1 /* 2 * Copyright 2017, OpenCensus Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package io.opencensus.contrib.agent; 18 19 import static com.google.common.base.Preconditions.checkArgument; 20 import static com.google.common.base.Preconditions.checkNotNull; 21 22 import com.google.common.annotations.VisibleForTesting; 23 import com.google.common.base.Strings; 24 import com.typesafe.config.Config; 25 import com.typesafe.config.ConfigFactory; 26 import io.opencensus.common.Internal; 27 28 /** 29 * The {@code Settings} class provides access to user-configurable settings. 30 * 31 * @since 0.10 32 */ 33 public class Settings { 34 35 private static final String CONFIG_ROOT = "opencensus.contrib.agent"; 36 37 private final Config config; 38 39 /** Creates agent settings. */ 40 @Internal 41 @VisibleForTesting Settings(Config config)42 public Settings(Config config) { 43 this.config = checkNotNull(config); 44 } 45 load()46 static Settings load() { 47 return new Settings(readConfig()); 48 } 49 readConfig()50 private static Config readConfig() { 51 Config config = ConfigFactory.load(); 52 config.checkValid(ConfigFactory.defaultReference(), CONFIG_ROOT); 53 54 return config.getConfig(CONFIG_ROOT); 55 } 56 57 /** 58 * Checks whether a feature is enabled in the effective configuration. 59 * 60 * <p>A feature is identified by a path expression relative to {@link #CONFIG_ROOT}, such as 61 * {@code context-propagation.executor}. The feature is enabled iff the config element at the 62 * requested path has a child element {@code enabled} with a value of {@code true}, {@code on}, or 63 * {@code yes}. 64 * 65 * @param featurePath the feature's path expression 66 * @return true, if enabled, otherwise false 67 * @since 0.10 68 */ isEnabled(String featurePath)69 public boolean isEnabled(String featurePath) { 70 checkArgument(!Strings.isNullOrEmpty(featurePath)); 71 72 return config.getConfig(featurePath).getBoolean("enabled"); 73 } 74 } 75