| /** |
| * 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.bookkeeper.meta; |
| |
| import java.io.IOException; |
| |
| import org.apache.bookkeeper.client.BKException; |
| import org.apache.bookkeeper.proto.BookkeeperInternalCallbacks.GenericCallback; |
| import org.apache.bookkeeper.util.ZkUtils; |
| import org.apache.commons.lang.StringUtils; |
| import org.apache.zookeeper.AsyncCallback; |
| import org.apache.zookeeper.AsyncCallback.StringCallback; |
| import org.apache.zookeeper.CreateMode; |
| import org.apache.zookeeper.KeeperException; |
| import org.apache.zookeeper.ZooDefs.Ids; |
| import org.apache.zookeeper.ZooKeeper; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * ZooKeeper based ledger id generator class, which using EPHEMERAL_SEQUENTIAL |
| * with <i>(ledgerIdGenPath)/ID-</i> prefix to generate ledger id. Note |
| * zookeeper sequential counter has a format of %10d -- that is 10 digits with 0 |
| * (zero) padding, i.e. "<path>0000000001", so ledger id space is |
| * fundamentally limited to 9 billion. |
| */ |
| public class ZkLedgerIdGenerator implements LedgerIdGenerator { |
| static final Logger LOG = LoggerFactory.getLogger(ZkLedgerIdGenerator.class); |
| |
| final ZooKeeper zk; |
| final String ledgerIdGenPath; |
| final String ledgerPrefix; |
| |
| public ZkLedgerIdGenerator(ZooKeeper zk, |
| String ledgersPath, |
| String idGenZnodeName) { |
| this.zk = zk; |
| if (StringUtils.isBlank(idGenZnodeName)) { |
| this.ledgerIdGenPath = ledgersPath; |
| } else { |
| this.ledgerIdGenPath = ledgersPath + "/" + idGenZnodeName; |
| } |
| this.ledgerPrefix = this.ledgerIdGenPath + "/ID-"; |
| } |
| |
| @Override |
| public void generateLedgerId(final GenericCallback<Long> cb) { |
| ZkUtils.asyncCreateFullPathOptimistic(zk, ledgerPrefix, new byte[0], Ids.OPEN_ACL_UNSAFE, |
| CreateMode.EPHEMERAL_SEQUENTIAL, |
| new StringCallback() { |
| @Override |
| public void processResult(int rc, String path, Object ctx, final String idPathName) { |
| if (rc != KeeperException.Code.OK.intValue()) { |
| LOG.error("Could not generate new ledger id", |
| KeeperException.create(KeeperException.Code.get(rc), path)); |
| cb.operationComplete(BKException.Code.ZKException, null); |
| return; |
| } |
| |
| /* |
| * Extract ledger id from generated path |
| */ |
| long ledgerId; |
| try { |
| ledgerId = getLedgerIdFromGenPath(idPathName); |
| cb.operationComplete(BKException.Code.OK, ledgerId); |
| } catch (IOException e) { |
| LOG.error("Could not extract ledger-id from id gen path:" + path, e); |
| cb.operationComplete(BKException.Code.ZKException, null); |
| return; |
| } |
| |
| // delete the znode for id generation |
| zk.delete(idPathName, -1, new AsyncCallback.VoidCallback() { |
| @Override |
| public void processResult(int rc, String path, Object ctx) { |
| if (rc != KeeperException.Code.OK.intValue()) { |
| LOG.warn("Exception during deleting znode for id generation : ", |
| KeeperException.create(KeeperException.Code.get(rc), path)); |
| } else { |
| LOG.debug("Deleting znode for id generation : {}", idPathName); |
| } |
| } |
| }, null); |
| } |
| }, null); |
| } |
| |
| // get ledger id from generation path |
| private long getLedgerIdFromGenPath(String nodeName) throws IOException { |
| long ledgerId; |
| try { |
| String parts[] = nodeName.split(ledgerPrefix); |
| ledgerId = Long.parseLong(parts[parts.length - 1]); |
| } catch (NumberFormatException e) { |
| throw new IOException(e); |
| } |
| return ledgerId; |
| } |
| |
| @Override |
| public void close() throws IOException { |
| } |
| |
| } |