| /* |
| * 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.cassandra.diag.store; |
| |
| import java.util.NavigableMap; |
| |
| import org.apache.cassandra.diag.DiagnosticEvent; |
| |
| /** |
| * Enables storing and retrieving {@link DiagnosticEvent}s. |
| * @param <T> type of key that is used to reference an event |
| */ |
| public interface DiagnosticEventStore<T extends Comparable<T>> |
| { |
| /** |
| * Initializes the store. |
| */ |
| void load(); |
| |
| /** |
| * Stores provided event and returns the new associated store key for it. |
| */ |
| void store(DiagnosticEvent event); |
| |
| /** |
| * Returns a view on all events with a key greater than the provided value (inclusive) up to the specified |
| * number of results. Events may be added or become unavailable over time. Keys must be unique, sortable and |
| * monotonically incrementing. Returns an empty map in case no events could be found. |
| */ |
| NavigableMap<T, DiagnosticEvent> scan(T key, int limit); |
| |
| /** |
| * Returns the greatest event ID that can be used to fetch events via {@link #scan(Comparable, int)}. |
| */ |
| T getLastEventId(); |
| } |