| /** |
| * 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.mledger.impl; |
| |
| import org.apache.bookkeeper.client.api.ReadHandle; |
| import org.apache.bookkeeper.mledger.AsyncCallbacks.ReadEntriesCallback; |
| import org.apache.bookkeeper.mledger.AsyncCallbacks.ReadEntryCallback; |
| import org.apache.commons.lang3.tuple.Pair; |
| |
| /** |
| * Cache of entries used by a single ManagedLedger. An EntryCache is compared to other EntryCache instances using their |
| * size (the memory that is occupied by each of them). |
| */ |
| public interface EntryCache extends Comparable<EntryCache> { |
| |
| /** |
| * @return the name of the cache |
| */ |
| String getName(); |
| |
| /** |
| * Insert an entry in the cache. |
| * |
| * <p/>If the overall limit have been reached, this will triggered the eviction of other entries, possibly from |
| * other EntryCache instances |
| * |
| * @param entry |
| * the entry to be cached |
| * @return whether the entry was inserted in cache |
| */ |
| boolean insert(EntryImpl entry); |
| |
| /** |
| * Remove from cache all the entries related to a ledger up to lastPosition included. |
| * |
| * @param lastPosition |
| * the position of the last entry to be invalidated (non-inclusive) |
| */ |
| void invalidateEntries(PositionImpl lastPosition); |
| |
| void invalidateEntriesBeforeTimestamp(long timestamp); |
| |
| /** |
| * Remove from the cache all the entries belonging to a specific ledger. |
| * |
| * @param ledgerId |
| * the ledger id |
| */ |
| void invalidateAllEntries(long ledgerId); |
| |
| /** |
| * Remove all the entries from the cache. |
| */ |
| void clear(); |
| |
| /** |
| * Force the cache to drop entries to free space. |
| * |
| * @param sizeToFree |
| * the total memory size to free |
| * @return a pair containing the number of entries evicted and their total size |
| */ |
| Pair<Integer, Long> evictEntries(long sizeToFree); |
| |
| /** |
| * Read entries from the cache or from bookkeeper. |
| * |
| * <p/>Get the entry data either from cache or bookkeeper and mixes up the results in a single list. |
| * |
| * @param lh |
| * the ledger handle |
| * @param firstEntry |
| * the first entry to read (inclusive) |
| * @param lastEntry |
| * the last entry to read (inclusive) |
| * @param isSlowestReader |
| * whether the reader cursor is the most far behind in the stream |
| * @param callback |
| * the callback object that will be notified when read is done |
| * @param ctx |
| * the context object |
| */ |
| void asyncReadEntry(ReadHandle lh, long firstEntry, long lastEntry, boolean isSlowestReader, |
| ReadEntriesCallback callback, Object ctx); |
| |
| /** |
| * Read entry at given position from the cache or from bookkeeper. |
| * |
| * <p/>Get the entry data either from cache or bookkeeper and mixes up the results in a single list. |
| * |
| * @param lh |
| * the ledger handle |
| * @param position |
| * position to read the entry from |
| * @param callback |
| * the callback object that will be notified when read is done |
| * @param ctx |
| * the context object |
| */ |
| void asyncReadEntry(ReadHandle lh, PositionImpl position, ReadEntryCallback callback, Object ctx); |
| |
| /** |
| * Get the total size in bytes of all the entries stored in this cache. |
| * |
| * @return the size of the entry cache |
| */ |
| long getSize(); |
| } |