scanner; |
| /** |
| * Connection to use. |
| * Could pass one in and have this class use it but this class wants to be standalone. |
| */ |
| private Connection connection; |
| private Table table; |
| |
| /** |
| * Should QutoaRetriever manage the state of the connection, or leave it be. |
| */ |
| private boolean isManagedConnection = false; |
| |
| QuotaRetriever() { |
| } |
| |
| void init(final Configuration conf, final Scan scan) throws IOException { |
| // Set this before creating the connection and passing it down to make sure |
| // it's cleaned up if we fail to construct the Scanner. |
| this.isManagedConnection = true; |
| init(ConnectionFactory.createConnection(conf), scan); |
| } |
| |
| void init(final Connection conn, final Scan scan) throws IOException { |
| this.connection = Objects.requireNonNull(conn); |
| this.table = this.connection.getTable(QuotaTableUtil.QUOTA_TABLE_NAME); |
| try { |
| scanner = table.getScanner(scan); |
| } catch (IOException e) { |
| try { |
| close(); |
| } catch (IOException ioe) { |
| LOG.warn("Failed getting scanner and then failed close on cleanup", e); |
| } |
| throw e; |
| } |
| } |
| |
| @Override |
| public void close() throws IOException { |
| if (this.table != null) { |
| this.table.close(); |
| this.table = null; |
| } |
| // Null out the connection on close() even if we didn't explicitly close it |
| // to maintain typical semantics. |
| if (isManagedConnection) { |
| if (this.connection != null) { |
| this.connection.close(); |
| } |
| } |
| this.connection = null; |
| } |
| |
| public QuotaSettings next() throws IOException { |
| if (cache.isEmpty()) { |
| Result result = scanner.next(); |
| // Skip exceedThrottleQuota row key because this is not a QuotaSettings |
| if (result != null |
| && Bytes.equals(result.getRow(), QuotaTableUtil.getExceedThrottleQuotaRowKey())) { |
| result = scanner.next(); |
| } |
| if (result == null) { |
| return null; |
| } |
| QuotaTableUtil.parseResultToCollection(result, cache); |
| } |
| return cache.poll(); |
| } |
| |
| @Override |
| public Iterator<QuotaSettings> iterator() { |
| return new Iter(); |
| } |
| |
| private class Iter implements Iterator<QuotaSettings> { |
| QuotaSettings cache; |
| |
| public Iter() { |
| try { |
| cache = QuotaRetriever.this.next(); |
| } catch (IOException e) { |
| LOG.warn(StringUtils.stringifyException(e)); |
| } |
| } |
| |
| @Override |
| public boolean hasNext() { |
| return cache != null; |
| } |
| |
| @Override |
| public QuotaSettings next() { |
| QuotaSettings result = cache; |
| try { |
| cache = QuotaRetriever.this.next(); |
| } catch (IOException e) { |
| LOG.warn(StringUtils.stringifyException(e)); |
| } |
| return result; |
| } |
| |
| @Override |
| public void remove() { |
| throw new RuntimeException("remove() not supported"); |
| } |
| } |
| |
| /** |
| * Open a QuotaRetriever with no filter, all the quota settings will be returned. |
| * @param conf Configuration object to use. |
| * @return the QuotaRetriever |
| * @throws IOException if a remote or network exception occurs |
| */ |
| public static QuotaRetriever open(final Configuration conf) throws IOException { |
| return open(conf, null); |
| } |
| |
| /** |
| * Open a QuotaRetriever with the specified filter. |
| * @param conf Configuration object to use. |
| * @param filter the QuotaFilter |
| * @return the QuotaRetriever |
| * @throws IOException if a remote or network exception occurs |
| */ |
| public static QuotaRetriever open(final Configuration conf, final QuotaFilter filter) |
| throws IOException { |
| Scan scan = QuotaTableUtil.makeScan(filter); |
| QuotaRetriever scanner = new QuotaRetriever(); |
| scanner.init(conf, scan); |
| return scanner; |
| } |
| } |