001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017package org.apache.logging.log4j.core.appender.nosql;
018
019import java.io.Closeable;
020
021/**
022 * Represents a connection to the NoSQL database. Serves as a factory for new (empty) objects and an endpoint for
023 * inserted objects.
024 *
025 * @param <T> Specifies which implementation of {@link NoSqlObject} this connection provides.
026 * @param <W> Specifies which type of database object is wrapped by the {@link NoSqlObject} implementation provided.
027 */
028public interface NoSqlConnection<W, T extends NoSqlObject<W>> extends Closeable {
029    /**
030     * Instantiates and returns a {@link NoSqlObject} instance whose properties can be configured before ultimate
031     * insertion via {@link #insertObject(NoSqlObject)}.
032     *
033     * @return a new object.
034     * @see NoSqlObject
035     */
036    T createObject();
037
038    /**
039     * Creates an array of the specified length typed to match the {@link NoSqlObject} implementation appropriate for
040     * this provider.
041     *
042     * @param length the length of the array to create.
043     * @return a new array.
044     * @see NoSqlObject
045     */
046    T[] createList(int length);
047
048    /**
049     * Inserts the given object into the underlying NoSQL database.
050     *
051     * @param object The object to insert.
052     */
053    void insertObject(NoSqlObject<W> object);
054
055    /**
056     * Closes the underlying connection. This method call should be idempotent. Only the first call should have any
057     * effect; all further calls should be ignored. It's possible the underlying connection is stateless (such as an
058     * HTTP web service), in which case this method would be a no-op. This method should also commit any open
059     * transactions, if applicable and if not already committed.
060     * <p>
061     * If this connection is part of a connection pool, executing this method should commit the transaction and return
062     * the connection to the pool, but it should not actually close the underlying connection.
063     * </p>
064     */
065    @Override
066    void close();
067
068    /**
069     * Indicates whether the underlying connection is closed. If the underlying connection is stateless (such as an
070     * HTTP web service), this method would likely always return true. Essentially, this method should only return
071     * {@code true} if a call to {@link #insertObject(NoSqlObject)} <b>will</b> fail due to the state of this object.
072     *
073     * @return {@code true} if this object is considered closed.
074     */
075    boolean isClosed();
076}