internal PluginDescriptorAlreadyExistsException(PluginDescriptor descriptor) :
base(string.Format("The PluginDescriptor '{0}' already exists in the collection.", descriptor.ToString()))
{
_descriptor = descriptor;
}
/// <summary>
/// Adds an array of plugin descriptors to the collection.
/// </summary>
/// <param name="descriptors">The array of descriptors to add.</param>
internal void Add(PluginDescriptor[] descriptors)
{
if (descriptors == null)
throw new ArgumentNullException("descriptors");
foreach (PluginDescriptor descriptor in descriptors)
{
this.Add(descriptor);
}
}
/// <summary>
/// Determines if the collection contains a PluginDescriptor to the same Type as the one specified.
/// </summary>
/// <param name="descriptor">The PluginDescriptor to check for</param>
/// <returns></returns>
public bool Contains(PluginDescriptor descriptor)
{
if (descriptor == null)
throw new ArgumentNullException("descriptor");
return (this[descriptor.PluginType] != null);
}
/// <summary>
/// Stops the specified plugin.
/// </summary>
/// <param name="progressViewer">The callback object implementing IProgressViewer that will be used to monitor progress.</param>
/// <param name="descriptor">The descriptor that contains the plugin to stop.</param>
private static void StopPlugin(IProgressViewer progressViewer, PluginDescriptor descriptor)
{
ProgressViewer.SetExtendedDescription(progressViewer, string.Format("Stopping Plugin: '{0}'.", descriptor.PluginName));
// stop the plugin
descriptor.PluginInstance.OnStop(PluginContext.Current, new PluginDescriptorEventArgs(descriptor));
}
/// <summary>
/// Adds a PluginDescriptor to the collection.
/// </summary>
/// <param name="descriptor">The descriptor to add to the collection</param>
internal void Add(PluginDescriptor descriptor)
{
if (this.Contains(descriptor))
throw new PluginDescriptorAlreadyExistsException(descriptor);
lock (base.SyncRoot)
{
base.InnerList.Add(descriptor);
}
}
/// <summary>
/// Determines if the dependencies for a PluginDescriptor are created.
/// </summary>
/// <param name="descriptor">The descriptor to check dependencies for.</param>
/// <param name="descriptors">The collection of PluginDescriptor(s) to check against.</param>
/// <returns></returns>
private static bool AreDependenciesCreated(PluginDescriptor descriptor, PluginDescriptorCollection descriptors)
{
foreach (Type type in descriptor.PluginDependencies)
if (descriptors[type].PluginInstance == null)
return false;
return true;
}
/// <summary>
/// Creates an instance of the Type described by the PluginDescriptor and asserts that it derives from Plugin.
/// </summary>
/// <param name="progressViewer">The callback object implementing IProgressViewer that will be used to monitor progress.</param>
/// <param name="descriptor">The PluginDescriptor that contains the Type to create.</param>
private static void CreatePluginInstance(IProgressViewer progressViewer, PluginDescriptor descriptor)
{
try
{
TypeUtilities.AssertTypeIsSubclassOfBaseType(descriptor.PluginType, typeof(Plugin));
string message = string.Format("Creating Plugin: '{0}'.", descriptor.PluginName);
ProgressViewer.SetExtendedDescription(progressViewer, message);
Log.WriteLine(message);
Plugin plugin = (Plugin)TypeUtilities.CreateInstanceOfType(descriptor.PluginType, Type.EmptyTypes, new object[] {});
descriptor.AttachPluginInstance(plugin);
}
catch(Exception ex)
{
Log.WriteLine(ex);
}
}
// /// <summary>
// /// Marks the descriptor if it is missing a dependency
// /// </summary>
// /// <param name="descriptor">The descriptor to check</param>
// /// <param name="descriptors">The collection of PluginDescriptors to check against</param>
// private static void MarkDescriptorIfMissingDependency(PluginDescriptor descriptor, PluginDescriptorCollection descriptors)
// {
// // we may already know that
// if (descriptor.IsMissingDependency)
// return;
//
// // check each Type the Plugin depends upon to determine if it is missing
// foreach(Type type in descriptor.PluginDependencies)
// {
// // if the dependency Type is equivalent to Missing, then there is an Assembly reference missing
// if ((object)type == Type.Missing)
// {
// // we know the plugin can't be started now so we're done with this one
// descriptor.IsMissingDependency = true;
// return;
// }
//
// // check each Type the Plugin depends upon to determine if the Type is listed somewhere in the other descriptors
// // it is possible the Type reference could be valid because the correct Assembly is loaded, but the Plugin that is
// // required isn't being exported as a Plugin yet. Sometimes the developers forget to export their plugins.
// bool found = false;
// foreach(PluginDescriptor otherDescriptor in descriptors)
// {
// // if some other descriptor's PluginType is the Type of this dependency
// if (otherDescriptor.PluginType == type)
// {
// // and we aren't comparing the same descriptor
// if (otherDescriptor != descriptor)
// {
// // then this particular dependency is exported and is in the list of descriptors
// found = true;
// break;
// }
// }
// }
//
// // if the Type wasn't found in the list of descriptors then this descriptor's Plugin is missing a dependency
// if (!found)
// {
// // we know the plugin can't be started now so we're done with this one
// descriptor.IsMissingDependency = true;
// return;
// }
// }
// }
/// <summary>
/// Marks a descriptor if is is circularly dependent with any other descriptor
/// </summary>
/// <param name="descriptor">The descriptor to check</param>
/// <param name="descriptors">The collection of PluginDescriptors to check against</param>
private static void MarkDescriptorIfCircularlyDependent(PluginDescriptor descriptor, PluginDescriptorCollection descriptors)
{
// check each dependency in that descriptor depends on
foreach(Type type in descriptor.PluginDependencies)
{
// against all the other descriptors
foreach(PluginDescriptor otherDescriptor in descriptors)
{
// when we find a descriptor that describes the Type the first descriptor needs
if (otherDescriptor.PluginType == type)
{
// it better not depend on the first
if (otherDescriptor.DependsOn(descriptor))
{
// if it does, it's a circular dependency which we cannot have
descriptor.IsCircularlyDependent = true;
return;
}
}
}
}
}
/// <summary>
/// Marks a descriptor if it has dependencies that themselves are missing dependencies or are circularly dependent
/// </summary>
/// <param name="descriptor">The descriptor to check</param>
/// <param name="descriptors">The collection of PluginDescriptors to check against</param>
private static void MarkDescriptorIfDependenciesAreMissingDependencyOrAreCircularlyDependent(PluginDescriptor descriptor, PluginDescriptorCollection descriptors)
{
// check each dependency in that descriptor depends on
foreach(Type type in descriptor.PluginDependencies)
{
// against all the other descriptors
foreach(PluginDescriptor otherDescriptor in descriptors)
{
// when we find a descriptor that describes the Type the first descriptor needs
if (otherDescriptor.PluginType == type)
{
// the other dependency better not be missing a dependency
if (otherDescriptor.IsMissingDependency)
{
// if it does, the whole chain is jacked
descriptor.IsDependentOnTypeThatIsMissingDependency = true;
return;
}
// the other dependency better not be circularly dependent
if (otherDescriptor.IsCircularlyDependent)
{
// if it does, the whole chain is jacked
descriptor.IsDependentOnTypeThatIsCircularlyDependent = true;
return;
}
}
}
}
}
/// <summary>
/// Creates PluginDescriptors from each Plugin Type specified.
/// </summary>
/// <param name="progressViewer">The callback object implementing IProgressViewer that will be used to monitor progress.</param>
/// <param name="types">The collection of Plugin Types to create descriptors for.</param>
/// <returns></returns>
public static PluginDescriptorCollection CreatePluginDescriptors(IProgressViewer progressViewer, TypeCollection types)
{
PluginDescriptorCollection descriptors = new PluginDescriptorCollection();
foreach (Type type in types)
{
try
{
string message = string.Format("Creating PluginDescriptor, Type: '{0}'.", type.FullName);
ProgressViewer.SetExtendedDescription(progressViewer, message);
Log.WriteLine(message);
PluginDescriptor descriptor = new PluginDescriptor(type);
descriptors.Add(descriptor);
}
catch(Exception ex)
{
Log.WriteLine(ex);
}
}
return descriptors;
}
/// <summary>
/// Initializes a new instance of the PluginDescriptorEventArgs class
/// </summary>
/// <param name="descriptor"></param>
public PluginDescriptorEventArgs(PluginDescriptor descriptor)
{
_descriptor = descriptor;
}
/// <summary>
/// Sorts an array of PluginDescriptors from least dependent first to most dependent last, or vice versa.
/// </summary>
/// <param name="descriptors">The array of descriptors to sort</param>
/// <param name="leastDependentFirst">The order in which to sort them</param>
/// <returns></returns>
public static bool Sort(PluginDescriptor[] descriptors, bool leastDependentFirst)
{
try
{
for (int i = 0; i < descriptors.Length - 1; i++)
{
for (int j = i + 1; j < descriptors.Length; j++)
{
bool dependsOn = descriptors[i].DependsOn(descriptors[j]);
if ((leastDependentFirst ? dependsOn : !dependsOn))
{
// swap i with j, where i=1 and j=2
PluginDescriptor descriptor = descriptors[j];
descriptors[j] = descriptors[i];
descriptors[i] = descriptor;
}
}
}
return true;
}
catch (Exception ex)
{
Log.WriteLine(ex);
}
return false;
}
/// <summary>
/// Determines if this Plugin depends upon the PluginType described by the specified PluginDescriptor.
/// </summary>
/// <param name="descriptor">The PluginDescriptor to check against this PluginDescriptor's dependencies</param>
/// <returns>true if this descriptor depends on the specified descriptor's Type</returns>
internal bool DependsOn(PluginDescriptor descriptor)
{
try
{
//Log.WriteLine("Determining if Type '{0}' depends on Type '{1}'", _type.Name, descriptor.PluginType.Name);
foreach (Type type in _dependencies)
if (Type.Equals(type, descriptor.PluginType))
{
//Log.WriteLine(string.Format("'{0}' depends on '{1}'", this.PluginType.Name, type.Name));
return true;
}
}
catch (Exception ex)
{
Log.WriteLine(ex);
}
//if ((object)type != Type.Missing && type == descriptor.PluginType)
// return true;
return false;
}
/// <summary>
/// Marks a descriptor if it has dependencies that themselves are missing dependencies or are circularly dependent
/// </summary>
/// <param name="descriptor">The descriptor to check</param>
/// <param name="descriptors">The collection of PluginDescriptors to check against</param>
private static void MarkDescriptorIfDependenciesAreMissingDependencyOrAreCircularlyDependent(PluginDescriptor descriptor, PluginDescriptorCollection descriptors)
{
// check each dependency in that descriptor depends on
foreach (Type type in descriptor.PluginDependencies)
{
// against all the other descriptors
foreach (PluginDescriptor otherDescriptor in descriptors)
{
// when we find a descriptor that describes the Type the first descriptor needs
if (otherDescriptor.PluginType == type)
{
// the other dependency better not be missing a dependency
if (otherDescriptor.IsMissingDependency)
{
// if it does, the whole chain is jacked
descriptor.IsDependentOnTypeThatIsMissingDependency = true;
return;
}
// the other dependency better not be circularly dependent
if (otherDescriptor.IsCircularlyDependent)
{
// if it does, the whole chain is jacked
descriptor.IsDependentOnTypeThatIsCircularlyDependent = true;
return;
}
}
}
}
}
