eolivelli commented on a change in pull request #510: Issue-605 BP-15 New CreateLedger API URL: https://github.com/apache/bookkeeper/pull/510#discussion_r142381203
########## File path: bookkeeper-server/src/main/java/org/apache/bookkeeper/client/api/ReadHandle.java ########## @@ -0,0 +1,97 @@ +/** + * 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.client.api; + +import java.util.concurrent.CompletableFuture; + +/** + * Provide read access to a ledger. + * + * @since 4.6 + */ +public interface ReadHandle extends Handle { + + /** + * Read a sequence of entries asynchronously. + * + * @param firstEntry + * id of first entry of sequence + * @param lastEntry + * id of last entry of sequence, inclusive + * @return an handle to the result of the operation + */ + CompletableFuture<Iterable<LedgerEntry>> read(long firstEntry, long lastEntry); + + /** + * Read a sequence of entries asynchronously, allowing to read after the LastAddConfirmed range. + * <br>This is the same of + * {@link #asyncReadEntries(long, long, org.apache.bookkeeper.client.AsyncCallback.ReadCallback, java.lang.Object) } + * but it lets the client read without checking the local value of LastAddConfirmed, so that it is possibile to + * read entries for which the writer has not received the acknowledge yet. <br> + * For entries which are within the range 0..LastAddConfirmed BookKeeper guarantees that the writer has successfully + * received the acknowledge.<br> + * For entries outside that range it is possible that the writer never received the acknowledge + * and so there is the risk that the reader is seeing entries before the writer and this could + * result in a consistency issue in some cases.<br> + * With this method you can even read entries before the LastAddConfirmed and entries after it with one call, + * the expected consistency will be as described above for each subrange of ids. + * + * @param firstEntry + * id of first entry of sequence + * @param lastEntry + * id of last entry of sequence, inclusive + * @return an handle to the result of the operation + * + * @see #read(long, long) + * @see #readLastConfirmedEntryId() + */ + CompletableFuture<Iterable<LedgerEntry>> readUnconfirmed(long firstEntry, long lastEntry); + + /** + * Obtains asynchronously the last confirmed write from a quorum of bookies. This + * call obtains the the last add confirmed each bookie has received for this ledger + * and returns the maximum. If the ledger has been closed, the value returned by this + * call may not correspond to the id of the last entry of the ledger, since it reads + * the hint of bookies. Consequently, in the case the ledger has been closed, it may + * return a different value than getLastAddConfirmed, which returns the local value + * of the ledger handle. + * + * @return an handle to the result of the operation + * @see #getLastAddConfirmed() + * + */ + CompletableFuture<Long> readLastConfirmedEntryId(); Review comment: ok wil change to readLastAddConfirmed ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
