package org.apache.bookkeeper.meta;
/**
* 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.
*/
import java.io.Closeable;
import java.io.IOException;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
import org.apache.zookeeper.AsyncCallback;
import org.apache.bookkeeper.client.BKException;
import org.apache.bookkeeper.client.LedgerMetadata;
import org.apache.bookkeeper.proto.BookkeeperInternalCallbacks.LedgerMetadataListener;
import org.apache.bookkeeper.proto.BookkeeperInternalCallbacks.GenericCallback;
import org.apache.bookkeeper.proto.BookkeeperInternalCallbacks.Processor;
import org.apache.bookkeeper.versioning.Version;
/**
* LedgerManager takes responsibility of ledger management in client side.
*
* <ul>
* <li>How to store ledger meta (e.g. in ZooKeeper or other key/value store)
* </ul>
*/
public interface LedgerManager extends Closeable {
/**
* Create a new ledger with provided ledger id and metadata
*
* @param ledgerId
* Ledger id provided to be created
* @param metadata
* Metadata provided when creating the new ledger
* @param cb
* Callback when creating a new ledger. Return code:<ul>
* <li>{@link BKException.Code.OK} if success</li>
* <li>{@link BKException.Code.LedgerExistException} if given ledger id exist</li>
* <li>{@link BKException.Code.ZKException}/{@link BKException.Code.MetaStoreException}
* for other issue</li>
* </ul>
*/
public void createLedgerMetadata(long ledgerId, LedgerMetadata metadata, GenericCallback<Void> cb);
/**
* Remove a specified ledger metadata by ledgerId and version.
*
* @param ledgerId
* Ledger Id
* @param version
* Ledger metadata version
* @param cb
* Callback when remove ledger metadata. Return code:<ul>
* <li>{@link BKException.Code.OK} if success</li>
* <li>{@link BKException.Code.MetadataVersionException} if version doesn't match</li>
* <li>{@link BKException.Code.NoSuchLedgerExistsException} if ledger not exist</li>
* <li>{@link BKException.Code.ZKException} for other issue</li>
* </ul>
*/
public void removeLedgerMetadata(long ledgerId, Version version, GenericCallback<Void> vb);
/**
* Read ledger metadata of a specified ledger.
*
* @param ledgerId
* Ledger Id
* @param readCb
* Callback when read ledger metadata. Return code:<ul>
* <li>{@link BKException.Code.OK} if success</li>
* <li>{@link BKException.Code.NoSuchLedgerExistsException} if ledger not exist</li>
* <li>{@link BKException.Code.ZKException} for other issue</li>
* </ul>
*/
public void readLedgerMetadata(long ledgerId, GenericCallback<LedgerMetadata> readCb);
/**
* Write ledger metadata.
*
* @param ledgerId
* Ledger Id
* @param metadata
* Ledger Metadata to write
* @param cb
* Callback when finished writing ledger metadata. Return code:<ul>
* <li>{@link BKException.Code.OK} if success</li>
* <li>{@link BKException.Code.MetadataVersionException} if version in metadata doesn't match</li>
* <li>{@link BKException.Code.ZKException} for other issue</li>
* </ul>
*/
public void writeLedgerMetadata(long ledgerId, LedgerMetadata metadata, GenericCallback<Void> cb);
/**
* Register the ledger metadata <i>listener</i> on <i>ledgerId</i>.
*
* @param ledgerId
* ledger id.
* @param listener
* listener.
*/
public abstract void registerLedgerMetadataListener(long ledgerId, LedgerMetadataListener listener);
/**
* Unregister the ledger metadata <i>listener</i> on <i>ledgerId</i>.
*
* @param ledgerId
* ledger id.
* @param listener
* ledger metadata listener.
*/
public abstract void unregisterLedgerMetadataListener(long ledgerId, LedgerMetadataListener listener);
/**
* Loop to process all ledgers.
* <p>
* <ul>
* After all ledgers were processed, finalCb will be triggerred:
* <li> if all ledgers are processed done with OK, success rc will be passed to finalCb.
* <li> if some ledgers are prcoessed failed, failure rc will be passed to finalCb.
* </ul>
* </p>
*
* @param processor
* Ledger Processor to process a specific ledger
* @param finalCb
* Callback triggered after all ledgers are processed
* @param context
* Context of final callback
* @param successRc
* Success RC code passed to finalCb when callback
* @param failureRc
* Failure RC code passed to finalCb when exceptions occured.
*/
public void asyncProcessLedgers(Processor<Long> processor, AsyncCallback.VoidCallback finalCb,
Object context, int successRc, int failureRc);
/**
* Loop to scan a range of metadata from metadata storage
*
* @return will return a iterator of the Ranges
*/
public LedgerRangeIterator getLedgerRanges();
/*
* Used to represent the Ledgers range returned from the
* current scan.
*/
public static class LedgerRange {
// returned ledgers
private final SortedSet<Long> ledgers;
public LedgerRange(Set<Long> ledgers) {
this.ledgers = new TreeSet<Long>(ledgers);
}
public int size() {
return this.ledgers.size();
}
public Long start() {
return ledgers.first();
}
public Long end() {
return ledgers.last();
}
public Set<Long> getLedgers() {
return this.ledgers;
}
}
/**
* Interface of the ledger meta range iterator from
* storage (e.g. in ZooKeeper or other key/value store)
*/
interface LedgerRangeIterator {
/**
* @return true if there are records in the ledger metadata store. false
* only when there are indeed no records in ledger metadata store.
* @throws IOException thrown when there is any problem accessing the ledger
* metadata store. It is critical that it doesn't return false in the case
* in the case it fails to access the ledger metadata store. Otherwise it
* will end up deleting all ledgers by accident.
*/
public boolean hasNext() throws IOException;
/**
* Get the next element.
*
* @return the next element.
* @throws IOException thrown when there is a problem accessing the ledger
* metadata store. It is critical that it doesn't return false in the case
* in the case it fails to access the ledger metadata store. Otherwise it
* will end up deleting all ledgers by accident.
*/
public LedgerRange next() throws IOException;
}
}