/* * Copyright (c) Contributors, http://opensimulator.org/ * See CONTRIBUTORS.TXT for a full list of copyright holders. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of the OpenSim Project nor the * names of its contributors may be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ using System; using System.IO; using System.Xml; using System.Collections.Generic; using System.Reflection; using log4net; using Mono.Addins; namespace OpenSim.Framework { /// <summary> /// Exception thrown if an incorrect number of plugins are loaded /// </summary> public class PluginConstraintViolatedException : Exception { public PluginConstraintViolatedException () : base() {} public PluginConstraintViolatedException (string msg) : base(msg) {} public PluginConstraintViolatedException (string msg, Exception e) : base(msg, e) {} } /// <summary> /// Classes wishing to impose constraints on plugin loading must implement /// this class and pass it to PluginLoader AddConstraint() /// </summary> public interface IPluginConstraint { string Message { get; } bool Apply (string extpoint); } /// <summary> /// Classes wishing to select specific plugins from a range of possible options /// must implement this class and pass it to PluginLoader Load() /// </summary> public interface IPluginFilter { bool Apply (PluginExtensionNode plugin); } /// <summary> /// Generic Plugin Loader /// </summary> public class PluginLoader <T> : IDisposable where T : IPlugin { private const int max_loadable_plugins = 10000; private List<T> loaded = new List<T>(); private List<string> extpoints = new List<string>(); private PluginInitialiserBase initialiser; private Dictionary<string,IPluginConstraint> constraints = new Dictionary<string,IPluginConstraint>(); private Dictionary<string,IPluginFilter> filters = new Dictionary<string,IPluginFilter>(); private static readonly ILog log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType); public PluginInitialiserBase Initialiser { set { initialiser = value; } get { return initialiser; } } public List<T> Plugins { get { return loaded; } } public T Plugin { get { return (loaded.Count == 1)? loaded [0] : default (T); } } public PluginLoader () { Initialiser = new PluginInitialiserBase(); initialise_plugin_dir_ ("."); } public PluginLoader (PluginInitialiserBase init) { Initialiser = init; initialise_plugin_dir_ ("."); } public PluginLoader (PluginInitialiserBase init, string dir) { Initialiser = init; initialise_plugin_dir_ (dir); } public void Add (string extpoint) { if (extpoints.Contains (extpoint)) return; extpoints.Add (extpoint); } public void Add (string extpoint, IPluginConstraint cons) { Add (extpoint); AddConstraint (extpoint, cons); } public void Add (string extpoint, IPluginFilter filter) { Add (extpoint); AddFilter (extpoint, filter); } public void AddConstraint (string extpoint, IPluginConstraint cons) { constraints.Add (extpoint, cons); } public void AddFilter (string extpoint, IPluginFilter filter) { filters.Add (extpoint, filter); } public void Load (string extpoint) { Add (extpoint); Load(); } public void Load () { foreach (string ext in extpoints) { log.Info("[PLUGINS]: Loading extension point " + ext); if (constraints.ContainsKey (ext)) { IPluginConstraint cons = constraints [ext]; if (cons.Apply (ext)) log.Error ("[PLUGINS]: " + ext + " failed constraint: " + cons.Message); } IPluginFilter filter = null; if (filters.ContainsKey (ext)) filter = filters [ext]; foreach (PluginExtensionNode node in AddinManager.GetExtensionNodes (ext)) { log.Info("[PLUGINS]: Trying plugin " + node.Path); if ((filter != null) && (filter.Apply (node) == false)) continue; T plugin = (T) node.CreateInstance(); Initialiser.Initialise (plugin); Plugins.Add (plugin); } } } public void Dispose () { foreach (T plugin in Plugins) plugin.Dispose (); } private void initialise_plugin_dir_ (string dir) { if (AddinManager.IsInitialized == true) return; log.Info("[PLUGINS]: Initializing"); AddinManager.AddinLoadError += on_addinloaderror_; AddinManager.AddinLoaded += on_addinloaded_; clear_registry_(); suppress_console_output_ (true); AddinManager.Initialize (dir); AddinManager.Registry.Update (null); suppress_console_output_ (false); } private void on_addinloaded_(object sender, AddinEventArgs args) { log.Info ("[PLUGINS]: Plugin Loaded: " + args.AddinId); } private void on_addinloaderror_(object sender, AddinErrorEventArgs args) { if (args.Exception == null) log.Error ("[PLUGINS]: Plugin Error: " + args.Message); else log.Error ("[PLUGINS]: Plugin Error: " + args.Exception.Message + "\n" + args.Exception.StackTrace); } private void clear_registry_ () { // The Mono addin manager (in Mono.Addins.dll version 0.2.0.0) // occasionally seems to corrupt its addin cache // Hence, as a temporary solution we'll remove it before each startup try { if (Directory.Exists("addin-db-000")) Directory.Delete("addin-db-000", true); if (Directory.Exists("addin-db-001")) Directory.Delete("addin-db-001", true); } catch (IOException) { // If multiple services are started simultaneously, they may // each test whether the directory exists at the same time, and // attempt to delete the directory at the same time. However, // one of the services will likely succeed first, causing the // second service to throw an IOException. We catch it here and // continue on our merry way. // Mike 2008.08.01, patch from Zaki } } private static TextWriter prev_console_; public void suppress_console_output_ (bool save) { if (save) { prev_console_ = System.Console.Out; System.Console.SetOut(new StreamWriter(Stream.Null)); } else { if (prev_console_ != null) System.Console.SetOut(prev_console_); } } } public class PluginExtensionNode : ExtensionNode { [NodeAttribute] string provider; [NodeAttribute] string type; Type typeobj; public string Provider { get { return provider; } } public string TypeName { get { return type; } } public Type TypeObject { get { if (typeobj != null) return typeobj; if (type.Length == 0) throw new InvalidOperationException ("Type name not specified."); return typeobj = Addin.GetType (type, true); } } public object CreateInstance () { return Activator.CreateInstance (TypeObject); } } /// <summary> /// Constraint that bounds the number of plugins to be loaded. /// </summary> public class PluginCountConstraint : IPluginConstraint { private int min; private int max; public PluginCountConstraint (int exact) { min = exact; max = exact; } public PluginCountConstraint (int minimum, int maximum) { min = minimum; max = maximum; } public string Message { get { return "The number of plugins is constrained to the interval [" + min + ", " + max + "]"; } } public bool Apply (string extpoint) { int count = AddinManager.GetExtensionNodes (extpoint).Count; if ((count < min) || (count > max)) throw new PluginConstraintViolatedException (Message); return true; } } /// <summary> /// Filters out which plugin to load based on its "Provider", which is name given by in the addin.xml /// </summary> public class PluginProviderFilter : IPluginFilter { private string provider; public PluginProviderFilter (string p) { provider = p; } public bool Apply (PluginExtensionNode plugin) { return (plugin.Provider == provider); } } }