001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.eclipse.aether.spi.remoterepo;
020
021import org.eclipse.aether.RepositorySystemSession;
022import org.eclipse.aether.repository.RepositoryKeyFunction;
023
024/**
025 * A factory to create {@link RepositoryKeyFunction} instances.
026 *
027 * @since 2.0.14
028 */
029public interface RepositoryKeyFunctionFactory {
030    /**
031     * Returns system-wide repository key function.
032     *
033     * @param session The repository session, must not be {@code null}.
034     * @return The repository key function.
035     * @see #repositoryKeyFunction(Class, RepositorySystemSession, String, String)
036     * @see org.eclipse.aether.ConfigurationProperties#REPOSITORY_SYSTEM_REPOSITORY_KEY_FUNCTION
037     */
038    RepositoryKeyFunction systemRepositoryKeyFunction(RepositorySystemSession session);
039
040    /**
041     * Method that based on configuration returns the "repository key function". The returned function will be session
042     * cached if session is equipped with cache, otherwise it will be non cached. Method never returns {@code null}.
043     * Only the {@code configurationKey} parameter may be {@code null} in which case no configuration lookup happens
044     * but the {@code defaultValue} is directly used instead.
045     *
046     * @param owner The "owner" of key function (used to create cache-key), must not be {@code null}.
047     * @param session The repository session, must not be {@code null}.
048     * @param defaultValue The default value of repository key configuration, must not be {@code null}.
049     * @param configurationKey The configuration key to lookup configuration from, may be {@code null}, in which case
050     *                         no configuration lookup happens but the {@code defaultValue} is used to create the
051     *                         repository key function.
052     * @return The repository key function.
053     */
054    RepositoryKeyFunction repositoryKeyFunction(
055            Class<?> owner, RepositorySystemSession session, String defaultValue, String configurationKey);
056}