Configurable cache file name (#49)

* Added support for custom cache file name.

Handy when you have configured two feeds pointing to the same packages
folder.

* added some air after commas in type parameter

* added curlies, even on one liners

* renamed misleading InitializeServerPackageStore method to InitializeServerPackageCache

* Updated XML comment explaining the custom cache file name option

* Throwing up on invalid cache file name. Added tests to prove it.

* compacting test arrange code

Author: apeneve

samples/NuGet.Server.V2.Samples.OwinHost/DictionarySettingsProvider.cs

@@ -1,15 +1,16 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information. 
+using System;
 using System.Collections.Generic;
 using NuGet.Server.Core.Infrastructure;
 
 namespace NuGet.Server.V2.Samples.OwinHost
 {
     public class DictionarySettingsProvider : ISettingsProvider
     {
-        readonly Dictionary<string, bool> _settings;
+        readonly Dictionary<string, object> _settings;
 
-        public DictionarySettingsProvider(Dictionary<string, bool> settings)
+        public DictionarySettingsProvider(Dictionary<string, object> settings)
         {
             _settings = settings;
         }
@@ -18,8 +19,13 @@ public DictionarySettingsProvider(Dictionary<string, bool> settings)
         public bool GetBoolSetting(string key, bool defaultValue)
         {
             System.Diagnostics.Debug.WriteLine("getSetting: " + key);
-            return _settings.ContainsKey(key) ? _settings[key] : defaultValue;
+            return _settings.ContainsKey(key) ? Convert.ToBoolean(_settings[key]) : defaultValue;
 
         }
+
+        public string GetStringSetting(string key, string defaultValue)
+        {
+            return _settings.ContainsKey(key) ? Convert.ToString(_settings[key]) : defaultValue;
+        }
     }
 }

samples/NuGet.Server.V2.Samples.OwinHost/Program.cs

@@ -24,7 +24,7 @@ static void Main(string[] args)
 
             // Set up a common settingsProvider to be used by all repositories. 
             // If a setting is not present in dictionary default value will be used.
-            var settings = new Dictionary<string, bool>();
+            var settings = new Dictionary<string, object>();
             settings.Add("enableDelisting", false);                         //default=false
             settings.Add("enableFrameworkFiltering", false);                //default=false
             settings.Add("ignoreSymbolsPackages", true);                    //default=false

src/NuGet.Server.Core/Infrastructure/DefaultSettingsProvider.cs

@@ -8,5 +8,10 @@ public bool GetBoolSetting(string key, bool defaultValue)
         {
             return defaultValue;
         }
+
+        public string GetStringSetting(string key, string defaultValue)
+        {
+            return defaultValue;
+        }
     }
 }

src/NuGet.Server.Core/Infrastructure/ISettingsProvider.cs

@@ -5,5 +5,6 @@ namespace NuGet.Server.Core.Infrastructure
     public interface ISettingsProvider
     {
         bool GetBoolSetting(string key, bool defaultValue);
+        string GetStringSetting(string key, string defaultValue);
     }
 }

src/NuGet.Server.Core/Infrastructure/ServerPackageRepository.cs

@@ -58,7 +58,7 @@ public ServerPackageRepository(
             _runBackgroundTasks = true;
             _settingsProvider = settingsProvider ?? new DefaultSettingsProvider();
             _logger = logger ?? new TraceLogger();
-            _serverPackageCache = InitializeServerPackageStore();
+            _serverPackageCache = InitializeServerPackageCache();
             _serverPackageStore = new ServerPackageStore(
                 _fileSystem,
                 new ExpandedPackageRepository(_fileSystem, hashProvider),
@@ -81,7 +81,7 @@ internal ServerPackageRepository(
             _runBackgroundTasks = runBackgroundTasks;
             _settingsProvider = settingsProvider ?? new DefaultSettingsProvider();
             _logger = logger ?? new TraceLogger();
-            _serverPackageCache = InitializeServerPackageStore();
+            _serverPackageCache = InitializeServerPackageCache();
             _serverPackageStore = new ServerPackageStore(
                 _fileSystem,
                 innerRepository,
@@ -105,9 +105,39 @@ internal ServerPackageRepository(
         private bool EnableFileSystemMonitoring =>
             _settingsProvider.GetBoolSetting("enableFileSystemMonitoring", true);
 
-        private ServerPackageCache InitializeServerPackageStore()
+        private string CacheFileName => _settingsProvider.GetStringSetting("cacheFileName", null);
+
+        private ServerPackageCache InitializeServerPackageCache()
         {
-            return new ServerPackageCache(_fileSystem, Environment.MachineName.ToLowerInvariant() + ".cache.bin");
+            return new ServerPackageCache(_fileSystem, ResolveCacheFileName());
+        }
+
+        private string ResolveCacheFileName()
+        {
+            var fileName = CacheFileName;
+            const string suffix = ".cache.bin";
+
+            if (String.IsNullOrWhiteSpace(fileName))
+            {
+                // Default file name
+                return Environment.MachineName.ToLowerInvariant() + suffix;
+            }
+
+            if (fileName.LastIndexOfAny(Path.GetInvalidFileNameChars()) > 0)
+            {
+                var message = string.Format(Strings.Error_InvalidCacheFileName, fileName);
+
+                _logger.Log(LogLevel.Error, message);
+
+                throw new InvalidOperationException(message);
+            }
+
+            if (fileName.EndsWith(suffix, StringComparison.OrdinalIgnoreCase))
+            {
+                return fileName;
+            }
+
+            return fileName + suffix;
         }
 
         /// <summary>

src/NuGet.Server.Core/Strings.Designer.cs

@@ -117,6 +117,9 @@
   <resheader name="writer">
     <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </resheader>
+  <data name="Error_InvalidCacheFileName" xml:space="preserve">
+    <value>Configured cache file name '{0}' is invalid. Keep it simple; No paths allowed.</value>
+  </data>
   <data name="Error_PackageAlreadyExists" xml:space="preserve">
     <value>Package {0} already exists. The server is configured to not allow overwriting packages that already exist.</value>
   </data>

src/NuGet.Server.Core/Strings.resx

@@ -28,5 +28,11 @@ public bool GetBoolSetting(string key, bool defaultValue)
             bool value;
             return !bool.TryParse(settings[key], out value) ? defaultValue : value;
         }
+
+        public string GetStringSetting(string key, string defaultValue)
+        {
+            var settings = _getSettings();
+            return settings[key] ?? defaultValue;
+        }
     }
 }

src/NuGet.Server/Infrastructure/WebConfigSettingsProvider.cs

@@ -22,6 +22,12 @@
     -->
     <add key="packagesPath" value="" />
 
+    <!--
+    Change the name of the internal cache file. Default is machine name (System.Environment.MachineName).
+    This is the name of the cache file in the packages folder. No paths allowed.
+    -->
+    <add key="cacheFileName" value="" />
+
     <!--
     Set allowOverrideExistingPackageOnPush to false to mimic NuGet.org's behaviour (do not allow overwriting packages with same id + version).
     -->

src/NuGet.Server/Web.config

@@ -7,8 +7,8 @@ namespace NuGet.Server.Core.Tests.Infrastructure
 {
     class FuncSettingsProvider : ISettingsProvider
     {
-        readonly Func<string, bool, bool> _getSetting;
-        internal FuncSettingsProvider(Func<string,bool,bool> getSetting)
+        readonly Func<string, object, object> _getSetting;
+        internal FuncSettingsProvider(Func<string, object, object> getSetting)
         {
             if (getSetting == null)
             {
@@ -20,7 +20,12 @@ internal FuncSettingsProvider(Func<string,bool,bool> getSetting)
 
         public bool GetBoolSetting(string key, bool defaultValue)
         {
-            return _getSetting(key, defaultValue);
+            return Convert.ToBoolean(_getSetting(key, defaultValue));
+        }
+
+        public string GetStringSetting(string key, string defaultValue)
+        {
+            return Convert.ToString(_getSetting(key, defaultValue));
         }
     }
 }