| using Microsoft.Extensions.Configuration; |
| using Microsoft.Extensions.Primitives; |
| using System; |
| using System.Collections.Concurrent; |
| using System.Collections.Generic; |
| using System.Linq; |
| using System.Security; |
| |
| namespace Lucene.Net.Configuration |
| { |
| /* |
| * 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. |
| */ |
| |
| /// <summary> |
| /// An environment variable based <see cref="IConfigurationProvider"/>. |
| /// </summary> |
| internal class EnvironmentVariablesConfigurationProvider : IConfigurationProvider |
| { |
| private readonly bool ignoreSecurityExceptionsOnRead; |
| private readonly string _prefix; |
| |
| /// <summary> |
| /// Initializes a new instance. |
| /// </summary> |
| public EnvironmentVariablesConfigurationProvider(bool ignoreSecurityExceptionsOnRead = true) : this(string.Empty, ignoreSecurityExceptionsOnRead) |
| { } |
| |
| /// <summary> |
| /// Initializes a new instance with the specified prefix. |
| /// </summary> |
| /// <param name="prefix">A prefix used to filter the environment variables.</param> |
| public EnvironmentVariablesConfigurationProvider(string prefix, bool ignoreSecurityExceptionsOnRead = true) |
| { |
| _prefix = prefix ?? string.Empty; |
| this.ignoreSecurityExceptionsOnRead = ignoreSecurityExceptionsOnRead; |
| } |
| |
| /// <summary> |
| /// Loads the environment variables. |
| /// </summary> |
| public void Load() |
| { |
| Data = new ConcurrentDictionary<string, string>(); |
| } |
| |
| /// <summary> |
| /// The configuration key value pairs for this provider. |
| /// </summary> |
| protected ConcurrentDictionary<string, string> Data { get; set; } |
| |
| public virtual bool TryGet(string key, out string value) |
| { |
| value = Data.GetOrAdd(key, (name) => |
| { |
| if (ignoreSecurityExceptionsOnRead) |
| { |
| try |
| { |
| return Environment.GetEnvironmentVariable(_prefix + name); |
| } |
| catch (SecurityException) |
| { |
| return null; |
| } |
| } |
| else |
| { |
| return Environment.GetEnvironmentVariable(_prefix + name); |
| } |
| }); |
| return (!string.IsNullOrEmpty(value)); |
| } |
| |
| |
| /// <summary> |
| /// Sets a value for a given key. |
| /// </summary> |
| /// <param name="key">The configuration key to set.</param> |
| /// <param name="value">The value to set.</param> |
| public virtual void Set(string key, string value) |
| => Data[key] = value; |
| /// <summary> |
| /// Returns the list of keys that this provider has. |
| /// </summary> |
| /// <param name="earlierKeys">The earlier keys that other providers contain.</param> |
| /// <param name="parentPath">The path for the parent IConfiguration.</param> |
| /// <returns>The list of keys for this provider.</returns> |
| public virtual IEnumerable<string> GetChildKeys( |
| IEnumerable<string> earlierKeys, |
| string parentPath) |
| { |
| var prefix = parentPath == null ? string.Empty : parentPath + ConfigurationPath.KeyDelimiter; |
| |
| return Data |
| .Where(kv => kv.Key.StartsWith(prefix, StringComparison.OrdinalIgnoreCase)) |
| .Select(kv => Segment(kv.Key, prefix.Length)) |
| .Concat(earlierKeys) |
| .OrderBy(k => k); |
| } |
| |
| private static string Segment(string key, int prefixLength) |
| { |
| var indexOf = key.IndexOf(ConfigurationPath.KeyDelimiter, prefixLength, StringComparison.OrdinalIgnoreCase); |
| return indexOf < 0 ? key.Substring(prefixLength) : key.Substring(prefixLength, indexOf - prefixLength); |
| } |
| |
| private readonly IChangeToken _reloadToken = new ConfigurationReloadToken(); |
| |
| /// <summary> |
| /// Returns a <see cref="IChangeToken"/> that can be used to listen when this provider is reloaded. |
| /// </summary> |
| /// <returns></returns> |
| public IChangeToken GetReloadToken() |
| { |
| return _reloadToken; |
| } |
| } |
| } |