001// *************************************************************************************************************************** 002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file * 003// * distributed with this work for additional information regarding copyright ownership. The ASF licenses this file * 004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance * 005// * with the License. You may obtain a copy of the License at * 006// * * 007// * http://www.apache.org/licenses/LICENSE-2.0 * 008// * * 009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an * 010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the * 011// * specific language governing permissions and limitations under the License. * 012// *************************************************************************************************************************** 013package org.apache.juneau.config.store; 014 015import static org.apache.juneau.internal.StringUtils.*; 016 017import java.io.*; 018import java.util.concurrent.*; 019 020import org.apache.juneau.*; 021import org.apache.juneau.annotation.*; 022 023/** 024 * Filesystem-based storage location for configuration files. 025 * 026 * <p> 027 * Points to a file system directory containing configuration files. 028 */ 029@ConfigurableContext 030public class ConfigMemoryStore extends ConfigStore { 031 032 //------------------------------------------------------------------------------------------------------------------- 033 // Configurable properties 034 //------------------------------------------------------------------------------------------------------------------- 035 036 static final String PREFIX = "ConfigMemoryStore"; 037 038 //------------------------------------------------------------------------------------------------------------------- 039 // Predefined instances 040 //------------------------------------------------------------------------------------------------------------------- 041 042 /** Default memory store, all default values.*/ 043 public static final ConfigMemoryStore DEFAULT = ConfigMemoryStore.create().build(); 044 045 046 //------------------------------------------------------------------------------------------------------------------- 047 // Instance 048 //------------------------------------------------------------------------------------------------------------------- 049 050 /** 051 * Create a new builder for this object. 052 * 053 * @return A new builder for this object. 054 */ 055 public static ConfigMemoryStoreBuilder create() { 056 return new ConfigMemoryStoreBuilder(); 057 } 058 059 @Override /* Context */ 060 public ConfigMemoryStoreBuilder builder() { 061 return new ConfigMemoryStoreBuilder(getPropertyStore()); 062 } 063 064 private final ConcurrentHashMap<String,String> cache = new ConcurrentHashMap<>(); 065 066 /** 067 * Constructor. 068 * 069 * @param ps The settings for this content store. 070 */ 071 protected ConfigMemoryStore(PropertyStore ps) { 072 super(ps); 073 } 074 075 @Override /* ConfigStore */ 076 public synchronized String read(String name) { 077 return emptyIfNull(cache.get(name)); 078 } 079 080 @Override /* ConfigStore */ 081 public synchronized String write(String name, String expectedContents, String newContents) { 082 083 // This is a no-op. 084 if (isEquals(expectedContents, newContents)) 085 return null; 086 087 String currentContents = read(name); 088 089 if (expectedContents != null && ! isEquals(currentContents, expectedContents)) 090 return currentContents; 091 092 update(name, newContents); 093 094 return null; 095 } 096 097 @Override /* ConfigStore */ 098 public synchronized boolean exists(String name) { 099 return cache.containsKey(name); 100 } 101 102 @Override /* ConfigStore */ 103 public synchronized ConfigMemoryStore update(String name, String newContents) { 104 if (newContents == null) 105 cache.remove(name); 106 else 107 cache.put(name, newContents); 108 super.update(name, newContents); // Trigger any listeners. 109 return this; 110 } 111 112 /** 113 * No-op. 114 */ 115 @Override /* Closeable */ 116 public void close() throws IOException { 117 // No-op 118 } 119 120 //----------------------------------------------------------------------------------------------------------------- 121 // Other methods. 122 //----------------------------------------------------------------------------------------------------------------- 123 124 @Override /* Context */ 125 public ObjectMap toMap() { 126 return super.toMap() 127 .append("ConfigMemoryStore", new DefaultFilteringObjectMap() 128 ); 129 } 130}